Tyrosine‐protein kinase Met—also known as c‐Met or HGFR—is a membrane receptor protein with associated tyrosine kinase activity physiologically stimulated by its natural ligand, the hepatocyte growth factor (HGF), and is involved in different ways in cancer progression and tumourigenesis. Targeting c‐Met with pharmaceuticals has been preclinically proved to have significant benefits for cancer treatment. Recently, evaluating the protein status during and before c‐Met targeted therapy has been shown of relevant importance by different studies, demonstrating that there is a correlation between the status  of the HGFR with therapy response and clinical prognosis. Currently, clinical imaging based on positron emission tomography (PET) appears as one of the most promising tools for the in vivo real‐time scanning of irregular alterations of the tyrosine‐protein kinase Met and for the diagnosis of c‐Met related cancers. In this study, we review the recent progress in the imaging of c‐Met aberrant cancers with PET. Particular attention is directed on the development of PET probes with a range of different sizes , and radiolabeled with different radionuclides. The goal of this review is to report all the preclinical imaging studies based on PET imaging reported until now for in vivo diagnosis of c‐Met in oncology to support the design of novel and more effective PET probes for in vivo evaluation of c‐Met. This protein, once activated, stimulates a range of intracellular signaling pathways such as those related to proliferation, motility, and invasion/migration of cancer cells.It is reasonable to hypothesize that, in future clinical settings, noninvasive imaging with PET and using these new tracers will support the diagnosis of c‐Met overexpressed cancers and the selection/evaluation (responding and nonresponding) of patients for c‐Met–targeting drugs.264Cu for c‐Met‐targeted molecular imaging.Due to the specificity and high binding affinity of the natural ligand for c‐Met, the HGF structure was initially selected for the first imaging studies of the receptor (by MRI).64Cu‐NOTA‐rh‐HGF was assessed by flow cytometry using human glioblastoma cell lines (U87‐MG) with moderate c‐Met expression and human breast cancer (MDA‐MB‐231) with lower (compared to U87‐MG) c‐Met expression, confirming the specific binding of the labeled HGF to c‐Met overexpressing cells. U87‐MG xenografts mice were used for in vivo experiments, revealing rapid tumor absorption of 64Cu‐NOTA‐rh‐HGF that was distinctly visible at 30 min postinjection with a peak at 9 h . Contrarily, a lower absorption was reported for MDA‐MB‐231 mice xenografts. These results are consistent with the different expressions of the protein in the two cell lines used in the xenografts. Heating of the 64Cu‐NOTA‐rh‐HGF resulted in denaturation of the protein and the denatured product, termed 64Cu‐NOTAdnrh‐HGF, had notably reduced uptake in U87‐MG bearing mice than the unheated 64Cu‐NOTA‐rh‐HGF. The specificity of 64Cu‐NOTA‐rh‐HGF was also established by the fact that its uptake in all other main organs was comparable between the natural and the denatured form of the tracer. As expected, the liver and kidney uptake values were similar between xenografts injected with the natural and the denatured form, because these organs represent the clearance tissues for a molecule of this size (~70 kDa). This study demonstrates the potential application of imaging agents based on the structure of the endogenous HGF for c‐Met imaging. Limitation of this approach, precluding its clinical translation, could be due to the concomitant presence of endogenous HGF that will induce the classical biological effects of the HGF, that is, cell proliferation/survival, and could also promote tumor growth. Moreover, the higher concentration of the endogenous ligand could preclude the interaction of the radiolabeled ligand with c‐Met with subsequent reduction of the contrast ratio of the tumor PET images.2‐S‐(4‐Isothiocyanatobenzyl)−1,4,7‐triazacyclononane‐1,4,7‐triacetic acid (p‐SCNBn‐NOTA) was covalently bonded to rh‐HGF. The resulting product 3Various monoclonal antibodies (mAbs) and anticalines targeting c‐Met or its ligand (HGF), for example, DN30, rilotumumab, onartuzumab, and PRS‐100, have been recently tested in both preclinical and clinical trials, with encouraging results for the management of cancer.89Zr for detecting c‐Met receptor. The radioactive isotope of zirconium was combined to the mAb through N‐Succinyldesferrioxamine‐DN30 . Biodistribution studies were carried out with different xenografted mice models, with high and low expression of the receptor . The absorption of 89Zr‐N‐sucDf‐DN30 in the low expressing c‐Met cell line was substantially lower than that in GTL‐16, reflecting the different c‐Met concentrations in the two cell lines; precisely, at 3 days postinjection 7.8 ± 1.2% ID/g was detected in FaDu and 18.1 ± 4.5% ID/g in GTL‐16 xenografts. In line with these results, human gastric cancer as small as 11 mg lesions were sharply visualized.In 2008, DN30 (a mAb against c‐Met) was first radiolabeled and used in in vivo PET imaging experiments by Perk et al.76Br and 89Zr for the radiolabeling of onartuzumab in 2012 and tested the labeled monoclonal antibody against c‐Met overexpressing human cancer cell lines and xenografted mouse models. Onartuzumab was labeled with 89Zr using desferrioxamine as chelating moiety while 76Br was directly covalently bonded. Biodistribution studies were conducted in MKN‐45  and U87‐MG tumors (moderate level c‐Met expression). Uptake of both the studied radioisotopes was consistent with the targeted receptor expression levels in the two different studied cell lines, namely uptake in MKN‐45 was higher than U87‐MG. The distribution in nontarget tissues was similar for the two different labeled onartuzumab in all tumor models. Competitive blocking by unlabeled onartuzumab in the MKN‐45 xenografts resulted in 3.8‐fold decreased uptake of the tracer. Between the two labeled compounds, the 76Br‐onartuzumab showed lower retention in the tumor tissue with a faster clearance. MKN‐45 xenografts were detected by micro PET imaging at 18–24 h postinjection with 76Br‐onartuzumab , whereas images generated with 89Zr‐onartuzumab continued to improve in quality over 5‐day postinjection. The accumulation of 89Zr‐onartuzumab in the gastrointestinal tract, lungs, heart, blood, and muscle decreased gradually over time, with more than 50% decrement from 18 h to 5 days, whereas uptake in kidney and liver increased progressively over the studied period, remarking renal and hepatobiliary clearance. Of note, a high bone absorption up to 7% ID/g was also measured at 5‐day postinjection, possibly due to free zirconium released from the tracer.Jagoda et al.89Zr. U87‐MG glioblastoma xenografts were used for biodistribution studies. Both the tracers (1E2‐Alb8 and 6E10‐Alb8) showed decreasing blood levels over 7‐day postinjection while tumor uptake levels remained relatively stable during the same period, making them suitable probes for PET scanning. The absorption in other tissues was minor than in tumor tissues, aside from kidneys that control the clearance of these proteins. In addition, the two nanobodies were evaluated for their therapeutic effect, due to their anti‐HGF activity, resulting in tumor growth inhibition after treatment with 100 mg intraperitoneal injections, 3 injections per week over 5 weeks.A different approach to target the HGF/c‐Met pathway was investigated by van Dongen et al. in 2012, where two anti‐HGF (αHGF) nanobodies, named 1E2 and 6E10, were developed to investigate HGF in vivo concentration by PET imaging  and Hcc827 tumors (human NSCLC with low c‐Met expression). The uptake was greater in Hcc827‐GR6 cell lines at 4 and 20 h postinjection in accordance with the c‐Met cellular expression levels. Hcc827‐GR6 showed an uptake of 1.8 ± 0.2% ID/g, compared to Hcc827 with only 0.65 ± 0.15% ID/g, as evaluated by ex vivo biodistribution studies.scFv‐cysdimers H2, a human single‐chain variable fragments‐cys‐diabody was radiolabeled with 89Zr. PET scans were done for mice bearing H441 (high c‐Met expression), U87‐MG (moderate c‐Met expression), and A2780 (low c‐Met expression) cell lines. Specific tumor uptake was clearly seen for 89Zr‐PRS‐110 in both H441 and U87‐MG xenografts whereas the A2780 mice revealed a lower absorption compared to the control . PET scans of H441 xenografts mice resulted in a peak uptake at 48 h post 89Zr‐PRS‐110 injection that was substantially higher than for 89Zr‐Tlc‐PEG, in agreement with the ex vivo experiments of biodistribution (5.9% ID/g for 89ZrPRS‐110 vs. 3.9% ID/g for 89Zr‐Tlc‐PEG). In PET scans of A2780 bearing mice, both tracers resulted in similar uptake, in agreement with c‐Met expression levels . Biodistribution data showed that the uptake in other nontumour organs was comparable except for lungs; this could be explained by possible metastasis of H441 tumors.Due to their small size (less than 20 kDa), anticalins could represent a valid alternative to mAb (150 kDa) with higher tumor uptake and tissue penetration and hence potentially improved characteristics for PET tracers.89Zr PET imaging agent.89Zr‐DFO‐AMG102 at 120 h postadministration was high for U87MG mice (36.8 ± 7.8% ID/g), but low (only 5.0 ± 1.3% ID/g) for MKN45. Uptake experiments in the four patient‐derived gastric cancer xenograft models suggested a low concentration of HGF (4%–7% ID/g). The low levels of the HGF in these tumors were then confirmed by ex vivo ELISA assays. This result shows how 89Zr‐DFO‐AMG102 could be useful to real time and noninvasively diagnosis of local HGF levels in tumors.A similar approach to van Dongen89Zr‐labeled onartuzumab (c‐Met antibody) was studied for its application as PET probe for discriminating the fluctuation in c‐Met expression induced by erlotinib (tyrosine kinase inhibitor) and luminespib  in human NSCLC xenografts by Pool et al.89Zr‐onartuzumab by detecting the protein upregulation due to erlotinib induced