Salmonella (NTS) infections in children is still controversially debated in clinical practice. Patients might even be put at risk, with necessary antibiotic therapy being withheld due to the widespread concern of prolonged post-convalescent shedding. The authors conducted a systematic review to assess whether antibiotic treatment influences fecal excretion or the clinical course in children with NTS infection. (2) Methods: The review was carried out following the PRISMA guidelines. In a Medline database search, studies assessing the influence of antibiotic therapy on excretion and/or the clinical course of NTS infections were selected. Studies reporting on adults only were not considered. Out of 532 publications which were identified during the systematic literature search, 14 publications were finally included . Quality and bias assessment was performed using the Newcastle-Ottawa scale (NOS) or the Cochrane risk-of bias tool (ROB-2). (3) Results: Four early studies from decades ago demonstrated a prolongation of intestinal NTS excretion in children after antibiotic treatment, whereas most studies published more recently observed no significant influence, which might be due to having used more “modern” antibiotic regimes (n = 7 studies). Most studies did not describe significant differences regarding the severity and duration of symptoms between untreated patients and those treated with antibiotics. Quality and bias were mainly moderate (NOS) or variable (ROB-2), respectively. (4) Conclusions: There is no substantial evidence of prolonged excretion of NTS in pediatric patients after treatment with newer antimicrobials. Consequently, clinicians should not withhold antibiotics in NTS infection for children at risk, such as for very young children, children with comorbidities, and those with suspected invasive disease due to concerns about prolonged post-convalescent bacterial excretion. In the majority of cases with uncomplicated NTS diarrhea, clinicians should refrain from applying antibiotics.(1) Background: Although published recommendations are available, the use of antibiotics in non-typhoidal  Salmonellae are gram-negative facultative intracellular enterobacteria. As the taxonomic classification is somewhat intricate in daily practice, clinicians still subdivide the anthropopathogenic serovars of Salmonella enterica subspecies I enterica into typhoidal and non-typhoidal Salmonellae (NTS), with S. typhimurium and S. enteritidis being the most prominent non-typhoidal serotypes. NTS are one of the most common bacterial pathogens worldwide causing enterocolitis, with an estimated 95 million cases globally in 2017 being a burden both in developing and developed countries [NTS are present in a wide range of reservoirs and hosts, mainly in poultry, and less frequently in other animals, like reptiles or amphibians kept in households, as well as in humans themselves. Infections with NTS are usually associated with contaminated food , most coThe most commonly encountered noninvasive NTS-disease is clinically hard to distinguish from enteric infections caused by other microbes. It usually presents as self-limiting diarrhea, abdominal pain and, to a lesser extent, nausea, vomiting, or fever ,10. In mStreptococcus pneumoniae and Haemophilus influenzae type b. Sometimes patients present “typhoid-like” or with the picture of enterocolitis, high fever, and an acutely ill appearance. Rarely, such patients might even be misdiagnosed with NTS infections in cases of perforated appendicitis with diarrhea [per se only presents with diarrhea in roughly one third of the patients [In parts of the developing world, though, notably sub-Saharan Africa, NTS have even become a predominant invasive pathogen following the effective establishment of vaccination programs against diarrhea . Howeverpatients ,13. It tpatients ,15,16,17patients ,19. Thispatients . Especiapatients ,22.Salmonellae for one year or longer [Salmonella spreading. In an unselected pediatric population without diarrheal symptoms, the carriage rate was found to be 1% in more than a thousand schoolchildren in India [Principally, prolonged carriage or fecal shedding is a well-recognized consequence of intestinal NTS infection, especially in young children under the age of five ,24. In sr longer . Apart fin India . Therefoin India ,29,30, aSalmonella spp. and acknowledgement of the importance of more favorable pharmacokinetic properties of the antimicrobial agents applied [The use of antibiotics for the treatment of such NTS infections was broadly discussed in the last decades, while the antibiotic regimens applied have undergone substantial modifications during this time ,31,32,33 applied ,35. Thro applied ,37,38.Accordingly, the objective of this work was to shed light on the value of antibiotic therapy for NTS infection in children focusing on the impact on intestinal shedding and on the clinical course of the disease based on the current literature.The methodology of our review was consistent with the Preferred Recording Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. The corresponding checklist is provided in Salmonella”, “Salmonellosis”, “infections”, “enteritis”, “enterocolitis”, “food poisoning”, “nontyphoid”, “non-typhoidal Salmonella”, “NTS”, “bacteremia”, “children”, “childhood”, “infants”, “pediatric”, “infancy”, “antibiotics”, “antibiotic therapy”, “antimicrobial therapy”, “fecal excretion”, “shedding”, “post-convalescent”, “excretion”, “symptoms”, and “clinical course”.A review of the literature was performed independently by two investigators (J.L.L. and R.A.) using the MEDLINE database. The search algorithm was constructed using the following medical subject heading terms (MeSH) and text words in various combinations: “The search was not restricted by the date of publication or the type of studies. After the literature search, titles and abstracts were screened to identify potentially appropriate articles. Subsequently, a detailed evaluation of these articles including crosschecking of the references was performed. Only studies reporting on children and adults or children only were included. Studies about adults only were excluded from this review. Only original articles (no reviews or case reports) were included in this analysis. Data acquisition started in October 2020 and was finished in July 2021.The assessed characteristics of the considered articles included the type of study , the pathogen, the number of patients, the ratio of children (<18 years), and the administered antibiotics. The findings of these studies were investigated with the focus on the influence of antibiotic treatment on the intestinal excretion of NTS or on the clinical course of patients, respectively.Quality assessment was performed independently by two investigators (J.L.L. and R.A.). Any disagreement in scoring was solved by general consensus.For non-randomized studies, the Newcastle-Ottawa scale  was usedA flow-chart illustrating the study selection is shown in The results of the quality assessment are described in Altogether, the selected studies comprised 3273 patients, with 95.8% of them being children . An overview of these articles is shown in Of these studies, five were prospective randomized controlled trials, five were retrospective case series, two were prospective controlled trials, and two were prospective case series. The randomized controlled trials were allocated between “antibiotic treatment” and “no antibiotic treatment” or placebo in patients with NTS infection ,42,43,45Salmonella spp. was not specified in all of the investigated studies. In 12 of 14 studies, all NTS species were included, whereas in two studies S. typhimurium was the predominantly diagnosed pathogen. The antibiotic agents which were used changed over time. The most commonly administered substances before 1990 were chloramphenicol, ampicillin, and neomycin, while in more recent studies, fluoroquinolones and cephalosporins were predominantly applied.The sub-group of S. typhimurium [Salmonella excretion of 70 patients with symptomatic and asymptomatic NTS infections and found that patients who were treated with antibiotics had a substantially longer excretion time [In 13 articles, the duration of excretion was investigated ,47,48,49himurium . Seven wion time . After tThese results were confirmed by a further study that demonstrated that patients who were given antibiotics were more likely to be symptomless excreters in a six-week period after treatment than those given a placebo (lactose) .Ho et al. also reported a prolongation of fecal shedding, albeit only in children receiving inappropriate antibiotic treatment defined as either not active in vitro or given to patients without severe disease. They did not observe a prolongation of intestinal NTS excretion after adequate antibiotic therapy (active in vitro or given to patients with a high severity score) or in the group receiving no antibiotics .Shortening of the duration of excretion was found in one study (including 30 patients) published by Chiu et al., who observed a significantly higher rate of clearance of NTS from stools after antibiotic therapy using ceftriaxone in children with bacteremia . The autNo influence of antibiotics on NTS excretion was found in six studies  ,43,44,45All four studies that observed a prolongation of NTS excretion after antibiotic treatment in children were published in 1974 or earlier. No such phenomenon was reported since then in the literature assessed for this review. The impact of antibiotic treatment on the clinical course of the infection was reported in 11 studies ,47,48,49In one study, a higher frequency of persistent symptoms after antibiotic therapy was observed . In thisn = 69 patients), “appropriate antibiotic therapy” , and “inappropriate antibiotic therapy”  groups. The “appropriate antibiotic therapy” group had a similar fecal excretion time compared to the “no antibiotic therapy” group (9.64 ± 6.22 days versus 11.13 ± 7.01 days). In a multivariate analysis, the authors showed that an inappropriate antibiotic therapy significantly prolonged the fecal excretion time (18.24 ± 24.67 days).A recent study observed a worse clinical outcome only in children with inappropriate antibiotic treatment, but not after treatment with appropriate antibiotic agents . The autFurther subsequent works on this subject, such as the ones published by Lin et al. in 2003 and by Tsai et al. in 2011, reported potential positive effects of a short-term antibiotic therapy for three to five days ,46. Lin Salmonella in pediatric patients treated with antibiotics is still a relevant matter of debate in routine clinical practice. Substantial insecurity about this issue among colleagues is not rare . Warnings to varying extend about this assumed risk can be found in virtually all publications on the subject of NTS infections in children. In addition to the aspect of prolonged shedding, a second issue frequently discussed is the effect of antibiotic therapy on the severity and duration of symptoms in pediatric patients with invasive NTS infection.The adequate therapy for children suffering from infections caused by NTS species is principally well described in published recommendations ,52,53,54Salmonella excretion and on the patients’ symptoms [The uncertainty regarding the administration of antibiotics is based on several clinical studies published over the last decades which reported both positive and negative, but also often nonsignificant effects of an antibiotic treatment for NTS infection on symptoms ,57,58,59The very first study that systemically assessed these factors was the work by MacDonald et al. published in 1954 . The autAnother study describing protracted clearance of NTS after antibiotic treatment was published by Rosenstein et al. in 1967 . LimitatFurther work propagating a lower clearance of NTS in antibiotically treated patients was published by the “Joint Project by Members of the Association for the Study of Infectious Disease” in 1970 in a randomized controlled trial, in which 168 patients (108 < 12 years) were assigned to receive either oral neomycin or placebo (lactose). Clearance rates and differences in fecal NTS excretion for the whole cohort including adults were calculated after just three weeks. For a fraction of 76 patients, there was a tendency for prolonged shedding after six weeks following neomycin treatment (36% vs. 25%). No clear differentiation between age groups was performed and severity of symptoms was not assessed. Therefore, the conclusions drawn by the authors regarding the influence of antibiotics on NTS shedding is debatable.Salmonella clearance was discrete and the authors themselves stated that this effect may not have been related to antibiotic therapy alone, as it was applied