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International audience; ObjectivesRheumatoid arthritis (RA) is a debilitating disease, but patient management and treatment have been revolutionized since the advent of bDMARDs. However, about one third of RA patients do not respond to specific bDMARD treatment without clear identified reasons. Different bDMARDs must be tried until the right drug is found. Here, we sought to identify a predictive protein signature to stratify patient responsiveness to rituximab (RTX) among patients with an insufficient response to a first anti-TNFα treatment.MethodsSerum samples were collected at baseline before RTX initiation. A proteomics study comparing responders and nonresponders was conducted to identify and select potential predictive biomarkers whose concentration was measured by quantitative assays. Logistic regression was performed to determine the best biomarker combination to predict good or nonresponse to RTX (EULAR criteria after 6 months’ treatment).ResultsEleven biomarkers potentially discriminating between responders and nonresponders were selected following discovery proteomics. Quantitative immunoassays and univariate statistical analysis showed that fetuin-A and thyroxine binding globulin (TBG) presented a good capacity to discriminate between patient groups. A logistic regression analysis revealed that the combination of fetuin-A plus TBG could accurately predict a patient’s responsiveness to RTX with an AUC of 0.86, sensitivity of 80%, and a specificity of 79%.ConclusionIn RA patients for whom a first anti-TNFα treatment has failed, the serum abundance of fetuin-A and TBG before initiating RTX treatment is an indicator for their response status at 6 months. ClinicalTrials.gov identifier: NCT01000441.

COVID-19 is caused by the human pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in widespread morbidity and mortality. CD4+ T cells, CD8+ T cells and neutralizing antibodies all contribute to control SARS-CoV-2 infection. However, heterogeneity is a major factor in disease severity and in immune innate and adaptive responses to SARS-CoV-2. We performed a deep analysis by flow cytometry of lymphocyte populations of 125 hospitalized SARS-CoV-2 infected patients on the day of hospital admission. Five clusters of patients were identified using hierarchical classification on the basis of their immunophenotypic profile, with different mortality outcomes. Some characteristics were observed in all the clusters of patients, such as lymphopenia and an elevated level of effector CD8+CCR7- T cells. However, low levels of T cell activation are associated to a better disease outcome; on the other hand, profound CD8+ T-cell lymphopenia, a high level of CD4+ and CD8+ T-cell activation and a high level of CD8+ T-cell senescence are associated with a higher mortality outcome. Furthermore, a cluster of patient was characterized by high B-cell responses with an extremely high level of plasmablasts. Our study points out the prognostic value of lymphocyte parameters such as T-cell activation and senescence and strengthen the interest in treating the patients early in course of the disease with targeted immunomodulatory therapies based on the type of adaptive response of each patient.

International audience; Introduction: Fertility disorders in autoimmune diseases are well described. However, little is known about the presence of a humoral serum autoimmunity in case of infertility (antinuclear antibodies, ACAN or antiphospholipid, APL) without criteria of autoimmune disease.Methods: We studied the prevalence, associated factors, and efficacy of immunomodulatory therapy in patients with unexplained infertility. Two groups were created retrospectively among patients followed in medically assisted procreation (PMA) for infertility: a group with serum autoimmunity (AI+) (ACAN, APL or anti-thyroperoxidase antibodies) and a group without serum autoimmunity (HAVE-). Clinical, biological, and therapeutic data were collected.Results: The prevalence of autoimmunity was 33% among consultant patients. One hundred patients were seen in internal medicine consultation, 70 were included in the AI+ group and 30 in the AI- group. In the AI+ group, 76% had ACANs, 29% had anti-TPOs and 23% had APLs. There was a significant correlation between ACAN level and the presence of endometriosis (P=0.048). Immunomodulatory therapy was introduced for 68 of the 70 women in the AI+ group; pregnancy occurred in 28 patients (40%) during the treatment period, compared with 7 in the "AI-" group (23%), with a tendency to significance (P=0.09). In conclusion, there is an increased prevalence of serum autoimmunity in patients with fertility disorders, possibly with the efficacy of an immunomodulatory treatment to confront prospective therapeutic studies.

International audience; Bradykinin mediated angioedema (BK-AE) can be associated either with C1Inhibitor deficiency (hereditary and acquired forms), either with normal C1Inh (hereditary form and drug induced AE as angiotensin converting enzyme inhibitors…). In case of high clinical suspicion of BK-AE, C1Inh exploration must be done at first: C1Inh function and antigenemy as well as C4 concentration. C1Inh deficiency is significant if the tests are below 50 % of the normal values and controlled a second time. In case of C1Inh deficiency, you have to identify hereditary from acquired forms. C1q and anti-C1Inh antibody tests are useful for acquired BK-AE. SERPING1 gene screening must be done if a hereditary angioedema is suspected, even if there is no family context (de novo mutation 15 %). If a hereditary BK-AE with normal C1Inh is suspected, F12 and PLG gene screening is suitable.

Ficolins are recognition proteins of the lectin pathway of the complement system and also play an important role in innate immunity and in the maintenance of tissue homeostasis. They deserve special attention in the context of autoimmunity since they are involved in the uptake of dying cells. Because the monitoring of systemic lupus erythematosus (SLE) patients is particularly difficult, it is crucial to find new relevant serum biomarkers. The ability to detect autoantibodies in the patients' sera provides a diagnostic and prognostic advantage. We describe in this chapter quantitative enzyme linked immunosorbent assays (ELISA) to detect the presence of autoantibodies targeting ficolin-2 and ficolin-3 in human sera. Recombinant ficolins produced in a mammalian expression system are used as coating antigens. The described in-house ELISAs provide a valuable tool to efficiently quantify anti-ficolin autoantibodies in the sera of SLE patients.