resistance, as well as downregulation of the receptor followed by HSP90‐directed therapy in human NSCLC xenograft‐bearing mice. Onartuzumab was conjugated to tetrafluorophenol‐N‐succinyldesferal‐Fe3+ (Df) and then studied in animal models. Mice bearing HCC827 (human NSCLC) and HCC827ErlRes (erlotinib resistant human NSCLC with c‐Met upregulation) tumors went through 89Zr‐onartuzumab PET scans. The pharmacological treatment of the cells with erlotinib or luminespib resulted in 213 ± 44% c‐Met upregulation in HCC827ErlRes tumors compared to HCC827 tumors, whereas the receptor was downregulated (minus 69 ± 9%) in HCC827 cells following the application of the Hps90 inhibitor. PET scans resulted in a 24% higher 89Zr‐onartuzumab absorption in HCC827ErlRes than in HCC827 tumors, moreover, biodistribution data showed that the uptake of the studied probe was higher in HCC827ErlRes (38.1 ± 8.4% ID/g) than in HCC827 cell lines (30.2 ± 3.5% ID/g) confirming that 89Zr‐onartuzumab used in PET scan productively contradistinguish modification in c‐Met protein levels.Another 68Ga t1/2 = 68 min) with a high molecular weight probe is suboptimal, however, the same HBED‐CC‐azepin‐MetMAb could have other potential other applications with smaller peptides or could be labeled with 67Ga  or 111In  and exploited for radioimmunotherapy (RIT) or as single‐photon emission computed tomography (SPECT).An alternative approach for the functionalization of onartuzumab was recently reported by Holland et al. who photoconjugated the anti‐c‐Met antibody with a chelating moiety then labeled the conjugate with gallium‐68.89Zr‐onartuzumab 89Zr‐onartuzumab was used to show that in PDAC otherwise resistant to c‐Met kinase activity inhibitors, immuno‐PET can diagnose potential patients for targeted radioligand therapy.89Zr‐onartuzumab was evaluated against Suit2, Capan2, BxPC3, and MIA PaCa‐2, all tumors resistant to tyrosine kinases inhibitors, despite overexpression of c‐Met. The viability of the cell lines was decreased in vitro by crizotinib and cabozantinib, whereas the less potent capmatinib showed no tyrosine kinase inhibition in PDAC lines. Selective absorption of 89Zr‐labeled DFO‐onartuzumab in xenografts mice injected with PDAC cell lines expressing high levels of c‐Met  was observed, but no uptake was observed in xenografts with lower levels of c‐Met (MIA PaCa‐2). Onartuzumab was then labeled with lutetium‐177, a beta‐emitting nuclide. [177Lu]Lu‐DTPA‐onartuzumab was subcutaneously administered at 9.25MBq (250 μCi)/20 μg in three injections separated by three days in xenograft mice bearing BxPC3 (high c‐Met expression) or MIA PaCa‐2 (lower c‐Met expression). In both animal models, an important delay in tumor growth and survival benefit was accomplished in comparison to control experiments; the benefit was long‐lasting and generally stronger in the BxPC3 animals treated with the lutetium‐177 labeled radiopharmaceuticals. These results revealed that while the overexpression of the studied protein is not prognosticative of the tyrosine kinase inhibitor response, PET scan can identify overexpression of c‐Met in vivo and anticipate therapeutic response to radioligand treatment.In a recent study, the already reported 89Zr‐radiolabeled onartuzumab was recently proposed by Holland et al. Differently to the already discussed method,89ZrDFO‐azepin‐onartuzumab was produced in the same reaction between 89Zr‐oxalate, MetMAb and the photoactive chelator DFO‐aryl azide (DFO‐ArN3), exploiting the chelating properties of DFO and the formation of an azepine ring between the azido group of the DFO and a lysine of the protein.89ZrDFO‐Bn‐NCS‐onartuzumab was also produced in a more classical two‐step way exploiting the same antibody and DFO‐BnNCS. Both compounds were immunoreactive to c‐Met and stable in human serum. MKN‐45 xenograft mice were used for PET imaging and along with biodistribution experiments demonstrate high tumor absorption for both the studied tracers. The uptake was studied at 72 h, in these experiments, the 89ZrDFO‐azepin‐onartuzumab tumor and liver uptake peaked at 15.37 ± 5.21%, 6.56 ± 4.03% ID/g, respectively89; ZrDFO‐Bn‐NCS‐onartuzumab uptake was 21.38 ± 11.57% ID/g for the tumor and 18.84 ± 6.03% ID/g for the liver, demonstrating again that photoradiosynthesis is a valid option for the production of zirconium‐89 radiolabeled antibodies easily in simple formulation medium. Blocking experiments were also performed and resulted in a significant reduction in tumor uptake of 89ZrDFO‐azepin‐onartuzumab to only 6.34 ± 0.47% ID/g.Another photosynthetic approach for producing another 89Zr antibody, Amivantamab. Amivantamab is a novel antibody with bispecific activity capable of synchronously targeting c‐Met and the epidermal growth factor receptor (EGFR). The bispecific antibody was covalently bonded to desferrioxamine and subsequently radiolabeled to obtain [89Zr]ZrDFO‐amivantamab (specific activity of 148 MBq/mg), synthesized with a radiochemical yield higher than 95%. The binding of the labeled conjugate was then studied in vitro and in vivo. Biodistribution studies were performed in MDA‐MB‐468 xenografts mice, differently a panel of triple‐negative breast cancer xenografts mice with various levels of c‐MET and EGFR expression was employed for the PET/CT imaging using the reported zirconium‐89 labeled antibody that, accordingly with c‐Met expression, resulted in higher cellular accumulation of the tracer in MDA‐MB‐231 and MDA‐MB‐468. The imaging findings were also confirmed by the biodistribution studies that showed that the tumor uptake of the radiolabeled tracer in the MDA‐MB‐468 mice was higher than those in the MDA‐MB‐231 and MDA‐MB‐453 xenografts . c‐MET and EGFR expression levels were studied by Western blot and radioligand binding studies confirming the order of the proteins expression levels: HCC827 (positive control) > MDA‐MB‐468 > MDA‐MB‐231 > MDA‐MB‐453, demonstrating that the novel amivantamab based tracer showed specificity to cell lines with high level of c‐MET and EGFR. The standard uptake value of the radiolabeled amivantamab in TNBC xenografted was also in agreement with the different receptors expression levels of the studied cells.Recently, Cavaliere et al.89Zr, can detect the protein expression in vitro and in vivo in mice models. These promising probes could not only be useful for the diagnosis of c‐Met aberrant cancer but also could enable real‐time monitoring for the selection of patients for c‐Met targeting drugs by the identification of responding and nonresponding patients for c‐Met targeted therapeutics.In agreement to findings of the above‐reported works, monoclonal antibodies, single‐chain variable fragment diabodies, and anticalins able to target c‐Met, mostly radiolabeled with 4Compared to the high molecular weight antibody‐based imaging probes, molecular imaging agents with peptide structures present diverse advantages cause of their lower molecular weight. Among them are lower toxicity, higher permeability, favorable pharmacokinetics and tissue distribution, limited immunogenicity, and convenient for controlled chemical modification.18F‐AH113804 for c‐Met detection via PET. The peptide was shown to bind c‐Met with high specificity and with a binding affinity of about 2 nM (Kd). The measured levels of radioactivity 1 h postinjection were 2.0 ± 0.2%ID/ml in the blood, 2.9 ± 0.3%ID/ml in liver, and 4.9 ± 0.6%ID/ml in kidney.18F‐AH113804 uptake in the tumor site was 1.5 ± 0.2%ID/ml, compared with both muscle 0.8 ± 0.1%ID/ml and contralateral mammary fat pad 0.8 ± 0.1%ID/ml at 60 min after injection.18F‐AH113804 was then used in PET imaging to reveal reappearance after surgical excision of HCC1954 human basal‐like breast cancer implanted mice with high c‐Met levels as early as 6 days after the operation, showing the great potential of the probe in PET imaging as a clinical screening after surgical ablation of HCC1954 breast cancer. Moreover, by virtue of the peptide‐like properties  18F‐AH113804 (3.2 kDa) permitted high‐contrast image (1 h postinjection), that is, improved sensitivity for cancer detection. A peptide similar to 18F‐AH113804 named AH‐113018 was also proposed by Jagoda et al.,99mTc and used for SPECT imaging. The clinical safety of 18F‐AH113804 was confirmed by a phase‐1 biodistribution study in healthy adult volunteers.Based on an already published fluorescent peptide (GE‐137)ut 2 nM Kd. The meut 2 nM Kd. The me18F‐2‐ fluoropropionate resulting in 18F‐FP‐Met‐pep1. UM‐SCC‐22B (head and neck human squamous carcinoma with high c‐Met expression) cells were used to measure the internalization, cellular uptake, and efflux of the fluorine‐18 labeled Met‐pep1, while tumor‐bearing nude mice and PET imaging were used to measure the biodistribution and the pharmacokinetics. The uptake of the radiotracer was high in UM‐SCC‐22B mice with excellent PET imaging results. Both the cellular uptake and the internalization of the tracer followed a similar trend displaying a fast increase during the first 15 min, encompassing their concentration peak after 30 min and decreasing at 60 min. Efflux experiments showed that in the first 15 min 47% of the radiotracer was taken out of the cells, after 30 min the efflux rate slowed down and at the end of the incubation the tracer bound to cells was about 36%. PET imaging experiments showed that UM‐SCC‐22B tumors were clearly visible with uptakes of 4.72%, 3.83%, and 3.11% ID/g at 30, 60, and 120 min postinjection, respectively. Coadministration of unlabeled Met‐pep1 was used to confirm the specificity of the tracer that resulted in decreased tumor uptake showing a high specificity. High values of organ absorption were measured in the kidneys (6.15 ± 0.71% ID/g) and in the liver (11.5 ± 0.7% ID/g), but a rapid renal clearance (65% excreted within 2 h after) suggested a mainly renal‐urinary excretion of the tracer. Muscle and other organs , had very low uptake during all time points.Met‐pep1, a c‐Met binding peptide,Kd of 0.4 nM and a koff of 0.4 × 10−3 s−1 (dissociation