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Introduction Interstitial inflammation and peritubular capillaritis are observed in many diseases on native and transplant kidney biopsies. A precise and automated evaluation of these histological criteria could help stratify patients’ kidney prognoses and facilitate therapeutic management. Methods We used a convolutional neural network to evaluate those criteria on kidney biopsies. 423 kidney samples from various diseases were included. 83 kidney samples were used for the neural network training, 106 for comparing manual annotations on limited areas to automated predictions, and 234 to compare automated and visual gradings. Results The Precision, the Recall, and the F-score for leukocyte detection were respectively 81%, 71% and 76%. Regarding peritubular capillaries detection the Precision, the Recall, and the F-score were respectively 82%, 83%, and 82%. There was a strong correlation between the predicted and observed grading of total inflammation, as for the grading of capillaritis (r = 0.89 and r = 0.82 respectively, all p Conclusion We developed a tool using deep learning that scores the total inflammation and capillaritis, demonstrating the potential of artificial intelligence in kidney pathology.

With the development of three-dimensional (3D) printing, 3D-printed products have been widely used in medical fields, such as plastic surgery, orthopedics, dentistry, etc. In cardiovascular research, 3D-printed models are becoming more realistic in shape. However, from a biomechanical point of view, only a few studies have explored printable materials that can represent the properties of the human aorta. This study focuses on 3D-printed materials that might simulate the stiffness of human aortic tissue. First, the biomechanical properties of a healthy human aorta were defined and used as reference. The main objective of this study was to identify 3D printable materials that possess similar properties to the human aorta. Three synthetic materials, NinjaFlex (Fenner Inc., Manheim, USA), FilasticTM (Filastic Inc., Jardim Paulistano, Brazil), and RGD450+TangoPlus (Stratasys Ltd.©, Rehovot, Israel), were printed in different thicknesses. Uniaxial and biaxial tensile tests were performed to compute several biomechanical properties, such as thickness, stress, strain, and stiffness. We found that with the mixed material RGD450+TangoPlus, it was possible to achieve a similar stiffness to healthy human aorta. Moreover, the 50-shore-hardness RGD450+TangoPlus had similar thickness and stiffness to the human aorta.

Acute graft-versus-host disease (aGVHD) is a major limitation of the therapeutic potential of allogeneic hematopoietic cell transplantation. Lipopolysaccharides (LPS) derived from intestinal gram-negative bacteria are well-known aGVHD triggers and amplifiers. Here, we explored the LPS metabolism in aGVHD mouse models using an innovative quantification method. We demonstrated that systemic LPS accumulation after transplantation was due, at least partly, to a defect in its clearance through lipoprotein-mediated transport to the liver (i.e., the so-called reverse LPS transport). After transplantation, reduced circulating HDL concentration impaired LPS neutralization and elimination through biliary flux. Accordingly, HDL-deficient (Apoa1

BACKGROUND AND OBJECTIVES: The prognosis of patients undergoing kidney tumor resection or kidney donation is linked to many histologic criteria. These criteria notably include glomerular density, glomerular volume, vascular luminal stenosis, and severity of interstitial fibrosis/tubular atrophy. Automated measurements through a deep-learning approach could save time and provide more precise data. This work aimed to develop a free tool to automatically obtain kidney histologic prognostic features. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 241 samples of healthy kidney tissue were split into three independent cohorts. The “Training” cohort (n=65) was used to train two convolutional neural networks: one to detect the cortex and a second to segment the kidney structures. The “Test” cohort (n=50) assessed their performance by comparing manually outlined regions of interest to predicted ones. The “Application” cohort (n=126) compared prognostic histologic data obtained manually or through the algorithm on the basis of the combination of the two convolutional neural networks. RESULTS: In the Test cohort, the networks isolated the cortex and segmented the elements of interest with good performances (>90% of the cortex, healthy tubules, glomeruli, and even globally sclerotic glomeruli were detected). In the Application cohort, the expected and predicted prognostic data were significantly correlated. The correlation coefficients r were 0.85 for glomerular volume, 0.51 for glomerular density, 0.75 for interstitial fibrosis, 0.71 for tubular atrophy, and 0.73 for vascular intimal thickness, respectively. The algorithm had a good ability to predict significant (>25%) tubular atrophy and interstitial fibrosis level (receiver operator characteristic curve with an area under the curve, 0.92 and 0.91, respectively) or a significant vascular luminal stenosis (>50%) (area under the curve, 0.85). CONCLUSION: This freely available tool enables the automated segmentation of kidney tissue to obtain prognostic histologic data in a fast, objective, reliable, and reproducible way.