International audience; Introduction: Hepatitis E virus (HEV) infection has been reported to be associated with neurological disor-ders. However, the real prevalence of acute hepatitis E in those diseases is still unknown. We determinedthe prevalence of anti-HEV IgM antibody in a population with acute non-traumatic, non-metabolic,non-vascular neurological injury.Method: A registry was created in Grenoble Hospital University from 2014 to 2018 to collect data onpatients with acute (

International audience; The complement is a powerful cascade of the innate immunity and also acts as a bridge between innate and acquired immune defence. Complement activation can occur via three distinct pathways, the classical, alternative and lectin pathways, each resulting in the common terminal pathway. Complement activation results in the release of a range of biologically active molecules that significantly contribute to immune surveillance and tissue homeostasis. Several soluble and membrane-bound regulatory proteins restrict complement activation in order to prevent complement-mediated autologous damage, consumption and exacerbated inflammation. The crucial role of complement in the host homeostasis is illustrated by association of both complement deficiency and overactivation with severe and life-threatening diseases. Autoantibodies targeting complement components have been described to alter expression and/or function of target protein resulting in a dysregulation of the delicate equilibrium between activation and inhibition of complement. The spectrum of diseases associated with complement autoantibodies depends on which complement protein and activation pathway are targeted, ranging from autoimmune disorders to kidney and vascular diseases. Nevertheless, these autoantibodies have been identified as differential biomarkers for diagnosis or follow-up of disease only in a small number of clinical conditions. For some autoantibodies, a clear relationship with clinical manifestations has been identified, such as anti-C1q, anti-Factor H, anti-C1 Inhibitor antibodies and C3 nephritic factor. For other autoantibodies, the origin and the functional consequences still remain to be elucidated, questioning about the pathophysiological significance of these autoantibodies, such as anti-mannose binding lectin, anti-Factor I, anti-Factor B and anti-C3b antibodies. The detection of autoantibodies targeting complement components is performed in specialized laboratories; however, there is no consensus on detection methods and standardization of the assays is a real challenge. This review summarizes the current panorama of autoantibodies targeting complement recognition proteins of the classical and lectin pathways, associated proteases, convertases, regulators and terminal components, with an emphasis on autoantibodies clearly involved in clinical conditions.

Background Studies of normal bone marrow (BM) cell composition by flow cytometry are scarce. Presently, we aimed to quantify 14 cell subsets from infants to elderly patients. Methods Cell subsets in BM samples from 180 individuals without morphologically abnormal leukocytes were analyzed using a single combination of eight antibodies: CD3/CD10/CD38/CD19/CD36/CD16/CD34/CD45. Results By comparison with the Holdrinet score, we first validated the immature granulocyte/neutrophil (IGRA/N) ratio as a readily obtainable criterion of BM sample purity in 145 cases. Then, the 115 highly pure samples were selected (IGRA/N ≥ 1.2) and analyzed according to age group. CD34+ myeloblasts became progressively more infrequent with age: median 1.4% in infancy to 0.5% in the elderly. Neutrophils increased: 10.7% to 22.8%; all other myeloid subsets, IGRA, eosinophils, basophils and monocytes remained stable: respectively 40.3% to 46.7%, 2.0% to 2.8%, 0.2% to 0.3%, and 4.4% to 5.0% throughout life. Erythroblasts were lower in children (8.4% to 10.3%) than in adults (12.5% to 15.1%). For lymphoid cells, hematogones and transitional B-cells decreased: 15.5% to 0.6% and 3.6% to 0.1%, respectively; mature lymphocytes remained stable: B-cells: 1.4% to 2.8%, T-cells: 5.8% to 8.7%, and NK-cells: 0.7% to 1.4%. Plasma cells varied slightly: 0.1% to 0.5%. Differences of about 40% were seen in moderately pure (IGRA/N: 0.5 to 1.2) BM samples. Conclusion We thus provide the first values for 14 myeloid and lymphoid subsets characterizing BM cell composition in 5 age ranges. They should provide important information when screening patients for hematological disorders or abnormal bone marrow development. © 2018 International Clinical Cytometry Society.

The defence collagens C1q and mannose-binding lectin (MBL) are immune recognition proteins that associate with the serine proteinases C1r/C1s and MBL-associated serine proteases (MASPs) to trigger activation of complement, a major innate immune system. Bone morphogenetic protein-1 (BMP-1)/tolloid-like proteinases (BTPs) are metalloproteinases with major roles in extracellular matrix assembly and growth factor signalling. Despite their different functions, C1r/C1s/MASPs and BTPs share structural similarities, including a specific CUB-EGF-CUB domain arrangement found only in these enzymes that mediates interactions with collagen-like proteins, suggesting a possible functional relationship. Here we investigated the potential interactions between the defence collagens C1q and MBL and the BTPs BMP-1 and mammalian tolloid-like-1 (mTLL-1). C1q and MBL bound to immobilized BMP-1 and mTLL-1 with nanomolar affinities. These interactions involved the collagen-like regions of the defence collagens and were inhibited by pre-incubation of C1q or MBL with their cognate complement proteinases. Soluble BMP-1 and mTLL-1 did not inhibit complement activation and the defence collagens were neither substrates nor inhibitors of BMP-1. Finally, C1q co-localized with BMP-1 in skin biopsies following melanoma excision and from patients with recessive dystrophic epidermolysis bullosa. The observed interactions provide support for a functional link between complement and BTPs during inflammation and tissue repair.

Detection of circulating anti-GBM antibodies has a key role for the diagnosis of Goodpasture syndrome but immunoassays using purified or recombinant alpha3(IV)NC1 as antigen do not recognize all anti-GBM antibodies. We show that anti-GBM antibodies directed against epitopes in their native conformation or cryptic epitopes are detected by indirect immunofluorescence.