rate) was measured by surface plasmon resonance. The reported HGF‐inhibitory activity in cellular assays (as IC50) was 8 nM. The water solubility and the pharmacokinetics of the macrocyclic peptide were improved by the inclusion of a polyethylene glycol chain to the C‐terminus. The selectivity of HiP‐8 to HGF was also compared with other similar proteins human growth factors, resulting in a high selectivity for HGF. Murine HGF was also evaluated and HiP‐8‐PEG11 displayed binding to the nonhuman grow factor with 50‐fold less affinity. The use of HiP‐8‐PEG11 was then evaluated for PET scansion of HGF–Met activation in tumors. To achieve this, the molecule was chemically engineered and an ‐N3 group was added to a lysine by using a Fmoc‐Lys(N3)‐OH, that was subsequently conjugated to the copper chelating ligand DBCO(dibenzocyclooctyne)‐PEG4‐CB‐TE1K1P .64Cu, resulting in a radiochemical purity ≥95% measured by radio‐HPLC. The tracer was then administered intravenously to SCID mice xenografts with PC‐9 tumors (HGF− and HGF+) showing liver absorption, a fast renal clearance, and tumor accumulation. The tumor uptake reached a peak between 10 and 17 min, the tumor/muscle ratio of radioactivity—contrast index—showed accumulation of the tracer in HGF positive tumors with high selectivity , demonstrating that 64Cu‐HiP‐8‐PEG11 is an outstanding probe for noninvasive imaging of HGF–Met status in tumors on an animal model by PET imaging. Moreover, due to the optimal characteristics of the c‐Met targeting peptide and to the practicality of chemical modification, HiP‐8 could be exploited for other applications in imaging by conjugation with different chelating units and/or other chemical modifications.Exploiting random nonstandard peptides integrated discovery (RaPID) selection,68Ga‑EMP‑100 was recently designed and used in a pioneer in‐human imaging and biodistribution study.68Ga‐EMP‐100 is a recently reported peptide‐based PET tracer that targets tumoral c‐Met relying on the chelation capabilities of DOTA that was conjugated on the peptide for gallium‐68 chelation. As frequently observed in other cancers, the upregulation of the c‐Met in renal cell carcinoma (RCC) is associated with the overall survival in the metastatic stage (mRCC) of the disease, and the staging of the receptor expression could improve the patient management . Mittlmeier et al.68Ga‐EMP‐100 in mRCC patients with the aim to evaluate the uptake in primary lesion and in metastases of RCC. Twelve patients with advanced metastatic RCC underwent PET imaging with the novel reported probe and the biodistribution in normal organs and in the lesion were studied. Eighty‐seven tumor lesions were analyzed and 68 were recognized as c‐Met‐positive. Comparing the different analyzed sites, the highest uptake was reported in tumor burden at the primary site followed by bone, lymph node, and visceral metastases. All the other c‐Met negative lesions were heterogeneously distributed intra‐ and interindividually and mostly present as lung and liver metastases. 68Ga‐EMP‐100 was physiologically accumulated in the urinary bladder content and kidneys, and only moderate to low uptake was measured in the liver, spleen, pancreas, and intestine. The clinical success of the reported study warrants further research studies investigating the clinical use of 68Ga‐EMP‐100 and other similar probes as a biomarker in mRCC patients.Based on the structure of GE‐137,511C‐SU11274. The designed probe is based on SU11274 is a c‐Met tyrosine kinases inhibitor that was then labeled with carbon‐11 generating 11C‐SU11274. The molecule was radiolabeled in a single‐step reaction starting from synthesized molecule 1  have the same structure, so the specificity and the binding affinity of the probe are preserved. The imaging properties were evaluated by micro‐PET in mice bearing H1975 (c‐Met positive human NSCLC) and mice bearing H520 (c‐Met negative human NSCLC). The measured tumor uptake was significantly higher for H1975 mice than H520; in particular, the one of 11C‐SU11274 in c‐Met positive animal model reached its maximum at 80 min postinjection and was constantly higher than the c‐Met negative animal, confirming the usefulness of 11C‐SU11274 as a radioactive tracer for detection of the activation of c‐Met by PET imaging.HGF, antibodies, and peptide‐based PET probes all have in common that their c‐Met binding sites are located in the extracellular portion of the protein; however, the catalytic activity of c‐Met, that triggers the signal transduction, is activated in its intracellular domain. Thus, small molecules imaging agents that bind the receptor within its intracellular catalytic domain could provide useful knowledge about the activation status of the receptor. Also, small molecules probes, thanks to their low molecular weight and size, are highly permeable in tissue and potentially in cells, and easily cleared. The first study of such compounds for c‐Met was reported by Wu et al.1 Figure . The two18F‐cabozantinib was reported by Lien et al.2  was chosen over 11C for optimal clinical applications and availability. Due to the electron‐donating features of the amide group the SNAr reaction for the introduction of 18F would have been impractical, resulting in a multistep reaction starting from 18F‐dinitrobenzene, consecutive reduction to aniline, and then formation of the amide bond.18F‐labeled molecules based on the use of boronic acid pinacol esters in copper‐catalyzed reactions with 18F‐fluoride they synthesize the 18F marked cabozantinib in about 2.8% yield and with a molar activity of 17 ± 8 GBq/μmol. The precursor 2 was produced in four‐step reactions. The method produced only 18F‐cabozantinib as a radioactive species and only impurities due to hydrolysis of 2 were identified . A total of ~280 MBq of 18F‐cabozantinib was isolated, despite the yield, satisfactory for applications in small animal PET studies that were however not reported in the study.Cabozantinib is another c‐Met kinase inhibitor that was FDA‐approved for the treatment of different types of cancer (advanced RCC and medullary thyroid cancer). The radiosynthesis of 2 Figure . 11C‐lab18F‐labeling , while the uptake in kidney and liver was 29.40 ± 1.77% ID/g and 30.61 ± 1.77% ID/g after 1 h injection, respectively. The metabolism of the molecule was through the hepatobiliary pathway as proved by an increasing ID/g in the large intestine (4.85 ± 2.10% ID/g at 2 h postinjection to 10.12 ± 5.44% ID/g at 6 h postinjection). Optimal uptake over time was measured for cancer tissue that reached 13.68 ± 1.96% ID/g at 1 h postinjection, 6.02 ± 2.83% ID/g at 4 h postinjection, with an optimal tumor to lung ratio of about 3.5 at 2–4 h postinjection. Imaging of xenograft mice H1993 tumor (c‐Met positive NSCLC) or A549 tumor was then performed with 18F‐FPC at 4 h postinjection. The radioactivity in H1993 tumor was higher than that in A549, and the uptake of H1993 tumor can be repressed by high doses of crizotinib, confirming 18F‐FPC as an optimal candidate for PET scansions of c‐Met‐positive NSCLC tumor.More recently another kinase inhibitor‐based PET probe was reported by Lin et al.g Figure . TPC was18F‐FDG (fluorodeoxyglucose) to track c‐Met inhibition by CE‐355621 in the glioblastoma U87MG. Cullinane et al.18F‐FLT (fluorothymidine), whereas 18F‐FDG can only be used in GTL‐16. The two tracers 18F‐FDG and 18F‐FLT were also useful for prompt monitoring of the effect of BAY 853474 in cancer.More generic small‐molecule PET tracers could also be useful for monitoring c‐Met activity in cancer and treatment efficacy. For example, Tseng et al.668Ga‑EMP‑100, Table 18F.68Ga‐EMP‐100, Table The frequency of c‐Met receptor misregulation in cancer diseases and its known influence on the pathology evolution make this membrane protein an interesting molecular target for the design of novel diagnostic and therapeutic pharmaceuticals in several cancer types. The already approved c‐Met inhibitor drugs and other Phases II and III clinical studies have shown promising results with a remarkable benefit for the patients in different types of cancers.18F‐FDG can localize early‐stage bone marrow metastases before they appear on bone scintigraphy or CT with PET scansion.11C) resulting in cyclotron produced limiting availability, still limited role in primary staging and first diagnosis, target  high dependency, high bone marrow uptake, which may limit the detection of bone metastases, and significant liver and/or other tissue uptake, which may reduce the detection of metastatic disease in those areas.Despite the scarcity of the clinical data for c‐Met targeting PET probes, and only the recent first in human application of such tools, some general advantages and drawbacks for this pharmaceutical class can be summarized as commonly reported for the application of other PET radiopharmaceuticals and should be taken into account when considering the future application of c‐Met PET probes. For instance, the application of PET probes other than the already discussed diagnosis and therapy monitoring is the use of PET and PET/CT for tumor ablation and guided biopsies.67/68Ga).The merging of accurate imaging radiotracers with PET will allow noninvasive and real‐time diagnosis of specific cancer types with accurate picture of tumors and metastases and thus precise staging of the disease. Moreover, the assessment of the studied protein expression, the uptake kinetics, and the pretherapeutic dosimetry may grant a better selection of the treatments as well as monitoring the patient response to the applied therapy and anticipate detection of recurring disease resulting in personalized medicine and radiotheranostic (e.g., probe based on The recent progress in the research field of c‐Met based PET imaging here reviewed are highly encouraging, even if the optimization of a PET probe for clinical purposes still faces challenges, suggesting that this family of tracers could be useful as a diagnostic tool for patients selection and for therapeutic applications in the near future.