Background Although the MEST-C classification is among the best prognostic tools in immunoglobulin A nephropathy (IgAN), it has a wide interobserver variability between specialized pathologists and others. Therefore we trained and evaluated a tool using a neural network to automate the MEST-C grading. Methods Biopsies of patients with IgAN were divided into three independent groups: the Training cohort (n = 42) to train the network, the Test cohort (n = 66) to compare its pixel segmentation to that made by pathologists and the Application cohort (n = 88) to compare the MEST-C scores computed by the network or by pathologists. Results In the Test cohort, >73% of pixels were correctly identified by the network as M, E, S or C. In the Application cohort, the neural network area under the receiver operating characteristics curves were 0.88, 0.91, 0.88, 0.94, 0.96, 0.96 and 0.92 to predict M1, E1, S1, T1, T2, C1 and C2, respectively. The kappa coefficients between pathologists and the network assessments were substantial for E, S, T and C scores (kappa scores of 0.68, 0.79, 0.73 and 0.70, respectively) and moderate for M score (kappa score of 0.52). Network S and T scores were associated with the occurrence of the composite survival endpoint (death, dialysis, transplantation or doubling of serum creatinine) [hazard ratios 9.67 (P = .006) and 7.67 (P Conclusions This work highlights the possibility of automated recognition and quantification of each element of the MEST-C classification using deep learning methods.

Human norovirus (HuNoV) infection is associated with an active FUT2 gene, which characterizes the secretor phenotype. However, nonsecretor individuals are also affected by HuNoV infection although in a lesser proportion. Here, we studied GII.3, GII.4, and GII.17 HuNoV interactions in nonsecretor individuals using virus-like particles (VLPs). Only GII.4 HuNoV specifically interacted with nonsecretor saliva. Competition experiments using histo-blood group antigen (HBGA)-specific monoclonal antibodies (MAbs) demonstrate that GII.4 VLPs recognized the Lewis a (Le(a)) antigen. We also analyzed HuNoV VLP interactions on duodenum tissue blocks from healthy nonsecretor individuals. VLP binding was observed for the three HuNoV genotypes in 10 of the 13 individuals, and competition experiments demonstrated that VLP recognition was driven by an interaction with the Le(a) antigen. In 3 individuals, binding was restricted to either GII.4 alone or GII.3 and GII.17. Finally, we performed a VLP binding assay on proximal and distal colon tissue blocks from a nonsecretor patient with Crohn’s disease. VLP binding to inflammatory tissues was genotype specific since GII.4 and GII.17 VLPs were able to interact with regenerative mucosa, whereas GII.3 VLP was not. The binding of GII.4 and GII.17 HuNoV VLPs was linked to Le(a) in regenerative mucosae from the proximal and distal colon. Overall, our data clearly showed that Le(a) has a pivotal role in the recognition of HuNoV in nonsecretors. We also showed that Le(a) is expressed in inflammatory/regenerative tissues and interacts with HuNoV in a nonsecretor individual. The physiological and immunological consequences of such interactions in nonsecretors have yet to be elucidated. IMPORTANCE Human norovirus (HuNoV) is the main etiological agent of viral gastroenteritis in all age classes. HuNoV infection affects mainly secretor individuals where ABO(H) and Lewis histo-blood group antigens (HBGAs) are present in the small intestine. Nonsecretor individuals, who only express Lewis (Le) antigens, are less susceptible to HuNoV infection. Here, we studied the interaction of common HuNoV genotypes (GII.3, GII.4, and GII.17) in nonsecretor individuals using synthetic viral particles. Saliva binding assays showed that only GII.4 interacted with nonsecretor saliva via the Lewis a (Le(a)) antigen Surprisingly, the three genotypes interacted with nonsecretor enterocytes via the Le(a) antigen on duodenal tissue blocks, which were more relevant for HuNoV/HBGA studies. The Le(a) antigen also played a pivotal role in the recognition of GII.4 and GII.17 particles by inflammatory colon tissue from a nonsecretor Crohn’s disease patient. The implications of HuNoV binding in nonsecretors remain to be elucidated in physiological and pathological conditions encountered in other intestinal diseases.