most frequently in infants less than 3 months of age and mainly in very sick patients [One more study described a prolongation of NTS excretion after antibiotic treatment in 117 children. Here, the tendency of protracted patients .S. typhimurium outbreak. Fifteen children seven years or older were included, eight hospitalized and antibiotically treated, of whom three children excreted NTS longer than four weeks. It remains unclear whether disease severity itself led to hospitalization or the antibiotic therapy per se was responsible for prolonged shedding in the small number of children [All studies that reported a prolongation of fecal NTS excretion in pediatric patients were published no later than 1974. Since then, only one observational study, which predominantly included adult patients, also observed a prolongation of excretion. In this observation, 51 out of 105 patients were followed with stool cultures subsequently to a foodborne children . AlthougInappropriate use of antibiotics, however, does seem to significantly prolong the time of excretion, as shown in patients with mild disease receiving antibiotics or patients with severe disease receiving antibiotics later being found to be resistant in vitro ,60. So, Another parameter identified as a risk factor for a prolonged excretion was an antibiotic therapy course longer than seven days, suggesting that a short-term antibiotic treatment might be beneficial . The adeThe majority of the studies assessed which were published in the last decades, including three randomized controlled trials, could not demonstrate any significant influence of antibiotic therapy on the duration of excretion ,42,43,45When weighing the possible risk of bacterial shedding and the potential influences of an antibiotic therapy, it also has to be considered that even without antibiotic treatment, the excretion of NTS is often prolonged, lasting up to 20 weeks especially in young children (under the age of five) .A possible explanation for the higher rate of prolonged fecal excretion in patients treated with antibiotics can be derived from the design of most of the non-randomized studies. In many studies, the indication for an antibiotic treatment was mainly based on the severity of the disease and the patients’ age. Consequently, especially very sick and young children had received antibiotics. Therefore, one possible explanation for the observed prolongation of bacterial shedding could be a presumably higher bacterial load in these more severely affected and young children leading to higher concentrations of NTS in the stool independent from an antibiotic intervention.Apart from the impact of antibiotic treatment on fecal excretion, the influence on patients’ symptoms and the clinical course of the disease might be even more important, especially for patients at risk, such as very young children as well as immunocompromized patients and those with co-morbidities. The majority of the analyzed studies reported no significant difference regarding the severity or duration of the children’s symptoms after antibiotic therapy. The most recent studies even reported potential benefits of an antibiotic treatment using ceftriaxone for a subgroup of patients with a severe clinical course ,46,63. HAs mentioned above, the armamentarium of antibiotic agents has broadened in the last decades, with regimes being refined regarding the duration of treatment and the substances used. Chloramphenicol, for example, is nowadays considered as reserve antibiotic and is even not officially approved for young children in some parts of the world. “Newer” antibiotic agents, such as third-generation cephalosporins, did not cause a prolongation of excretion and were associated with potentially beneficial effects on the patients’ symptoms ,48. AdeqAnother promising group of antibiotics for the treatment of NTS infection are fluoroquinolones ,64. HoweA systematic Cochrane review published by Onwuezobe et al. in 2012 which analyzed antibiotic treatment for symptomatic NTS infection concluded that there was no evidence for the benefit of antibiotics in NTS diarrhea in otherwise healthy people. However, the authors were unable to comment on the antibiotic therapy of very young and very old patients or people with severe and extraintestinal disease as the trials included did not specifically address these subgroups of patients .According to our literature review, adequate antibiotic treatment in vulnerable groups or children already presenting considerably ill with substantially elevated CRP-levels or fever seems to outweigh the questionable risk of a prolongation of fecal NTS excretion. Targeted antibiotic therapy should be performed whenever possible according to antimicrobial activity in vitro susceptibility testing ,60.Salmonella enteritis cases, patients should be selected with scrutiny and restricted use of antibiotics should be a major goal to prevent further development of antibiotic resistance, even more as vaccines against NTS infections are still not available yet [The current recommendation to administer third generation cephalosporins (and ciprofloxacin) for complicated NTS infections should be followed in the light of antimicrobial resistance to these drugs being reported in still low but increasing numbers ,67,68. Cable yet .n = 8) or low (n = 1) and the risk of bias for randomized trials was high for three of the five included studies. Another limitation is the heterogeneity of the antibiotic agents administered. Especially antibiotics that had been applied in earlier studies are nowadays no longer common in clinical practice. Furthermore, in the non-randomized studies, the indication for an antibiotic treatment was made depending on the clinical status of the patients , which is a potential bias for the effect of an antibiotic therapy. In addition, no study explicitly examined other factors, such as coinfections, possibly influencing prolonged excretion of NTS or persistence of symptoms.We acknowledge that this review has some limitations. The designs of the included studies were heterogeneous, comprising randomized trials and retrospective cases series, which limits the comparability and the conclusions drawn. Besides that, the quality of the included non-randomized studies was only moderate  on the patient’s symptoms in selected cases. This discrepancy between earlier and later observations can be attributed to considerable changes in the antibiotic agents used over time. The restriction of antibiotic treatment for NTS infection, especially in very young children, children with comorbidities, and in those with suspected invasive infection should be critically questioned and the ostensible risk of prolongation of excretion should not lead to a withholding of a treatment with modern antimicrobial agents in these vulnerable subgroups of patients.


Antibiotic resistance (ABR) is a global problem with the overuse of antibiotics accelerating this process. Antibiotic stewardship aims to optimise antibiotic treatment to enable cost-effective therapy and improve patients’ outcome whilst limiting ABR. The study aimed to evaluate intern medical doctors’ knowledge and perceptions about antibiotic stewardship and their perceptions regarding education on relevant topics.This was a cross-sectional study on interns rotating at Bloemfontein Academic Complex. An anonymous, self-administered questionnaire was completed. The questionnaire recorded demographic information, perception and knowledge of antibiotic stewardship, and the quality of education as perceived by the interns.Escherichia coli (E. coli) bacteraemia. The interns perceived that they have a lack of training and preparedness in certain areas of prescribing antibiotics. Though 77.2% of the interns had received education on starting antibiotic treatment, 29.3% claimed to be unsure when to start antibiotic therapy. Interns indicated that formal lectures (81.3%) and bedside tutorials (86.7%) have a high educational value.Of the 120 possible participants, 92 (76.7%) responded to all or part of the questionnaire. The median age of the respondents was 25 years, and 56.7% of the respondents were female. The mean score for the knowledge-based case scenarios was 5.4 out of 10. Only 4.4% participants could manage a drip site infection correctly, whilst 18.5% could treat Intern medical doctors do not have sufficient knowledge to establish antibiotic stewardship but have a desire for improvement. The results identified specific areas where better antibiotic training is required. In a healthcare system that is already struggling to cope with the burden of disease, the prolongation of hospital stay because of ABR will be devastating on a country’s healthcare system.2 Antibiotic stewardship aims to optimise antibiotic treatment to enable cost-effective therapy and improve patients’ outcome whilst limiting ABR.5Antibiotic stewardship can be defined as a set of strategies that encourage the practice of giving the correct antibiotics and dosage via the correct application route for the right amount of time.6The World Health Organization (WHO) has constructed an action plan regarding antimicrobial resistance that was presented at the May 2015 World Health Assembly. The action plan mainly consists of spreading awareness about ABR, improving knowledge through research, minimising infection by improving prevention strategies and increasing investment in interventions.7 Improved communication skills will also help to convey this information to patients.7Antibiotic stewardship education is crucial to provide foundational knowledge regarding antibiotics and ABR, making the correct diagnosis and infection management and appropriate prescribing. Education on appropriate prescribing for healthcare providers has shown to improve other antibiotic stewardship interventions.8In South Africa, the primary obstacle in antimicrobial stewardship programmes in almost all public and private health facilities has been insufficient resources and expertise about infectious diseases.9 Australia10 and South Africa11 have found that medical students have limited knowledge and confidence regarding antibiotic prescription. Similarly, studies in the United Kingdom13 have highlighted the needs and challenges faced by junior doctors (who frequently are the prescribers of antibiotics) regarding antibiotic prescribing.Studies in Europe,This study aimed to determine the knowledge and perceptions of intern medical doctors in Bloemfontein regarding antibiotic prescribing and stewardship and their perceptions on the usefulness of different educational activities for learning about antibiotic-related topics.This was a cross-sectional study. The target population included all 120 first- and second-year intern medical doctors rotating at the Bloemfontein Academic Complex through eight departments from August 2017 to October 2017. The departments included: Family Medicine, Surgery, Anaesthesiology, Paediatrics, Orthopaedics, Obstetrics and Gynaecology, Internal Medicine, and Psychiatry.An anonymous, self-administered questionnaire in English was handed out to interns at the end of a formal lecture after the study, and its aim was explained by the researchers. Lecturers assisted in questionnaire distribution and collection, ensuring that questionnaires were completed individually and not as group work. Completed questionnaires were handed in at the door.11 Some of the questions were altered to accommodate the difference between the study populations of the two studies.Permission was granted by Dr Sean Wasserman (University of Cape Town) to use a questionnaire composed by researchers from the University of Cape Town who conducted a study on antibiotic stewardship on final-year medical students at three medical schools .The questionnaire consisted of sections on demographics , knowledge  and perceptions regarding antibiotics, their causes and outcomes, the usefulness of various educational activities to learn about antibiotic classes, antibiotic prescribing and resistance.Results were summarised by frequencies and percentages  and means, medians and interquartile ranges (IQRs) . The analysis was done by the Department of Biostatistics, Faculty of Health Sciences, UFS.A pilot study was conducted mainly to determine the amount of time needed to complete the questionnaire. The pilot study consisted of a group of 11 fifth-year medical students from UFS, who were selected on a single day as a convenient sample at National District Hospital. Questionnaires were handed out to the students after a formal lecture and were collected as the students left the venue. No changes were made to the questionnaire.The protocol was approved by the Health Sciences Research Ethics Committee, UFS (HSREC-S 13/2017). Permission was obtained