On the basis of social information processing theory, this study proposes a model of the influence mechanism of self-serving leadership (SL) on employee innovative behavior (IB), with psychological entitlement as the mediating variable and moral identity as the moderating variable. The paired data of 82 leaders and 372 employees collected at three time points are analyzed by the hierarchical linear modeling. Results corroborate that SL impairs employee IB. Moreover, the relationship between SL and employee IB is mediated by psychological entitlement. Finally, moral identity has a negative moderating effect of SL on psychological entitlement and an indirect effect on employee IB through psychological entitlement. With the continuous changes in international markets and technological advances, an increasing number of companies realize that innovation is a crucial source to ensure their long-term development and maintain their sustainable competitive advantage . MeanwhiEmployee IB refers to a series of actions including the creation, promotion, and implementation of new ideas . StudiesOur study intends to explore how and when SL affect employee IB drawing from social information processing (SIP) theory, from which leaders are important information sources in organizations providing employees with various information clues, then employees adjust their own cognition and behavior norms by interpreting and judging the information . SL refeIn addition, SIP maintains that the formation of employee cognition and behavior is affected not only by information characteristics but also by relevant employee factors . As SL sAccordingly, drawing from SIP, our study aims to clarify the potential impact mechanism between SL and employee IB and delve into the mediation and moderation roles of employee psychological entitlement and moral identity, respectively. We thus construct the theoretical model of how SL affects employee IB, as illustrated in This study has several contributions. First, finding that SL negatively affects IB, this research, to a certain extent, fills the long-standing gap of lacking empirical evidence to explore the relationship between the two. Second, based on SIP, this study confirms that psychological entitlement plays a mediating role between SL and IB, which further enriches the mediation mechanism between them and expands the scope of SIP application. Third, this work introduces the concept of moral identity from the individual characteristic perspective, which not only helps clarify the boundary conditions of SL effects, but also breaks the limitation of existing literature that only takes organizational and leader factors as moderating variables.A systematic literature review on IB reveals that leadership style is an important antecedent. Positive leadership styles, such as transformational leadership, transactional leadership, ethical leadership, servant leadership, inclusive leadership, spiritual leadership, entrepreneurial leadership, and leader humor, have been found to positively influence IB; whereas negative leadership styles, such as abusive supervision, authoritarian leadership, leader narcissism, and exploitative leadership, negatively influence IB . In termAs a complex and spontaneous behavior, IB includes a series of activities related to generating and implementing new ideas , that isSL is defined as leaders who put their own well-being and benefits above employee pursuits and organization targets . HoweverConsequently, our study posits that SL has a certain negative impact on employee IB. SIP suggests that individual activities are influenced by complex social environments , and theH1: SL is negatively related to employee IB.Psychological entitlement is defined as a stable cognitive state with a high degree of self-interest, that is, individuals are in an inflated self-awareness state of deserving high praises and rewards regardless of their actual performance . NaumannConsequently, our study believes that working with SL, employees can hardly perceive due respect and fair treatment which then brings out a heavy sense of psychological entitlement. In more detail, encountering SL, an impact on employees’ cognition comes first . For oneOur study further argues that employee psychological entitlement induced by SL negatively impacts employee IB. First, employees with psychological entitlement opine that they should have more than they do now , that isH2: Employee psychological entitlement engages in the mediating role between SL and employee IB.Moral identity is a relatively stable self-concept framed around specific moral characteristics such as honesty, fairness, compassion, etc. . It inclDrawing from SIP, employee perception and behavior formations are influenced not only by information characteristics themselves but also by their own related factors, resulting in differences in individual perceptions and behaviors . In pracH3: Employee moral identity negatively moderates the relationship between SL and employee psychological entitlement, that is, the higher the moral identity, the lower SL influence on employee psychological entitlement, and vice versa.This study further proposes a moderated mediation model where the interaction between SL and moral identity has an impact on employee IB through psychological entitlement. In detail, employees with low moral identity do not value their personal moral values, their self-concepts are easily influenced by external situational factors , and theH4: The mediating impact of SL on employee IB via psychological entitlement is moderated by employee moral identity, that is, the higher the moral identity of employees, the lower the influence of SL on employee psychological entitlement, and vice versa.We used paper-based questionnaires to collect data from employees and their supervisors of enterprises in Southwest China. The researcher first contacted the human resource (HR) directors of these enterprises and introduced the research purpose to them to obtain their permission. After a brief introduction to precautions and data receipt methods, we recruited participants with the assistance of these HR directors. Then, the questionnaires were sent to the site and participants were told to post the completed questionnaires to the designated address. Data were collected from three-time points to decrease the likelihood of possible common method biases, with an interval of 2 weeks between each time point. At Time 1, data included SL, moral identity, and control variables collected from employees. A total of 440 employee questionnaires were distributed at this stage, and 408 questionnaires were returned. At Time 2, employees were asked to evaluate their psychological entitlement. We sent out 408 copies, and 392 were collected. At Time 3, employees were asked to invite their direct supervisors to evaluate employee IB, and a total of 98 leader questionnaires were distributed at this stage, and 89 questionnaires were returned. After eliminating invalid questionnaires, the matched data of 82 leaders and 372 employees were finally collected. Among employee participants, 221 males were recorded, representing 59.4%. In terms of age, 267 employees were 26–35 years old (71.8%). In terms of education level, 201 participants had college or undergraduate degrees (54.0%). In terms of tenure with leaders, 120 participants served for 7–12 months account 32.3%. The maximum and minimum values of tenure with leaders are 0.25 years and 7.5 years, respectively.All measurement scales in this study were from highly reliable and valid scales widely used in related research. A five-point Likert method was used to score each item, where 1 referred to “completely disagree” and 5 meant “completely agree.”SL: A four-item scale exploited by Moral Identity: The five-item scale developed by Psychological Entitlement: The four-item scale developed by Employee IB: The six-item scale developed by Control Variables: Previous studies  found th2χ/df = −1.918, CFI = 0.979, TLI = 0.976, RMSEA = 0.050) had the best indices, implying that the discrimination validity of the four variables included in the four-factor model was in line with the expected effect and was good.Before hypothesis testing, we performed reliability and validity tests see , 2. The r = −0.313, p < 0.01), providing evidence for our hypotheses.The averages, standard deviations, and correlation coefficients of variables are shown in wg average, and median values of SL are 0.446, 0.785, 0.862, and 0.928 respectively, which meet the polymerization requirements. In addition, the ICC (1) values of psychological entitlement and employee IB are 0.253 and 0.268, respectively. We performed hierarchical regression analysis to test the SL influence on employee IB, and data inspection results are presented in p < 0.001). Consequently, H1 is supported.The ICC (1), ICC (2), Rβ = 0.368, p < 0.001, Model 1 in β = −0.273, p < 0.001), and the SL impact on employee IB remains salient . Based on these analyses, psychological entitlement acts as a partial mediator between SL and employee IB. Hence, H2 is preliminarily supported.To further interpret the mediating effect of psychological entitlement, we led SL and psychological entitlement into the regression equation simultaneously; heretofore, we tested if SL negatively affects employee IB. According to Model 1, SL is notably and positively associated with psychological entitlement  = , excluding 0. Thus, H2 is supported.β = 0.337, p < 0.001, Model 2 in β = −0.158, p < 0.05), indicating that moral identity can effectively regulate the relationship between SL and psychological entitlement. To further embody the moderation impact of moral identity on SL and psychological entitlement, our study drew a moderating effect map of moral identity ; meanwhile, the higher the moral identity, the weaker the positive correlation between SL and employee psychological entitlement . Therefore, H3 is supported.We investigated the moderation impact of moral identity on the relationship between SL and psychological entitlement. First, we tested whether SL has a significant effect on psychological entitlement. Second, we simultaneously led the interaction items of SL, moral identity, centralized SL, and moral identity into the regression equation to test the significance of SL coefficients and interactive items. Given that the significant relationship between SL and psychological entitlement has been proven, after including interactive items  in the regression equation, SL displayed a substantial positive reinforcement influence on psychological entitlement  and low  moral identity levels; and the difference  is also significant. Thus, H3 is further verified. Similarly, b = −0.047, 95% CI = ) and low  moral identity levels; the difference  is also significant. Evidently, moral identity acts as a moderator in the mediating effect of psychological entitlement between SL and employee IB. Accordingly, H4 is supported.We used the Bootstrap method to investigate the moderated mediating effect, and the results are shown in First, this study investigates the impact of SL on employee IB and expands the research of SL outcome variables. Previous studies have made many meaningful explorations on employee behavior caused by SL, including employees’ knowledge hiding , turnoveSecond, our study enriches the potential mechanism between SL and employee IB and reveals the role of employees’ affective reaction process in this mechanism. According to social exchange theory, prior studies elaborated on the mediating effect of employee affective commitment between SL and employee counterproductive work behavior , as wellThird, our work expands on the boundaries of the influence of SL on employee behaviors. According to the moderation role of moral identity, our study clarifies the circumstances under which SL affects employee psychological entitlement. Previous studies mainly investigated the boundaries of SL from two aspects, employees’ values  and task characteristics  , while fFirst, to avoid the negative consequences caused by SL should be brought to the forefront, our study confirms that SL can inhibit employee IB. Therefore, when selecting managers, enterprises should take their moral cultivation as the top priority, that is, leadership style tests can effectively prevent individuals with selfish tendencies from becoming managers. Moreover, enterprises should strengthen moral training for existing managers. Managers constantly improve their moral cultivation and do not easily exhibit encroaching behavior on organization and employee interests. During the training process, managers must be fully aware of the hazards of self-serving behaviors, be encouraged to reflect on self-serving behaviors, and be guided to establish altruistic values.Second, organizations should properly guide and intervene in employee psychological entitlement. We find that employee psychological entitlement refrains employees from engaging in IB that is beneficial to organizations. Thus, employees should be supported to clarify their rights and responsibilities. (1) Organizations should show solicitude for basic employee psychological needs, for example, let employees participate in decision-making; encourage communication among superiors, subordinates, and colleagues; and enhance internal enterprise cohesion. (2) The change in employee psychological state is the other factor that should be followed closely. A comprehensive evaluation system around employee psychological state can be established to get to know employee psychological state in a timely manner and intervene seasonably through group counseling and other methods, then alleviate employee coping style in a negative cognitive situation.Third, as our study confirms that moral identity is an “effective medicine” to refrain employee negative cognition, organizations should strive to create a pleasant moral atmosphere, which indicates that organizations may transform moral standards into organizational rules and regulations through education and guidance to a certain extent and thus restrain leader and employee behaviors. Organizations can also hold publicity activities to emphasize the importance of fairness and ethics, including the benefits and values of acting in a fair and ethical manner. Moreover, organizations should emphasize the rules and regulations of order and professional codes so that when facing ethical decisions, employees can make judgments mainly according to organization systems and procedures and always alert themselves to high ethical standards.Our study also contains several limitations that should be further improved. First, we only examined the role of psychological entitlement in the relationship between SL and employee IB, ignoring other potential mediating mechanisms. SL will consume employees’ emotional resources and lead to their emotional exhaustion, and employees may be reluctant to engage in IB just to avoid further resource losses . Thus, fvia psychological entitlement is also affected by the negative moderating effect of moral identity. The lower the moral identity, the stronger the indirect effect, and vice versa.Drawing from SIP, our study lays emphasis on the link between SL and employee IB and examines the mediating and moderating roles of employee psychological entitlement and moral identity in between. We find the following conclusions: SL significantly negatively impacts employee IB. As a mediator, employee psychological entitlement mediates the link between SL and employee IB. Moreover, the influence of SL on employee psychological entitlement is negatively moderated by moral identity. The lower the moral identity, the mightier the positive effect of SL on employee psychological entitlement. Lastly, the indirect effect of SL on employee IB 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 Guizhou University of Finance and Economics (GUFE). The patients/participants provided their written informed consent to participate in this study.HM: conceptualization, data curation, and writing-original draft. SP: data analysis and writing-original draft. LZ: conceptualization, writing and editing. YZ: writing—original draft. All authors contributed to the article and approved the submitted version.This work was supported by Startup Foundation for Distinguished Scholars of Guizhou University of Finance and Economics (2019YJ065).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.