Resume L’arterite a cellules geantes (ACG) est la plus frequente des vascularites affectant l’artere temporale (AT). Neanmoins, d’autres types de pathologies vasculaires, qu’il s’agisse de vascularite ou non, peuvent toucher l’AT. Parmi les vascularites, on peut citer les vascularites necrosantes, en particulier les vascularites associees aux anticorps anti-cytoplasme des polynucleaires neutrophiles (ANCA) qui peuvent affecter les petits vaisseaux peri-adventitiels de la paroi de l’AT et mimer certains symptomes de l’ACG, ces derniers n’etant generalement pas isoles, ce qui doit faire rechercher les ANCA. Certaines vascularites infectieuses peuvent egalement toucher l’AT comme l’infection par le virus varicelle-zona (VZV) dont l’aspect histologique est tres proche de l’ACG a tel point que certains auteurs ont suggere un role du VZV dans le declenchement de l’ACG. Une vascularite de l’AT peut egalement etre secondaire a une maladie associee aux IgG4 ou d’origine medicamenteuse (inhibiteurs de checkpoint immunitaire). En dehors des vascularites, l’AT peut etre le siege d’autres vasculopathies non inflammatoires comme la maladie atheromateuse, l’arteriolopathie uremique calcifiante ou encore les atteintes post-traumatiques comme les faux-anevrysmes ou les fistules arterioveineuses de l’AT. Dans cette revue, nous decrivons ces differents types d’atteinte pouvant toucher l’AT.

International audience; BACKGROUND: Cardiovascular risk is increased in giant cell arteritis (GCA). We aimed to characterize myocardial infarction (MI) in a GCA cohort, and to compare the GCA and non-GCA population affected by MI. METHODS: In patients with a biopsy-proven diagnosis of GCA between 1 January 2001 and 31 December 2016 in Côte D'Or (France), we identified patients with MI by crossing data from the territorial myocardial infarction registry (Observatoire des Infarctus de Côte d'Or) database. Five controls (non-GCA + MI) were paired with one case (GCA + MI) after matching for age, sex, cardiovascular risk factors and prior cardiovascular disease. MI were characterized as type 1 MI (T1MI), resulting from thrombus formation due to atherothrombotic disease, or type 2 MI (T2MI), due to a myocardial supply/demand mismatch. GCA-related MI was defined as MI occurring within 3 months of a GCA flare (before or after). RESULTS: Among 251 biopsy-proven GCA patients, 13 MI cases were identified and paired with 65 controls. MI was GCA-related in 6/13 cases, accounting for 2.4% (6/251) of our cohort. T2MI was more frequently GCA-related than GCA-unrelated (80% vs. 16.7%, p = 0.080), and GCA diagnosis was the only identified triggering factor in 75% of GCA-related T2MI. GCA-unrelated MI were more frequently T1MI and occurred in patients who had received a higher cumulative dose of prednisone (p = 0.032). GCA was not associated with poorer one-year survival. CONCLUSIONS: GCA-related MI are mainly T2MI probably caused by systemic inflammation rather than coronaritis. GCA-unrelated MI are predominantly T1MI associated with atherothrombotic coronary artery disease.

Resume Introduction Afin de valider notre strategie d’amelioration continue et chercher d’eventuelles nouvelles pistes pour une performance accrue, nous avons audite l’ensemble des processus du service en utilisant les principes du lean management. Materiel et methodes L’application de la methodologie Lean-6-sigma (Gemba Walk, Value Stream Mapping, diagramme spaghetti, atelier Kaizen et matrice de priorisation) a permis d’analyser les processus des secteurs conventionnels et moleculaires, de definir les goulets d’etranglement, d’evaluer les actions sans valeur ajoutee et de proposer des solutions. Resultats L’audit a identifie les principaux goulets d’etranglement qui interessaient les secteurs pre-analytique (enregistrement), analytique (cytologie, immunohistochimie, sequencage, pathologistes) et post-analytique (absence de secretaire et diffusion du courrier). Il a souligne une marche en avant insuffisante, l’impact important de l’augmentation de la charge de travail (8 %/an) sur la reception et la microscopie malgre l’externalisation et une maquette de postes techniques souvent critique qui ne permettait pas de realiser des taches sans valeur ajoutee (qualite, validation de methodes, protocoles) et parfois quotidiennes (coupes, immunohistochimie). Au terme des 72 tâches du plan d’action pour gerer la surproduction, l’amelioration des conditions de travail et le developpement de nouvelles activites, les delais de reponse sont partiellement maitrises et notre demarche d’automatisation bien avancee. Discussion et conclusion L’audit a valide notre strategie d’amelioration et mieux standardise nos conditions de travail. Meme s’il n’a permis qu’une maitrise partielle des delais de reponse, il a initie une dynamique medicale et technique positive vertueuse pour continuer a avancer vers les prochaines etapes de notre reorganisation (automatisation, agrandissement du service).

