The plastic shrinkage tests were carried out in a specially designed chamber, according to ASTM C1579. Various environmental conditions are examined, and their impact on compressive strength and crack potential is assessed. A digital image analysis technique is used to measure length, width, and the area of the crack on the exposed surface to gain additional insights into crack behaviour. The results show a slight early-age (one-day) increase in compressive strength for the concrete exposed to the various environmental conditions, mostly as a result of higher temperatures. Through the use of the crack reduction ratio (CRR), both RTSF and MSF are shown to be successful in controlling plastic shrinkage and micro cracks, with the RTSF being superior due to the fact that they are better distributed in the concrete volume. The addition of 30 kg/m3 of RTSF was effective in preventing crack development in most environments or restraining cracks in extremely harsh environments. The adoption of these results will lead to more sustainable concrete slabs in the harsher environmental conditions created by climate change.Early-age plastic shrinkage cracks can reduce the durability of concrete slabs by creating direct paths for the ingress of aggressive agents and thus accelerating degradation due to environmental attack, in particular, in hot and windy environments. The elimination of such cracks is essential for durable and sustainable concrete structures. This paper parametrically investigates the effect of manufactured steel fibres (MSF) and recycled tyre steel fibres (RTSF) on restraining plastic shrinkage and micro cracks at different dosages (10, 20, and 30 kg/m Early-age cracking due to autogenous and plastic shrinkage is a key issue that affects concrete durability and reduces the lifespan of concrete structures. It is estimated that plastic shrinkage cracking is the source of roughly 80% of the early-age cracking in reinforced concrete structures ,2. ThougPlastic shrinkage cracks are the result of volume changes that occur during the plastic stage, i.e., before the concrete hardens. These include air void expulsion and aggregate plastic settlement, as well as the bleeding and evaporation of water . As the Plastic shrinkage cracks occur due to rapid evaporation; hence, they are a direct consequence of environmental conditions, such as elevated temperature, low relative humidity, solar radiation, and exposure to high wind flows ,12,13,142/h, which is most likely to occur in hot weather concreting in arid climates [Plastic shrinkage cracking is expected to develop when the evaporation rate is greater than 1.0 kg/mclimates . Kwak anclimates  investigSoon after casting and during the initial setting time (2–4 h) see , the denAfter the initial setting time, the rate of bleeding water stabilises and then ceases. During the final set (4–8 h), the hydration of cement causes the surface temperature to increase, and, as a result, the evaporation rate can exceed the bleeding rate. A high rate of evaporation, also aggravated by dry conditions and wind, can lead to plastic shrinkage cracking before the final set ends .Boshoff and Combrinck  and SayaMost recent research on plastic shrinkage cracks focuses on performance and durability enhancement of concrete as a material ,23,24 anLee and Won  evaluateBooya et al.  examinedFor example, Karalar et al.  conducteWith around 1.5 billion tyres worldwide being discarded every year, each containing about 10% of highly engineered steel cord as reinforcement , variousRecycled tyre steel fibres (RTSF) are typically characterised by a range of lengths and a smaller diameter than conventional MSF and may offer a more holistic shrinkage crack control (from plastic to drying), as well as structural reinforcement benefits. Su et al.  tested tAs for all shrinkage cracks, plastic shrinkage cracks appear on the surface of the concrete as a result of external restraint. Hence, in plastic shrinkage tests, there is an attempt to amplify restraint, so as to accelerate cracking. Four main plastic shrinkage test techniques are used to evaluate plastic shrinkage cracks: ring, longitudinal, slab, and substrate restraint.Bjøntegaard and Sellevold  adopted A test method relying on prisms with a size of 40 × 40 × 500 mm  was first proposed in . The arrTracking plastic shrinkage cracks is challenging due to the random initiation time, location of crack, and irregular crack shape, which renders conventional strain measurements inadequate. Therefore, dynamic manual and image-based techniques are necessary. Manual methods include the use of microscopes and crack magnifiers to measure the crack width and length. It is accepted that it is necessary to obtain the measurements at more than one point and utilise the average of the measurements ,55,56,57Image-based techniques include digital image correlation (DIC) and digital image processing (DIP). Those methods tilize high-resolution cameras that capture images of the entire concrete surface and these images are subsequently processed by specially developed algorithms. These methods can track the crack width, length, and area at the surface of the concrete from the time of casting to the end of the test. Recently, DIC has been used extensively in studies monitoring cracks on hardened concrete surfaces ,58. In tThis paper aims to examine the impact of RTSF on plastic shrinkage cracking of concrete. A direct comparison is made with MSF and the impact of fibre distribution on crack initiation and development is investigated. Crack measurements are obtained through the implementation of a digital image processing method, in an attempt to have a more in-depth understanding of crack development and remove subjectivity. The use of finer structural fibres may lead to more sustainable and durable steel-fibre-reinforced concrete (SFRC) structures.In this study, hooked-end fibres  were selIn this study, specially processed recycled tyre steel fibres (RTSF), as shown in The diameter was measured at 3 points along the fibre length. The average diameter was found to be 0.35 mm (SD = 0.036 mm), with measurements ranging between 0.32 and 0.41 mm see b. The av3 was selected, as this increases the likelihood of plastic shrinkage cracking.The mix design used in this experimental study is shown in OD), specific gravity saturated surface dry (SGSSD), apparent specific gravity (ASG)) and absorption were also determined, as recommended in ASTM C127-15 [Natural river sand and gravel were used as fine and coarse aggregates, and their total evaporable moisture content was determined by drying, as per . The rel C127-15 . All thef = 0%—control samples), 10 kg (Vf = 0.13%), 20 kg (Vf = 0.26%), and 30 kg  per m3 of concrete, to examine their impact on plastic shrinkage cracks.MSF and RTSF were used in different amounts, 0 kg ) ASTM C1579 [2/h; otherwise, the test is rejected [E: Evaporation rate, kg/m2/h; M2 − M1: the mass loss between successive weighings, g; and T2 − T1: the time interval between successive weighings, h.To quantify the base water evaporation rate in the chamber, two aluminium pans were filled with water and were placed next to each slab specimen. The exposed water surface area of each pan was 0.019 mTM C1579 ; the masrejected .(1)E=M2The plastic shrinkage tests were designed to give a comparative analysis of crack behaviour  between two slabs in the same environmental conditions. The specimens were rectangular with dimensions of 560 mm in length, 355 mm in width, and 100 mm in depth. A tall triangular stress riser was fixed at the middle of the mould’s steel base to induce cracking, and two shorter triangular internal restraints were fixed close to the sides of the mould  on eitheThe chamber was turned on two hours prior to the start of the test to pre-heat and stabilise the environment to the desired temperature (36 ± 3 °C) and relative humidity (30 ± 10%), as recommended by . ImmediaRecords of the water mass loss and water evaporation rate were taken every 30 min, according to ASTM C1579 . The setMeasurements of the plastic shrinkage cracks  were carried out using a digital image processing method, whereby a camera is placed above the samples during the test to capture images of the samples at different times. The images were then analysed using a digital imaging processing script written in MATLAB. The MATLAB script was written and developed by . The scrAt 24 h, measurements of crack width were obtained by using both digital image analysis, as explained above, and an optical micrometre at more than 25 locations along the crack length to calculate the average of crack width. These measurements were made for comparison purposes between the two methods.The average plastic shrinkage crack width is used to calculate the crack reduction ratio (CRR) at 6 and 24 h from the start of the test and uses the following equation, as recommended in :(2)CRR=3, 20 kg/m3, and 30 kg/m3, respectively. The corresponding reductions in workability were less when using MSF and were equal to 13%, 25%, and 36%. This is because the number of RTSF fibres is much higher for a single fibre volume compared to MSF, and this also increases the shear resistance of fresh concrete making it harder to flow [The concrete workability is affected by various factors. It was observed that the addition of RTSF and MSF lead to a reduction in the slump of concrete compared with plain concrete, as shown in  to flow . These r to flow ,69.The compressive strength of control specimens (plain concrete—PC) and steel-fibre-reinforced concrete (RTSF and MSF) at 1 day and 28 days, measured on cubes that were conditioned inside and outside the chamber, are shown in As expected, given the work of ,71,72, tHowever, the one-day compressive strength after exposure in the chamber for 6 h is around 10% higher than for cubes that were kept outside the chamber see a,c. DzayThe evaporation rate is accepted as one of the main factors that influence the likelihood of plastic shrinkage cracking. When the evaporation rate increases, the crack area and width increases ,78. In t2/h required by ASTM C1579 [TM C1579 .The evaporation rate of all mixes increases roughly in a similar manner, irrespective of fibre amount and type. The increase in the evaporation rate is consistent with the increase in temperature during the test. Initially, the evaporation rate is more or less constant, but after two to three hours of the test the evaporation rate increases slightly. This could indicate an increase in bleed water, but this is unlikely as cracks also appear at this stage, which means that this is likely due to increased surface temperature due to hydration. The development of cracks means that by now the bleeding rate has slowed down or stopped, which is in agreement with other works ,80.A digital image analysis technique was used to evaluate the evolution of plastic shrinkage cracking during the test. Photos of the concrete surface were taken every 10 min until the cracks first appeared (about two to three hours), and every 30 min thereafter until the end of the test (six hours). Photos were also taken at 24 h, as recommended in . All phoMost cracks appear after 2 h, corresponding to the initial setting time, while they show a fast evolution (width) during the first two to three hours after initiation and tend to stabilise towards the end of the test when the concrete is reaching or has reached its final setting time. As expected, after the end of the test and up to 24 h, none of the cracks showed any significant increase in width. These results are in agreement with other similar studies ,81,82.The rapid increase in crack width immediately after cracking is attributed to the evaporation rate being equal to or higher than the bleeding rate, which indicates the stage that the concrete surface begins to dry and a negative pore pressure is created ,84,85. TMeasurements at 24 h were made using digital image analysis and optical methods for comparison purposes and are also shown