from the Free State Department of Health to include intern medical doctors in this study.Of the 120 interns, 92 (76.7%) responded to all or part of the questionnaire. The 28 interns who did not respond consisted of 11 who were on leave, 1 who refused and 16 who were unavailable during the time of data collection. The median age of the respondents was 25 years (IQR: 24–26 years) and 56.7% of the respondents were female. All South African medical schools were represented amongst the respondents with the UFS representing the largest percentage (34.1%). Five respondents indicated that they received their medical training outside South Africa.According to 59.3% (51 of 86) of the respondents, the hospitals where they work have antibiotic guidelines. The majority of respondents  indicated that they have used or consulted antibiotic guidelines.Half  of the respondents reported being very familiar with the term ‘antibiotic stewardship’ and 34.8% reported being familiar, that is, they have heard the term mentioned in lectures or tutorials, but it was not explained further.The mean score for the knowledge-based case scenarios was 5.4 out of 10. Only 6.5% of the respondents had a score of 8 or more out of 10 and 77.2% had a score of 5 or more out of 10.n = 70) knew what antibiotic to prescribe when managing an uncomplicated urinary tract infection. However, only 29.4% (n = 27) knew what antibiotic to prescribe for methicillin-sensitive Staphylococcus aureus.Most of the respondents  knew how to assess the severity and management of community-acquired pneumonia. Less than two-thirds  of the interns knew how to interpret an antibiogram and de-escalate antibiotic treatment, and the same percentage knew how to manage an upper respiratory tract infection.The majority of the respondents  of the respondents. Half  knew how to correctly assess the severity and management of a Clostridium difficile infection.The correct management of a drip site infection was only identified by 4.4% (Escherichia coli bacteraemia was made by 18.5% (n = 17) of the respondents. Perioperative antibiotic prophylaxis duration and risks of excessive use were assessed correctly by 73.9% (n = 68) of the respondents. The majority of respondents  knew how to manage the poor response to empiric antibiotic therapy.The correct antimicrobial selection for extended-spectrum beta-lactamases (ESBL)-positive Respondents’ answers regarding perceptions relating to antibiotic prescribing indicated that the majority were aware of ABR, its causes and outcomes and would like more education on ABR and appropriate use of antibiotics . Only 50As summarised in As indicated in n = 79), indications for starting antibiotics , dosing and duration of antibiotic therapy for specific infection , indications for intravenous antibiotics , rational use of antibiotics in general  and basic principles of infection prevention and control .The majority of respondents had attended lectures or tutorials for the following: diagnosis of infection , more applications for smart devices  and more exposure to infectious diseases specialists  were ways to prepare newly qualified doctors to prescribe antibiotics. Less than half suggested more formal bedside tutorials , more formal lectures  and more time in microbiology . Only 10.9% (n = 10) selected ‘more computer-based tutorials’ as a preparation method.The respondents indicated that a local handbook or guidelines on treating common infections . It can be assumed that most of the interns’ knowledge is acquired during training in medical school.In the study done on final-year medical students,11 This can be expected as urinary tract infections and pneumonia are relatively common diseases in South Africa.14From the knowledge questions, it was clear that interns knew what antibiotics to prescribe for a urinary tract infection and how to assess the severity and management of community-acquired pneumonia. This is in accordance with the South African final-year medical student study.Staphylococcus aureus, only 29.4% of interns knew what antibiotics to prescribe. A reason for this low score could be the fact that the question was not read carefully. The term ‘methicillin-resistant’ is usually used when referring to ABR. Thus, the term ‘methicillin-sensitive’ may have been misread. It should be noted, however, that this correlates with the fact that only 54.4% of respondents felt adequately prepared to prescribe antibiotics.In a clinical case scenario of the correct antibiotic use for methicillin-sensitive 15 and it would be expected that most interns would know how to manage it correctly. Most upper respiratory tract infections are caused by viral infections where antibiotic prescribing will have no effect. Research has demonstrated high rates of unnecessary antibiotic prescribing for these types of infections, which promotes ABR.15 In order to promote antibiotic stewardship, better management of upper respiratory tract infections is needed.In the clinical case scenario, the correct management of upper respiratory tract infection was reported by 62.0% of interns. This percentage is lower than expected because upper respiratory tract infections are commonly seen,16The correct management of a drip site infection was only identified by 4.4% of the interns. Serious intervention is needed to improve the management of drip site infections as it is a fairly common occurrence in hospital environments.Clostridium difficile infection. Better management of the infection is needed as Clostridium difficile is the number one causative agent of antibiotic-associated and healthcare-associated infective diarrhoea in hospital environments.16Less than half of the respondents (47.8%) knew how to correctly assess the severity and management of Escherichia coli bacteraemia was made by 18.5% of interns. As extended spectrum infections are becoming more common as a result of ABR,11 correct treatment is needed to contain ABR. Overall, knowledge about antibiotic prescribing regimens and ABR are moderate to poor, which correlates with the South African final-year medical student study.11The correct antimicrobial selection for ESBL-positive The responses to the clinical case scenarios in the study questionnaire showed that some interns struggle to choose the right antibiotic treatment although 55.4% indicated that they felt prepared to choose the correct antibiotic.17The majority of intern medical doctors (85.9%) in this study realised that ABR is a problem in South Africa, but only 63.0% perceived ABR as a problem in hospitals where they have rotated. Studies have shown that a large number of medical students or doctors are ignorant to the fact that ABR is a problem in their immediate environment and this may contribute to over-prescription.Nearly a fifth of the respondents (19.6%) disagreed that the unnecessary use of broad-spectrum antibiotics increases ABR. As one of the main factors of increased ABR is the unnecessary use of antibiotics, interns need to become more aware about the causes of ABR. It is encouraging to see that the majority (89.1%) of interns indicated that they would like more education on ABR.11 In a study done on junior doctors in London,12 less than 15% of participants indicated that their previous antimicrobial education was effective, and 60% of participants who had qualified the previous year stated that they required further education in antimicrobial prescribing. This latter percentage was 74.0% for more experienced junior doctors. Specific topics identified for further education in that study were: ‘(i) principles of antimicrobial prescribing, (ii) diagnosis of infections, (iii) clinical review of patients with infections, (iv) prescribing in the context of antimicrobial resistance and (v) laboratory testing and test results’ (p. 9).12In our study, interns indicated that they lack training and preparedness in certain areas of antibiotic prescribing. This finding is in accordance with the study done on final-year medical students in South Africa.Three quarters of participating interns attended lectures or tutorials on the dosing duration of antibiotic treatment for specific infections. However, less than half of interns felt like they were prepared when it comes to the dosing duration of antibiotics. This gap can possibly be attributed to ineffective educational methods, too little time spent on preparing interns for dosing duration or intern medical doctors not frequently educated on the subject throughout their undergraduate training and career.Half of the interns felt very prepared on how and when to transition from intravenous to oral antibiotic treatment compared to nearly 80% of the interns who reported to have had education on the indications of intravenous antibiotics. The disparity between education and knowledge is once again apparent.11Only 59.8% of interns have a perceived high understanding of the basic mechanisms of ABR; a fact that is troubling because understanding what causes resistance is an important way to curb ABR. When interns do not know that some of their actions can promote ABR, they will continue to unintentionally contribute to the problem. The fact that only 50.0% interns agreed that poor hand hygiene to ABR is concerning. This correlates with the final-year medical student study.11Interns’ responses to the various available education’s effectiveness give an indication of what they would prefer. The majority reported that formal lectures, formal bedside tutorials, and consultant ward rounds are useful for learning about antibiotic spectrums, resistance and prescribing. Areas where intern medical doctors felt the least prepared were an interpretation of antibiograms, knowledge of dosing duration and performing de-escalation in antibiotic therapy. In the study done on final-year medical students, these were also the areas in which students felt the least prepared.18Interns’ suggestions regarding useful approaches to prepare them for prescribing antibiotics place emphasis on alternative approaches rather than formal classes. An Australian study on junior doctors found that an educational session in conjunction with pocket guidelines improved self-confidence regarding vancomycin prescribing and monitoring.The study had a high response rate and made use of an existing questionnaire that enabled direct comparison with the recent South African study on final-year medical students. Whilst evaluating the theoretical knowledge of antibiotic dosing and duration, it should be acknowledged that interns in the clinical setting make use of resource material such as the Internet to guide them. This could indicate that they would fare better in practice than shown in this study.For antibiotic stewardship programmes to improve, attention must be given to each aspect of antibiotic stewardship. More attention must be given to choosing the correct antibiotics and dosage, via the correct application route for the right amount of time, as well as better infection control. Better inpatient care practices should be taught and applied so that hand hygiene is not one of the leading causes of ABR.There is a definite gap between undergraduate training, theoretical knowledge and clinical knowledge in intern medical doctors. Certain areas of medical value should be emphasised more. Changes need to be made in the educational method in which interns learn about starting antibiotic treatment and the dosing duration of antibiotic therapy. Ward rounds can focus more on the indications for intravenous antibiotic treatment and when to transfer to other application routes.Intern medical doctors should be made more aware of the basic mechanisms of ABR, as this study has proven that most interns admit to not knowing the fundamental principles of ABR. This can be achieved through training during weekly meetings or training during medical school.All doctors should be made aware, preferably at an early stage during medical school training, that ABR is a problem in their immediate environment to promote the applicability of antibiotic stewardship programmes. Small steps can be taken to improve antibiotic stewardship programmes such as promoting the practice of proper hand hygiene routines.Educational methods in the medical curriculum should be adapted according to indications of what interns and final-year medical students would prefer.Future research should investigate factors contributing to poor antibiotic prescribing knowledge amongst intern medical doctors.Our results show that intern medical doctors do not have basic antibiotic prescribing knowledge, but there is a desire for more education in this area. Provision of more information and adapted teaching methods for interns may contribute to a reduction in the prevalence of ABR and promote antibiotic stewardship.