Rheumatoid arthritis (RA) is a debilitating disease, but patient management and treatment have been revolutionized since the advent of bDMARDs. However, about one third of RA patients do not respond to specific bDMARD treatment without clear identified reasons. Different bDMARDs must be tried until the right drug is found. Here, we sought to identify a predictive protein signature to stratify patient responsiveness to rituximab (RTX) among patients with an insufficient response to a first anti-TNFα treatment.Serum samples were collected at baseline before RTX initiation. A proteomics study comparing responders and nonresponders was conducted to identify and select potential predictive biomarkers whose concentration was measured by quantitative assays. Logistic regression was performed to determine the best biomarker combination to predict good or nonresponse to RTX (EULAR criteria after 6 months' treatment).Eleven biomarkers potentially discriminating between responders and nonresponders were selected following discovery proteomics. Quantitative immunoassays and univariate statistical analysis showed that fetuin-A and thyroxine binding globulin (TBG) presented a good capacity to discriminate between patient groups. A logistic regression analysis revealed that the combination of fetuin-A plus TBG could accurately predict a patient's responsiveness to RTX with an AUC of 0.86, sensitivity of 80%, and a specificity of 79%.In RA patients for whom a first anti-TNFα treatment has failed, the serum abundance of fetuin-A and TBG before initiating RTX treatment is an indicator for their response status at 6 months. ClinicalTrials.gov identifier: NCT01000441. Key Points • Proteomic analysis revealed 11 putative predictive biomarkers to discriminate rituximab responder vs. nonresponder RA patients. • Fetuin-A and TBG are significantly differentially expressed at baseline in rituximab responder vs. nonresponder RA patients. • Algorithm combining fetuin-A and TBG accurately predicts response to rituximab in RA patients with insufficient response to TNFi.

International audience; The complement system has been implicated in several kidney diseases, such as antibody-mediated rejection after kidney transplantation. Antibody-depletion techniques allow successful ABO- and/or HLA-incompatible transplantation. Considering the IgG removal, the use of semi-selective immunoadsorption (IA) has been advocated. However, because of results on incomplete IgM depletion, the adjunctive use of membrane filtration (MF) has been proposed to enhance the removal of macromolecules and to interfere with complement activation. This secondary endpoint analysis of a recently published randomized, controlled, cross-over trial was designed to investigate the effect of combined treatment IA + MF compared to IA alone on complement depletion. Two treatment sequences, a single session of IA + MF followed by IA (and vice versa), were analyzed with regard to C5b-9, properdin, and mannose-binding lectin (MBL) levels. Neither IA alone nor IA + MF provoked complement activation as demonstrated by stable low levels of C5b-9 after the procedure as compared to the previous. The combined treatment substantially lowered properdin (77% vs. 26% reduction, P

Fertility disorders in autoimmune diseases are well described. However, little is known about the presence of a humoral serum autoimmunity in case of infertility (antinuclear antibodies, ACAN or antiphospholipid, APL) without criteria of autoimmune disease.We studied the prevalence, associated factors, and efficacy of immunomodulatory therapy in patients with unexplained infertility. Two groups were created retrospectively among patients followed in medically assisted procreation (PMA) for infertility: a group with serum autoimmunity (AI+) (ACAN, APL or anti-thyroperoxidase antibodies) and a group without serum autoimmunity (HAVE-). Clinical, biological, and therapeutic data were collected.The prevalence of autoimmunity was 33% among consultant patients. One hundred patients were seen in internal medicine consultation, 70 were included in the AI+ group and 30 in the AI- group. In the AI+ group, 76% had ACANs, 29% had anti-TPOs and 23% had APLs. There was a significant correlation between ACAN level and the presence of endometriosis (P=0.048). Immunomodulatory therapy was introduced for 68 of the 70 women in the AI+ group; pregnancy occurred in 28 patients (40%) during the treatment period, compared with 7 in the "AI-" group (23%), with a tendency to significance (P=0.09). In conclusion, there is an increased prevalence of serum autoimmunity in patients with fertility disorders, possibly with the efficacy of an immunomodulatory treatment to confront prospective therapeutic studies.

Background Bone marrow analysis by flow cytometry is part of the routine diagnosis of hematological disorders in medical laboratories. Differential leukocyte count and identification of abnormal cell subsets is currently performed through morphological examination on bone marrow smears by skilled cytologists. In this work, we propose a single 8-color tube for providing equivalent information, using flow cytometry. Methods 99 bone marrow samples were classified into 2 groups, (i) 51 samples, obtained from either healthy donors (n = 4) or patients with various diseases at diagnosis or during remission that did not present a hematological malignancy (n = 47), and (ii) 48 pathological samples with quantitative and/or qualitative abnormalities. A panel of eight antibodies-CD3-FITC/CD10-PE/CD38-PerCP-Cy5.5/CD19-PECy7/CD36-APC/CD16-APC-H7/CD34-BV421/CD45-V500-was tested to identify the main cell subsets at different stages of maturation using a FACSCanto-II analyzer. Results We first proposed a strategy of sequential gating leading to the identification of 14 leukocyte subsets, that is, erythroblasts, monocytes, B-lymphoid cells from hematogones to plasma-cells (5 subsets), T- and NK-cells, polymorphonuclear cells (neutrophils, eosinophils, and basophils), myeloblasts and other immature granular cells. This approach was validated by comparing flow cytometry and microscopic morphological examination, both in cases of normal and abnormal samples. Interestingly, cell identification, and numeration by flow cytometry was easy to perform and highly reproducible. Conclusion A very simple, rapid, and reproducible flow cytometric approach, using a combination of eight antibodies allows determination of the cellular composition of bone marrow with high precision. © 2016 International Clinical Cytometry Society.

International audience

International audience; Lupus nephritis (LN) is one of the most frequent and severe manifestations of systemic lupus erythematosus (SLE), considered as the major predictor of poor prognosis. An early diagnosis of LN is a real challenge in the management of SLE and has an important implication in guiding treatments. In clinical practice, conventional parameters still lack sensitivity and specificity for detecting ongoing disease activity in lupus kidneys and early relapse of nephritis. LN is characterized by glomerular kidney injury, essentially due to deposition of immune complexes involving autoantibodies against cellular components and circulating proteins. One of the possible mechanisms of induction of autoantibodies in SLE is a defect in apoptotic cells clearance and subsequent release of intracellular autoantigens. Autoantibodies against soluble protective molecules involved in the uptake of dying cells, including complement proteins and pentraxins, have been described. In this review, we present the main autoantibodies found in LN, with a focus on the antibodies against these protective molecules. We also discuss their pathogenic role and conclude with their potential interest as serological biomarkers in LN.