in Overall, the addition of fibres has a beneficial effect in delaying and preventing plastic cracks, as also reported in ,86, likeAll of the crack reduction ratios (CRR) of this study were determined at the end of the tests, according to Equation (2), and are shown in 3 of RTSF. This was also observed in [Both fibre types (RTSF and MSF) show a good performance in controlling plastic shrinkage cracking. Better crack control is achieved at increasing fibre dosages, and cracking is avoided completely when using 30 kg/merved in .The impact of RTSF on plastic shrinkage cracking has not been discussed in previous studies. Overall, the results show that RTSF outperforms MSF at all dosages, and the qualitative image analysis presented below seems to confirm that the number of fibres, their weight, and their overall rigidity play a role in their performance. Cross-sections of the RTSF and MSF slabs were cut in the proximity of the stress riser, as shown in The evaporation rates are similar for all specimens and increase with increasing temperature.Cracking initiates after approximately 2 h from casting, indicating the initial setting time, and substantially stopped after 6 h, which can be considered as the final setting time.Exposure to the higher temperature in the chamber increases the hydration rate and 24 h strength of the concrete, although this had no major impact on the 28-day strength. The fibres only have a minor enhancing effect on compressive strength.3 (Vf = 0.13%), 20 kg/m3 (Vf = 0.26%), and 30 kg/m3 (Vf = 0.38%), respectively. The better performance of RTSF is attributed to their larger number and better distribution within the concrete volume when compared to MSF.RTSF outperform MSF in mitigating plastic shrinkage cracking at all dosages, with CRR values of 42%, 75%, and 100% for fibre dosages of 10 kg/mThis paper investigates the effect of different dosages of RTSF and MSF on restraining concrete plastic shrinkage and micro cracks at the fresh stage. Plain concrete and fibre-reinforced concrete slab specimens are tested according to the test method recommended in ASTM C1579 under controlled environmental conditions, and their crack initiation and development is examined, along with other physical parameters. From the analysis of the results presented in this paper, the following conclusions can be drawn:3 (Vf = 0.38%) can be used to prevent plastic shrinkage cracking completely in most typical applications and environmental conditions.Although an appropriate fibre volume should be selected depending on mix design and target overall performance, a fibre dosage of 30 kg/mThis study provides compelling experimental evidence that RTSF are a sustainable and effective alternative to MSF in preventing plastic shrinkage cracks, in the same way as they are effective against drying shrinkage. The use of finer fibres has a beneficial effect in controlling plastic shrinkage cracks and their use (or the use of blends of MSF and RTSF) is expected to provide structural, durability, and sustainability benefits, particularly in the harsher environmental conditions created by climate change.Future studies should examine the synergistic effects of using sustainable fibre alternatives, such as the RTSF used in the work presented in this paper, with different cement and aggregate replacements, as well as different curing methods to reduce or prevent plastic shrinkage cracking in concrete.


There is not a prevailing consensus on appropriate antibiotic choice, route, and duration in the treatment of bacterial pleural empyema after appropriate source control. Professional society guidelines identify a wide range of antibiotic durations, and generally recommend an antibiotic with broad-spectrum activity against anaerobes , while noting the lack of comparative trials with which to guide recommendations.We performed a hypothesis-generating retrospective chart review analysis of clinical outcomes in 355 adult inpatients who had pleural drainage, via either chest tube or surgical intervention, for known or suspected empyema. The aims of the investigation were to compare clinical outcomes with regard to 1) the use of antibiotics with broad activity against anaerobes, 2) total antibiotic duration, and 3) IV antibiotic duration. Mann-Whitney U test with Bonferroni multiplicity adjustment was used to compare outcomes with regard to these variables.p-value 0.003) and lower all-cause 30-day readmission . Longer total antibiotic duration was associated with lower empyema-specific 30-day readmission rates , with a non-significant trend towards lower all-cause 30-day readmission (22.1 ± 20.9 vs 15.0 ± 8.3). IV antibiotic duration was not associated with a difference in 30-day readmission (data not shown).A longer course of an anti-anaerobic antibiotic was associated with both lower 30-day readmission rates for empyema (11.9 ± 13.8 antibiotic days in non-readmission group, n = 321 vs 2.2 ± 2.7 days in readmission group, n = 17, Our data support the premise that routine use of anti-anaerobic antibiotics is indicated in the treatment of pleural empyema. However, our study casts doubt on the benefits of extended IV rather than oral antibiotics in the treatment of empyema. This represents a target for future investigation with the aim of limiting complications associated with the excessive use of IV antibiotics.All Authors: No reported disclosures.


Ecological concrete could reduce the environment impacts of the tremendous construction of infrastructures due to its favorability to plant growth. Nonetheless, the alkalinity of the ecological concrete is usually too high when using ordinary Portland cement (OPC). To solve this problem, the magnesium ammonium phosphate cement (MPC) was used to prepare a novel porous ecological concrete instead of OPC. The pH value and compressive strength of MPC were analyzed and the pore structure was evaluated. The chemical composition and morphology were investigated by an X-ray diffraction test and scanning electron microscope observation. In addition, the void ratio, compressive strength and planting-growing characteristic of MPC-based porous ecological concrete were also studied. The pH value of the MPC suspension ranged from 6.8 to 8.5, which was much lower than that of OPC. The pH value of MPC gradually increased with the increment of phosphorus/magnesium molar ratio (P/M) and the compressive strength reached a maximum value of 49.2 MPa when the P/M value was 1/4. Fly ash (FA) and ground blast furnace slag (GBFS) could improve the pore structure and compressive strength; however, the pH value was slightly increased. As the paste-to-aggregate ratio increased, the void ratio of concrete gradually decreased, while the compressive strength gradually increased. The meadow grass was planted in the MPC-based ecological concrete, and the seeds germinated in one week and showed a better growth status than those planted in the OPC-based ecological concrete. Concrete is the most consumed material except for water  and has Porous ecological concrete is prepared by mixing low alkalinity cementitious material and single graded aggregate in a certain proportion, which has the dual attributes of safety protection and plant growth. The use of ecological concrete has a bright future in the fields of riverbank slope protection, wetland restoration and urban transformation due to its high environmental compatibility. Therefore, scholars have extensively studied on ecological concrete ,5,6,7,8.Magnesium ammonium phosphate cement (MPC) is a new type of hydraulic cementitious material ,22,23,24Aiming to solve the problems of high alkalinity and poor planting performance of traditional OPC-based ecological concrete, this paper attempts to use MPC to prepare porous ecological concrete, and regulates its alkalinity, strength and void ratio through mix design so as to validate its planting performance.3. Ammonium dihydrogen phosphate (NH4H2PO4), fly ash (FA), ground blast furnace slag (GBFS) and borax (Na2B4O7·10H2O) were also used in this study. The physical and chemical characteristics of MgO, FA and GBFS are shown in 4H2PO4 was industrial-grade white crystalline powder with a purity of 98%. The borax (Na2B4O7·10H2O) in the form of white crystalline powder with a purity of 99.5% was used as a retarder. The single gradation crushed stone was used as coarse aggregate with a particle size of 19–26.5 mm.The magnesia oxide (MgO) powder was used to make an MPC tendon with a density of 3.46 g/cm4H2PO4 to MgO (P/M) here is a molar ratio. The content of borax is the mass percentage of borax to MgO. The ratio of water to the total amount of cementitious materials is represented as W/B, and cementitious materials refer to MgO, NH4H2PO4, FA, GBFS and borax. The content of FA or GBFS is expressed as the mass percentage of FA or GBFS to the sum of cementitious materials.The mixes of MPC are shown in The mixes of porous ecological concrete are shown in The alkalinity of porous ecological concrete is mainly determined by the alkalinity of the cementitious material. Thus, the alkalinity of MPC was tested using a pH meter to evaluate the alkalinity of the porous ecological concrete. A sample of 5 g of MPC was soaked in 50 g deionized water and was sealed to prevent carbonation. The alkalinity of soaking solution was measured by a pH meter. Each set of the samples was tested 6 times.Cement Mortar Strength Testing Method (ISO) ). With the addition of FA, the main components of MPC/FA are struvite, unreacted MgO, mullite and SiO2 without any precipitation of new products. It is similar to the addition of GBFS; the main components of MPC/GBFS are struvite and unreacted MgO without new products. The results confirm that FA and GBFS only play a role in microporous filling without a major contribution to the chemical reaction.It can be seen from The microstructure of MPC was observed using SEM. According to Poa pratensis L.) was selected for ecological planting. The planting materials were composed of ordinary soil, water, a water-retaining agent and a water-reducing agent. The filling process of planting materials was based on an infiltration method. The fluidity was adjusted to the range of 180~240 mm. Then, the planting materials were poured into the pores of the porous ecological concrete. The average ambient temperature was 25 °C. The MPC-based porous ecological concrete sample, soil and seeds are shown in The porous ecological concrete (C-PA1/5) was used for plant-growing verification. MPC with 1/4 P/M and 20% GBFS was used for cementitious material, and OPC with 0.35 W/B was used for cementitious material for comparison. The meadow grass (The growing status is shown in (1)With the decrease of P/M, the alkalinity of the MPC gradually increased; however, the pH values were still much lower than the OPC. The compressive strength of MPC reached the maximum value of 49.2 MPa when P/M was 1/4.(2)The alkalinity and compressive strength of MPC increased with the addition of FA and GBFS, and the GBFS showed more significant effects on alkalinity and compressive strength than that of FA.(3)With the increase of the paste aggregate ratio, the void ratio of porous concrete gradually decreased from 37.3% to 30.8%, whereas the compressive strength gradually increased from 5.23 MPa to 6.12 MPa at 28 days. The compressive strength of porous concrete also increased with the addition of 20% FA and GBFS.(4)The seeds planted in the MPC-based porous ecological concrete began to germinate after one week and grew better than those in the OPC-based ecological concrete. Thus, the MPC-based porous ecological concrete showed feasibility in ecological rehabilitation projects.(5)At present, the setting time and cost of MPC-based ecological concrete are the main problems limiting its large-scale application. In the future, further research should be conducted in the field of research and development of environment-friendly retarders and the replacement of low-cost raw materials (such as recycled aggregate).