The conventional survival analysis model on HIV/AIDS prognosis is the Cox proportional hazard model, which deals with only one event type, death, regardless of the cause. Few studies have used a competing risk model to evaluate the predictors of AIDS-related mortality.+ cell counts on acquired immunodeficiency syndrome (AIDS)-related death among former plasma donors.To estimate the influence of antiretroviral therapy (ART) initiation time and baseline CD4sHRs) for AIDS-related mortality with baseline CD4+ cell counts and ART initiation time were determined using a competing risk model.A retrospective cohort study was conducted involving 11,905 human immunodeficiency virus (HIV) or AIDS patients in a high-risk area of Henan province in China between 1995 and 2016. Demographic and clinical data were collected. Sub-distribution hazard ratios  or had baseline CD4+ counts of >500 cells/μL  were associated with lower AIDS-related mortality risk. Patients with ART initiation time >1 year but CD4+ counts >350 cells/μL  had a higher AIDS-related mortality risk than those with ART initiation time >90 days but CD4+ counts ≤350 cells/μL .Patients who initiated ART within 90 days of HIV/AIDS diagnosis (+ cell counts and late ART had a 9% higher risk of AIDS-related death than those with low CD4+ cell counts and early ART. This study confirms the great significance of immediate ART initiation among former plasma donor HIV patients in China.Our results demonstrate that patients with high CD4 Human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) continue to be major global public health issues. According to the Chinese Center for Disease Control and Prevention statistics, there were 820,756 individuals living with HIV/AIDS in China in 2018, and approximately 253,031 individuals who had died from AIDS-related causes. A major factor in the widespread incidence of AIDS in China is that thousands of small, illegal, commercial plasma collection centers were established in rural areas of China between 1990 and 1994 [+ counts were >500 cells/μL could reduce mortality [+ cell counts than patients infected through other modes of transmission [+ cell counts to reduce AIDS-related mortality [+ cell counts.Previous studies found that immediate antiretroviral therapy (ART) when CD4ortality . HoweverHIV/AIDS patients may die of non-AIDS-related diseases. The occurrence of death from non-AIDS-related diseases necessarily prevents the occurrence of death from AIDS related diseases; these causes of death compete with each other ,7. Conve+ cell counts, and other prognostic factors on AIDS-related death among a cohort of FPD using a competing risk model. We also sought to evaluate the performance of this competing risk model.The primary aim of the present study was to explore the effect of ART initiation time, CD4+ cell counts, and time of ART initiation) were collected. In accordance with the time from HIV diagnosis to ART initiation, the whole population was classified into the immediate ART group (initiating treatment within 90 days of diagnosis), the delayed ART group (initiating after 90 days of diagnosis but no longer than one year after), and the late ART group (initiating after one year of diagnosis).This study is a retrospective cohort involving 13,579 HIV/AIDS patients from Zhumadian city in Henan Province between 1995 and 2016. Data were from National HIV/AIDS Integrated Information Management System. All patients were confirmed by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. HIV-infected patients and AIDS patients were followed up by trained interviewers every six or every three months, respectively. Demographic information  and clinical characteristics , patients without plasma donation information (n = 572), patients without follow-up information (n = 264), patients without ART information (n = 729), and cases of logical error (n = 74) were excluded. The present study was finally limited to 11,905 HIV/AIDS patients who met the eligibility criteria. This study was approved by the Ethics Committee of the Henan Center for Disease Control and Prevention (2019-KY-005-02).We defined AIDS-related death as the event of interest and non-AIDS-related death as the competing event. Causes of death were specified based on the International Classification of Diseases 10th revision (ICD-10). AIDS-related death was defined as diagnosis of dying from AIDS-related tumors, AIDS-related opportunistic infections, AIDS-related syndrome, or other AIDS-related diseases. All the other causes of death were classified as non-AIDS-related deaths. Patients alive until May 30, 2016, or those lost during the follow-up period, were defined as censored data. Survival time was calculated from the date of HIV diagnosis to the date of death.Cumulative incidence function (CIF) was used to estimate the probability of AIDS-related mortality . The subThe model’s discrimination was assessed by the time-dependent receiver operating characteristic (time-dependent ROC) curve. The area under the time-dependent ROC curve (AUC(t)) of more than 0.75 clearly reflected useful discrimination, 0.60 to 0.75 reflected possibly helpful discrimination, and less than 0.60 reflected poor discrimination .https://www.R-project.org/). The significance level was α = 0.05.All statistical analyses were performed using R version 3.5.2 . In the whole cohort, 3,198 (26.86%) died of AIDS-related diseases, 607 (5.10%) died owing to non-AIDS-related causes, while 8,100 (68.04%) were still alive or lost to follow-up. 7,220 (60.65%) patients had already progressed to AIDS at the time of diagnosis .Table 1.+ cell counts had a lower cumulative incidence of AIDS-related death . Patiened death ).Figure + cell counts were presented in + cell count groups. Being male, older, having a low educational level, and not being married were risk factors for AIDS-related mortality in both high and low CD4+ cell count groups. + cell counts, adjusted for confounding factors. Significantly higher sub-distribution hazard ratios (sHRs) were found with an increase of ART time and a decrease in CD4+ cell counts. ART initiation time >one year and CD4+ cell counts >350  presented higher AIDS-related mortality risks than ART initiation time of >90 days and CD4+ cell counts ≤350 .Results of stratified analysis according to baseline CD4sHR: 0.24, 95% CI: 0.22–0.27), while delayed ART provided more protection  than late ART. Higher baseline CD4+ cell counts were associated with lower AIDS-related mortality. In addition, being male , older , being a farmer , AIDS stage at diagnosis , and infection by blood transmission  were all associated with an increased risk of AIDS-related death. However, high educational level and marriage were protective factors for AIDS-related death.The results of the entire study cohort using the competing risk regression model were shown in As shown in + cell counts or low counts. Patients with CD4+ cell counts >350 who initiated ART after one year had 9% higher risk of AIDS-related death than those with CD4+ cell counts ≤350 whose ART initiation time was >90 days. Additional risk factors for mortality in this study were being male, being of older age, being a farmer, the patient’s AIDS stage at diagnosis, having been infected by blood transmission, having a low level of education, and being single. Our results were consistent with the WHO’s guidelines on the use of antiretroviral drugs for treating and preventing HIV infection.In the present study, results showed that there were 79% and 68% decrease in AIDS-related mortality risk with immediate ART and delayed ART, respectively, compared with late ART, whether in patients with high CD4+ cell counts has been reported as preventing HIV transmission and reducing the rate of clinical events [+ cell count is the most important laboratory indicator of immune function. When CD4+ cell counts decline below a certain level, HIV-infected individuals are at risk of immune deficiency and more susceptible to infection, resulting in progress to AIDS or death [+ cell counts and other confounders. Patients with high baseline CD4+ cell counts who initiated ART after one year had 9% higher risk of AIDS-related death than those with lower baseline CD4+ cell counts who initiated ART after 90 days but within one year of diagnosis. Patients with higher CD4+ levels at baseline who missed treatment opportunities had a worse prognosis than those with lower CD4+ levels at baseline [+ cell count threshold include concerns about drug resistance, side effects, and resource allocation [+ counts were >500 cells/μL could reduce the one-year mortality. Our results emphasized the importance of immediate ART initiation for long-term survival of former plasma donors with high and low CD4+ cell counts. Early screening and immediate treatment after diagnosis should therefore be advocated, including voluntary testing, counselling, and entry into the Chinese National Free Antiretroviral Treatment Program [The mechanism by which ART decreased the mortality risk was primarily through viral suppression and improved immunological recovery . A stratl events . CD4+ ceor death . This stbaseline ,17. Argulocation . Howeverlocation  discover Program .+ cell counts than patients infected by sexual transmission, resulting in faster progression of AIDS or earlier death [Illegal commercial plasma and blood collection activities were very common in rural central China before the national blood donation law was enacted . In the er death ,27. Higher death ,29. Educer death ,31. Loweer death .CI expanded. A possible reason is that the new reported mortality numbers after 12 years were very low . Under these circumstances, the competitive risk model is inapplicable in evaluating the prognostic factors of AIDS-related mortality.Discrimination is an important characteristic in the evaluation of model performance . In the + cell counts. Inevitably, this study has some limitations. We have not considered dynamic changes in CD4+ cell counts during follow-up, which may influence survival in HIV/AIDS patients. In addition, compliance with ART, which may influence HIV/AIDS prognosis, was not included in the present analysis because of unavailability of data. In future studies, details of the dynamic changes in CD4+ cell counts and ART compliance should be considered in order to explore their influence on AIDS-related mortality.The present study has several important strengths. Firstly, as far as we know, it is the first study to assess competing risk performance using the time-dependent ROC curve in AIDS-related mortality studies. It could avoid overestimation of cumulative incidence and bias in the effects of covariates. Secondly, our study had a large sample size  and long follow-up time (21 years). Lastly, we explored the association between time from HIV diagnosis to ART initiation and AIDS-related mortality in HIV/AIDS patients with high and low CD4+ cell counts, especially for elders, males, and patients infected through blood transmission. A competing risk model performs well in the short and medium term, providing a reference method for the development of HIV/AIDS risk prediction models in the future.Our results demonstrate the urgent need to advocate early ART for improving survival of HIV/AIDS patients, whether with high or low CD4