Objective Systemic lupus erythematosus (SLE) is a multi-system inflammatory disease characterized by production of various autoantibodies. The aim of this study was to investigate the presence of anti-ficolin-2 antibodies in SLE patients and to evaluate the association between the levels of these autoantibodies, clinical manifestations, and disease activity. Methods This is a comparative study using a cohort of 165 SLE patients and 48 healthy subjects. SLE patients were further divided into two groups, with “low disease activity” (SLEDAI score ≤ 4, n = 88) and with “high disease activity” (SLEDAI score > 4, n = 77). Clinical manifestations were defined according to the physician in charge. Active lupus nephritis (LN) was documented by kidney biopsy. Detection of anti-ficolin-2 antibodies was performed by ELISA. Results Levels of the anti-ficolin-2 autoantibodies were significantly higher in SLE patients as compared to healthy subjects and associated with the SLEDAI score. They were found positive in 61/165 (37%) SLE patients. Presence of anti-ficolin-2 antibodies was significantly related only to renal involvement, with a very high prevalence (86%) of anti-ficolin-2 antibodies in SLE patients with active LN. Patients with active proliferative LN had significantly more positive anti-ficolin-2 antibodies than those with non-proliferative LN. The combination of anti-ficolin-2, anti-ficolin-3 and anti-C1q demonstrated a very high specificity (98%) for the diagnosis of active LN. Conclusion Our results support the usefulness of anti-ficolin-2 as a complementary serological biomarker for the diagnosis of active lupus with renal manifestation. This article is protected by copyright. All rights reserved.

International audience; Traditionally, IBD diagnosis is based on clinical, radiological, endoscopic, and histological criteria. Biomarkers are needed in cases of uncertain diagnosis, or to predict disease course and therapeutic response. No guideline recommends the detection of antibodies (including ASCA and ANCA) for diagnosis or prognosis of IBD to date. However, many recent data suggest the potential role of new serological markers (anti-glycan (ACCA, ALCA, AMCA, anti-L and anti-C), anti-GP2 and anti-GM-CSF Ab). This review focuses on clinical utility of these new serological markers in diagnosis, prognosis and therapeutic monitoring of IBD. Literature review of anti-glycan, anti-GP2 and anti-GM-CSF Ab and their impact on diagnosis, prognosis and prediction of therapeutic response was performed in PubMed/MEDLINE up to June 2014. Anti-glycan, anti-GP2 and anti-GM-CSF Ab are especially associated with CD and seem to be correlated with complicated disease phenotypes even if results differ between studies. Although anti-glycan Ab and anti-GP2 Ab have low sensitivity in diagnosis of IBD, they could identify a small number of CD patients not detected by other tests such as ASCA. Anti-glycan Abs are associated with a progression to a more severe disease course and a higher risk for IBD-related surgery. Anti-GP2 Ab could particularly contribute to better stratify cases of pouchitis. Anti-GM-CSF Ab seems to be correlated with disease activity and could help predict relapses. These new promising biomarkers could particularly be useful in stratification of patients according to disease phenotype and risk of complications. They could be a valuable aid in prediction of disease course and therapeutic response but more prospective studies are needed.

International audience; On average, 10 % of infertile couples have unexplained infertility. Auto-immune disease (systemic lupus erythematosus, anti-phospholipid syndrome) accounts for a part of these cases. In the last 20 years, aspecific auto-immunity, defined as positivity of auto-antibodies in blood sample without clinical or biological criteria for defined diseases, has been evoked in a subpopulation of infertile women. A systematic review was performed (PUBMED) using the MESH search terms "infertility" and "auto-immunity" or "reproductive technique" or "assisted reproduction" or "in vitro fertilization" and "auto-immunity." We retained clinical and physiopathological studies that were applicable to the clinician in assuming joint management of both infertility associated with serum auto-antibodies in women. Thyroid auto-immunity which affects thyroid function could be a cause of infertility; even in euthyroidia, the presence of anti-thyroperoxydase antibodies and/or thyroglobulin are related to infertility. The presence of anti-phospholipid (APL) and/or anti-nuclear (ANA) antibodies seems to be more frequent in the population of infertile women; serum auto-antibodies are associated with early ovarian failure, itself responsible for fertility disorders. However, there exist few publications on this topic. The methods of dosage, as well as the clinical criteria of unexplained infertility deserve to be standardized to allow a precise response to the question of the role of serum auto-antibodies in these women. The direct pathogenesis of this auto-immunity is unknown, but therapeutic immunomodulators, prescribed on a case-by-case basis, could favor pregnancy even in cases of unexplained primary or secondary infertility.

Growth arrest and DNA damage-inducible gene 34 (GADD34) is an inducible cofactor of protein phosphatase 1, which has an important role in the unfolded protein response. GADD34 has been shown to be necessary for type I interferon and proinflammatory cytokine production in response to viral infection in murine models. We investigate the expression of GADD34 in rheumatoid arthritis (RA), in which proinflammatory cytokines have an important pathogenic role. The objective of this study was to evaluate the potential of GADD34 expression as a biomarker in RA patients. We report a case-control study on GADD34 gene expression in peripheral blood mononuclear cells of patients (n = 75) with RA and age- and sex-matched healthy controls (n = 25). The study was approved by the relevant local ethics committees. GADD34 gene expression level in peripheral blood mononuclear cells was measured by quantitative PCR and analyzed with Mann-Whitney test. The relation between GADD34 gene overexpression and clinical or biological characteristics was analyzed with univariate and multivariate analysis. GADD34 gene expression was significantly higher in RA patients compared with healthy controls (p ≤ 0.001). Interestingly, GADD34 overexpression in PBMC of patients was related to the presence of circulating anti-citrullinated protein antibodies (p = 0.030). Data of this study strengthen the evidence of an unfolded protein response during the course of RA and provide an insight of the potential interest in GADD34 as a relevant marker for RA.