Antibiotic-resistant pathogens cause over 35,000 preventable deaths in the United States every year, and multiple strategies could decrease morbidity and mortality. As antibiotic stewardship requirements are being deployed for the outpatient setting, community providers are facing systematic challenges in implementing stewardship programs. Given that the vast majority of antibiotics are prescribed in the outpatient setting, there are endless opportunities to make a smart and informed choice when prescribing and to move the needle on antibiotic stewardship. Antibiotic stewardship in the community, or “smart prescribing” as we suggest, should factor in antibiotic efficacy, safety, local resistance rates, and overall cost, in addition to patient-specific factors and disease presentation, to arrive at an appropriate therapy. Here, we discuss some of the challenges, such as patient/parent pressure to prescribe, lack of data or resources for implementation, and a disconnect between guidelines and real-world practice, among others. We have assembled an easy-to-use best practice guide for providers in the outpatient setting who lack the time or resources to develop a plan or consult lengthy guidelines. We provide specific suggestions for antibiotic prescribing that align real-world clinical practice with best practices for antibiotic stewardship for two of the most common bacterial infections seen in the outpatient setting: community-acquired pneumonia and skin and soft-tissue infection. In addition, we discuss many ways that community providers, payors, and regulatory bodies can make antibiotic stewardship easier to implement and more streamlined in the outpatient setting. Every year in the United States (US), antibiotic-resistant pathogens are implicated in at least 35,000 deaths and over 2.8 million infections . FundameIn the US in 2019, 250 million oral antibiotic prescriptions were written in the outpatient setting—roughly the equivalent of eight antibiotic prescriptions for every 10 people  3–5). O–5. O3–5)Clostridioides difficile–associated diarrhea and drug toxicity , but only if local Streptococcus pneumoniae resistance rates are < 25% .–21.Staphes > 25% .While some local public health agencies and health systems provide clinicians with local resistance information, these data are becoming more challenging to obtain . FurtherPrimary care physicians, advanced practice providers, and dentists account for the majority of outpatient antibiotic prescriptions written . Prescridemonstrate a commitment to optimizing antibiotic prescribing and patient safety, take at least one action for policy or practice to improve antibiotic prescribing, track prescribing practices and provide regular feedback to clinicians, and provide educational resources and expertise on optimizing antibiotic prescribing  and professional organizations (Infectious Diseases Society of America) have published a variety of resources for clinicians on antibiotic prescribing, for particular infections and for more appropriate use of antibiotics in general , 36–42. Patients (and parents of young patients) often expect and may even pressure a provider for an antibiotic prescription when it is not indicated. About 84% of providers surveyed said they feel at least moderate pressure from patients for an antibiotic prescription . PatientHere, we want to address smart prescribing for two of the most common bacterial infections seen in the outpatient setting, CAP and skin and soft-tissue infection (SSTI). For CAP and SSTI, several organizations have released updated clinical practice guidelines within the last 7 years , 38, 42.S. pneumoniae is the most commonly isolated bacterial pathogen in patients with pneumonia without underlying chronic lung disease; other causative pathogens include Haemophilus influenzae, Mycoplasma pneumoniae, S. aureus, and Legionella pneumophila  and remained stable from 2010 to 2014. There was a decrease in susceptibility rates over this period for other common antibiotics, such as amoxicillin, erythromycin, tetracycline (which can be used as a surrogate for doxycycline susceptibility), and trimethoprim–sulfamethoxazole  are approximately 40–50% in the US S. aureusS. aureus isolates between 1997 and 2016 showed susceptibility of methicillin-susceptible S. aureus (MSSA) isolates to many older agents was > 95%, except for penicillin and erythromycin , delafloxacin , and ceftaroline .Global susceptibility of hromycin  51). Th. ThS. auS. aureus , purulent SSTIs can often be treated by incision and drainage alone, while non-purulent SSTIs require antibiotics , 52, 53.. aureus , 54, 55.. aureus , 40, 42.Given the number of infections that occur annually for CAP and SSTI in the US, there are millions of chances to make a smart and informed choice when prescribing antibiotics. Antibiotic stewardship in the community, or “smart prescribing” as we suggest, should factor in antibiotic efficacy, safety, local resistance rates, and overall cost, in addition to patient-specific factors and disease presentation, to arrive at an appropriate therapy.Almost half of surveyed providers said they would need “a lot of help” to implement antibiotic stewardship practices . We recoFrom EMR prescribing data, providers can identify one or two issues within their practice to address , and determine what action to take –58. ProvRecommendations are provided for the most common pathogens and patient populations in CAP  and SSTICommunity prescribing tends to follow standard dosing of antibiotics, but providers should be aware of the potential need for dose adjustments, for example related to body size or comorbid conditions . For some patients, providers will need to take a different approach to antibiotic treatment based on certain patient or infection factors , 2. In aDelayed prescribing (“watchful waiting”) may assist in avoiding inappropriate prescribing related to patient pressure to prescribe, and thus reduce antibiotic resistance, by advising patients to return if symptoms do not improve within a few days or worsen , 60. It Ideally, a nurse or case manager should follow up with the patient at Day 2–3 after beginning antibiotic treatment to see if there are signs of an early response to treatment or any worsening symptoms. However, additional staffing may be needed to achieve this, which might be difficult to implement in certain practices. Alternatively, groups of providers can hold regular debriefing sessions to discuss cases and note any patterns of disease presentation or treatment failure. For patients with a skin infection, the provider can draw a circle around the initial extent of the infection and instruct the patient to call or send a photo of the lesion size at Day 1–2. This protocol also aids a second provider who sees the patient to assess the treatment response.Providers need guidance from experts that is easy to find and use, and reflects the real-world scenarios that they are faced with every day .Ask your local health department or community hospital for information . If thosRapid diagnostic tests are available for various viral and bacterial pathogens for respiratory, gastrointestinal, sexually transmitted, and central nervous system infections, most of which provide results within 15–45 min . Using hAdditional challenges to practical implementation of rapid assessments are sensitivity of the test and time and staff required to train and perform quality control of the test. Providers should also be aware that bacterial colonization (rather than infection) can return a positive result based on highly sensitive molecular diagnostic tests, which would not routinely warrant antibiotic treatment.Suppose providers feel that the patient or parent is expecting an antibiotic prescription. In that case, the provider can explain why an antibiotic isn’t needed and give other actionable treatment advice so the patient/parent feels that they walked away from the visit with useful information  2, 63)., 63.2, 6If a patient needs an antibiotic, encourage them to adhere to dosing instructions, and explain why this is important. In some situations, it may be worth explaining why you are prescribing a specific antibiotic  for the patient’s infection. In all cases, let the patient know about the likely disease course with treatment, potential side effects, and when to follow up.The College of Urgent Care Medicine offers an Antibiotic Stewardship Commendation to practices that provide evidence of their compliance with the CDC’s Core Elements . PracticEMR systems can be useful tools toward better antibiotic prescribing practices. In addition to making data collection easier (what was prescribed for a particular diagnosis), the EMR system can include prompts for particular interventions, automatically populated fields that comply with current guidelines, and step-through decision making . UnfortuN = 248 clinicians) found that the most significant reductions in inappropriate prescribing occurred after the providers (1) had to include written justification in the patient’s EMR for why the prescription was necessary, becoming a permanent part of the record; and (2) received regularly updated rankings of their prescribing rate compared with that of the top-performing peers , diagnostic uncertainty drives a substantial amount of unnecessary antibiotic prescribing . There ing peers , 72.Common laboratory tests, such as complete blood counts and basic metabolic profiles, can be used to generate a risk score for adults that is highly predictive of 30-day all-cause death . DiseaseCosts are part of the bigger picture of antibiotic treatment. In the outpatient setting, typically the only cost limit to the antibiotic is whether the patient’s health insurance will cover the prescription and if the patient can afford the co-pay. In the bigger picture of healthcare and societal costs of infections, while a patient may initially have an inexpensive treatment with an oral generic antibiotic for their particular infection, if the patient experiences treatment failure , then the overall cost of treating that infection escalates significantly . Cost saWhile there have been several new antibiotics developed in the last decade, their use is often limited by institutional policies that they should be “saved” for special/last-resort use , 79. In Regardless of the treatment setting where it is implemented, antibiotic stewardship is an evolving field , 83. ComAll authors contributed to data interpretation and reviewing/editing the manuscript and approved the final version to be published and were accountable for the work.