IgG4‐related lung disease (IgG4‐RLD) can present with various types of radiological findings such as nodule, ground‐glass opacity, alveolar interstitial, and bronchovascular involvement. IgG4‐RLD generally manifests as mild clinical symptoms, despite evidence from the image findings. Herein we report an asymptomatic patient with IgG4‐RLD mimicking multiple pleural disseminated lung cancer. Herein we report an asymptomatic patient with IgG4‐related lung disease mimicking multiple pleural disseminated lung cancer. A 68‐year‐old woman, a 30‐pack‐year smoker with a medical history of diabetes and hypertension, presented to our department for assessment of multiple subpleural pulmonary nodules detected through chest computed tomography (CT). The laboratory examinations including tumour markers, infection, and vasculitis were unremarkable. One month later, the nodules rapidly grew in size and number Figure , then prAll authors contributed to the study conception. The literature search was performed and the first draft of the manuscript was written by Koya Ito and Toshiyuki Harada. Yukiko Maeda, Akane Mita, Saori Aizawa, Arei Mizushima, Natsuko Taniguchi, and Katsura Nagai contributed data curation and formal analysis. Hiroki Shomura performed surgical resection. Atuso hattori contributed the pathological diagnosis. All authors commented on previous versions of the manuscript. All authors have prepared, read and approved the final manuscript.None declared.The authors declare that appropriate written informed consent was obtained for the publication of this manuscript and accompanying images.


Postpartum hygiene self-care practices were collected in the 6th week. The results found that there were no statistical differences in mean scores for all questions on postpartum hygiene self-care practices between the infected and non-infected groups . One of the factors associated with antibiotic prophylaxis was third to fourth degree of tear and episiotomy . There was no significance difference in postpartum infection among patients receiving antibiotic and those who did not receive antibiotics. Third to fourth degree of tear and episiotomy were significantly factors related to antibiotic prophylaxis in women with vaginal delivery after labour. This study supports practice guidelines and helps healthcare team to be assured on the use of antibiotics in no more than 10% of women experiencing normal vaginal delivery.Antibiotic consumption accounted for approximately 15–20% of total drug costs in Thailand. From 2017 to 2018, 24.86% of Thai women who experienced vaginal delivery during normal term labour received antibiotics for postpartum infection. The Thai national practice guidelines set the target use of antibiotic prophylaxis in women following vaginal delivery of normal term labour to be no more than 10%. This study aimed to determine the incidence of postpartum infections and the outcomes and factors associated with antibiotic prophylaxis in women following vaginal delivery. The prospective cohort study was collected from 909 eligible patients who delivered infants in 7 secondary hospitals in Chiang Mai from July 2020 to February 2021. Antibiotic prescribing data and infections in women experiencing vaginal delivery during normal term labour were collected. The incidence of postpartum infections was calculated at 2 periods, 48 h and 6 weeks, after labour. Factors associated with the prescription of antibiotic prophylaxis in vaginal delivery were analysed using multivariate logistic regression. The results showed that the prevalence of antibiotic prescribing was 12.87% in a cohort of 117 patients. Postpartum infection was reported in 3 of 117 patients with antibiotics prophylaxis and 11 of 792 without antibiotics, with no statistically significant difference (RR: 1.04, 95% CI: 0.26–4.14;  The World Health Organisation (WHO) reported that more than half of patients receive antibiotics inappropriately , particuAntibiotic consumption accounted for approximately 15–20% of total drug costs in Thailand . The MinFrom 2017 to 2018, 24.86% of Thai women experiencing vaginal delivery during normal term labour received antibiotics for postpartum infection .Prescribing antibiotics reduced the mortality rate and decreased the incidence of postpartum infection, in particular, surgical and vaginal deliveries with grade 3–4 perineal wounds. The study found that antibiotics in women with grade 3–4 perineal wounds were able to reduce the incidence of wound infections  . The repThe RDU programme is focused as a health service plan in Thailand . Practicstreptococcus infection or the microbial cultured presence of Group B streptococcus. Sample size was calculated using 2-sample non-inferiority or superiority of postpartum infections during 6-week follow-up after delivery between antibiotic and non- antibiotic groups.This was a multi-centre prospective cohort study among women admitted for normal vaginal delivery at seven secondary care hospitals in Chiang Mai, Thailand. All women attending the study hospitals for vaginal delivery of normal term labour from July 2020 to February 2021 were recruited into the study. Women with a normal vaginal delivery, no pyrexia  and amniotic sac ruptures no later than 24 h before delivery were included in the study. Women were excluded from the study if vacuum extraction (forceps delivery) was used for delivery, antepartum or postpartum haemorrhage, and diagnosis of Group B Maternal intrapartum antibiotic prophylaxis (IAP) was identified as a systemic or oral antibiotic was prescribed for women with normal vaginal delivery for an indication to prevent postpartum infections and documented in hospital medical records. Antibiotic prescribing for women after delivery at discharge was also identified as antibiotic prophylaxis. Women received antibiotic for postpartum infection prophylaxis was antibiotic group. Women with no record of antibiotic prescribing for postpartum infection prophylaxis was considered a non-antibiotic or control group.The criteria for determining postpartum infection were the presence of at least 2 clinical symptoms, i.e., abnormal vaginal discharge, pyrexia , abnormal smell/foul odour discharge, delay in uterine involution (less than 2 cm per day during the first 8 days after delivery), and pelvic pain, assessed by the trained clinicians. The signs and symptoms of infection were reviewed by gynaecologists to confirmed postpartum infections at 48 h after normal delivery and at the 6-week follow-up visit.The study was approved by the research ethics committee, Faculty of Pharmacy, Chiang Mai University (No. 12/2563). Written informed consent was obtained from the participants at enrolment. Trained clinicians collected data from medical records, including demographic data, data related to delivery, antibiotic prescribing, and sign and symptoms of postpartum infections at 48-h and 6-week follow-up at outpatient clinic for puerperium care. Participating clinicians were trained for participant recruitment and data collection. Factors associated with antibiotic prophylaxis were collected, including occupation, age, duration of labour, anaemia, completed antenatal care, BMI, total number of pregnancies, degree of vaginal tear. A standardised self-administered questionnaire on self-care practices and hygiene was completed by women after hospital discharge using during home stay before the 6-week follow-up. Postpartum hygiene self-care practices during 6 weeks after delivery were assessed using a 5-item self-administered questionnaire on hygienic practices including showering, handwashing, perineal hygiene, changing sanitary pad, and delaying sexual relation. A 5-point Likert scale was used to rate the practices, ranging from 1 = “never,” 2 = “rarely,” 3 = “sometimes,” 4 = “often,” and 5 = “always.” The reliability test revealed that the Cronbach’s alpha coefficient of this questionnaire was 0.73. The responses were grouped into “often-always” and “never – sometimes.”t-test was used for continuous variables and Chi-square test for categorical variables. Relative risk (RR) was calculated at 48 h and 6 weeks after delivery to indicate the incidence of postpartum infections in antibiotic and non-antibiotic groups. The study was powered to detect an 80% difference in the postpartum infection outcome. Multivariable logistic regression was performed to adjust for potential confounders, such as maternal age, history of self-administered antibiotic, length of hospital stay, duration of labour, degree of vaginal tear, anaemia, and number of pregnancies. Multivariable logistic regression was used to identify factors of antibiotic prescribing for postpartum infection prophylaxis. Statistical significance was determined by p < 0.05 for the study outcome. All analyses were conducted using STATA version 14.0 .Descriptive statistics were used to describe patient characteristics. To test the differences of characteristics of women received or not received antibiotic prophylaxis for postpartum infection, student’s The prospective cohort study consisted of 909 women who had a normal vaginal delivery at the secondary care hospital, Chiang Mai province, Thailand, between July 2020 and February 2021. Statistical analysis, including univariate and multivariable logistic regression were conducted to assess the incidence of postpartum infection and factors associated with antibiotic prophylaxis .2, were unemployed and completed antenatal care 5 times  were diagnosed with postpartum infection. It was found that all of them had abnormal vaginal discharge, with symptoms presenting according to other diagnostic criteria. Most of the infected women had an abnormal smell/foul odour discharge and pelvic pain. By dividing at the time of inspected at 48 h and 6 weeks, there were 6 cases and 8 cases diagnosed postpartum infection at those time, respectively.The results on the incidence of postpartum infection between the antibiotic and non-antibiotic groups were reported. In the antibiotic group, 3 of the 117 cases had postpartum infections, while there were 11 out of 792 cases in the non-prescribed antibiotic group who had postpartum infections . The incThe most commonly prescribed antibiotic in the hospital for prophylactic infection in 117 cases was oral amoxicillin, with a usage level of 77 times in 63 cases, as a percentage 53.8% in the antibiotic group. The next highest were ampicillin and ceftriaxone in 31 cases (26.5%) and 14 cases (12%), respectively.p = 0.037 and OR: 2.41, 95% CI: 1.24–4.70; p = 0.010, respectively; Univariable and multivariable logistic regression were used to determine factors associated with antibiotic prescription for prophylaxis postpartum infection in women following normal vaginal delivery. The results showed that the degree of tear as third to fourth degree and episiotomy were a statistically significant factor for antibiotic prescribing in women experiencing normal vaginal delivery . At the six-week follow-up visit, the mean scores of postpartum hygiene and self-care were not different between women received antibiotics and no antibiotics . The level of tear in third to fourth degree  and episiotomy  were the factors associated with antibiotic prescribing for postpartum infection prophylaxis.This study found that 117 of a total 909 women with normal vaginal delivery (12.87%) were prescribed antibiotics for postpartum infection prophylaxis, of which 53.8% of the women received oral amoxicillin. Postpartum infection was found in 3 of 117 women treated with antibiotics and 11 of 792 women with no antibiotic prophylaxis . The systematic review by Bonet (p < 0.622). Another study in Thailand  in the antibiotic-treated group were infected compared to the non-antibiotic groups, with 11 out of 792 cases (1.4%). There was no statistically significant difference in the proportion of postpartum infections between the two groups . According to the study by Sharma et al.  were diagnosed with postpartum infection. The incidence of postpartum infection was 1.04 times (3/114 women) higher in the antibiotic group compared to the non-antibiotic group (11/781 women). There was no significance difference in the use of antibiotics or not for prophylaxis in postpartum infection. The degree of tear at the level of third to fourth degree and episiotomy are the factors considered when prescribing antibiotics to prevent infection in women following vaginal delivery. Evidence-based practice using data to empower and encourage healthcare teams in the awareness of prescribing antibiotics to no more than 10% of patients following vaginal delivery in normal term labour for the prevention of postpartum infection.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 ethics committee on human research of the Faculty of Pharmacy, Chiang Mai University (12/2563). The patients/participants provided their written informed consent to participate in this study.TS, PK, and WK: conceptualization, methodology, writing – original draft, and writing – review and editing. TS: data curation, formal analysis, investigation, project administration, and software. PK and WK: supervision. SN: validation. All authors contributed to the article and approved the submitted version.