International audience; Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of multiple autoantibodies. Antibodies against Ficolin-3 were previously identified in the sera of some SLE patients, but their prevalence and significance have not been yet investigated. The aims of this study were to determine the prevalence of anti-ficolin-3 antibodies among SLE patients and to investigate their potential as diagnostic and/or prognostic biomarkers in SLE. In this retrospective study, sera from SLE patients (n = 165) were selected from a preexisting declared biological collection. Samples from healthy controls (n = 48) were matched with SLE sera. Disease activity was determined according to the SLEDAI score. Anti-ficolin-3, anti-dsDNA and anti-C1q antibodies levels were measured in sera by ELISA. First, a highly significant difference was found in the anti-ficolin-3 levels between SLE patients and healthy subjects. Anti-ficolin-3 antibodies were detected as positive in 56 of 165 (34%) SLE patients. The titer of anti-ficolin-3 antibodies was correlated with the SLEDAI score (r = 0.38, p

A precise identification and phenotypic characterization of human B-cell subsets is of crucial importance in both basic research and medicine. In the literature, flow cytometry studies for the phenotypic characterization of B-lymphocytes are mainly focused on the description of a particular cell stage, or of specific cell stages observed in a single type of sample. In the present work, we propose a backbone of 6 antibodies (CD38, CD27, CD10, CD19, CD5 and CD45) and an efficient gating strategy to identify, in a single analysis tube, a large number of B-cell subsets covering the whole B-cell differentiation from precursors to memory and plasma cells. Furthermore, by adding two antibodies in an 8-color combination, our approach allows the analysis of the modulation of any cell surface marker of interest along B-cell differentiation. We thus developed a panel of seven 8-colour antibody combinations to phenotypically characterize B-cell subpopulations in bone marrow, peripheral blood, lymph node and cord blood samples. Beyond qualitative information provided by biparametric representations, we also quantified antigen expression on each of the identified B-cell subsets and we proposed a series of informative curves showing the modulation of seventeen cell surface markers along B-cell differentiation. Our approach by flow cytometry provides an efficient tool to obtain quantitative data on B-cell surface markers expression with a relative easy-to-handle technique that can be applied in routine explorations.

Introduction Le traitement des uveites chroniques non-infectieuses peut inclure l’utilisation d’anticorps monoclonaux anti-TNFα, dont l’adalimumab (ADA) et l’infliximab (IFX). Grâce a l’utilisation de tests commerciaux ELISA, la detection d’anticorps anti-adalimumab (AAA) ou anti-infliximab (AAI) et le dosage de la concentration sanguine d’anti-TNFα peuvent etre realises en pratique clinique courante. L’objectif de notre etude est d’evaluer l’interet de ces dosages, dans la prise en charge des patients presentant une uveite chronique non infectieuse. Patients et methodes Une etude observationnelle monocentrique retrospective a ete realisee en 2017 au Centre Hospitalier Universitaire Grenoble Alpes. Les patients presentant une uveite chronique non infectieuse, traites par adalimumab ou par infliximab, et ayant eu un dosage du taux plasmatique du medicament et une recherche d’anticorps anti-traitement (AAA ou AAI), ont ete inclus. Le dosage du medicament et la recherche d’anticorps induits ont ete realises par technique ELISA (Theradiag®). La reponse ophtalmologique de l’uveite (totale, partielle ou absente) etait determinee a chaque dosage. Cette reponse etait definie, par rapport a l’etat clinique a l’instauration du traitement, selon un critere clinique composite ophtalmologique base sur la presence d’inflammation dans la chambre anterieure ou le vitree, d’un œdeme maculaire cystoide ou d’anomalies a l’angiographie. Resultats Vingt et un patients suivis pour une uveite chronique non infectieuse sous anti-TNFα, dont 12 traites par adalimumab et 9 par infliximab, ont beneficie d’au moins une recherche d’anticorps anti-medicament et d’un dosage sanguin d’anti-TNFα. Trois dosages ont ete realises chez 7 patients, 2 dosages chez 3 patients et enfin, 1 dosage chez 11 patients. Trois patients ont developpe des anticorps. Ils etaient transitoires pour un patient traite par adalimumab. Ce patient poursuit actuellement le traitement sans perte d’efficacite. Ils etaient stables pour deux patients (un traite par IFX et un par ADA) qui ont arrete le traitement pour inefficacite clinique. Alors qu’une reponse clinique totale et partielle etait retrouvee chez 60,5 % des patients en absence d’anticorps, une absence de reponse clinique etait systematiquement retrouvee en presence d’AAA ou d’AAI permanents. En presence d’AAA ou d’AAI, la concentration sanguine d’anti-TNF α etait plus faible : 3,2 ± 5,4 μg/mL [0,1–9,4] vs 9,8 ± 5,0 μg/mL [0,1–16] (p = 0,032). Neanmoins, aucune association entre concentration sanguine et efficacite clinique n’a pu etre mise en evidence. Conclusion Aucune relation, entre l’apparition d’anticorps anti-medicament et l’efficacite clinique sur l’uveite chronique non infectieuse, n’a pu etre mise en evidence. Neanmoins, tous les patients ayant developpes des AAA ou AAI stables ont arrete le traitement pour absence d’efficacite clinique. L’apparition d’anticorps anti-medicament est associee a une diminution de la concentration sanguine de l’anti-TNFα. Une etude prospective semble interessante a mener, pour montrer l’interet des dosages sanguin d’anti-TNFα et d’anticorps anti-medicament dans les uveites chroniques non-infectieuses.