Aberrant activation of the MET receptor in cancer is sustained by genetic alterations or, more frequently, by transcriptional upregulations. A fraction of MET-amplified or mutated tumors are sensible to MET targeting agents, but their responsiveness is typically short-lasting, as secondary resistance eventually occurs. Since in the absence of genetic alterations MET is usually not a tumor driver, MET overexpressing tumors are not/poorly responsive to MET targeted therapies. Consequently, the vast majority of tumors exhibiting MET activation still represent an unmet medical need.Here we propose an immunotherapy strategy based on T lymphocytes expressing a Chimeric Antigen Receptor (CAR) targeting MET overexpressing tumors of different histotypes. We engineered two different MET-CAR constructs and tested MET-CAR-T cell cytotoxic activity against different MET overexpressing models, including tumor cell lines, primary cancer cells, organoids, and xenografts in immune-deficient mice.We proved that MET-CAR-T exerted a specific cytotoxic activity against MET expressing cells. Cell killing was proportional to the level of MET expressed on the cell surface. While CAR-T cytotoxicity was minimal versus cells carrying MET at physiological levels, essentially sparing normal cells, the activity versus MET overexpressing tumors was robust, significantly controlling tumor cell growth in vitro and in vivo. Notably, MET-CAR-T cells were also able to brake acquired resistance to MET targeting agents in MET amplified cancer cells carrying secondary mutations in downstream signal transducers.We set and validated at the pre-clinical level a MET-CAR immunotherapy strategy potentially beneficial for cancers not eligible for MET targeted therapy with inhibitory molecules, including those exhibiting primary or secondary resistance.The online version contains supplementary material available at 10.1186/s13046-022-02479-y. MET is the oncogene that solely sustains transformation) [The MET gene product, a receptor tyrosine kinase, stands out as one of the most important oncogenes activated in cancer. Upon paracrine stimulation by its specific ligand – the Hepatocyte Growth Factor – MET controls a network of intracellular signals including pro-mitogenic, pro-invasive, and anti-apoptotic cues, essential during embryogenesis and tissue regeneration , 2. The rmation) –7. In thrmation) –12. MET rmation) –17. Nevermation) .‘per se’ it does not confer MET addiction, resulting in a lack of effectiveness of classical targeting agents. Thus, the vast majority of tumors exhibiting MET activation cannot be included in protocols of MET-targeted therapy.While MET gene amplification and exon 14 skipping are quite rare - less than 4% of total cancers - MET activation due to transcriptional overexpression is rather common, especially among carcinomas , 20. Indi.e. the CD3ζ, that, upon activation by phosphorylation, elicits the cytotoxic response [The transfer of ex vivo expanded T lymphocytes characterized by a redirected tumor reactivity by the expression of Chimeric Antigen Receptors (CARs) represents a highly promising approach in the field of cancer immunotherapy . CARs arresponse . To furtresponse , thus reIn this paper, we describe the design and validation at the pre-clinical level of a CAR-based immunotherapy strategy to hit MET overexpressing cancers, not eligible for MET targeting agents.A549, NCI-H1993, NCI-H226, NCI-H441 human lung adenocarcinoma cells, Hs746T human gastric carcinoma cells, Caki-I kidney carcinoma cells, and 293T embryonic kidney cells were from the American Type Culture Collection (ATCC/LGC Standards Srl). EBC-1 human lung carcinoma cells were from the Japanese Collection of Research Bioresources. GTL-16 is a clone derived from MKN-45 human gastric carcinoma cells . GTL-16_+: A549 cells were plated 50.000 cells/well in 6 well plates in complete medium. After 24 hrs, the medium was replaced and the cells were transduced with 400 ng/mL p24 of LV-TETMET, a lentiviral vector expressing MET wild-type under the control of tetracycline (TET)-inducible promoter (TET-off system) [A549_MET system)  with polA549_koMET: Single guides RNA (sgRNA) were designed on the second exon of the MET gene. Sequences were: i) forward CACCG GGTGTTTCCGCGGTGAAGTT; ii) reverse AAAC AACTTCACCGCGGAAACACC C. sgRNA were cloned in the Px456 plasmid (Addgene), containing Puromycin resistance and the Cas9 sequence. This plasmid was used to transfect A549 cells with the TransIT-X2 Dynamic Delivery System (Mirus) in accordance with the manufacturer’s protocol. Cells were cultured for 7 days with Puromycin  and then were seeded in 96 well plates to obtain single clones limiting dilution. Knock-out of the MET gene was checked by gDNA sequencing.k and IgG1 sequences, respectively. cDNA synthesis, protein expression in mammalian HEK293E cells, and purification of the single-chain antibody fragments were performed by U-Protein Express BV.From the sequence of the DO24 monoclonal antibody  we desigDO24 single-chain binding affinities were determined by ELISA assay; the MET extracellular domain fused in frame with a human Fc domain  was in the solid phase and increasing concentrations of the purified DO24 antibody formats (range 0–33 nM) were in the liquid phase. Binding was revealed using horseradish peroxidase (HRP)-conjugated anti-human k light chain antibodies (Sigma-Aldrich). The colorimetric signal was quantified by the multi-label reader VICTOR X4 (Perkin Elmer Instrument INC.). To calculate Kd and Bmax, data were analyzed and fitted according to nonlinear regression, one-site binding hyperbola curve, using GraphPad Prism software (GraphPad Software).DO24 scFv and scFAb were cloned as XmaI-SalI fragments in sense into a lentiviral vector (LV) with a bidirectional expression cassette carrying a cDNA encoding the eGFP (enhanced Green Fluorescent Protein) in the antisense position with respect to the internal promoter hPGK . Then, aLV stocks were obtained by transient transfection of 293T cells with 37.5 μg of transfer vector, 16.5 μg of the packaging plasmids pMDLg/pRRE, 6.25 μg of the plasmid pRSV.REV, and 9 μg of the vesicular stomatitis virus (VSV) envelope plasmid pMD2.VSV-G as described in . DetermiT cells were purified from peripheral blood mononuclear cells (PBMC) of healthy donors or of patients with gastric carcinoma. PBMC were isolated by density gradient centrifugation  and then were activated by anti-Biotin MACSi Bead Particles loaded with anti-CD2, anti-CD3, and anti-CD28 antibodies (Miltenyi Biotec) for 24 hrs. PBMC were maintained in culture medium + human recombinant IL-2  for a further 24 hrs and then transduced with MET-CAR-LVs (MOI 10) for 8 hrs in the presence of polybrene (8 μg/mL). Not-transduced T cells (NTD) were used as a paired control. CAR-T or NTD-T cells were expanded for a maximum of 3 weeks in the presence of IL-2 (100 U/mL). Transduction efficiency  ranged from 30 to 70% of the total population.Primary antibodies: anti-MET ; anti-IgG1/CH2CH3 regions (Alexa Fluor® 647 AffiniPure F (ab’)2 Fragment Goat Anti-Human IgG (H + L) antibody, Jackson Immuno Research); anti-CD4 ; anti-CD3 ; anti-CD8 ; anti-CD56  all from BD Biosciences. Isotype control antibodies: APC, FITC, or PE mouse IgG1 κ Isotype Control, Clone MOPC-21 (BD Biosciences). Cells were counterstained with DAPI and analyzed by Cyan ADP flow cytometer (Beckman Coulter S.r.l.). Data were elaborated using Summit 4.3 software (Dako). For plots in which the isotype control is not shown, the Mean Fluorescence Intensity (MFI) derived from the Isotype control was set within the first logarithm (0 < MFI < 10). Cells were considered positive for the analyzed marker if the signal was higher than 10 (MFI > 10).For determination of MET expression, Quantum™ Simply Cellular® microbeads (Bangs Laboratories) were used to build a calibration curve to which cell samples have been compared. Cells of interest and calibration microbeads characterized by an increasing antibody binding capacity (ABC) were labeled simultaneously to saturation with the anti-MET antibody . A non-binding microbead population represents the negative control. Beads and labeled cells were acquired on Cyan ADP flow cytometer and analyzed using Summit 4.3 software. The obtained median values, subtracted of the median value of each relative isotype control, were used to calculate the ABC of each cell population, using the lot-specific QuickCal® analysis template provided by the supplier.Bioluminescent cell viability essay: Target cells (5000/well in a 96 well plate) were co-cultured with effector cells at various effectors/target (E:T) ratios  for 24 hours  or 48 hours  in culture medium with IL-2 (100 U/mL). Cell viability was determined by Cell Titer-Glo Luminescent Cell Viability Assay (Promega). The chemiluminescent signal was detected with VICTOR X4. To determine MET-CAR-T killing specificity, target cells were pre-incubated and co-cultured with 1 μM of decoyMET  producedGTR-498-derived organoids were plated in Matrigel (BD Pharmingen) domes in 8-well glass-bottom chamber slides . After 48–72 hours organoids were overnight labeled with NucBlue (NucBlue™ Live Ready Probes™ Reagent) directly in the culture chamber slide wells. Then GTR-498-derived organoids were co-cultured with MET-CAR T or paired NTD cells stained with PKH26 dye at an E:T ratio of 2:1 in culture medium in the presence of IL-2 (100 U/mL). After 48 hrs of co-culture, T cells were removed, and organoids were fixed and covered with mounting medium, to be observed using a TCS SPE Leica microscope. Image acquisition was performed by maintaining the same laser power, gain, offset, and magnification (20x). To quantify T cell recruitment and infiltration maximum intensity projections for each analyzed organoid were generated with LAS X Software (Leica). Images of the total PKH26 red fluorescence area present either at the boundary or inside the organoids were analyzed using ImageJ software.A plate containing organoids prepared and treated as above was subjected to image recording by Iris 15 camera (Photometrics) mounted on high content imaging system LIPSI (Nikon Instrument Inc.). Images were taken up to 7 days at identical positions in intervals of 4 hours at 10x magnification. All images were analyzed with NIS Elements software. The percentage of tumor cell lysis was calculated as above.Target cells (2000/well in 96 well plates) were seeded in complete medium. After 24 hours culture medium was replaced with fresh one containing increasing concentrations of anti-MET small molecules TKIs , or the anti-MET antibody MvDN30 (produced and purified by U-Protein Express BV). Cell viability was determined after further 72 hours by Cell Titer-Glo Luminescent Cell Viability Assay, as described above.Genomic DNA from cells was obtained by Maxwell RSC® Cell DNA purification kit (Promega). MET gene copy number was determined by Real-Time qPCR using the Taqman probe Hs04993403_cn (Thermo Fisher Scientific). To normalize gDNA in