To assess the efficacy of dysdrogesterone in the treatment of chronic endometritis (CE) treated with antibiotic in premenopausal women with endometrial polyps (EPs).Routine detection of endometrium was simultaneously conducted to determine whether there was CE by syndecan-1 (CD138), while women underwent hysteroscopic polypectomy in our hospital. Antibiotic was given for the treatment of CE. A total of 235 premenopausal women with CE who underwent hysteroscopic polypectomy were enrolled in the retrospective observational study. In the control group, single antibiotic was given for the treatment of CE form January 2016 to December 2018, and in the treatment group additional dydrogesterone was used from January 2019 to November 2020. Comparison of cure rates of CE with different treatment regimens was performed.The cure rates of CE in dydrogesterone and antibiotic combination group and the single antibiotic group were 85.2% and 74.3%, respectively, with overall cure rate of 80.0% (188/235). The combination group showed better effects regarding the cure rate of CE (P < .05). Multivariate analysis confirmed that the cure rate of CE was not affected by age, body mass index, number of EPs, the status of estrogen receptor and the status of progesterone receptor. Conversely, dydrogesterone and endometrial scratching were beneficial factors for cure rate increase with antibiotic treatment.Combination of dydrogesterone and antibiotic was more effective for cure rate of CE than antibiotic alone in premenopausal women after hysteroscopic polypectomy. Endometrial scratching also contributed to the cure rate increase with antibiotic treatment. Endometrial polyps (EPs) is common benign gynecological protrusions which represent a localized hyperplastic overgrowth of stroma and endometrial glands; the prevalence of EPs ranges from 7.8 to 34.9% across different populations . PreviouCE is a persistent localized inflammatory condition of endometrium characterized by the presence of plasma cell infiltrate in the stroma , 5. CE iDydrogesterone is a selective progesterone receptor agonist with excellent oral bioavailability and potent progestogenic activity, while having no androgenic, glucocorticoid or estrogenic activity, making it a good option for progestin therapy . The safIn the retrospective study we investigated whether addition of dydrogesterone with antibiotic treatment increases the cure rate of CE in premenopausal women who underwent hysteroscopic polypectomy.This retrospective study was conducted from January 2016 to November 2020 in the Department of Obstetrics and Gynecology of the Affiliated Hospital of North Sichuan Medical College in Nanchong, China. Women diagnosed with CE by CD138 while underwent hysteroscopic polypectomy in proliferative phase were enrolled in this study. The study was approved by the Institutional Review Board of the Affiliated Hospital of North Sichuan Medical College. All patients signed the written informed consent form before participation in the study.The inclusion criteria were EPs with CE diagnosed by CD138; agreement to undergo hysteroscopy, hysteroscopic resection, and endometrial biopsy; no contraindications to dydrogesterone or doxycycline; no severe systemic diseases. The exclusion criteria were history or presence of endometrial carcinoma; use of hormone replacement therapy or hormonal therapy in the preceding 3 months.In the retrospective observational study, single antibiotic was given for the treatment of CE previously, and addition of dydrogesterone was used to prevent recurrence of EPs in women with CE with antibiotic treatment. The assignment of the medical intervention is not at the discretion of the investigator. From January 2016 to December 2018, women with CE who underwent hysteroscopic polypectomy were given single antibiotic for the treatment of CE, oral doxycycline 200 mg daily for 14 days. From January 2019 to November 2020, women with CE who underwent hysteroscopic polypectomy were given one course of dydrogesterone to prevent recurrence of EPs, oral dydrogesterone of 10 mg twice a day, from day 15 to day 24 of the menstrual cycle, except for the above antibiotic, oral doxycycline 200 mg daily for 14 days. In both groups, antibiotic was given once CE was diagnosed by CD138. A second look hysteroscopy was performed and endometrial biopsy sample was obtained after completion of therapy in the next proliferative phase to assess the response to treatment. Comparison of cure rates of CE with different treatment regimens was performed.Hysteroscopic polypectomy was conducted in the proliferative phase under intravenous anesthesia using a bipolar resection system, containing a 3-mm 15° inside rigid hysteroscope and an 8.5-mm outside sheath . Endometrial biopsies were performed to exclude endometrial lesions using a unelectrified plasma cutting ring away from the local polyps. Second look outpatient hysteroscopy was conducted in the proliferative phase without any anesthesia using a 3-mm 30° inside rigid hysteroscope and an 4.5-mm outside sheath . Endometrial biopsies were obtained with the use of a metal curette, from the hysteroscopic features area, if not, from the upper uterine cavity blindly.Endometrial scratching was performed in women with childbearing desire, using a unelectrified plasma cutting ring while hysteroscopic polypectomy. The scratching was performed once in each quadrant of the endometrium, away from the local EPs.+ cells/HPF [Currently, there is no consensus on the diagnostic criteria of CE. CD138 was the preferred immunohistochemical stain to identify plasma cells , 20–22. ells/HPF . Howeverells/HPF , 20–22. Slides immunostained for ER (estrogen receptor) and PR (progesterone receptor) were scored using the Allred Score , 24. TheAll analyses were conducted with the use of SPSS version 22.0 and a P value of < 0.05 was considered to be represent statistical significance. After analyzing the distribution of our data and confirming that age and body mass index (BMI) in the population were not normally distributed, we adopted a nonparametric method to analyze the age and BMI. Data are expressed as median (interquartile range) or percentage. The other intergroup differences were compared using Chi-squared test. Chi-square test was used to compare the conversion of CD138 between groups and subgroups. Logistic regression was carried out to investigate the factors associated with cure rate of CE.During the 5-year study period, A total of 251 premenopausal women with CE who underwent hysteroscopic polypectomy were enrolled in this study. Sixteen cases were excluded for various reasons. Finally, 235 cases were enrolled in the statistical analysis, including 122 cases with dydrogesterone and doxycycline, and 113 cases with doxycycline alone . The dydrogesterone and antibiotic group showed better effects regarding the cure rate of CE  in women with solitary EP and 88.6% (31/35) in women with multiple EPs, respectively  is the main cause of most intrauterine diseases, such as EPs, unexplained infertility and endometrial cancer . Unlike In this study, women with combination of dydrogesterone and antibiotic had a higher cure rate of CE in one course compared with women with antibiotic alone. The overall cure rate of CE in premenopausal women was 80.0%. The cure rate of CE with single doxycycline was 74.3%, which is consistent with previous studies , 12, 17.It remains unclear if endometrial scratching improves the chance of pregnancy and, if so, for whom . The proThere are limitations in this study which should be considered. For example, in the retrospective review, we can not cover plentiful enough impact factors for cure rate of CE, concealed factors need to be explored. Furthermore, only women with CE on EPs were enrolled, women with CE on other diseases are needed for widely application. Large, prospective studies will be necessary to confirm the beneficial role of co-treatment with dydrogesterone and antibiotic in patients with CE and the potential mechanisms.In conclusion, combination of dydrogesterone and antibiotic was more effective for CE than antibiotic alone in premenopausal women after hysteroscopic polypectomy. Synergistic effect occurred with the effect of dydrogesterone to reduce the severity of CE. With the same reason, endometrial scratching also contributed to the cure rate increase with antibiotic treatment. However, there was no duplicate effect.


Clostridioides difficile infection (CDI) and evidence suggests the magnitude of risk varies by spectrum of antibiotic activity and days of therapy (DOT). We quantified the risk of hospital-associated (HA) CDI associated with antibiotic therapy considering spectrum of activity and DOT.Antibiotic therapy is a known risk factor for We performed a retrospective cohort study of adult (≥18 years) inpatient encounters at a 576-bed academic medical center in Portland, OR between January 2018 and February 2020. We excluded patients with hospital stays under 4 days and those known to have recurrent (CDI in the previous 12 weeks) or community-acquired  CDI. The primary exposure of antibiotic utilization was measured using the Antibiotic Spectrum Index (ASI), where spectrum-based weights are applied to each agent and DOT over the time at risk, summed over the encounter, and divided by the number of antibiotic days. The primary outcome was HA-CDI. We estimated the independent association between aggregate ASI and HA-CDI using multivariable logistic regression.Among 37,629 inpatient encounters, 68% patients received at least one antibiotic. We identified 159 cases of non-recurrent HA-CDI, which corresponds to 4.8 cases per 10,000 patient-days. Compared to those without HA-CDI, those with HA-CDI had a greater median number of distinct antibiotics prescribed (4 vs 1), greater median days of antibiotic therapy (22 vs 2), a greater median time at-risk (9 vs 6 days), and greater median Elixhauser Comorbidity Index (9 vs 4) . There were no significant differences by age or sex. Patients with HA-CDI had a greater mean ASI per antibiotic day than those without . After adjusting for time at-risk and Elixhauser Comorbidity Index, each one-unit of ASI per antibiotic day was associated with 1.29 times increased odds of developing HA-CDI .The Antibiotic Spectrum Index was strongly associated with HA-CDI. ASI may be a useful tool for quantifying the risk of CDI according to the specific antibiotic therapy received among hospitalized patients.All Authors: No reported disclosures.