Although IgG4‐RD has CNS manifestations, cerebellar involvement has only been reported in three cases. Our patient presented with cerebellar symptoms, several cerebellar infarcts were evident on the brain MRI, and CT abdomen revealed retroperitoneal tumor. Endoscopic biopsy confirmed IgG4‐RD. Steroids are the first‐line therapy for IgG4‐RD, but our patient was lost to follow‐up before treatment. IgG4‐related disease (IgG4‐RD) is a multiorgan, inflammatory disease with specific histopathological features. This is one of the few cases in which a patient presented with cerebellar symptoms as the initial symptoms for IgG4‐RD. Many essential pathological and clinical similarities exist in affected organs, including tumor‐like enlargement, lymphoplasmacytic infiltration rich in IgG4‐positive plasma cells, and varying degrees of fibrosis with a characteristic "storiform" pattern.2A 60‐year‐old man with a history of hyperlipidemia presented to the emergency department with worsening dizziness and blurry vision. He has had these symptoms for several months prior to arrival. On further examination, he also endorsed pain in his right hand that started around several months prior; the pain was described as numb and uncomfortable. He also noted some discoloration of his right fingers. Review of systems was negative for fevers, chills, shortness of breath, chest pain, abdominal pain, rash, joint pain, or family history of autoimmune disease. He is originally from Mexico and denied any use of alcohol, cigarettes, or illicit drugs. Vital signs were within normal limits. Physical examination was notable for a faint, purple discoloration of the tip of the right fingers. The patient was admitted for further management.Initial laboratory work showed an elevated erythrocyte sedimentation rate of 48 mm/h and C‐reactive protein of 13.9 mg/L. His basic metabolic panel, complete blood count, hemoglobin A1C, antinuclear antibody, cryoglobulin, rheumatoid factor, antiphospholipid serology, complement 3 and 4, and hepatitis panel were all unremarkable. Magnetic resonance (MR) imaging of the brain with and without contrast revealed a small, acute right cerebellar infarct, subacute left cerebellar infarct, and mild bifrontal chronic microvascular ischemic changes Figure . AssociaThe gastroenterology team was consulted for an endoscopic ultrasound with biopsy. The results showed lymph node tissue with plasmacytosis and >40% plasma cells positive for IgG4, compatible with IgG4 lymphadenopathy. The specimen was composed of lymphoid tissue lacking germinal centers with plasmacytosis. Immunohistochemical staining was performed. Cytokeratin AE1/AE3 was negative for epithelial malignancy. CD20 demonstrated an increase in B cells, and CD138 showed an increase in plasma cells. Kappa and lambda in situ hybridization showed polytypic expression. CD3 and CD43 highlighted background T cells. HHV8 was also negative, providing no support for Castleman disease.Prior to the pathology results, the patient was scheduled to be seen by hematology/oncology service and was sent home on apixaban, clopidogrel, and aspirin. Steroids were not initiated given the etiology of the stroke was believed to stem from his risk factors . However, the patient was discharged and lost to follow‐up before being aware of the pathology results.3IgG4‐RD is a multiorgan, fibroinflammatory condition with tumefactive lesions of unknown etiology and characteristic histopathological features. Virtually, any organ can be involved, most commonly being the pancreas, kidneys, orbital adnexal structures, and retroperitoneum. The pathological hallmark of this disease is dense lymphoplasmacytic infiltrate with IgG4‐positive plasma cells.Based on the Japanese comprehensive clinical diagnostic criteria for IgG4‐RD, our patients’ presenting symptoms were likely due to IgG4‐related disease.The patient's multiple cerebellar infarcts and discoloration of the fingertips could indicate a component of an underlying vasculitis. There have been only a small number of cases reporting cerebral vasculitis associated with IgG4‐RD, but none have reported cerebellar symptoms prior to diagnosis of IgG4‐RD. Cerebral vasculitis due to IgG4‐RD reported with pathological findings was documented in three previous cases Table . In the In conclusion, cerebellar symptoms in IgG4‐RD are an atypical initial presentation that has been reported in only a handful of cases. Based on previous reports, early initiation of corticosteroids can result in substantial improvement. While this disease is not entirely understood, it is important for clinicians to be aware of this unique presentation and to have a high clinical index of suspicion when presented.The authors declare that they have no conflicts of interest to declare.BI, UD, DS, and MF were involved in patient care . VJ, GN, and NP contributed to the writing of the manuscript, editing, and manuscript revision. All authors approved the final version.Ethical approval is not required for this type of study in accordance with local guideline.Written informed consent was obtained from the patient for publication of this case report.


This paper presents the results of an experimental study aimed at determining the influence of wood fly ash (WFA) from three Croatian power plants on the properties of concrete. First, the chemical and physical properties of WFA’s were determined. It was found that these properties are highly influenced by combustion technology, the type and parts of wood used as fuel, and the local operating conditions. Subsequently, workability, heat of hydration, stiffness development, 28-day compressive strength, apparent porosity, and capillary absorption were determined on concrete mixes prepared with WFA as cement replacement from 5–45% by weight. Cement replacement up to 15% with the finest WFA accelerated hydration, stiffness development, and increased compressive strength of concrete up to 18%, while replacement with coarser WFA’s led to a decrease in compressive strength of up to 5% and had more gradual heat liberation. The dominant effect that could explain these findings is attributed to the filler and filling effect mechanisms. At the same time replacement content of up to 45% had very little effect on capillary absorption and could give concrete with sufficiently high compressive strength to be suitable for construction purposes. The need to reduce greenhouse gas emissions accelerates the transition to renewable energy sources. Biomass is the largest source of renewable energy in the European Union (EU), of which 60% comes directly or indirectly from forests ,2. The mDespite the fact that different possibilities of WBA recycling have been recognized most of the ash is being landfilled ,7,8,9,10Within the EU many biomass plants are burning wood residues to produce heat and/or electrical energy . During 2 emissions caused primarily through the reduction of Portland cement content in concrete [The cement and concrete industry has been identified as one of the main potentials for biomass ash utilization . The useconcrete . Besidesconcrete ,23,24,25concrete ,27. In cconcrete . If the concrete . The temconcrete . Using aconcrete . The checoncrete ,31.The application of WFA is currently outside the scope of the standard for fly ash for concrete (EN 450-1:2012) . ExtensiMost of the studies on the influence of WFA produced during combustion in biomass plants on the properties of cement composites have been tested on cement pastes and mortars and only a small number of experiments have been scaled up to the concrete level. To develop guidelines for the use of WFA in structural concrete, the interdependence between properties of WFA and the properties of fresh and hardened concrete must be clearly established. The aim of the experimental work presented here is to show the influence of WFA with different physical and chemical properties, used as partial cement replacements, on the properties of fresh and hardened concrete and to identify the most probable mechanisms that govern these changes. The WFA used originates from three different power plants with two types of incineration technologies.Wood fly ash (WFA) is collected from three powerplants in Croatia. All three plants are co-generation biomass plants producing both heat and electrical energy. Plant F4 is the smallest plant with 1 MW of electrical capacity and 4.1 MW of heat capacity. It is located in the mountain part of Lika-Senj County. Wood species mostly used as a fuel are given in The information about the incineration temperature of wood biomass is given by the technologists in the power plant. The chemical and physical properties of WFA used in this work are presented in 2O3-SiO2 ratios similar to Portland cement, while ash F5 has an oxide ratio in the area of coal fly ash [The ternary diagram in  fly ash . WFA F5  fly ash . 3 is determined by thermogravimetric analysis (TGA) (for details see [−4 Pa and 10 kV settings.The particle-size distribution (PSD) was analyzed by a laser diffraction method using a dry measurement . Elemental composition is determined by X-ray fluorescence according to standard ISO/TS 16996:2015 . The amoails see ). Loss oails see ,48,49. Td50) is given in The PSD for cement and WFA is presented in WFA was stored in the laboratory for a period of approximately six months before being used in concrete. During storage, WFA was kept sealed in plastic bags and then stored in closed plastic containers.3 and absorption of 0.47%, 0.66%, and 0.32% for fractions 0/4, 4/8, and 8/16 mm, respectively. The particle size distribution curves are presented in The cement used in this study was Portland cement type CEM I 42.5 R conforming to European standard EN 197-1:2011 . The aggThe compositions of the concrete mixes are given in The mixing of the concrete was performed in a compulsory mixer with a capacity of 75 L. Before mixing, all constituents were conditioned to a temperature of 20 ± 2 °C. The mixing procedure described in the standard EN 480-1:2014  was usedThe following properties of concrete were measured in the fresh state: consistency by slump test (EN 12350-2:2019), density (EN 12350-6:2019), air content (EN 12350-7:2019), and temperature ,53,54. TThe heat of hydration is monitored with the ToniCAL 7336 heat flow differential calorimeter. During the measurement, the calorimeter was placed in the room where the temperature was maintained at 19 ± 2 °C. The measuring vessel of the calorimeter contains two measuring cells, one for the concrete specimen and another for the inert (reference) specimen. The inert specimen was maintained at the preselected temperature of 23 °C. All concrete components were tempered prior to mixing so that the temperature of the fresh concrete was as close as possible to the temperature of the inert specimen. After mixing the fresh concrete, a specimen of concrete was compacted in a cylindrical steel mould with a diameter of 150 mm and a height of 300 mm, and the mould was then placed in the calorimeter vessel. The heat generated by the hydration of the