Introduction Les auto-anticorps (auto-Ac) anti-SSA et anti-SSB sont presents dans plusieurs pathologies dysimmunitaires, parmi lesquelles le syndrome de Goujerot Sjogren (SGS), le lupus erythemateux dissemine (LED) ou la Polyarthrite Rhumatoide (PR). Si la sensibilite et la specificite de ces auto-Ac sont actuellement bien decrites, nous avons voulu determiner les etiologies associees a la presence de ces auto-Ac. Patients et methodes Nous avons mene une etude retrospective, observationnelle, monocentrique au CHU de Grenoble-Alpes. Tous les patients ayant beneficie d’une recherche positive d’auto-Ac anti-SSA et/ou anti-SSB entre janvier 2013 et decembre 2015 ont ete inclus ; seuls les premiers dosages pour chaque patient ont ete retenus. Pour chaque dossier, etaient relevees les donnees demographiques, cliniques et biologiques. Resultats Deux cent vingt-neuf recherches positives d’auto-Ac anti-SSA et/ou SSB ont ete recensees sur la periode. Parmi elles, 100 patients avaient beneficie de cette recherche pour la premiere fois au CHUGA. Une recherche d’auto-Ac anti-nucleaires (ACAN) etait positive en immunofluorescence pour 97 patients. La presence d’auto-Ac anti-SSA60, -SSA52 et -SSB etait isolee respectivement dans 96 %, 59 % et 45 % des cas. Les diagnostics principalement associes a un dosage positif etaient : SGS (42 %), LED (27 %), syndrome des anti-phospholipides isole (7 %), thyroidite auto-immune (6 %), PR (5 %), pseudo polyarthrite rhizomelique (2 %), sclerodermie (3 %) ( Tableau 1 ). Pour 20 patients, 2 diagnostics etaient associes, notamment LES et SAPL (6 %), LES et SGS (5 %). Par ailleurs, on notait 1 cas de vascularite urticarienne hypo-complementemique, et 9 (9 %) tableaux cliniques evocateurs de pathologie dysimmunitaire sans diagnostic retenu. Les symptomes rapportes (pour 83 patients) etaient : syndrome sec (43 %), arthralgie (46 %), manifestation cutanee (19 %) et syndrome de Raynaud (17 %). Conclusion Cette etude monocentrique retrospective sur 100 patients presentant un premier dosage positif d’auto-Ac anti-SSA et/ou SSB, confirme la part importante de SGS associee, mais montre aussi les prevalences non negligeables de LED et de SAPL.

To cite this article: Vitrat-Hincky V, Gompel A, Dumestre-Perard C, Boccon-Gibod I, Drouet C, Cesbron JY, Lunardi J, Massot C, Bouillet L. Type III hereditary angio-oedema: clinical and biological features in a French cohort. Allergy 2010; 65: 1331–1336. Abstract Background: Hereditary angio-oedema (HAE) has been associated with C1inhibitor deficiency. The first cases of type III HAE were described in patients with normal C1Inh antigenic protein level and function and normal C4 levels in 2000. This finding has been reported mostly in women with a family history and may be influenced by exogenous oestrogen exposure. Objectives: The purpose of this article is to describe the clinical, biological and genetic characteristics of a French population suffering from type III HAE. Patients and Methods: We conducted a retrospective analysis of angio-oedema (AE) cases seen in the National Reference Centre of AE between 2000 and 2009. Results: We found 26 patients (from 15 unrelated families) with type III HAE. All but four were women and presented with typical AE attacks, exacerbated by pregnancy or oral contraceptives containing oestrogens (OC). We also found that 54.5% of women were worsened with oestrogen and 23% were oestrogen dependent. All patients improved on long-term prophylactic tranexamic acid treatment; some acute attacks improved with C1Inh concentrate infusion. All of the patients had normal C1Inh and C4 levels. C1Inh function was also normal, except in women receiving OC or during a pregnancy: transient, moderately low levels (32–74% of the normal range) were found in 18 patients tested (67%). No SERPING1 gene mutation was found. Six patients from three unrelated families were heterozygous for an F12 gene variant. Conclusion: Diagnosis of type III HAE should be based on clinical (typical attacks, often hormonally influenced), laboratory (normal C1Inh antigenic protein) and genetic (F12 gene mutation) evidence.

Ficolins are oligomeric innate immune recognition proteins consisting of a collagen-like region and a fibrinogen-like recognition domain that bind to pathogen- and apoptotic cell-associated molecular patterns. To investigate their carbohydrate binding specificities, serum-derived L-ficolin and recombinant H- and M-ficolins were fluorescently labeled, and their carbohydrate binding ability was analyzed by glycan array screening. L-ficolin preferentially recognized disulfated N-acetyllactosamine and tri- and tetrasaccharides containing terminal galactose or N-acetylglucosamine. Binding was sensitive to the position and orientation of the bond between N-acetyllactosamine and the adjacent carbohydrate. No significant binding of H-ficolin to any of the 377 glycans probed could be detected, providing further evidence for its poor lectin activity. M-ficolin bound preferentially to 9-O-acetylated 2-6-linked sialic acid derivatives and to various glycans containing sialic acid engaged in a 2-3 linkage. To further investigate the structural basis of sialic acid recognition by M-ficolin, point mutants were produced in which three residues of the fibrinogen domain were replaced by their counterparts in L-ficolin. Mutations G221F and A256V inhibited binding to the 9-O-acetylated sialic acid derivatives, whereas Y271F abolished interaction with all sialic acid-containing glycans. The crystal structure of the Y271F mutant fibrinogen domain was solved, showing that the mutation does not alter the structure of the ligand binding pocket. These analyses reveal novel ficolin ligands such as sulfated N-acetyllactosamine (L-ficolin) and gangliosides (M-ficolin) and provide precise insights into the sialic acid binding specificity of M-ficolin, emphasizing the essential role of Tyr271 in this respect.

Mice defective for C1q complement factor show enhanced resistance to peripheral prion inoculation, and previous work demonstrated a direct interaction between C1q and conformationally modified PrP. However, the nature and physiological consequences of this interaction remain uncharacterized. PrP amino acids 141-159 has been identified as a potential C1q binding site; we show, by both surface plasmon resonance (SPR) spectroscopy and ELISA, that C1q and its globular region bind to PrP mutagenized in the region of interest with comparable efficiency to that of wild-type protein. To test PrP's ability to activate complement, soluble oligomers of the PrP constructs were made. Only PrP and mutagenized PrP oligomers activate the classical complement cascade while PrP monomer and the C-terminal domain, both in oligomeric and in monomeric form, failed to induce activation. This suggests that a conformational change in PrP, which occurs both when PrP is bound to an SPR sensor chip and when it undergoes oligomerization, is requisite for PrP/C1q interaction and activation of the complement cascade. We propose that C1q may act as a natural sensor for prions, leading to activation of the classical complement cascade, which could result in local inflammation and subsequent recruitment of the immune cells that prions initially infect.