the samples RNAase-P Taqman probe Hs00468130_cn (Thermo Fisher Scientific) was used. The MET gene copy number was normalized to those of A549 or 293T diploid control cells.4 cells/well in a 48 well plate) at a 2:1 ratio. After 48 hours, culture supernatants were collected and analyzed for Perforin and Granzyme B concentrations using an ELISA assay , as recommended by the manufacturer.Effector cells were co-cultured in the presence of IL-2 (100 U/mL) with EBC-1 target cells (10Effector cells were co-cultured in the presence of IL-2 (100 U/mL) with EBC-1 target cells (5000 cells/well in a 96 well plate) at a 10:1 ratio. After 48 hours culture supernatants were collected and cytokines quantification was determined with a multi-analyte ELISArray Kit .All procedures in mice were performed according to protocols approved by the Ethical Committee for animal experimentation of the Candiolo Cancer Institute and by the Italian Ministry of Health.6 EBC-1 cancer cells + 106 T cells  were co-injected subcutaneously into the right posterior flank of adult NOD-SCID mice. Tumor size was evaluated every 2 days with a caliper. Tumor volume was calculated as described [3. Animals were euthanized 26 days after cell injection.10escribed . Mice we6 cell/mouse) resuspended in 100 μl of Iscove medium + 100 μl of Matrigel matrix (Corning Inc.) were injected subcutaneously into the right posterior flank of adult NOD-SCID mice. After 4 days, animals were randomized into 3 experimental arms (n = 6) and assigned to the different treatments: Vehicle (PBS), NTD, and #948 MET-CAR-T. T cells (107/mouse) were delivered by tail vein injection on day 4, 7, 10. Tumor size was evaluated periodically with a caliper. Tumor volume was calculated as above. Mice were euthanized on day 35.Caki-I (3 × 10n = 5), NTD , and #949 MET-CAR-T . Tumor size evaluation and tumor volume calculation were done as above. Mice were euthanized on day 56.GTR-210 PDXs were generated as described in . Six dayAverage, standard deviation (SD), and standard error of the mean (SEM) were calculated using Microsoft Office Excel 2010 software (Microsoft Corporation). Statistical significance was determined using One-way Anova or Two-way Anova corrected Bonferroni, using GraphPad Prism software. All the in vitro experiments were repeated at least two times. Figures show one representative experiment.+, in the majority of the cases co-expressing CD8. A subpopulation was CD56+, suggesting potential CAR- and MHC-independent tumor killing properties from this Natural Killer-like cell subset   ratio , carrying a wild-type diploid MET gene and expressing a well detectable level of MET at the cell surface in virtually all the cell population . This resulted in a remarkable control of tumor growth. At the end of the experiment (26 days after tumor injection), 4 out of 5 mice of the #948 treated group and all the mice treated with #949 MET-CAR-T were still tumor-free Fig. C.In addition to the killing properties, we evaluated perforin and granzyme B secretion by MET-CAR-T and the production of a panel of cytokines , either at baseline or after MET antigen engagement. These analyses are representative of T cell activation and inflammatory responses. To this aim, cell supernatants collected from CAR-T or NTD cells co-cultured with target cells were subjected to ELISA assays. MET-CAR-T increased the secretion of granules containing perforin and granzyme B only in the presence of MET overexpressing target cells , thus MET targeting agents are effective [The above described tumor models feature a high grade of MET-gene amplification. In this condition, MET represents the driver of the malignancy . MET-CAR-T efficiently counteracted cancer cell growth  characterized by MET overexpression in the absence of high MET gene amplification . Moreover, MET-CAR-T killing was effective also when overexpressed MET was not phosphorylated (as in the case of L1.13 CUP cells) or when the activation of downstream transducers bypassed MET signaling impairment (as in the case of GTL-16_Res). MET-CAR-T activity proved to be specific, as it was always much more potent compared to T cells not expressing MET-CAR, even when those effectors induced detectable levels of cytotoxicity. This background, scored in some experiments, was probably related to the presence of CD56+ immune cells that expanded under the IL-2 enriched culture conditions.In this paper, we describe a novel precision medicine strategy based on CAR-mediated redirection of the immune response against MET overexpressing cancers not eligible for treatments with MET targeting molecules. We demonstrated that MET-CAR-T successfully controlled tumor expansion in the presence of MET overexpression, sparing not transformed cells expressing MET at physiological levels. This activity was independent of the role of MET in sustaining the disease , MET can be the ‘driver’ of the malignancy. In this condition, MET targeting molecules are predicted to be effective, and therefore they should be the elective treatment choice. Nevertheless, clinical experience indicates that the emergence of resistant clones eventually limits the response duration. Secondary resistance is indeed the major drawback of targeted therapies, especially when the inhibition of receptor signaling is obtained by TKIs. Nowadays, several approaches to address the issue of secondary resistance are under evaluation. To be successful, they require a rational driven application, based on the knowledge of the mechanism(s) sustaining resistance. As cancer cells can develop different mechanisms of secondary resistance, an effective solution addressing only one of them will not permanently solve the problem. When secondary resistance is sustained by an identified newly emerged driver mutation, the use of combination therapies able to concomitantly hit more than one oncogenic pathway could be possible. Nevertheless, it results to be often cumbersome, potentially prone to toxicity, and predicted as well to be not durable, because tertiary resistance is frequently observed. Considering all these issues, MET-CAR-T immunotherapy can represent a valuable therapeutic opportunity to be explored in cases of secondary resistance. Indeed, the major requirement for its application is the high level of MET expression, a feature characterizing the majority of MET 'addicted' malignancies, which is bypassed - but not abolished - during resistance.CAR-T cells targeting MET have been previously developed, showing the potential of this therapeutic strategy in preclinical models, either alone or in combination with chemotherapy or targeting agents. These studies focused on sub-histotypes of the breast , lung 4, liver , and kidRecently, two different MET targeting drug-conjugated antibodies (ADC) – Telisotuzumab-Vedotin/ABBV-399 and METxMET-M114 , 59 - haAs a general perception, the use of CAR-T is considered potentially risky, because severe side effects, such as cytokine release syndrome or neurological toxicities, have been observed in some of the treated patients . Our in i.e. a target overexpressed in cancer cells but also found in normal cells at lower levels) in place of a tumor-specific one . Considering this option, a MET-CAR should be an appropriate choice. As discussed above, MET overexpression can be considered a hallmark of transformation, due to its primary role during cancer onset and progression. Moreover, being MET expression an inherent distinctive trait of several cancer stem cell types [MET-CAR immune therapy inevitably focuses on solid tumors. While CAR-cell adoptive transfer showed dramatic potency for the treatment of B-cell malignancy, its applications in solid tumors have not yet achieved striking results . In thisll types , 64, METll types . Thus, ell types , 51 or ill types . Neverthll types  and consAnother relevant issue that hampers the efficacy of CAR cell therapy in solid tumors is the presence of intrinsic intracellular pathways sustaining immune tolerance. In the case of MET-CAR, different strategies have been developed aimed at addressing this point. They included the construction of a MET/PDL-1 tandem CAR blocking the interaction between PD-1 and PD-L1 , the devA highly efficient MET-CAR strategy having the potential to break solid tumor barrier must also incorporate features suitable to maximize the effector’s ability to infiltrate the malignant lesions, and to overcome the unfavorable microenvironment characterized by high concentrations of immunosuppressive molecules and cells. Thus, more complex engineering strategies of the MET-CAR expressing immune effectors suitable for a tumor-site restricted delivery of enzymes able to degrade the extracellular matrix  and/or oFinally, the selection of MET negative transformed cells or expressing MET at a low level is an event that can occur under the therapy pressure, as a consequence of tumor heterogeneity and adaptability. In this perspective, the option of expressing the MET-CAR in effector cells characterized by intrinsic CAR independent killing properties must be evaluated, to efficiently counteract clonal selection events .We designed and validated at the pre-clinical level an immunotherapy strategy against MET overexpressing cancer cells. This potentially offers a treatment option for cancers in which MET receptor is present at high levels on the cell surface but they are not eligible for anti-MET targeting molecules, due to primary or secondary resistance of the malignant lesion.Additional file 1. Supplementary Video 1. NTD-T cell infiltration of GTR-498-derived 3D organoids.Additional file 2. Supplementary Video 2. MET-CAR-T cell infiltration of GTR-498-derived 3D organoids. Additional file 3: Supplement Table 1. MET gene amplification in different cell lines and primary cells derived from human tumors of different origin.Additional file 4: Supplementary Figure 1. Design and binding properties of DO24 single chain antibody fragments. Supplementary Figure 2. Analysis by flow cytometry of cell surface MET expression. Supplementary Figure 3. Quantitative flow cytometer analysis of surface MET levels in A549 wild type, genetically modified, and not transformed human cells. Supplementary Figure 4. Analysis by flow cytometry of cell surface MET expression in carcinoma cells featuring MET overexpression due to high MET gene copy number. Supplementary Figure 5. Analysis of perforin and granzyme B concentrations in the culture supernatants of T cells co-cultured with target cells expressing different surface MET levels. Supplementary Figure 6. Analysis of cytokine expression in the culture supernatants of T cells expressing the MET-CAR co-cultured or not with target cells. Supplementary Figure 7. MET expression on carcinoma cells featuring MET gene amplification and overexpression resistant to anti-MET agents. Supplementary Figure 8. MET expression analyzed on carcinoma cells featuring MET overexpression due to transcriptional upregulation of the MET gene, present as diploid or at a low copy number.