cement was evaluated from the voltage difference detected by the thermoelectric conductors placed around the specimens. The rate of heat generation was monitored during the first 5 days of hydration. During the heat generation measurement, the temperature of the concrete specimen changes and it is measured by a Pt-100 probe approximately in the center of the concrete specimen. The initial temperature of the specimen was between 22–23 °C, it increased depending on the rate of heat generation in the specimen, reached a maximum, and then decreased to the preselected temperature of 23 °C. The measurement of the temperature is complementary to the measurement of the heat flow and provides important information for the interpretation of the results, because the increase of the temperature additionally accelerates the hydration, so the heat evolution occurs at a higher rate than would be the case under isothermal conditions, but also at a slower rate than in the semi-adiabatic calorimeter. Concrete stiffness development was monitored by measuring ultrasonic pulse velocity (UPV) at 1, 2, 7, and 28 days of age using a portable ultrasonic instrument with 54 kHz longitudinal wave transducers. The measurement was performed on concrete cubes with a side length of 150 mm. The same cubes were used for testing the compressive strength of concrete at 28 days of age according to standardized procedure (EN 12390-3:2019) .The capillary absorption measurement was performed on cylinder specimens 150 mm in diameter and height 50 mm, obtained by sawing from the standard cylinder 150 mm in diameter and height 300 mm. Upper and bottom slices of the cylinder were not tested to avoid effects of different boundary conditions. The first 10 mm of side surface in contact with water was coated with epoxy resin. Prior to testing, the specimens were oven-dried at a temperature of 105 ± 5 °C until the change in mass for two consecutive weighing became less than 0.5 g (≈0.025 % of mass). After cooling to ambient temperature, the specimens were placed in a water container on cylindrical rods, and the water level was adjusted so that the bottom surface of the specimens was immersed in the water 2–5 mm. The mass of the specimens was measured at an interval of 5, 15, 30, 60, 120, 240, and 1500 min. From each mix, three specimens were tested for capillary absorption.z,dryρ) and saturated conditions , apparent solid density (aρ), and apparent porosity (ap) were calculated according to Equations (1)–(4). The term apparent is used here because it is assumed that only open pores are filled with water.drym is the mass of dry material, satm is the mass of saturated material, sat,wm is the mass of saturated material weighted in water, and wρ is the density of water (1000 kg/m3).After the capillary absorption test, the water level in a water container was gradually increased at the rate of approximately ¼ of the height of the specimens per day until the specimens were completely immersed. The specimens were kept under water until the mass of the specimens changed by less than 0.5 g after two consecutive measurements. The specimens were then weighted in surface dry conditions in air and in water. Bulk density in dry , while the opposite was found for ash with coarser particles (d50 ≈ 100 µm) [No clear conclusion can be drawn from the previously published data on the impact of WFA on the water demand of concrete mixes, as both increased and decreased water demand have been reported. Increased water demand or decreased workability in mixes with WFA was attributed to the irregular shape and higher specific surface area due to the porous WFA particles ,57,58. B 100 µm) . It was Reduced interparticle friction during flow caused by the spherical shape and plain surface of admixture particles—ball-bearing effect .Fine particles fill the void space between relatively large cement grains and release entrapped water and enhance fluidity—filling effect . The cirAdsorption of admixture particles on the surface of the cement particles due to electrical charges, which deflocculates the cement particles and increases mobility .Changes in the workability of concrete caused by mineral admixtures are attributed to the various mechanisms of interaction between solid particles. Many of these mechanisms are governed by the physical properties of the solid particles such as fineness, shape, surface texture, and porosity of the particles, but they also depend on grain composition, mix proportions, and the presence of other admixtures ,59,60,61Increase in solid surface area due to the presence of very fine particles that have a tendency to adsorb water ,59.Replacement with a filler containing large particles (>45 µm) .Open porosity of the particles which increases the specific surfaces ,61.On the other hand, the reduction of workability due to the addition of mineral admixtures is often attributed to:Considering the SSA from It is known that the addition of fine mineral admixtures enhances cohesiveness and reduces the size and volume of voids . The redAM, which evaluates the increase in solid surface induced by filler addition:r represents the mass percentage replacement of cement by filler. A larger value of AM indicates that the filler is finer or that it is present in a larger amount. According to the AM value, the 5% replacement with ash F6 is approximately equal to the 15% replacement with ash F4 or F5. The 15% replacement with ash F6 gives a larger AM value than the mix with 30% replacement of ash F4 and F5. In AM value. The correlation between slump and AM in mixtures containing ash F4 and F6 shows a similar trend, indicating that there is a cement replacement level where workability is increased by WFA addition. Mixes containing ash F5 do not show the same correlation between slump and AM value, as mixes made with ash F4 and F6, which is attributed to the particle size distribution of ash F5.Oey et al.  characteThe existence of optimum WFA content in terms of concrete workability has been observed by Yang et al.  and attr2O content /SiO2, could serve as a good indicator of hydraulic activity when its value is >1. Rajamma et al. [2 + Al2O3 + Fe2O3) is <25%. However, the sum of the pozzolanic oxides does not have to be directly proportional to their pozzolanic activity [Estimation of the potential reactivity of WFA is usually based on its chemical composition. Berra et al.  assumed a et al.  expecteda et al.  expect tactivity ,37,42. Iactivity .2-Al2O3 ratio is close to that of coal fly ash (The hydraulic index of ashes F4, F5, and F6 from this study are 3.1, 0.8, and 3.9, respectively, which according to  indicate fly ash , therefo fly ash  indicateThe increase in UPV of longitudinal waves in early-aged concrete is related to the increase in Youngs and shear modulus ,84. A coAfter 24 h of curing, the largest UPV is measured in the concrete specimens made with ash F6. Compared to mixture M0, this increase is 3% in both mixtures F6-5 and F6-15. The accelerated stiffness development in mixture F6-15 continued in the time period from 24–48 h. Šiler et al.  attributDuring the first two days, the mixtures with 15% cement replaced by ash F4 and F5 exhibited slower stiffness development compared to the mixture M0. The results of UPV measurements during the first days of curing correspond well with the results of calorimetry testing. Mixtures containing ash F6 showed an increased rate of heat generation so the accelerated stiffness development can be attributed to an improved hydration process. Mixtures made with ash F4 and F5 exhibited a decrease in heat generation rate so that fewer hydration products were formed within the first days of hydration and the stiffness development is slowed down accordingly.Measurements over the 2–28-day period indicate that the addition of WFA changed the course of stiffness development. In the reference mixture, the period of 2–7 days shows the largest increase in UPV and a very low increase in UPV from 7–28 days. In mixtures with WFA, the increase in UPV is two to five times larger in the period of 7–28 days compared to the reference mixture. This could be due to the reactivity of ash with the species present in the pore solution.w/c ratio of 0.5. Specimens from mixtures containing ashes F4 and F5 with 15% and 30% replacement levels had only slightly increased porosity compared to mixture M0. A significant increase in porosity was only present in specimens with 45% replacement with ash F5. An opposite effect on porosity was observed for specimens with ash F6, where porosity decreased with the increase in cement replacement level. It was found that the incorporation of biomass fly ash increased the pore content of C-S-H compared to the mixtures made with coal fly ash [The average values of apparent porosity ranged from 12.4% to 14.5% , which i fly ash . The decThe average values of water intake into the specimens due to capillary absorption are presented in The chemical and physical properties of WFA are largely influenced by combustion technology, the type and parts of wood used as fuel, and local operating conditions. The incorporation of WFA in concrete as a partial cement replacement can have a large impact on the fresh and hardened concrete properties. Mixtures made with WFA F6 with a particle size distribution close to that of cement exhibited increased cohesivity, which in turn reduced slump and required more energy for compaction of concrete. At the same time, this type of ash accelerated hydration and stiffness development. The increased cohesiveness of the fresh concrete resulted in concrete with a denser structure and lower porosity, which had a positive influence on the compressive strength and permeability. All these effects can be explained by the filler and filling mechanisms. Mixtures made with WFA F4 that had a similar chemical composition to ash F6 but consisted of coarser particles showed no evidence of the filler effect mechanisms. This suggests that governing mechanisms introduced by the cement replacement with fly ash are connected to the physical interactions between the phases.When WFA is used as a cement replacement, the workability of the concrete is influenced by the quantity, porosity, and particle size distribution of the WFA. The water demand of the concrete is balanced by the amount of water adsorbed by the WFA particles and the amount of released entrapped water due to the filling effect. The results obtained on mixtures containing F4 and F6 ashes indicate that there may be an optimum content of WFA at which the water demand could be reduced. Increasing the WFA content beyond the optimum will increase the quantity of water required to achieve targeted workability.The research presented shows that replacing up to 45% of the cement with WFA has very little effect on capillary absorption and can give concrete with a sufficiently high compressive strength to be suitable for construction purposes. Therefore, from the standpoint of thinking of concrete as storage for large quantities of WFA produced, it seems that the construction industry can give a large contribution in this area by using it as a filler material rather than as a cement replacement.