Human norovirus (HuNoV) infection is associated with active FUT2 status, which characterizes the secretor phenotype. However, non-secretor individuals are also affected by HuNoV infection although in a lesser proportion. Here, we study GII.3, GII.4 and GII.17 HuNoV interactions in non-secretor individuals using baculovirus-expressed virus-like particles (VLPs). Only GII.4 HuNoV specifically interacted with non-secretor saliva. Competition experiments using HBGA-specific mAbs demonstrate that GII.4 VLPs recognized the Lewis a antigen (Lea). We also analyzed HuNoV VLP interactions on duodenum tissue blocks from healthy non-secretor individuals. VLP binding was observed for the three HuNoV genotypes in 10 of the 13 individuals, and competition experiments demonstrated that VLP recognition was driven by interaction with the Lea antigen. In 3 individuals, binding was restricted to either GII.4 alone or GII.3 and GII.17. One patient did not display VLP binding for any of the three genotypes.Finally, we performed a VLP binding assay on proximal and distal colon tissue blocks from a non-secretor patient with Crohn’s disease. VLP binding to inflammatory tissues was genotype-specific since GII.4 and GII.17 VLPs were able to interact with regenerative mucosa whereas GII.3 VLP was not. Binding of GII.4 and GII.17 HuNoV VLPs was linked to Lea in regenerative mucosae from the proximal and distal colon. Overall, our data clearly showed that Lea has a pivotal role in the recognition of HuNoV in non-secretors. We also showed that Lea is expressed in inflammatory/regenerative tissues and that it can interact with HuNoV in secretor and non-secretor individuals. The physiological and immunological consequences of such interactions in non-secretors has yet to be elucidated.IMPORTANCEHuman norovirus (HuNoV) is the main etiological agent of viral gastroenteritis in all age classes. HuNoV infection mainly affects secretor individuals, who are characterized by the presence of the ABO(H) and Lewis histo-blood group antigens at the surface of the small intestine. Non-secretor individuals, who only express Lewis antigens (Le), are less susceptible to HuNoV infection. Here we study the interaction of three frequently encountered HuNoV genotypes (GII.3, GII.4 and GII.17) in non-secretor individual using baculovirus-expressed viral particles. Preliminary saliva binding assays showed that only GII.4 interacted with non-secretor saliva via the Lea antigen.Surprisingly, in the binding assays on duodenal tissue blocks, the three genotypes interacted with non-secretor enterocytes via Lea. This suggests that HBGA status in the saliva does not necessarily reflect interactions in the intestines and, secondly, that Lea plays a pivotal role in HuNoV attachment in non-secretors. Similarly, Lea was involved in the recognition of GII.4 and GII.17 HuNoV particles by inflammatory colon tissue from a non-secretor Crohn’s disease patient. The molecular implications of HuNoV binding in non-secretors remains to be elucidated in physiological and pathological conditions encountered in other intestinal diseases.