This literature review discusses the use of antibiotic loaded polymethylmethacrylate bone cements in arthroplasty. The clinically relevant differences that have to be considered when antibiotic loaded bone cements (ALBC) are used either for long-term implant fixation or as spacers for the treatment of periprosthetic joint infections are outlined. In this context, in vitro findings for antibiotic elution and material properties are summarized and transferred to clinical use. Antibiotics and bone cements are ubiquitously used in orthopedic and trauma surgery. Methylmethacrylate (MMA) is the main component of bone cements ,2. MMA mTo a certain extent antibiotics added to the starting components before mixing will be released from the cured cement. Thus, bone cements combine two basic principles for surgery of the musculoskeletal system: stable fixation and anti-sepsis. Because of these qualities, antibiotic loaded bone cements (ALBC) have gained outstanding significance in the field of arthroplasty. In this context, ALBCs are mainly used for two indications, i.e., infection prophylaxis and treatment of implant associated infections .This literature review summarizes the use of ALBCs in arthroplasty. Their application for implant fixation and as spacers is outlined. The in vitro results on antibiotic elution and mechanical properties of ALBCs are discussed from a clinical point of view.Two different indications for ALBCs need to be discriminated .ALBCS are predominantly used for long-term implant fixation. In the 1970s, Wahlig and Buchholz from Hamburg performed the first antibiotic elution tests from PMMA . To dateThe second indication for ALBCs is the two-stage exchange of an infected prosthesis. Herein, ALBCs are used in the form of temporary spacers. During the first surgery, the infected prosthesis is removed and replaced with the spacer. When the infection has resolved the spacer is removed and the joint is reconstructed with a new prosthesis in a second operation. In this context, ALBCs fill voids, provide temporary stability, and serve as a drug carrier for local antibiotic administration. The ALBC- spacer yields high local antibiotic concentrations that cannot be achieved by systemic administration, and at the same time minimizes the risk of toxic side effects ,6,16,17.PMMA cements have to provide sufficient strength against bending, impact, tension, torsion, and shear forces . The Int® R+G  and Copal® spacem  were compared after antibiotic loading. Although slight differences were observed, these were not significant [Various in vitro studies investigated the effects of antibiotic loading on mechanical properties. However, comparability is often limited because they vary considerably in their set up. There are only a few studies that directly compared the effect of manual antibiotic loading while taking into account the cement brand or type. In a study by the authors, compression strengths of Palacosnificant . To dateAntibiotic loading reduces mechanical stability because antibiotic molecules interfere with the curing of the cement. Particularly liquid antibiotics interfere extensively with the polymerization process. For example, Hsieh et al. reported a reduction of compressive strength of 37% when liquid gentamicin was added to Simplex bone cement  . Thus, a® R+G and Copal® spacem, an antibiotic proportion of 2.5% in the cement powder reduced compression strength to a value close to the required 70 MPa [®  and Copal® G+C . After an addition of 5% vancomycin, the compression strength remained significantly above 70 MPa for both cements. Even with an addition of 10% vancomycin, compressive strength was reduced only by 18.15% and 17.48%, respectively, and the compressive strengths of both cements remained above the 70 MPa cut-off value. However, only the Palamed® cement type was significantly above this limit [The more antibiotic is added, the more the stability of the cured cement will be reduced. However, the maximum proportion of antibiotic in the cement powder is not conclusively established. Although many studies investigated the effect on stability with variable proportions of antibiotic in the bone cement ,22,23, ois limit ,16,22,24Two different and in part contradictory recommendations for adding the antibiotic to the cement powder are discussed: Kuhn et al. propagate a thorough homogenization of the antibiotic powder and the cement powder. The crystalline antibiotic is ground in a mortar and then added to the cement powder in several steps. This mixing technique is supposed to provide consistent and reproducible cement properties after hardening . In cont® R+G and Copal® spacem, antibiotic loading with more than 10% of vancomycin led to significant compressive strength reduction after 4 weeks of antibiotic elution [® P, Palacos® and CMWTM  loaded with 10% of vancomycin [The legal implications of manually loading bone cements intended for TKA or THA fixation have to be considered. Aseptic loosening is still the number one reason for implant failure after TKA and THA ,10. Anti elution . Comparancomycin . Thus, aAntibiotic elution from ALBCs is a diffusion process. Antibiotic proportion in the cement, surface size, and porosity of the cement are regarded as the most important drivers of antibiotic release from PMMA ,28. Tabl® R+G and high viscosity Palacos® R+G exemplifies the cement specific release: although both cements contain the same proportion of antibiotic, more gentamicin is released from Palacos® R+G.Bone cements differ in their compositions depending not only on the intended use but also on the manufacturer. Commercially available ALBCs have individual proportions of the incorporated antibiotic, are available with antibiotic combinations, and have specific antibiotic elution properties. Therefore, each cement brand and type has its own release behavior. The comparison of medium viscosity Palacos® P bone cement by comparing different geometries and volumes. While the antibiotic release did not correlate with specimen volume, a positive linear correlation with the surface area was observed [® P bone cement showed significant increase of tobramycin elution when the surface area was enlarged, but the cement volume remained constant. In contrast, when the cement volume was reduced but the surface area remained the same, no significant change could be measured [The geometry of the implanted cement body depends predominantly on the anatomic presuppositions. Duey et al. investigated the release of vancomycin and tobramycin from Simplexobserved . The outmeasured . This ismeasured . Thus, aPores in the cement matrix increase the surface area and therefore antibiotic elution. As discussed before, porosity of the cement can be modified by adjusting the extent of homogenization of the antibiotic and the powder. Miller et al. produced a highly porous ALBC through the addition of vancomycin chunks. Significantly higher antibiotic release was observed in comparison to a cement for which the antibiotic was thoroughly ground prior to adding it to the cement . ConversIrrespective of the loading technique, porosity can be modified by the use of a vacuum mixing system, which is designed to reduce air entrapment in the cement matrix .® R+G and Cobalt® G-HV , it was reduced for Cemex® Genta , SmartSet® GMV  and VersaBond® AB  [However, the influence of a vacuum mixing system on antibiotic elution depends on further factors, such as water solubility of the antibiotic, the diffusion gradient, and above all the choice of cement . Meyer edon, UK) .® spacem, which is particularly intended for the use as a spacer. Bitch et al. reported a microporous structure of the hardened cement in contrast to the solid structure of Palacos® R+G. Accordingly, a better elution of several antibiotics was observed for Copal® spacem [® spacem when a combination of vancomycin and gentamicin was loaded to these two cements [Porosity can further be modified in vitro by special additives . Shi et ® spacem . However cements . To summWith manual loading, the choice of antibiotics is restricted to those available as a sterile, heat-stable, and powdery substance with sufficient elution kinetic. Papers on the suitability of antibiotics for manual loading are published regularly. One of the largest overviews is given in Typically, antibiotics are either eluted with a continuous or with a burst pattern. Gentamicin is a typical example for an antibiotic with a continuous release kinetic . In cont® bone cement. The combination of both antibiotics increased the release of vancomycin by 145%, and of gentamicin by 45%, respectively [The combination of antibiotics further influences the elution. Synergistic and antagonistic effects are described. Especially for the combination of gentamicin and vancomycin, synergistic effects are described. Hsie et al. investigated antibiotic elution of gentamicin and vancomycin from Simplexectively . Paz et However, release kinetics are not only modified by the combination, but also by the relative masses of the combined antibiotics in the cement. A classic example is the significant increase of gentamicin release when the proportion of vancomycin in the cement is raised . Kaplan ® R+G and Copal® spacem. For both cements vancomycin elution was significantly increased when the vancomycin proportion was increased in the cement powder [For clinical use, the simplest way to increase antibiotic elution is to increase its proportion in the cement. Our own study investigated antibiotic elution from vancomycin and gentamicin loaded Palacost powder .As discussed above, the proportion of antibiotic in the cement is limited by the reduction of its mechanical properties. Again, it can be summarized that, for preparation of a temporary spacer, manual antibiotic loading up to a cumulative antibiotic proportion of 5–10% in the cement powder is considered advisable ,16,22,24Currently, PMMA is being further investigated, particularly for its function as a drug carrier. PLGA (Poly-Lactic-co-Glycol-Acid) is an interesting approach to achieving a controlled antibiotic release pattern. Antibiotics can be deposited in microspheres made from PLGA. When these microspheres are added to PMMA or to ALBC, their biodegradability can be modified to achieve a desired release period in vitro ranging from weeks to months . HoweverALBCs are used for prophylaxis and the treatment of periprosthetic infections. For prophylaxis the major concern is a loss of mechanical strength after implantation. Therefore, manually loading cannot be recommended. Instead commercially available ALBCs with consistent material properties should be used with a state-of-the-art cementing technique. For use as a spacer, ALBCs should be tailored by manually loading the spacer with up to 5–10% of a combination of antibiotics targeted to the pathogen. Only examined, crystalline antibiotics should be added to the cement powder after grinding and before initiation of the polymerization process under atmospheric pressure. The spacer should be implanted with the largest possible surface allowed by mechanical and surgical considerations. To date, special bone cements intended for use as a spacer are available. However, the best clinical practice remains to be proven.