Health care-related infections are frequent and among them surgical site infection (SSI) are the most frequent in hospitals. The objective was to evaluate the adequacy of antibiotic prophylaxis in patients undergoing neck surgery and its relationship with the incidence of surgical site infection (SSI). Prospective cohort study. The adequacy of antibiotic prophylaxis in patients undergoing neck surgery was evaluated. Antibiotic prophylaxis was considered adequate when it conformed to all items of the protocol . The cumulative incidence of SSI was calculated, and the relationship between SSI and antibiotic prophylaxis adequacy was determined using adjusted relative risk (RR). Antibiotic prophylaxis was administered in 63 patients and was adequate in 85.7% (95% CI 75.0–92.3) of them. The cumulative incidence of SSI was 6.4% (95% CI 3.4–11.8). There was no significant relationship between antibiotic prophylaxis inadequacy and the incidence of SSI . Adequacy of antibiotic prophylaxis was high and it did not affect the incidence of SSIs. The incidence of SSI depends on variables that are both intrinsic  and extrinsic  to the patient4 and ranges from 1 and 20% depending on the type of surgical procedure5.Surgical site infection (SSI) is the most common healthcare-associated infection (HAI)7 and between 25 and 85% when the surgery is clean-contaminated9. These types of infections are of great health importance because they increase the average length of hospital stay, morbidity and mortality, and the healthcare cost per patient11.Neck surgery is one of the most important types of otorhinolaryngological surgery. Specific studies that estimate the incidence of SSI in neck surgery report incidences of less than 1% when the surgery is clean13. The purpose of preoperative prophylaxis is for the antibiotic to reach an optimal concentration in the tissue during the surgical procedure and in the hours immediately following the closure of the incision. The choice of antibiotic will depend on the typical flora of each healthcare centre, the resistance map and the surgical site. For long surgeries, when the duration exceeds twice the half-life of the antibiotic, the dose should be repeated15.One of the most effective measures for reducing SSI is antibiotic prophylaxis, which is indicated in clean-contaminated and contaminated surgeries and in clean surgeries in which an implant is placed, the operative time is prolonged, the patient is immunosuppressed or that are performed on a specific siteThe use of antibiotic prophylaxis protocols facilitates adequacy, and in our hospital, we have a protocol that is periodically updated based on the recommendations in the literature. The protocol is reviewed and updated every two years by the infections commission.The objective of our study was to evaluate the adequacy of the antibiotic prophylaxis to our protocol in patients undergoing neck surgery and the relationship between the adequacy of antibiotic prophylaxis and the incidence of SSI.A prospective cohort study was conducted from January 2011 to December 2019. Consecutive patients over 18 years old who underwent neck surgery at the Alcorcón Foundation University Hospital  were sampled. Patients who at the time of surgery had an active infection or were receiving antibiotic treatment were excluded. The study was approved by the Ethics and Clinical Research Committee of HUFA (number 9/14).The sample size was calculated for an estimated proportion of compliance with the antibiotic prophylaxis protocol of 85%, a confidence level of 95%, an accuracy of 10% and considering losses of 5%. Thus, it was considered necessary to include 52 patients.16 and was evaluated jointly by the Preventive Medicine Unit and the Otorhinolaryngology Service. The surgical procedures included are shown in Table Sociodemographic variables , patient comorbidities , obesity, liver cirrhosis, malnutrition, addiction to parenteral drugs, neutropenia, kidney failure, immunodeficiency), surgical risk according to the American Society of Anaesthesiologists (ASA) classification, surgery-related variables  diagnosis, drainage, shaving or transfusion), antibiotic prophylaxis-related items , compliance with the protocol and SSI-related variables  were considered. Antibiotic prophylaxis stated in the hospital protocol is shown in Table Clinical follow-up of patients was performed from the time of surgery to 30 days after, which is the maximum incubation period for SSIs in surgeries not involving implant placement. They were actively monitored from the time of surgery until discharge and data were collected using an ad hoc form from the following data sources: hospital electronic medical records for surgery and hospital stay-related variables, in-hospital readmission, outpatients’ revision and care provided in the hospital’s emergency department. HORUS, the clinical history platform of the Community of Madrid for primary health-care was also used, which allowed follow-up through primary care visits from discharge to the end of the incubation period.2 test or Fisher’s exact test, as appropriate. The cumulative incidence of SSI was calculated, as was the relationship between SSI and antibiotic prophylaxis adequacy using the relative risk (RR). Statistical analysis was performed in SPSS 23.0, and a p-value < 0.05 was considered statistically significant.A descriptive analysis of the quantitative variables was performed using the mean and standard deviation or the median and interquartile range (IQR) if the variables were not normally distributed; these variables were compared using Student’s t test or the Mann–Whitney test in cases of nonnormality. Qualitative variables were described using frequency distributions and percentages and were compared using the Pearson χThis study was done in accordance with the strengthening the reporting of observational studies in epidemiology (STROBE) statement. Informed consent was obtained from all subjects.During the study period, 140 patients were included in the sample and all of the patients completed the 30-day follow up. The mean age was 65.8 ± 12.4 years. A total of 81.4% of the patients were male. Table No patient undergoing neck surgery had an addiction to parenteral drugs or neutropenia. Most of the admissions were scheduled (94.3%). The mean duration of surgery was 144 ± 118 min. The surgical checklist was properly completed for 66.5% of patients.One patient in whom antibiotic prophylaxis was not indicated received cefazolin. The administration of antibiotic prophylaxis was indicated for 76 patients and was administered for 63 (compliance 83%). For 4 patients, prophylaxis was not administered, and for 9 patients, data on this variable were not recorded. The administered prophylaxis was adequate for 85.7% of patients (95% CI 75.0–92.3) Fig. . The mosNine patients were diagnosed with SSI, with an overall cumulative incidence of 6.4% (95% CI 3.4–11.8). One of the infections occurred in the group of patients who did not receive prophylaxis The incidence of SSI in the group of patients with adequate antibiotic prophylaxis was 9.2% (95% CI 1.5–17.0), lower than that of 22.2% (95% CI 0.0–49.4) in the group of patients with inadequate antibiotic prophylaxis. Two of the patients who did not received prophylaxis had a SSI, with an overall cumulative incidence of 2.5% (95% CI 0.0–6.0).Enterobacter cloacae , while for patients with SSI, the median stay was 26 days (IQR 15.5–41 days) (p < 0.05).There was no significant relationship neither between inadequate antibiotic prophylaxis and the incidence of SSI  nor between patients with or without indication of prophylaxis and the incidence of SSI .17. The incidence of SSI in this study was 6.4%, higher than the incidence reported by the CDC (3.5%)18 and lower than that reported in other studies21, which have described an incidence of up to 85%. Our patients were mostly men (84% men and 16% women) with a mean age of 65.8 years, in line with what has been reported in other neck surgery studies22.A low incidence of SSI is directly related to an adequate surgical technique and is commonly used as an indicator of quality and safety in hospital care24. In neck surgery, there are few studies that evaluate the effect of antibiotic prophylaxis on the incidence of SSI. The results of our study showed a non-significant reduction in SSIs as a function of the administration of adequate antibiotic prophylaxis. There is some controversy between studies that show this relationship26 and others that do not show the efficacy of antibiotic prophylaxis27, although a recent systematic review by Vander Porten et al.28 concludes that the administration of antibiotic prophylaxis clearly reduces the incidence of SSIs in clean-contaminated surgery.Up to 60% of SSIs can be prevented with evidence-based clinical practices such as preoperative preparation or optimal antibiotic selection29. In our study, antibiotic prophylaxis was indicated for 67 patients (47.9%), and its administration was adequate for 85.7% (95% CI 75.0–92.3) of them. The surgeries for which antibiotic prophylaxis was not indicated were those classified under ICD-9-CM codes 30.22, “Vocal cordectomy”, and 31.45, “Open biopsy of the larynx and trachea”, which are classified as clean surgeries and for which the efficacy of antibiotic prophylaxis has not been observed31. Two patients in our series who developed SSI received inadequate prophylaxis, and the percentage of patients who did not receive prophylaxis, even when indicated, was 6.0%, which was lower than in other studies33 and higher than that reported by Hemssen et al.34. Our percentage of adequacy (85.7%) was high; however, it was lower than that reported in other studies35, higher than that of a study conducted in our area36 and in line with that of Takahashi et al.37. The main cause of inadequacy of the antibiotic prophylaxis protocol in our study was the choice of antibiotic, which is the most frequently reported cause of inadequacy38.The administration of the prophylactic antibiotic between 30 and 60 min before the surgical incision reduces SSIs and should be repeated if the surgery lasts more than 4 hStaphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, enterobacteria and Enterococcus spp.40, which are common colonizing microorganisms of the airways. In our study, most of the microorganisms were gram negative (Enterobacter cloacae), which is consistent with other studies that describe this group of microorganisms as the most frequently identified in postoperative infections in neck surgery41.The microorganisms isolated from SSIs during neck surgery are very diverse; the most frequent are 42.Monitoring the adequacy of the items of the antibiotic prophylaxis protocols can help controlling SSIs and the antibiotics to be effective, as shows different previous researchThe possible limitations of the study include the small sample size, although a sample size estimation was performed to ensure that the percentage of antibiotic prophylaxis adequacy was adequately estimated. The incidence of infection may be underestimated by the loss of exceptional cases of superficial infections with minimal symptoms for which the patient did not contact the emergency department, the otorhinolaryngology service or the primary care doctor. We believe that this bias has been controlled because the patients were followed during admission and after discharge and their attendance at different care facilities was prospectively evaluated for 30 days, the maximum incubation period of an SSI in surgeries without implant placement.We can conclude that antibiotic prophylaxis is one of the most cost-effective measures for reducing the incidence of SSIs, and compliance with existing protocols is a measure that is used to assess the quality of health care. Adequacy of antibiotic prophylaxis in our study was high, and the main cause of inadequacy was the choice of antibiotic. We observed a reduction in the incidence of SSI during neck surgery in patients who were adequately administered prophylaxis, although this relationship was not statistically significant. So, we would recommend to monitor the adequacy of the items of the antibiotic prophylaxis protocols, in order to control SSIs.