BACKGROUND AND AIMS IgA nephropathy prognosis depends on histological factors. The MEST-C score is used to grade those factors and assess the renal prognosis of this disease. Nevertheless, this manual evaluation is time-consuming, tedious and has a poor reproducibility. An automated analysis would be faster and more objective. This work aimed to use deep-learning techniques on whole kidney biopsies from patients suffering from IgA nephropathy to obtain an automated MEST-C score. METHOD We used a previously developed convolutional neural network (CNN) to isolate the cortical area. Then, two additional CNNs were independently trained. The first one was used to evaluate the Interstitial Fibrosis/Tubular Atrophy (IF/TA) and segment the glomeruli. The second one was used to segment the relevant glomerular lesions (mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis and crescents). A total of 95 kidney biopsies from patients suffering from IgA nephropathy were randomly sorted into either the training set or the validation set. From those samples, regions of interest (ROI) were selected and annotated to develop the two CNNs (358 ROI and 458 ROI, respectively). The main annotation categories for the first CNN were `non-sclerotic glomeruli’, `sclerotic glomeruli’, `normal tubules’, `atrophic tubules’, `veins’ and `arteries’. For the second CNN, the main categories were `mesangial hypercellularity’, `endocapillary hypercellularity’, `segmental glomerulosclerosis’ and `crescents. Then, the three CNNs were sequentially applied to the biopsies of 109 patients suffering from IgA nephropathy. From the data provided by the CNNs, an automated MEST-C was calculated. We assessed its performances to predict the criteria of the gold standard MEST-C (scored by nephropathologists) using Receiver Operator Characteristic (ROC). RESULTS The CNNs detected the renal structures of interest with good precision and recall up to 0.98 and 0.96 respectively for the non-sclerotic glomeruli. Normal and atrophic were also reliably recognized with 0.88 and 0.71 f-scores. Glomerular lesions were harder to recognize with a 0.67 f-score for mesangial hypercellularity, 0.76 f-score for endocapillary hypercellularity, 0.47 f-score for segmental glomerulosclerosis and 0.50 f-score for the crescents. Manual and automated evaluation of IF/TA were well correlated with a 0.76 Spearman coefficient (P CONCLUSION This deep-learning based tool can be used to segment relevant renal cortical structures and provide a reliable assessment of IF/TA. An automated MEST-C score can be provided by our tool. Nevertheless, improvements are needed to consider using this tool in clinical practice and obtain an objective evaluation on large and numerous samples. FIGURE 1:Kidney samples stained with Masson's trichrome before and after the two first consecutive convolutional neural networks predictions (B, C). B: Cortical area (red), capsule (deep blue), C: normal and atrophic tubules (red and orange), non-sclerotic glomeruli (yellow), sclerotic glomeruli (light blue), arteries (purple), vein (deep blue).FIGURE 2:Kidney samples stained with Masson's trichrome before (A) and after the last convolutional neural networks predictions (B). B: hilum (yellow), mesangial hypercellularity (red), endothelial hypercellularity (purple), segmental glomerulosclerosis (green).

PRDM16 (positive regulatory domain 16) is localized in the critical region for cardiomyopathy in patients with deletions of chromosome 1p36, as defined by Gajecka et al., American Journal of Medical Genetics, 2010, 152A, 3074-3083, and encodes a zinc finger transcription factor. We present the first fetal case of left ventricular non-compaction (LVNC) with a PRDM16 variant. The third-trimester obstetric ultrasound revealed a hydropic fetus with hydramnios and expanded hypokinetic heart. After termination of pregnancy, foetopathology showed a eutrophic fetus with isolated cardiomegaly. Endocardial fibroelastosis was associated with non-compaction of the myocardium of the left ventricle. Exome sequencing (ES) identified a de novo unreported p.(Gln353*) heterozygous nonsense variant in PRDM16. ES also identified two rare variants of unknown significance, according to the American College of Medical Genetics and Genomics guidelines, in the titin gene (TTN): a de novo missense p.(Lys14773Asn) variant and a c.33043+5A>G variant inherited from the mother. Along with the PRDM16 de novo probably pathogenic variant, TTN VOUS variants could possibly contribute to the severity and early onset of the cardiac phenotype. Because of the genetic heterogeneity of cardiomyopathies, large panels or even ES could be considered as the main approaches for the molecular diagnosis, particularly in fetal presentations, where multiple hits seem to be common.

In the presence of temporal arteritis, clinicians often refer to the diagnosis of giant cell arteritis (GCA). However, differential diagnoses should also be evoked because other types of vascular diseases, vasculitis or not, may affect the temporal artery. Among vasculitis, Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis is probably the most common, and typically affects the peri-adventitial small vessel of the temporal artery and sometimes mimics giant cell arteritis, however, other symptoms are frequently associated and more specific of ANCA-associated vasculitis prompt a search for ANCA. The Immunoglobulin G4-related disease (IgG4-RD) can cause temporal arteritis as well. Some infections can also affect the temporal artery, primarily an infection caused by the varicella-zoster virus (VZV), which has an arterial tropism that may play a role in triggering giant cell arteritis. Drugs, mainly checkpoint inhibitors that are used to treat cancer, can also trigger giant cell arteritis. Furthermore, the temporal artery can be affected by diseases other than vasculitis such as atherosclerosis, calcyphilaxis, aneurysm, or arteriovenous fistula. In this review, these different diseases affecting the temporal artery are described.