Mental health disparities directly tie to structural racism. Digital mental health (DMH), the use of technologies to deliver services, have been touted as a way to expand access to care and reduce disparities. However, many DMH fail to mitigate the persistent disparities associated with structural racism that impact delivery –and may even exacerbate them. Human-centered design (HCD) may be uniquely poised to design and test interventions alongside, rather than “for,” marginalized individuals. In employing HCD methodologies, developers may proceed with a vested interest in understanding and establishing empathy with users and their needs, behaviors, environments, and constraints. As such, HCD used to mindfully address structural racism in behavioral health care may address shortcomings of prior interventions that have neglected to elevate the voices of marginalized individuals. We argue that a paradigm shift in behavioral health services research is critically needed–one that embraces HCD as a key methodological framework for developing and evaluating interventions with marginalized communities, to ultimately promote more accessible, useful, and equitable care. The current commentary illustrates practical examples of the use of HCD methodologies to develop and evaluate DMH designed with marginalized populations, while also highlighting its limitations and need for even greater inclusivity. Following this, calls to action to learn from and improve upon HCD methodologies will be detailed. Acknowledging potential limitations of current design practices, methodologies must ultimately engage representative voices beyond research participation and invest in their active role as compensated and true collaborators to intervention design. Structural racism significantly impacts the reach of health services to diverse communities. For example, over 123 million Americans live in federally-designated Mental Health Professional Shortage Areas , 5].Digital mental health tools (DMH), the use of technologies to deliver mental and behavioral health services, have been touted as a promising solution in expanding access to evidence-based services and reducing mental health disparities . There aNamely, human-centered design (HCD) is uniquely poised to design and test interventions alongside, rather than “for” , marginalized individuals who are directly impacted by structural racism in behavioral health services . Indeed,In this commentary, we argue that a paradigm shift in behavioral health services research is critically needed. It is imperative to embrace HCD as a key methodological framework for developing and evaluating behavioral health service interventions with marginalized communities, to ultimately promote more accessible, useful, and equitable health care. This commentary will illustrate practical examples of the use of HCD methodologies to develop and evaluate DMH designed with marginalized populations, while also highlighting its limitations and need for even greater inclusivity. Following this, calls to action to learn from and improve upon HCD methodologies will be detailed.HCD involves a group of mixed-methods approaches to attempt to match a product  to the contexts of its use by people in their everyday lives . There aDespite HCD's framing as a collaborative approach with end users, power structures are insidious to its practice history . Indeed,Moving forward, HCD methodologies may be used to promote equity, but only if actively conducted intentionally from an anti-racist perspective . While Multiple actions can be taken to support more inclusive HCD methodologies–both in the development of DMH and broader behavioral health interventions and services. First, intervention designs and evaluations should be conducted by diverse research teams, with an emphasis on recruiting, retaining, and promoting team members with demographic membership that is in some way representative of potential participants and end users , 29. TheThough HCD methodologies have been successfully implemented in DMH research , the digNoticeably absent from DMH literature is quantitative and qualitative evidence describing HCD application and principles to mental health work focused on young, Black men. Young, Black men, especially those in college, continue to be at heightened risk of experiencing mental health symptoms; however, their utilization of traditional mental health services remains low , 44. DisAn HCD lens is being applied to a line of research focused on reducing mental health risk among Black undergraduate and graduate men, as well as designing DMH and social media tools that promote help-seeking. The subsequent goal of this work would be to implement and test a social media-based intervention for Black men who may or may not be experiencing anxiety and depressive symptoms and wish to seek help for such concerns. Recognizing that Black men in college are traditionally and significantly underrepresented in prevention and intervention work, a mixed-methods approach was used to quantitatively elucidate factors pervasive in increasing anxiety and depression risk among Black male students and qualitatively contextualize this risk and their willingness to engage in traditional, formal health services. Over 50% of a Black male student population experienced one or more anxiety symptoms and more than 80% experienced one or more depressive symptoms; yet their utilization of traditional, in-person, counseling services remained low compared to their male counterparts , 54. ThiGlobally, more than four billion people use social media  and moreThe use of multi-method approaches establishes a unique opportunity for Black men to partner with researchers to iteratively design messages that accurately address the social and attitudinal barriers most prevalent in impacting their engagement with DMH interventions. Their input provides insight and evidence into creating digital components that promote the inclusion of contextually and culturally relevant content into interventions, increasing potential users' long-term use, engagement, and accessibility . This apPrinciples of HCD are being applied to develop a personalized mobile intervention for medication taking among diverse adolescents and young adults (AYA) with cancer. AYA with cancer are considered a medically underserved age cohort who experience disparities in access to developmentally-oriented cancer care  and expeStill, adherence-promotion interventions for AYA with cancer are lacking, and those that are available have not elevated their needs and preferences. For example, one intervention involved text messaging to prompt caregivers to supervise youth as they took 6-MP . While tWe are developing an app to help AYA take 6-MP through personalized and daily adherence support . Combining principles of HCD and anti-racist practices, we have approached intervention development with the following guiding principles: 1) systemic racism and other forms of oppression influence treatment behaviors and oncology care, and can influence (implicitly or explicitly) researcher and participant perceptions; 2) AYA are the experts on their own experiences; 3) AYA are capable of engaging in the research process as collaborators (not only participants) when our research team is successful in making the research process inclusive; 4) AYA experiences with medications are not monolithic or “one-size-fits-all”; and 5) design is not a linear process and requires iterative cycles. Within this work, researchers deeply reflect on positionality and practice reflexivity in recognizing how their social positions can influence the research (including the inherent power dynamic that exists between the researcher and the participant). For example, researchers maintain ongoing vigilance for the urge to speak for participants.The British Design Council's Double Diamond Framework has guided our HCD methodological approach . This prNow, we are in the process of co-developing the intervention  with AYA. We formed a research advisory panel of AYA with a history of cancer where advisors serve as paid research consultants to ideate intervention content with the research team. Four advisors, either self-nominated or nominated by a member of their oncology team, were trained using Family, Youth, and Research Education (FYREworks), an interactive, web-based training that prepares youth to collaborate with researchers. We will engage with the advisors throughout the iterative intervention development process, most recently with a focus group that applied a “Blue Sky Thinking” design strategy to generate creative solutions for medication taking without imposed limits. In this activity, advisors were presented with two AYA patient stories or personas, and shared ideas for improving each patient's medication adherence. For example, advisors recommended linking medication-taking to an AYA's personal passions and goals to motivate adherence, as preventing a cancer relapse seemed too distal and focused on the AYA as a patient rather than a person. AYA end users have also developed intervention content, such as self-creating TikTok videos designed to promote adherence.We believe that partnering with AYA in the design process in this manner is an important first step toward creating an inclusive and engaging tool for medication taking. However, an app will not completely address systemic barriers to adherence , nor isTo ensure that HCD practices are conducted by and with diverse research teams and principal investigators, the recruitment, retainment, and promotion of researchers with marginalized identities must be an institutional priority. To achieve this goal, investing in marginalized youth cannot start early enough. Examples of such investment is the Rush Education and Career Hub (REACH), whose mission is to provide STEM training and exposure to underrepresented youth to support their academic and professional potentials from “cradle to career” , and theThe use of HCD methodologies must invest in creating active and compensated roles for community members in intervention design. Indeed, community members must not be viewed as “participants” but as part of the HCD research team itself. A key factor in this approach would be the practice of reflexivity and acknowledging the power imbalances that exist between and among all parties involved throughout the research process . AdditioFunding partners are needed to facilitate open access to HCD methodologies and promote their use. Federal and Non-federal funding mechanisms may provide opportunities to support this work, invest in the advancement of marginalized researchers, and promote service design aimed at systems-level changes in behavioral healthcare. Review boards are often siloed within their subspecialties and do not include experts in HCD methodologies, nor do they include individuals representative of the communities with whom the projects are intended to reach. We propose that bodies charged with disseminating funding for behavioral health research seek partnerships outside the behavioral health care field, including experts in HCD and community partners as discussed above. Additionally, funding bodies may consider HCD as a core component of any effort to increase health equity, thereby requiring researchers to include aspects of the HCD framework in their proposed work. For those specifically engaged in health disparities work, such requirements will serve to prevent the already documented phenomenon of white researchers without adequate training or understanding of these disparities capitalizing on funding opportunities without including their colleagues and community members of color .To increase the use of HCD, training in this methodology needs to be accessible as well. Although experts in digital health may be familiar with user-centered design, it is imperative that they consider the more inclusive HCD framework discussed in this commentary. Though some clinical researchers are embracing HCD , most hHCD practices of specifying the context of use may be harnessed to explicitly explore, identify, and address the role and impact of structural racism in behavioral healthcare through targeted and measurable means. First, interdisciplinary collaborations are needed and appropriate for determining, examining, and addressing the fundamental factors that impact underlying disparities and inequities which reinforce population health outcomes as well as policy. Second, while a primary focus of this commentary has been on employing HCD practices to co-develop DMH with community members, HCD can also be applied by clinicians and within clinics to develop: (1) DMH service protocols ; and (2) implementation plans . InIt is of note that while we propose that HCD methodologies may be used with intention to design DMH and broader behavioral and mental health interventions, these efforts cannot address inequities and racism alone. Systems-level changes are desperately needed, from a larger and more diverse workforce of behavioral health professionals to health care coverage for mental health services.It is necessary to incorporate HCD methodologies into DMH work to achieve mental and behavioral health equity. However, changes in the practice of engaging in HCD methodologies are merely the start of changes needed to promote equity, cultural inclusiveness, and anti-racism. Steps detailed in this commentary are most certainly not exhaustive of what should and could happen moving forward. We recognize that there are critiques of HCD methods for the promotion of equity and inclusiveness and we believe that ongoing research and initiatives that we describe will lead to the growth of HCD methods for addressing the complex problem of improving mental and behavioral health equity. Advances in HCD methodology will be needed to address these problems, but HCD is an approach that can be used to improve equity in the development of DMH and broader forms of behavioral interventions.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.CS-S: conceptualized the commentary. All authors contributed to the drafting of the manuscript and approved the final version. All authors contributed to the article and approved the submitted version.This work was supported by grants from the National Institutes of Health .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.