The aetiology of angio-oedema (AE) is difficult to determine; however, it is essential in emergency situations when two major contexts may be present: mast cell-mediated AE and bradykinin-mediated AE. Different forms of AE are currently distinguished based on clinical criteria (spontaneous duration of the attack, presence of concomitant or late-appearing superficial urticaria, history of atopy, and others), but specific biomarkers could improve patient management.In this prospective study, potential biomarkers have been identified, and their statistical characteristics were examined.Samples were taken on day 0 (D0) and D7 for 3 patient groups (n = 11 each): bradykinin-mediated AE [peripheral site of attack, ear, nose, throat (ENT), and abdominal involvement], mast cell-mediated AE, and non-bradykinin-mediated abdominal pain.Assay of the potential biomarkers revealed no significant differences in C1 inhibitor and C4 levels. In contrast, D-dimer levels peaked during bradykinin-mediated AE attacks (median 2.2 mg/l at D0 vs. 0.52 mg/l at D7; p10-3) as well as during mast cell-mediated AE attacks (1.97 vs. 0.65 mg/l; p = 0.04) and were high in bradykinin-mediated AE compared to the control group (0.69 mg/l; p = 0.01). A threshold value of 0.62 mg/l was found to have a negative predictive value of 100% for bradykinin-mediated AE compared to other causes of abdominal pain (group 3). Circulating VE-cadherin levels were also increased during an attack (1,990 at D0 vs. 1,566 ng/ml at D7; p = 0.01), but could not distinguish between bradykinin-mediated and mast cell-mediated AE, like D-dimers.Exploration of changes in fibrinolysis-related markers (particularly D-dimers) is thus promising for the diagnosis of AE attacks in difficult-to-diagnose abdominal forms, although it was not able to differentiate between bradykinin and mast cell-mediated AE.

International audience; Most patients with idiopathic membranous nephropathy (IMN) have IgG4 autoantibodies against phospholipase A2 receptor (PLA2R). C3 and C5b-9 are found in immune deposits of IMN kidney biopsy specimens, but the pathway of complement activation in IMN remains elusive. We report the case of a patient who developed IMN with intense staining for PLA2R, IgG4, C3, C5b-9, factor B, and properdin and very weak staining for C1q, C4d, and IgG1. Measurement of mannan binding lectin (MBL) antigenic level and activity revealed MBL deficiency. Genotyping revealed a heterozygous (A/C) polymorphism in codon 57 of MBL2 exon 1 associated with homozygous and heterozygous variations in the promoter region at -550 (L/L) and -221 (X/Y), respectively, suggesting that the patient harbored the LXA/LYC haplotypes linked to MBL deficiency. Genetic sequencing in 77 consecutive patients with IMN identified four patients with MBL2 promoter and coding region variations associated with MBL deficiency and the same complement pattern in immune deposits as the index patient. In contrast, patients with wild-type MBL2 had immune deposits with intense Cd4 staining. Thus, IMN can develop in patients with complete MBL deficiency, with complement activated mainly by the alternative pathway, whereas the lectin pathway is also activated in those with wild-type MBL2.

Background: Bradykinin-mediated angioedema (AE) is a rare disease characterised by recurrent angioedema linked to acquired (e.g. angiotensin converting enzyme inhibitor induced AE) or hereditary disorders (e.g. AE type I or II). As the clinical picture can be misleading, diagnosis of this disease is sometimes difficult. A bradykinin-mediated AE attack may be a therapeutic emergency which requires access to effective, but expensive, treatments. Their prescription must therefore be justified. No specific marker of acute bradykinin-mediated AE attacks has yet been identified to facilitate the therapeutic decision but it has been sought in many studies. Purpose: This article reviews the literature on this type of biomarker, comparing candidate bradykinin-mediated AE markers to candidate markers of mast cell activation. Conclusion: The most interesting biomarkers are those linked to endothelial stress (VE cadherin, E-selectin, endothelin-1, von Willebrand factor and its activity) which is significantly increased during an AE attack. All these markers must now be validated by prospective studies to determine their specificity and utility in diagnosis.

The objective of the present work was to set up a routine test adapted to screening for antiendothelial cell antibodies (AECAs) in serum samples with minimal interference from antinuclear antibodies (ANAs) or rheumatoid factors (RFs). We compared the titers of AECAs titrated following two enzyme-linked immunosorbent assays (ELISAs): (i) an ELISA with ethanol-fixed EA.hy926 monolayers as the antigenic substrate and (ii) an ELISA with nucleus-depleted lysates prepared from EA.hy926 cells and normalized for protein (1.0 to 1.7 mg/ml) and DNA (≤0.1 μg/ml) contents as a surrogate substrate (postnuclear supernatant ELISA [PNS-ELISA]). The AECA titers in 51 serum samples, including 28 samples containing ANAs, were compared. A significantly positive correlation ( r = 0.77; P < 0.001) between the two series was shown only for the ANA-negative serum samples. Conversely, ANAs or RFs in samples were shown not to interfere in tests for AECAs by the PNS-ELISA. AECAs recognize their antigenic targets in postnuclear supernatants, which is representative of the endothelial antigenic content, with improvement of the reliability of the assay, a prerequisite to application of the assay for their evaluation in clinical practice.