Objectives An increased risk of haematological malignancies (HM) has been reported in GCA patients. Our study aimed to investigate the incidence and the type of HM occurring in GCA. Methods All patients with GCA and HM living in Côte d’Or (France) were identified by crossing data from the RHEMCO (Registre des Hémopathies Malignes de Côte d’Or) and those having a positive temporal artery biopsy between 1 January 2001 and 31 December 2018. Results Among 276 biopsy-proven GCA patients, 14 HM were identified in 12 patients (4.3%). In comparison with the general population aged >50 y, the incidence of myeloid HM and myeloproliferative syndromes were increased in GCA patients [standardized incidence ratios (SIR) = 2.71 and 5.16, respectively], with a specific increase in men with GCA (SIR = 4.82 and 9.04, respectively) but not in women. In addition, the study of SIR depending on the chronology between GCA and HM diagnoses suggests that there was an increased risk of developing GCA in men but not in women, after a diagnosis of myeloid HM (SIR = 9.56), especially if it was a MPS (SIR = 17.56). Conclusions Our study shows a particular epidemiology of HM in GCA patients, which is characterized by an increased incidence of myeloid HM, especially MPS, in male GCA patients. The chronology of the diagnoses of GCA and HM raises the hypothesis that clonal hematopoiesis may be implicated in some cases of GCA.

Background The recent COVID-19 pandemic has raised concerns about patient diagnosis and follow-up of chronically ill patients. Patients suffering from chronic illnesses, concomitantly infected by SARS-CoV-2, globally tend to have a worse prognosis and poor outcomes. Renal tropism and acute kidney injury following SARS-CoV-2 infection has recently been described in the literature, with elevated mortality rates. Furthermore, patients with pre-existing chronic kidney disease, infected by SARS-CoV-2, should be monitored carefully. Here, we report the case of a 69-year-old patient with splenic marginal zone lymphoma, suffering from longstanding chronic kidney disease following SARS-CoV-2 infection. Case presentation A 69-year-old male patient previously diagnosed with pulmonary embolism and splenic marginal zone lymphoma (Splenomegaly, Matutes 2/5, CD5 negative and CD23 positive), was admitted to the hospital with shortness of breath, fever and asthenia. A nasopharyngeal swab test was performed in addition to a CT-scan, which confirmed SARS-CoV-2 infection. Blood creatinine increased following SARS-CoV-2 infection at 130 μmol/l, with usual values at 95 μmol/l. The patient was discharged at home with rest and symptomatic medical treatment (paracetamol and hydration), then readmitted to the hospital in August 2020. A kidney biopsy was therefore conducted as blood creatinine levels were abnormally elevated. Immunodetection performed in a renal biopsy specimen confirmed co-localization of SARS-CoV2 nucleocapsid and protease 3C proteins with ACE2, Lewis x and sialyl-Lewis x antigens in proximal convoluted tubules and podocytes. Co-localization of structural and non-structural viral proteins clearly demonstrated viral replication in proximal convoluted tubules in this chronically ill patient. Additionally, we observed the co-localization of sialyl-Lewis x and ACE2 receptors in the same proximal convoluted tubules. Reverse Transcriptase-Polymerase Chain Reaction test performed on the kidney biopsy was negative, with very low Ct levels (above 40). The patient was finally readmitted to the haematology department for initiation of chemotherapy, including CHOP protocol and Rituximab. Conclusions Our case emphasizes on the importance of monitoring kidney function in immunosuppressed patients and patients suffering from cancer following SARS-CoV-2 infection, through histological screening. Further studies will be required to decipher the mechanisms underlying chronic kidney disease and the putative role of sialyl-Lewis x and HBGA during SARS-CoV-2 infection.