More importantly, we highlight that, due to their impact on the entire bacterial population, these tolerance-inducing conditions completely mask persistence and the action of its molecular determinants. Finally, we show that even though tolerant populations display a high survival rate under bactericidal drug treatment, this feature comes at the cost of having impaired proliferation during infection. In contrast, persistence is a risk-limiting strategy that allows bacteria to survive antibiotic treatment without reducing the ability of the population to colonize their host. Altogether, our data emphasise that the distinction between these phenomena is of utmost importance to improve the design of more efficient antibiotic therapies.Genetically susceptible bacteria can escape the action of bactericidal antibiotics through antibiotic tolerance or persistence. However, one major difference between the two phenomena is their distinct penetrance within an isogenic population. While with antibiotic persistence, susceptible and persister cells co-exist, antibiotic tolerance affects the entire bacterial population. Here, we show that antibiotic tolerance can be achieved in numerous non-specific ways  Salmonella Typhimurium. The different fitness trade-offs associated with antibiotic tolerance and persistence have important consequences during infection. Understanding the distinct dynamics of these modes of recalcitrance will allow the design of more efficient antibiotic approaches.Even if antibiotics should eradicate entirely a genetically susceptible bacterial population, some cells escape the action of the drugs. This phenomenon is assumed to cause antibiotic treatment failure and infection relapse. Antibiotic recalcitrance is known to operate either on the entire population (antibiotic tolerance) or on a subset of cells (antibiotic persistence). Here, we show how conditions that induce bacterial tolerance can mask entirely persistence and its molecular determinants in the pathogen  Mycobacterium tuberculosis [Staphylococcus aureus [Yersinia pseudotuberculosis [Salmonella enterica [Antibiotic treatment failure can be attributed to the presence of resistant bacteria that proliferate and spread in the presence of a specific antibiotic, or of genetically-susceptible bacteria that transiently escape the action of antibiotics. The latter phenomenon, referred to as antibiotic recalcitrance or resilience, has been observed in many bacterial species, including various pathogens such as rculosis , Staphyls aureus , Yersinirculosis  and Salmenterica ,5. Theseenterica . Importaenterica ,8 and spenterica  of antibAntibiotic recalcitrance can be displayed by a subpopulation of cells within a fully susceptible population (antibiotic persistence) or the entire population (antibiotic tolerance) . At the Salmonella during infection [Notably, persisters are characterized by their co-existence with growing counterparts in environments that are thus, by extension, permissive for growth. Hence, they are often considered as a pool of cells set aside that maximise the chances of survival of the population in case of changes in the environment. By contrast, antibiotic tolerance is achieved under environmental or genetic conditions that are uniformly restrictive for growth, resulting in antibiotics being inefficient against the entire population. Accordingly, molecular determinants involved in antibiotic persistence may be dispensable in tolerance-inducing conditions. For instance, RecA, as a main actor of the double strand DNA break repair machinery, is required for persister survival in nfection  but is dnfection ,13. ThisSalmonella tolerance may mask antibiotic persistence both in vitro and in the context of infection. In addition, we show that due to their differential penetrance in the population, antibiotic persistence and tolerance have distinct fitness trade-offs. Our data show that antibiotic persistence is a more balanced strategy than tolerance, providing an equilibrium that allows survival and colonization both in the presence and absence of antibiotic treatment.Here, by quantifying antibiotic survival and by monitoring the growth status of the population at the single cell level, we illustrate how mutations and environmental conditions that induce Salmonella enterica serovar Typhimurium  have focused on two strains, SL1344 and ATCC 14028 . It is commonly assumed that data obtained with one are representative of both Typhimurium strains. However, some important differences exist between the two strains. For instance, in contrast to 14028, histidine biosynthesis is inactive in the SL1344 strain because of a non-functional hisGPro69 allele [hisG deletion mutant of 14028 behaved like WT SL1344, whereas restoration of the functional allele (hisGP69L) in SL1344, rescued growth in absence of histidine [Most published studies on 9 allele . Accordiistidine  Fig 1A)Salmonellistidine .Salmonella strains, we challenged them both with cefotaxime, a β-lactam antibiotic targeting actively growing cells , displayed antibiotic tolerance, similar to what was observed with the auxotrophic strains  exhibited higher survival than their prototrophic counterparts (SL1344 hisGP69L and 14028)  , indicatd 14028)  and S1A.niformly . As previbiotics  , demonstrating that histidine limitation does not contribute to the recalcitrance of these strains  and hypo- (ΔrecA) persistence mutations to measure their impact on antibiotic survival and bacterial growth dynamics in a tolerance context. Although we determined that histidine auxotrophy is the sole genetic determinant of the differential antibiotic recalcitrance of 14028 and SL1344, other genes vary between the two strains. We therefore chose to compare 14028 and 14028 hisG deletion mutant in histidine limiting environments, as immediately comparable examples of a strain surviving antibiotics through persistence or tolerance, respectively. Thus, we compared the impact of shpAB1 and recA mutations in these two genetic backgrounds  where all the bacteria adopted a non-growing state. Addition of histidine, by suppressing the tolerance phenotype of the hisG mutants, revealed the impact of shpAB1 on antibiotic persistence in this background shpAB1 wated here . AltogetSalmonella than laboratory medium conditions, we wondered if antibiotic tolerance could also mask the effects of persister determinants during macrophage infection. In agreement with what we observed in laboratory medium, the shpAB1 allele resulted in higher intracellular antibiotic survival  or a hyper-persistent (shpAB1) mutant strain to assess their relative fitness in the presence or absence of antibiotic  and Peyer’s patches (PP) as previously described [ΔhisG mutant was rapidly outcompeted by the WT strain during the acute phase of the infection  bacteraemia and subjected to rounds of antibiotic treatment [In clinical settings, periodic rounds of antimicrobial therapy have been often associated with the appearance of hyper-persistence –31. Inteent UTIs . Howeverreatment . These mreatment . Our datreatment .In conclusion, our data depict the trade-offs of two different types of recalcitrance . When itEscherichia coli DH5α and Salmonella strains used in this study were grown aerobically in Luria-Bertani (LB) broth (Invitrogen) or in synthetic M9 medium  containing 0.1% casamino acids (BD), 0.2% glucose (Sigma), 0.2% glycerol (Sigma), 0.2% arabinose  and/or 1mM histidine (Sigma) when indicated. Antibiotics were used at the following concentrations: carbenicillin , kanamycin , and chloramphenicol . For mutants generated by λ-Red recombination, the pKD4 plasmid was used as the template to amplify the kanamycin resistance cassette, and the amplification reaction products were transferred by electroporation into pKD46-containing bacteria expressing the λ-Red recombinase, as described previously [Salmonella enterica serovar Typhimurium strain 12023/14028 using P22 bacteriophage and then confirmed by PCR. Finally, the kanamycin cassette was excised using the temperature-inducible FLP recombinase encoded on the pCP20 recombination plasmid [Oligonucleotides, strains and plasmids used in this study are listed in Tables A, B and C, together with construction details provided in eviously . Then, t plasmid .Bacteria were grown overnight in minimal medium containing glucose and glycerol (M9GG) and supplemented with 1mM histidine—when indicated—to allow the growth of the auxotrophic strains. Bacterial cultures were washed twice with M9GG to remove residual histidine. Then, serial dilutions (10x) made in M9GG were plated onto M9GG solid media in presence or in absence of histidine and incubated at 37°C for 16 h.Bacteria were grown overnight in M9GG supplemented with 1mM histidine. Stationary phase bacteria were diluted 1:10 into M9GG media with or without histidine and incubated in a 37°C shacking incubator (220 rpm). After 30 min, samples were collected and CFU enumerated (T = 0 h). Cefotaxime (10 μg/ml) was added to the medium and cultures were incubated at 37°C. 16 and 24 h after the addition of the antibiotic, samples were taken and CFU enumerated (T = 16 h and 24 h) . For FigSalmonella strains containing the chromosomally-encoded fluorescence dilution reporter (reporter  were groreporter . Constit4Cl (Sigma) for 3 min and the remaining cells were seeded in 100 mm non-tissue culture treated plates (Corning) at a concentration of 3E+6 cells per plates in 8 ml of Dulbecco’s modified eagle medium with high glucose  containing 20% (vol/vol) of L929 supernatant (LCM), 10% (vol/vol) of fetal bovine serum , 10mM of HEPES (Sigma), 1mM of sodium pyruvate (Sigma), 0.05mM of β-mercaptoethanol (Sigma) and 100 U/ml of penicillin/streptomycin (Genesee Scientific). After 3 days, 10 ml of fresh medium was supplemented and the differentiated bone marrow derived macrophages were harvested 4 days later, on day 7. Macrophages were seeded in DMEM media supplemented with FBS, HEPES, sodium pyruvate and β-mercaptoethanol but without LCM or antibiotics in 6-well tissue culture treated plates at the concentration of 1E+6 macrophages per well if freshly harvested or 1.2E+6 macrophages per well if from frozen stock, to be infected the next day.Extraction and culture of bone marrow macrophages was performed as previously described . Bone mag). Infected macrophages were then incubated for 30 min at 37°C with 5% CO2 to allow bacterial internalization. Macrophage media was exchanged with fresh media containing either cefotaxime  or gentamycin  to test intramacrophage bacterial antibiotic survival or bacterial proliferation, respectively. At selected time points, infected macrophages were washed three times with PBS (Growcells) and lysed using 0.1% Triton X-100 (Sigma) to extract intracellular bacteria. Bacteria were collected, centrifuged for 3 min at 16,000 x g and resuspend in PBS prior further experiments.Macrophages infections and bacterial extraction were performed as previously described . BacteriSalmonella strains containing the chromosomally-encoded fluorescence dilution reporter  or gentamycin  to test intramacrophage bacterial antibiotic survival or bacterial proliferation, respectively. Histidine at the concentration of 2mM was added to the cefotaxime media when indicated . For cefotaxime, after 2 h, 24 h and 48 h of antibiotic treatment, infected macrophages were washed three times with 1xPBS and lysed using 0.1% Triton X-100. Bacteria were collected, centrifuged for 3 min at 16,000 x g, resuspended in PBS and either ten-fold serial diluted for the 2 h time point or plated entirely in LB agar plate to assess antibiotic survival. For gentamycin, after 24 h of antibiotic treatment, infected macrophages were washed three times with PBS and lysed using 0.1% Triton X-100. Bacteria were collected, centrifuged for 3 min at 16,000 x g, resuspended in PBS and ten-fold serial diluted. 20 μl drops were plated into LB agar to assess bacterial proliferation. For complementation of the shpAB1 strain —were grown overnight separately for 16 h without antibiotics in LB (Invitrogen) prior to infection. 