To elucidate heterogeneity of IgG4-related disease (IgG4-RD) based on B cell immunophenotyping.Immunophenotyping of 4 B-cell subsets in peripheral blood from patients with active IgG4-RD  was performed using flow cytometry to get preliminary B-cell heterogeneity spectrum. Then 10 B-cell subsets were characterized in aIgG4-RD (n = 49), remissive IgG4-RD , and healthy controls , followed by principal components analysis (PCA) and cluster analysis to distinguish B-cell immunophenotypes and classify IgG4-RD patients into subgroups.Cluster analysis identified two endotypes in 105 aIgG4-RD patients based on 4 B-cell subsets: Group1 with higher Breg and naive B cells (n = 48), and Group2 with higher plasmablasts and memory B cells (MBCs) (n = 57). PCA indicated that aIgG4-RD consisted of plasmablast-naive B cell and MBCs-Breg axes abnormalities. There was a negative relationship between naive B cells and disease activity. Both plasmablasts and MBCs were positively associated with serological biomarkers. Cluster analysis stratified aIgG4-RD patients into 3 subgroups based on 10 B-cell subsets: subgroup1 with low MBCs and normal Breg, subgroup2 with high MBCs and low Breg, and subgroup3 with high plasmablasts and low naive B cells. Patients in subroup2 and subgroup3 were more likely to be resistant to treatment.Patients with aIgG4-RD can be divided into 3 subgroups based on B cell heterogeneity. The B cell immunophenotyping could help elucidate the pathogenesis of IgG4-RD, identify patients with potential refractory IgG4-RD, and provide important information for the development of new therapies. IgG4-related disease (IgG4-RD) is an immune-mediated fibrotic disease characterized by elevated serum IgG4 concentration, tissue infiltration by IgG4+ plasma cells, and a marked responsiveness to both glucocorticoids and B cell depletion with rituximab (RTX) . VariousThe pathogenic role of B cell subsets has been given increasing attention since IgG4-RD was first recognized. In particular, plasmablasts are highly expanded and infiltrate tissue with extensive somatic hypermutation . CirculaTaken together, the above findings suggest B-cell compartment in IgG4-RD is phenotypically heterogeneous. Although RTX is effective for both induction therapy and treatment of relapses in IgG4-RD, the high rate of infections and the temporary effect of RTX might be hindrances to such strategy , for it Based on these considerations, it is worth raising three clinical questions: 1) What are the differences in B-cell immunophenotypes between IgG4-RD patients and healthy individuals, before and after treatment? 2) How do the B-cell immunophenotypes interact? 3) Can patients be divided into subgroups by immunophenotyping? 4) What’s the association of B-cell subsets abnormalities and clinical phenotypes ? To addrPeripheral blood (PB) was obtained from patients with active IgG4-RD , remissive IgG4-RD , and HC (n=47). IgG4-RD was diagnosed according to the 2011 comprehensive IgG4-RD diagnostic criteria  and the 6 PBMCs were stained for B-cell subsets for 30 minutes at 4°C after washing and re-suspend in cell staining buffer. Flow cytometric analysis was performed immediately after sample preparation , absolute eosinophil count (AEC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), complement (C3 and C4), immunoglobin , IgG1, IgG2, IgG3, and IgG4 subclasses. Peripheral blood mononuclear cells (PBMCs) were isolated from PB using Ficoll-Hypaque density gradient centrifugation. 1X10The treatments for IgG4-RD patients were classified into four categories: watchful waiting, GCs monotherapy, immunosuppressive agents (IM) monotherapy, and GCs + IM combination. IM applied in our study was graded as strong potency IM including cyclophosphamide (CTX) and mycophenolate mofetil (MMF), and weak potency IM including methotrexate (MTX) and leflunomide (LEF). The average follow-up period was 20 months. Remissive IgG4-RD included complete remission (CR) and partial remission (PR): CR was defined as IgG4-RD RI (2018) =0; PR was defined as IgG4-RD RI (2018) declining by ≥ 50%. Relapse was defined as a recurrence of symptoms and signs and/or worsening of imaging studies, with or without re-elevation of the serum IgG4 level. Potential refractory IgG4-RD was defined as no significant improvement on serological biomarkers especially reported risk factors , 16, alt+CD24+CD38− MBCs, CD19+CD24intCD38int naïve B cells, CD19+CD24hiCD38hi regulatory B cells (Bregs), and CD19+CD24−CD38hi plasmablasts cells)  , which w+CD24-CD38hi, CD19+CD27hiCD38hi, and CD19+IgD-CD38hi), 2 naive B cells , 4 MBCs , and CD19+CD24hiCD38hi Breg  was used among 3 groups. Non-normally distributed data between two groups were compared using the Mann-Whitney U-test, and Kruskall-Wallis was performed among 3 groups. Chi-squared tests were used to compare Categorical variables such as treatment categories, clinical phenotypes, and relapse state. The relationships between B-cell subsets and clinical features were analyzed by Pearson’s or Spearman’s correlation test. Paired t-tests were used to assess differences in serum biomarkers before and after treatments. P-values <0.05 were considered significant.For easy exploration and visualization of multiple variables, we used PCA to statistically aggregate 10 items of B-cell subsets, reducing the dimensionality of immunophenotyping data for subsequent cluster analysis, and exploring the correlation between these variables. According to eigenvalues (λ> 1) and cumulative contribution rate (>75%), we selected appropriate number of eigenvectors with the top highest eigenvalues as principal components (PCs). According to Component Matrix and eigenvalue, PC scores  were also calculated in individual samples as new variables for further cluster analysis , 21.Cluster analysis was performed three times in this study using a hierarchical and agglomerative clustering algorithm with the Ward method –22: direBaseline clinical characteristics and 4 B-cell subsets of 105 aIgG4-RD patients were shown in Cluster analysis classified aIgG4-RD patients into Group1 (n=48) and Group2 (n=57) based on 4 B-cell subsets   between aIgG4-RD patients and HCs, which were remarkably higher in aIgG4-RD patients and reduced drastically after treatments in rIgG4-RD patients. The proportion of CD19+IgD+CD27+ unswitched MBCs were lower in aIgG4-RD patients than HCs, and similar to that in rIgG4-RD patients. The result was worth discussing is that CD19+CD24hiCD38hi Breg proportion did not differ between aIgG4-RD patients and HCs, and decreased after treatments. No significant differences in proportions of CD19+CD24intCD38int naive B cell and CD19+IgD-CD38-CD27+ switched MBCs were observed among cohorts.First, we compared B-cell subsets proportions of the 3 cohorts (We extracted 3 PCs (accumulative contribution rate = 78%) in the mixed cohort based on ten B-cell subsets ratios: PC1 , PC2 , and PC3 . Then two distinct Clusters (based on 10 B-cell subsets profile) were identified by cluster analysis .To assess a potential pathophysiological link between circulating B-cell subsets frequencies and aIgG4-RD, we performed correlation analysis with the following validated clinical and serological biomarkers in aIgG4-RD cohort (n=49): number of organs involved, IgG4-RD RI (2018), serum IgG, IgG+CD24-CD38hi, CD19+CD27hiCD38hi, and CD19+IgD-CD38hi), while the negative side contained 2 types of naive B cells . In contrast, PC2 was mainly associated with MBCs and Breg. The positive side of PC2 contained CD19+CD24+CD38-, CD19+IgD-CD38-CD27+ switched, and CD19+IgD+CD27+ unswitched MBCs, while the negative side contained CD19+CD24hiCD38hi Breg. Specially, in memory B phenotype, CD19+IgD-CD27+ MBCs seemed to play a more significant role in PC1 than in PC2.To further investigate the abnormalities of B-cell subsets in aIgG4-RD, we separately used PCA in aIgG4-RD cohort to statistically aggregate these 10 immunophenotypes. Two PCs (accumulative contribution rate = 77%) were extracted based on ten B-cell subsets ratios: PC1 , and PC2  . Breg also showed positive correlation with CD19+IgD+CD38± naive B cell (P=0.046). While both CD19+CD24intCD38int and CD19+IgD+CD38± naive B cells were negatively correlated with MBCs, especially CD19+IgD-CD27+ MBCs (P<0.001). Interestingly, CD19+IgD-CD27+ MBCs and plasmablasts cells were statistically close in loading plot and showed great positive correlations , both were negatively correlated with naive B cells, and positively correlated with disease activity and severity associated indexes as previously mentioned   CD19 IgG4-RD ; (ii) B  IgG4-RD ; (iii) preatment ; (iv) GC relapse ; (vi) RTWe sketched out the general picture of B-cell heterogeneity spectrum in aIgG4-RD based on 4 immune cell subsets according to previous reports . Despite+IgD+CD38± naive B cells decreased in aIgG4-RD and further declined after treatment. Another study also reported GC-induced disease remission was accompanied by a reduction of CD19+CD20+CD27-CD38+ naïve B cells  patients in subgroup3 received the highest doses of initial GCs and stronger potency IM, but still had the highest serological biomarker levels even if disease achieved remission; (ii) although patients in subgroup1 and subgroup2 had similar levels of serological biomarkers at baseline, subgroup2 had no significant improvement in these biomarkers after treatments. The results further indicates that huge icebergs  are below the tip of the iceberg  in IgG4-RD, which help physicians in aiming at a complete assessment of individual patients for therapeutic decision-making, relapse risk prediction, and prognosis evaluation. Therapies targeting the B-cell lineage have been applied, including RTX targeting CD20 and XmAb5871 targeting CD19 . Our finThe association of B-cell subsets abnormalities and clinical phenotypes provided support for our findings that IgG4-RD was a heterogeneous condition immunologically with plasmablast-naive B cell and memory B cell-Breg axes abnormalities, patients with higher plasmablasts and MBCs had both higher serological biomarker levels and more serious clinical condition including more potential to be systemic involved and refractory. Conversely, relatively normal naïve and Breg, or lower CD19+IgD-CD27+ MBCs may be a mild sign to patients with IgG4-RD.Our study has limitations. First, the sample size was limited. Therefore we cannot perform stratified analysis according to different IgG4-RD types, such as types of organs involved, and different treatments. We also didn’t observe clear relapse in subgroup2&3, although they had higher levels of risk factors after remission. Second, no patient received RTX in our study, we cannot comment on the impact of B-cell depletion on the B-cell immune signatures. Third, although we explored 10 B-cell immune subsets, B-cell set is complicated and continually updated. Further molecular and genetic characterization of B-cell subsets could have offered a better understanding of their involvement in the pathogenesis of IgG4-RD and will be the focus of future studies.In conclusion, IgG4-RD is a heterogeneous condition immunologically with plasmablast-naive B cell and memory B cell-Breg axes abnormalities. Classification of patients with IgG4-RD based on B-cell immunophenotypes could help to identify potential refractory patients. A deeper understanding of these findings will improve our understanding of IgG4-RD pathogenesis, and lead to the development of more precise and effective therapies.The original contributions presented in the study are included in the article/The studies involving human participants were reviewed and approved by the medical ethics committee of Peking Union Medical College Hospital . The patients/participants provided their written informed consent to participate in this study.Design of research study: WZ and JL. Acquiring data: ZL, PZ, and WL. Data analysis: JL. Recruiting patients: HL, YP, LP, JZ, MW, HC, LZ, LW, CQ, and CH. Analyzing data: WZ and JL. Writing the manuscript: JL. Review of the manuscript: XZ, YZ, YF, and WZ. All authors contributed to the article and approved the submitted version.This work was supported by the National Natural Science Foundation of China , the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences (NWB20203346), Capital’s Funds for Health Improvement and Research (No. 2020-2-4017) and Beijing Municipal Science & Technology Commission (No. Z201100005520023).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.