International audience; This study aimed to assess the implication of mucosal-associated invariant T (MAIT) cells in GCA. Blood samples were obtained from 34 GCA patients (before and after 3 months of treatment with glucocorticoids (GC) alone) and compared with 20 controls aged >50 years. MAIT cells, defined by a CD3(+)CD4(-)TCRγδ(-)TCRVα7.2(+)CD161(+) phenotype, were analyzed by flow cytometry. After sorting, we assessed the ability of MAIT cells to proliferate and produce cytokines after stimulation with anti CD3/CD28 microbeads or IL-12 and IL-18. MAIT were stained in temporal artery biopsies (TAB) by confocal microscopy. MAIT cells were found in the arterial wall of positive TABs but was absent in negative TAB. MAIT frequency among total αβ-T cells was similar in the blood of patients and controls (0.52 vs. 0.57%; P = 0.43) and not modified after GC treatment (P = 0.82). Expression of IFN-γ was increased in MAIT cells from GCA patients compared to controls (44.49 vs. 32.9%; P = 0.029), and not modified after 3 months of GC therapy (P = 0.82). When they were stimulated with IL-12 and IL-18, MAIT from GCA patients produced very high levels of IFN-γ and displayed a stronger proliferation compared with MAIT from controls (proliferation index 3.39 vs. 1.4; P = 0.032). In GCA, the functional characteristics of MAIT cells are modified toward a pro-inflammatory phenotype and a stronger proliferation capability in response to IL-12 and IL-18, suggesting that MAIT might play a role in GCA pathogenesis. Our results support the use of treatments targeting IL-12/IL-18 to inhibit the IFN-γ pathway in GCA.

Diabetes is associated with an accelerated development of atherosclerosis. Specific mechanisms related to diabetes and hyperglycemia may play a role in this process. In particular, alterations of arachidonic acid (AA) metabolism have been reported. Our main goal was to investigate for differences in the concentration of LTB4 and RvD1 as well as selected cyclooxygenase-derived mediators in carotid plaques from diabetic and non-diabetic patients. We also aimed to analyze the relationship between omega 6 and omega 3 Poly-Unsaturated Fatty acids (PUFAs) content in the plaques and the concentrations of these lipid mediators.29 type 2 diabetic patients and 30 control patients admitted for surgical treatment of carotid stenosis were enrolled in the present study. Carotid plaques were harvested for in-depth lipidomic profiling.No differences for LTB4 or other lipid mediators were observed between diabetic and non-diabetic patients. RvD1 levels were below the threshold of quantification in most of the samples. A significant correlation was found between LTB4 and 5(S)-HETE levels. Omega 3 enrichment was not significantly different between control and diabetic plaques. There was a negative correlation between DHA/AA ratio and the level of 5(S)-HETE while there was a positive association with TXB2 and PGD2 concentrations.Our results does not support the hypothesis of a specific involvement of LTB4 or COX-derived mediators in diabetic atherosclerosis. The relationship between DHA enrichment and the concentrations of specific inflammatory mediators within the plaque is of interest and will need to be confirmed in larger studies.

Objectives To study the percentage, suppressive function and plasticity of Treg in giant cell arteritis (GCA), and the effects of glucocorticoids and tocilizumab. Methods Blood samples were obtained from 40 controls and 43 GCA patients at baseline and after treatment with glucocorticoids + IV tocilizumab (n = 20) or glucocorticoids (n = 23). Treg percentage and phenotype were assessed by flow cytometry. Suppressive function of Treg was assessed by measuring their ability to inhibit effector T‐cell (Teff) proliferation and polarisation into Th1 and Th17 cells. Results Treg (CD4+CD25highFoxP3+) frequency in total CD4+ T cells was decreased in active GCA patients when compared to controls (2.5% vs. 4.7%, P, In this study, we demonstrated quantitative and functional disruptions in the regulatory immune response of patients with giant cell arteritis, resulting in increased proliferation and Th17 polarization of effector T cells. In addition, our results suggest that, through a specific blockade of the IL‐6 pathway, tocilizumab associated with glucocorticoids restores a better quantitative and qualitative Treg immune response than glucocorticoids alone. GCA, giant cell arteritis. Teff, effector T‐cells; Th17, T helper‐17 cells; Treg, regulatory T‐cells.