8 to 10 week-old SPF C57BL/6 mice (Jackson Laboratories) were housed in groups of 5 and were inoculated by gavage with 200 μl of PBS containing approximately 1E+10 CFU of combined WT and ΔhisG or WT and shpAB1 at a ratio of 1:1. Three cages of 5 animals each received each mixture. One cage per mix was sacrificed 48 h post-infection. Mice were culled by carbon monoxide asphyxiation followed by cervical dislocation. The other cages received cefotaxime treatment  for 4 or 6 days. After completion of the 4 or 6 days of treatment, one cage per time point and per mix was sacrificed. For each time point, the spleens, mesenteric lymph nodes and 2 Payer patches per animal were collected and mechanically homogenised in cold PBS using screw cap 1.5 ml tubes (USA Scientific) containing three 3.2 mm steel beads (Biospec). Organs were homogenized (Retsch MM400) for 3 min at 30 Hz. Afterwards, homogenates were centrifuged for 3 min at 16000 x g, and the pellets were resuspended in cold water to lyse the mammalian cells. For the acute phase, the samples were diluted in PBS and dilutions were plated into LB agar (20 μl drops). For the 4 and 6 days antibiotic treatment time points, the whole resuspended organs were plated into LB agar. Plates were all incubated at 37°C to count the number of CFU in each organ. GFP and mCherry colonies were visualized using a ChemiDoc Imaging System (BioRad) and enumerated using the ImageJ software. Mice were housed with sterile bedding and nesting and received autoclaved chow and water over the course of the study. All experiments involving mice were pre-reviewed and approved by the Harvard Medical School Institutional Animal Care and Use Committee (IACUC).The three strains used—GFP+ (WT) and mCherry+ bacteria  Illustration of the fluorescence dilution principle. Both mcherry and sfgfp are encoded on the Salmonella genome. mCherry expression is driven by an arabinose-inducible promoter and GFP by a constitutive promoter. When expression of mCherry is induced by arabinose, the whole population is both green and red. After removal of the inducer, growing bacteria dilute the mCherry pool at each division whereas non-growers retain red and green fluorescence. (B) Illustration of fluorescence dilution within macrophages. (C) Representative flow cytometry contour (left) and histogram plots (right) of the SL1344 strain extracted from infected BMDM after 16 h of gentamicin in presence or absence of histidine. G, growers and NG, non-growers. (D) Quantification of the non-grower fraction in presence or in absence of histidine. Data represent the mean and SD of three biological repeats. Statistical significant difference by t-test are indicated as ***p<0.001.((PDF)Click here for additional data file.S2 FigA) WT, ΔhisG, shpAB1 and shpAB1ΔhisG or (B) WT, ΔhisG, ΔrecA and ΔrecA ΔhisG.Ten-fold dilution series were spotted on minimal medium plates in the absence (left) or presence (right) of histidine for ((PDF)Click here for additional data file.S3 FigA) 24 h cefotaxime survival of WT and shpAB1 Salmonella in BMDM normalized to values after 30 min internalization. WT and shpAB1 strains were complemented with an empty vector (pEV) or shpB (pshpB). Data represent the mean and SD of three biological repeats. Data were compared using one way ANOVA with Tukey’s multiple-comparison test, **p<0.01. (B-C) CFU enumeration of survival of WT, ΔhisG, shpAB1 and shpAB1ΔhisG (B) or WT, ΔhisG, ΔrecA and ΔrecA ΔhisG (C) to cefotaxime during BMDM infection in the presence of histidine in the infection medium. Data represent the mean and SD of at least three biological repeats. Data from the 48 h timepoint were compared using one way ANOVA with Tukey’s multiple-comparison test, *p<0.05, **p<0.01 ***p<0.001.((PDF)Click here for additional data file.S4 FigA-D) Bacterial survival in the mesenteric lymph nodes and in the Peyer’s patches of the WT/ΔhisG (A-B) and WT/shpAB1 (C-D) mix. After two days of infection in the absence of antibiotic (-AB), mice were treated for 4 to 6 days with cefotaxime (+AB). Results are expressed as percentage of the total population recovered on agar plates after 24 h incubation. Statistically significant differences at each timepoint by two-sided t-test are indicated as *p<0.05, * p<0.01, ***p<0.001; NS, not significant. In vivo mice experiments were carried out in at least 4 animals per time point.((PDF)Click here for additional data file.S5 Fig(A-B) Bacterial survival in the spleen, the mesenteric lymph nodes and in the Peyer’s patches of the WT/ΔhisG (A) and WT/shpAB1 (B) mix. After two days of infection in the absence of antibiotic, mice were treated for 4 to 6 days with cefotaxime. Results are expressed as the total number of bacteria per organ recovered on agar plates after 24 h incubation.(PDF)Click here for additional data file.S1 Supplementary methodsTable A. Oligonucleotides used in this study. Table B. Plasmids used in this study. Table C. Strains used in this study.(DOCX)Click here for additional data file.


The highest IgG4 levels were at baseline and disease recurrence, and lowest after initial treatment. At final follow-up, IgG4 levels differed in patients with remission (mean 326.25 mg/dL) and stable disease (mean 699.55 mg/dL). Subgroup analysis was performed in patients with remission, categorized according to whether IgG4 levels were normalized (9 patients) or elevated (10 patients) on last follow up. The elevated group had a higher percentage of bilateral disease, lacrimal gland involvement and recurrence. (4) Conclusions: IgG4-ROD patients with a greater response to initial steroid therapy were more inclined to have normalized IgG4 levels in the long term. Some patients remained in remission despite persistently elevated IgG4 levels, and had regular follow-up without treatment.(1) Background: To analyze the association between long-term changes in serum IgG4 levels and the clinical course of patients with IgG4-related ophthalmic disease (IgG4-ROD). (2) Methods: Retrospective analysis of 25 patients with IgG4-ROD. (3) Results: Mean age at diagnosis was 60.68 years. Fifty-six percent of patients had bilateral ocular involvement and 32% had systemic associations. The ocular structures involved were the lacrimal gland (76%), orbital soft tissue (36%), extraocular muscle (20%) and infraorbital nerve (20%). According to last follow-up, 9 (36%) patients had normalized IgG4 levels, and 16 (64%) patients had elevated IgG4 levels. Patients with normalized IgG4 levels had better response to initial steroid treatment and attained a significantly lower IgG4 level after treatment ( IgG4-related disease is a fibroinflammatory clinicopathological entity, characterized by dense infiltration of lymphocytes and IgG4-positive plasma cells in various tissues and organs ,2. The dIgG4-ROD is usually associated with an increase in serum IgG4 levels. The diagnostic criteria for IgG4-ROD includes imaging studies and histopathologic examinations of ophthalmic tissues, and blood tests showing elevated serum IgG4 ≥135 mg/dL), requiring at least two out of three criteria for diagnosis 5 mg/dL, ,12, seruThis research was designed as a single-institution, retrospective case series. Data collection and chart review were approved by the Institutional Review Board of Taipei Veterans General Hospital, Taipei, Taiwan (IRB-TPEVGH No.2021-10-002CC). The study was conducted in accordance with the tenets of the Declaration of Helsinki.Records of patients with diagnosis of IgG4-ROD from April 2010 to April 2020 were examined. We applied the diagnostic criteria for IgG4-ROD by Goto et al. , as follAnatomic locations of ocular lesions were evaluated both clinically and by reviewing orbital CT or MRI scans. Systemic involvement was determined by clinical manifestations and imaging studies by ultrasound, CT, MRI or PET/CT.Collected data included demographics, laterality of ocular disease , systemic involvement of IgG4 disease, ocular structure of involvement , presence of recurrent disease, serological results , duration of steroid treatment, and total follow-up time.Recurrence was defined as symptom re-emergence or lesion enlargement after initial steroid treatment. Remission was defined as resolution of clinical symptoms and/or radiologic lesions. For the main outcome measures, patients were categorized into groups based on last follow-up condition: Remission with normalized IgG4 levels (group 1), remission with elevated IgG4 levels (group 2), and stable with disease. A cutoff value of 135 mg/dL was used. For additional analysis, the study population was alternatively grouped into those with unilateral or bilateral ocular involvement. U tests. Statistical significance was defined as p ≤ 0.05 and all analyses were conducted using SPSS statistical software .Nonparametric tests were used for the following comparisons because most measurement data were not normally distributed. Categorical variables were analyzed using Fisher’s exact tests. Measurements were compared between groups 1 and 2, and unilateral and bilateral ocular involvement using Mann–Whitney A total of 25 patients diagnosed with IgG4-ROD were included in this study. On the basis of the diagnostic criteria for IgG4-ROD, the diagnosis was definite in 16 (64%) patients and possible in 9 (36%) patients. The demographics of the study population are summarized in p = 0.002). p = 0.043).After dividing the patients in remission into two groups depending on whether IgG4 levels were normalized (group 1) or elevated (group 2) on last follow up , group 2p = 0.003). Patients with bilateral disease also had higher IgG and IgG4 levels at baseline, and a greater reduction in IgG4 levels after initial steroid treatment .The study population was alternatively grouped into those with unilateral or bilateral ocular involvement . All patWe present a long-term follow-up of patients with IgG4-ROD focusing on the serial changes of serum IgG4 levels. To our knowledge, this case series of IgG4-ROD patients had the longest follow-up period compared with previous studies. In this cohort, up to 64% of patients had elevated IgG4 levels at last follow-up, which led us to investigate the correlation between IgG4 levels and their clinical significance.Out of all patients in remission, the IgG4 levels failed to normalize in 10 of 19 patients (52.6%). The patients with elevated IgG4 concentrations had a relatively higher rate of bilateral disease, lacrimal gland involvement and recurrence. These patients also had higher IgG4 titers throughout the follow-up period, with statistically higher titers compared to the normalized group at the lowest point after initial treatment. These clinical and serological factors may indicate greater disease activity and poorer response to initial steroid treatment, rendering this group of patients prone to a higher IgG4 titer in the long term. Similarly, Wallace et al. ,18, but IgG4 is one of four subclasses of IgG, typically less than 5% of total IgG . In geneApproximately half of the study population had bilateral ocular lesions. These patients had statistically higher baseline IgG and baseline IgG4 levels compared to unilateral disease. This is in agreement with previous studies, which showed bilateral disease accounting for 49–62% of patients ,27. WallThe lacrimal gland was the most common orbital structure affected in IgG4-ROD in our series and many previous studies ,26,28,29A few studies have looked into the treatment outcomes of IgG4-ROD. Regarding treatment regimens, an initial combination of glucocorticoid and immunosuppressant therapy had advantages over glucocorticoid monotherapy, with a longer relapse-free survival time , a lowerThere are some limitations of the current study that should be addressed. First, the study is a retrospective, non-randomized controlled investigation, which might limit the generalizability of our findings. Second, nine patients (36%) did not receive biopsy and were diagnosed as “possible” IgG4-ROD. This is mainly due to difficulty in obtaining specimens in patients with extraocular muscle or deep orbital soft tissue involvement. Nevertheless, the findings of the present study have important implications for understanding the prognosis of IgG4-ROD.Our results demonstrated that IgG4-ROD patients with greater response to initial steroid therapy, manifesting with lower serum IgG4 levels, would be more inclined to have normalized IgG4 levels in the long term. In addition, some patients can remain in remission despite persistently elevated serum IgG4 levels, and they can be followed up without treatment unless disease relapse. Moreover, different baseline serum IgG4 levels and disparities in disease course were observed between unilateral and bilateral ocular lesions. Future studies are needed to provide further insight into this complex disease.