Hypertrophic pachymeningitis (HP) is a rare inflammatory disorder characterized by local or diffuse thickening of the intracranial or spinal dura mater. The most frequent cause of HP is antineutrophil cytoplasmic antibodies (ANCA), followed by IgG4. However, few cases of IgG4-HP coexpressing ANCA have been reported. Herein, we present three cases of IgG4-HP coexpressing ANCA and review the relevant literature to document the overlap of these two HP causes as a potential clinical pattern.We retrospectively analyzed three patients with IgG4-HP coexpressing ANCA in our center and consulted the PubMed database to find other relevant cases reported in English from 1976 to April 2022. We used the following keywords: pachymeningitis, meningitis, dura, antineutrophil cytoplasmic antibody, myeloperoxidase, and proteinase-3. We analyzed the clinical, serological, radiological, and pathological characteristics of the obtained cases based on the ACR and Chapel Hill criteria and the exponential moving average (EMA) algorism for ANCA-associated vasculitis (AAV) and the IgG4-RD Comprehensive Diagnostic Criteria.We analyzed a total of 10 cases: seven literature reports and our three patients (52- and 61-year-old women and a 65-year-old man). The IgG4-related disease (IgG4-RD) diagnoses were definitive in four cases, and probable and possible in three cases. Eight patients had ANCA against myeloperoxidase (MPO), and two had ANCA against proteinase-3 (PR3). Two patients had both IgG4-RD and AAV, while the others only had ANCA seropositivity without additional clinical or pathological markers of AAV.With regard to HP, we reconfirmed the existence of the IgG4-RD and AAV overlap syndrome. Meanwhile, our review does not support the hypothesis that ANCA positivity in IgG4-RD results from an excessive B-cell response. We speculate that IgG4-RD and AAV have similar or associated pathogeneses, although uncovering the role of IgG4 and ANCA in these pathophysiological processes requires further investigation. Mycobacterium tuberculosis, fungi, or Borrelia burgdorferi), inflammatory diseases , sarcoidosis, Sjogren's syndrome, rheumatoid arthritis, or Wegener's granulomatosis) (Hypertrophic pachymeningitis (HP) is a group of rare disorders characterized by local or diffuse thickening of the intracranial or spinal dura mater causing intracranial hypertension, cranial nerve palsy, or spinal cord dysfunction. Headache is the most common initial symptom of HP . The maimatosis) . A natiomatosis) . ANCA-rematosis) , microscmatosis) , and eosmatosis) .The IgG4-RD is a chronic inflammatory disorder with the following pathological characteristics: lymphoplasmacytic infiltration of numerous IgG4+ cells, storiform fibrosis, and obliterative phlebitis in various organs  . The chaAn overlap between AAV and IgG4-RD has been described in some clinical patterns, such as tubulointerstitial nephritis, periaortitis, and prevertebral fibrosis. Therefore, we hypothesized that these two diseases could also overlap in the clinical pattern of HP. Herein, we present three new cases of patients with IgG4-HP coexpressing ANCA. In addition, we review the relevant literature to identify the clinical characteristics of IgG4-HP cases coexpressing ANCA and confirm whether the overlap of IgG4-RD and AAV also exists in HP.Mycobacterium tuberculosis antibodies, respiratory viral antigens, human immunodeficiency virus, and fungi antigen. Rheumatologic assays were negative , except for titers of serum cytoplasmic ANCA (1:32), myeloperoxidase antibodies (MPO-ANCA) (1:100) and elevated IgG4 , although the total IgG level was normal. Routine urinalysis was unremarkable. Cerebrospinal fluid (CSF) showed lymphocytosis (25 cells/mm3), and three well-defined oligoclonal bands were present in both the CSF and serum. The CSF infectious disease test was negative. Chest and paranasal sinus CT found no abnormalities. Gadolinium-enhanced brain magnetic resonance imaging (MRI) revealed enhanced and thickened dura mater, predominantly in the posterior fossa , 140 mm/h; C-reactive protein (CRP), 131 mg/L. Tests for infections were negative, including blood bacteria cultures, or fossa . Intrave3). The CSF infectious disease test was unremarkable. Chest and paranasal sinus CT found no abnormalities. The patient received methylprednisolone pulse therapy , followed by oral prednisone 60 mg/day, gradually reduced, and combined with oral cyclophosphamide 50 mg/day for about 3 months, with obvious relief of the headache and improvement of lingual symptoms.The second patient was a 52-year-old previously healthy woman with an ingravescent occipital headache for 6 months. The only notable neurological examination result was a right hypoglossal nerve palsy . The gadThe third patient was a 61-year-old woman admitted for weakness and stiffness in both lower limbs for about 1 year, accompanied by thoracic back pain and constipation for 8 months. The neurological examination on admission revealed paresis in the bilateral lower limbs (3 to 4/5), decreased pain and thermal sensation in the trunk and lower limbs below the T10 level, brisk bilateral knee and Achilles tendon reflexes, and bilateral extensor plantar response. The routine blood tests and inflammatory markers levels were normal. Infections assays were negative. Rheumatologic assays were negative, except for seropositivity for perinuclear ANCA , MPO-ANCA , and elevated IgG4 (441 mg/dl). Chest and paranasal sinus CT found no abnormalities. A spinal cord MRI revealed a ribbon-like thickening of the dura mater between vertebral levels T7 and T11 (which was moderately enhanced by gadolinium administration) and a compressed and flattened focal spinal cord –C. AlthoWe systematically searched the PubMed database for studies on humans, written in English, and published between 1976 and April 2022 using the keywords: “pachymeningitis, meningitis, dura, antineutrophil cytoplasmic antibody, myeloperoxidase, and proteinase-3.” We excluded cases described in insufficient detail. Ultimately, we analyzed 10 cases –14, inclIn our pooled analysis, two cases (Nos. 7 and 10) fulfilled the diagnostic criteria for both diseases, while the others only had ANCA seropositivity without additional clinical or pathological markers of AAV. Although IgG4-RD commonly involves multiple organs synchronously or metachronously, the clinical symptoms and radiological features of most patients in this study resulted from the involvement of a single organ (dura mater). They had elevated serum IgG4 levels (>135 mg/dl for most patients) and positive ANCA. Although AAV is an important differential diagnosis of IgG4-RD in both the 2019 ACR/EULAR classification criteria , 22. A pRecently, Martin-Nares et al.  reportedCurrently, the pathogenesis of AAV and IgG4-RD is not entirely understood. Several studies have confirmed that many patients with EGPA do have elevated blood IgG4 levels. These levels are correlated with disease activity, suggesting that AAV and IgG4-RD have similar or associated pathogeneses. Several studies have shown that, in both disorders, T-follicular helper cell levels increase and become polarized toward T-follicular helper 2 subtype cells, enhancing IgG4-plasma cell polarization . FurtherFinally, the therapeutic approach remains also important. Current treatment strategies for IgG4-RD include glucocorticoids and conventional steroid-sparing agents, such as low-dose cyclophosphamide and mycophenolate mofetil. Noteworthily, three patients used B-cell depletion therapy . Rituximab demonstrated efficacy against both AAV and IgG4-RD –29, inclThis study has several limitations. First, the inclusion and exclusion criteria in the selection of cases could not be rigorously applied according to the CDC and 2019 ACR/EULAR classification criteria for IgG4-RD, causing inevitable deficiencies in the literature cases. Second, we only performed a pathological examination on one of our cases and, therefore, cannot rule out other pathologies in the other two patients . Third, not all patients had documented CSF levels of ANCA and IgG4. Those were increased in some reports of HP related to IgG4-RD  and AAV In conclusion, we report three cases of IgG4-HP coexpressing ANCA. By analyzing them with previously reported cases, we confirmed the existence of an overlap syndrome for IgG4-RD and AAV in the clinical pattern of HP. Meanwhile, our results do not support the hypothesis that ANCA detected in IgG4-RD results from an excessive B-cell response in HP. Thus, we speculate that IgG4-RD and AAV have similar or associated pathogeneses, although further information is needed about the role of IgG4 and ANCA in their pathophysiological processes. Nevertheless, the question remains: do IgG4-RD and AAV belong to the spectrum of a single disease or simply overlap sometimes?The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Medical Ethical Research Committee of General Hospital of Northern Theater Command. The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.CX: drafting/revision of the manuscript for content, including medical writing for content, major role in the acquisition of data, and analysis or interpretation of data. PL: study concept or design. All authors have read and approved the final manuscript to be published.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.