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are progressive diseases affecting millions of people each year. Flare-ups during IBD result in severe mucosal alterations of the small intestine (in CD) and in the colon and rectum (in CD and UC)., Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is related to immunological and microbial factors, with the possible implication of enteric viruses. We characterized the interaction between human noroviruses (HuNoVs) and blood group antigens in refractory CD and UC using HuNoV virus-like particles (VLPs) and histological tissues. Immunohistochemistry was conducted on inflammatory tissue samples from the small intestine, colon, and rectum in 15 CD and 9 UC patients. Analysis of the regenerative mucosa of the colon and rectum revealed strong expression of sialylated Lewis a (sLea) and Lewis x (sLex) antigens and HuNoV VLP binding in the absence of ABO antigen expression in both UC and CD. Competition experiments using sialidase, lectins, and monoclonal antibodies demonstrated that HuNoV attachment mostly involved Lea and, to a lesser extent, Lex moieties on regenerative mucosa in both UC and CD. Further studies will be required to understand the implications of specific HuNoV binding to regenerative mucosa in refractory IBD. IMPORTANCE Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are progressive diseases affecting millions of people each year. Flare-ups during IBD result in severe mucosal alterations of the small intestine (in CD) and in the colon and rectum (in CD and UC). Immunohistochemical analysis of CD and UC samples showed strong expression of known tumoral markers sialyl Lewis a (CA19.9) and sialyl Lewis x (CD15s) antigens on colonic and rectal regenerative mucosa, concurrent with strong human norovirus (HuNov) VLP GII.4 affinity. Sialidase treatment and competition experiments using histo-blood group antigen (HBGA)-specific monoclonal antibodies and lectins clearly demonstrated the implication of the Lewis a moiety and, to a lesser extent, the Lewis x moiety in HuNov recognition in regenerative mucosa of CD and UC tissues. Further studies are required to explore the possible implications of enteric viruses in the impairment of epithelial repair and dysregulation of inflammatory pathways during severe IBD.

In order to validate our strategy of continuous improvement and to identify new ways to increase performance, an evaluation of all the procedures was conducted in our department using the principles of lean management.Lean-6-sigma methodology (Gemba Walk, Value StreamMapping, spaghetti diagram, Kaizen workshop and priorization matrix) was used to analyze the procedures of the conventional and molecular sectors, and to identify bottlenecks, actions without added value and solutions.The audit identified bottlenecks in pre-analytical (registration), analytical (cytology, immunohistochemistry, sequencing, pathologists) and post-analytical processes (absence of secretaries, delivery of reports by mail). It underlined a suboptimal flow of people and materials, the heavy impact of an increasing work load (8%/year) in reception and microscopy even though we had outsourced, and an often critical work place schedule for technicians which prevent them from achieving tasks without added value (quality control, validation of methods and protocols) or even daily tasks (cutting, immunohistochemistry). After completing the 72 actions aimed at managing overproduction, improving working conditions and developing new activities, turn-around time was partially under control and the automation process was well advanced.The audit validated our strategy of continuous improvement and advanced the standardization of our working conditions. Even if the turn-around time for reports was shortened, the audit initiated a positive medical and technical dynamic that should help us to implement the next steps of our reorganization (automation and extension of the department).

International audience; Autopsy investigation of a fatal case of rotavirus severe acute gastroenteritis and multiple organ failure in a 16-month boy with previous intrauterine growth retardation showed colocalization of nonstructural and structural rotavirus proteins within viroplasms in nephrons. This case brings new insights into extraintestinal rotavirus infection and new clues to its abilities to bind to human histo-blood group antigens.

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), is a multifactorial disease in which dietary, genetic, immunological, and microbial factors are at play. The role of enteric viruses in IBD remains only partially explored. To date, epidemiological studies have not fully described the role of enteric viruses in inflammatory flare-ups, especially that of human noroviruses and rotaviruses, which are the main causative agents of viral gastroenteritis. Genome-wide association studies have demonstrated the association between IBD, polymorphisms of the FUT2 and FUT3 genes (which drive the synthesis of histo-blood group antigens), and ligands for norovirus and rotavirus in the intestine. The role of autophagy in defensin-deficient Paneth cells and the perturbations of cytokine secretion in T-helper 1 and T-helper 17 inflammatory pathways following enteric virus infections have been demonstrated as well. Enteric virus interactions with commensal bacteria could play a significant role in the modulation of enteric virus infections in IBD. Based on the currently incomplete knowledge of the complex phenomena underlying IBD pathogenesis, future studies using multi-sampling and data integration combined with new techniques such as human intestinal enteroids could help to decipher the role of enteric viruses in IBD.