International audience; To identify patients with autoimmune diseases who are at high risk of developing vascular cell dysfunction, early biomarkers must be identified. This study was designed to detect and characterize circulating autoantibodies to VE-cadherin (AAVEs) in patients with early-stage autoimmune diseases. An enzyme-linked immunosorbent assay (ELISA) was developed to capture autoantibodies, using a recombinant human VE-cadherin fragment covering the extracellular domains as a target antigen. AAVEs specificity for the target antigen was confirmed by western blotting. Basal AAVEs levels were determined for healthy donors (n=75). Sera from patients (n=100) with various autoimmune diseases, including rheumatoid arthritis (n=23), systemic lupus erythematosus (SLE, n=31), systemic sclerosis (n=30), and Behçet's disease (BD, n=16) were also tested. Levels of AAVEs were significantly higher in rheumatoid arthritis (P

Mutations within the central region of prion protein (PrP) have been shown to be associated with severe neurotoxic activity similar to that observed with Dpl, a PrP-like protein. To further investigate this neurotoxic effect, we generated lines of transgenic (Tg) mice expressing three different chimeric PrP-Dpl proteins. Chi1 (amino acids 1–57 of Dpl replaced by amino acids 1–125 of PrP) and Chi2 (amino acids 1–66 of Dpl replaced by amino acids 1–134 of PrP) abrogated the pathogenicity of Dpl indicating that the presence of a N-terminal domain of PrP (23–134) reduced the toxicity of Dpl, as reported. However, when the amino acids 1–24 of Dpl were replaced by amino acids 1–124 of PrP, Chi3 Tg mice, which express the chimeric protein at a very low level, start developing ataxia at the age of 5–7 weeks. This phenotype was not counteracted by a single copy of full-length-PrPcbut rather by its overexpression, indicating the strong toxicity of the chimeric protein Chi3. Chi3 Tg mice exhibit severe cerebellar atrophy with a significant loss of granule cells. We concluded that aa25 to aa57 of Dpl, which are not present in Chi1 and Chi2 constructs, confer toxicity to the protein. We tested this possibility by using the 25–57 Dpl peptide in primary culture of mouse embryo cortical neurons and found a significant neurotoxic effect. This finding identifies a protein domain that plays a role in mediating Dpl-related toxicity.

Introduction Les angiœdemes acquis histaminiques idiopathiques (AOA-HI) sont une cause frequente d’angiœdemes (AO) sans urticaire [1] , [2] . Il s’agit d’une maladie mediee par les mastocytes, qui est decrite comme une forme clinique particuliere de l’urticaire chronique. Peu de donnees sont disponibles concernant cette variete d’AO. Les objectifs de cette etude sont de decrire les caracteristiques cliniques et epidemiologiques des patients souffrant d’AOA-HI. Methodes De 2014 a 2015, 534 patients ont ete vus au centre national de reference sur les angiœdemes (CREAK). Parmi eux, nous avons identifie 31 patients atteints d’AOA-HI, que nous avons inclus dans cette etude. Resultats Parmi les 31 patients souffrant d’AOA-HI, un ratio de 15 hommes pour 16 femmes a ete retrouve. Le delai diagnostique moyen etait de 6,3 ans. La duree moyenne des crises etait de 28,1 heures. La crise d’AO interessait la sphere ORL dans 54,8 % des cas. Une localisation linguale a ete trouvee dans 29 % des cas. Les hommes avaient un risque plus important que les femmes d’avoir une localisation ORL de leurs crises. Aucune intubation ni deces n’ont ete releves. La dose d’antihistaminiques necessaire pour controler les symptomes etait d’un comprime par jour pour 51,6 % des patients, 2 comprimes par jour pour 32 %, et 3 a 4 comprimes pour 16,1 % des patients. Conclusion Les AOA-HI sont caracterises par un retard diagnostique important, une atteinte frequente des voies respiratoires superieures pendant les crises, mais aucune atteinte severe avec mise en jeu du pronostic vital n’a ete rapportee. Comme au cours de l’urticaire chronique, un traitement antihistaminique de fond jusqu’a quatre fois la dose de l’AMM peut etre necessaire pour controler les symptomes.

Ficolins and pentraxins are soluble oligomeric pattern-recognition molecules that sense danger signals from pathogens and altered self-cells and might act synergistically in innate immune defense and maintenance of immune tolerance. The interaction of M-ficolin with the long pentraxin pentraxin 3 (PTX3) has been characterized using surface plasmon resonance spectroscopy and electron microscopy. M-ficolin was shown to bind PTX3 with high affinity in the presence of calcium ions. The interaction was abolished in the presence of EDTA and inhibited by N-acetyl-D-glucosamine, indicating involvement of the fibrinogen-like domain of M-ficolin. Removal of sialic acid from the single N-linked carbohydrate of the C-terminal domain of PTX3 abolished the interaction. Likewise, an M-ficolin mutant with impaired sialic acid-binding ability did not interact with PTX3. Interaction was also impaired when using the isolated recognition domain of M-ficolin or the monomeric C-terminal domain of PTX3, indicating requirement for oligomerization of both proteins. Electron microscopy analysis of the M-ficolin–PTX3 complexes revealed that the M-ficolin tetramer bound up to four PTX3 molecules. From a functional point of view, immobilized PTX3 was able to trigger M-ficolin–dependent activation of the lectin complement pathway. These data indicate that interaction of M-ficolin with PTX3 arises from its ability to bind sialylated ligands and thus differs from the binding to the short pentraxin C-reactive protein and from the binding of L-ficolin to PTX3. The M-ficolin–PTX3 interaction described in this study represents a novel case of cross-talk between soluble pattern-recognition molecules, lending further credit to the integrated view of humoral innate immunity that emerged recently.

International audience; Phagocytes play a central role in immune defense. Their dysfunction predisposes to infections. This study determined the expression level of nine receptors involved in Aspergillus immune response as well as the values of phagocytosis and production of radical oxygen species after Aspergillus stimulation, in a healthy adult population. The expression values of the CD11b, CD11c, CD14, CD18, CD35, CD181, CD182, CD282 and CD284 receptors on peripheral human monocytes and granulocytes was established. A heterogenous expression of the CD282 on granulocytes was observed as CD181, CD182 and CD284 on monocytes. Similarly, we observed considerable variation in the expression of these receptors over time. Only CD282 on granulocytes varied with sex. No variation with age was observed. Adherence of Aspergillus conidia to phagocytes was dependent of individual, sex, age and time. A better characterization of these innate immunity parameters is necessary to develop in the future an immunologic surveillance strategy for transplant recipients.