Original Approach for Automated Quantification of Antinuclear Autoantibodies by Indirect Immunofluorescence

Introduction. Indirect immunofluorescence (IIF) is the gold standard method for the detection of antinuclear antibodies (ANA) which are essential markers for the diagnosis of systemic autoimmune rheumatic diseases. For the discrimination of positive and negative samples, we propose here an original approach named Immunofluorescence for Computed Antinuclear antibody Rational Evaluation (ICARE) based on the calculation of a fluorescence index (FI). Methods. We made comparison between FI and visual evaluations on 237 consecutive samples and on a cohort of 25 patients with SLE. Results. We obtained very good technical performance of FI (95% sensitivity, 98% specificity, and a kappa of 0.92), even in a subgroup of weakly positive samples. A significant correlation between quantification of FI and IIF ANA titers was found (Spearman's ρ=0.80, P<0.0001). Clinical performance of ICARE was validated on a cohort of patients with SLE corroborating the fact that FI could represent an attractive alternative for the evaluation of antibody titer. Conclusion. Our results represent a major step for automated quantification of IIF ANA, opening attractive perspectives such as rapid sample screening and laboratory standardization

New treatment options for lupus – a focus on belimumab

Belimumab is the first biologic approved for patients with systemic lupus erythematosus (SLE). Belimumab is the first of a new class of drug targeting B cell-stimulating factors or their receptors to reach the market. Its target, BLyS, also known as BAFF (B cell-activating factor from the tumor necrosis factor family), is a type II transmembrane protein that exists in both membrane-bound and soluble forms. Additionally to a robust rational from murine experiments conducted in lupus prone mice, BLyS circulating levels are increased in SLE patients. After the negative results of a Phase II trial, two Phase III trials met their primary endpoints. Some SLE patients are still refractory to the standard options of care or necessitate prolonged high-dose corticotherapy and/or long-term immunosuppressive regimens. However, some experts still feel that the effect of this biologic might not be clinically relevant and blame the use of the new systemic lupus response index as well as the discrepancies between both trials and the noninclusion of the severe form of the disease as nephritis. In this review, we aim to discuss the characteristics of belimumab, critically evaluate the different steps of its development, and consider its future place in the arsenal against SLE, taking into account the patients’ perspectives

Vancomycin-induced Henoch-Schönlein purpura: a case report

<p>Abstract</p> <p>Introduction</p> <p>Henoch-Schönlein purpura is a small-vessel systemic vasculitis. Although its exact pathophysiology remains unknown, Henoch-Schönlein purpura has been reported in association with various medical conditions including hypersensitivity. We report the case of a patient with vancomycin-induced Henoch-Schönlein purpura.</p> <p>Case presentation</p> <p>A 42-year-old Caucasian man who had previously undergone a heart transplant was diagnosed as having an intra-abdominal abscess after he underwent a Hartmann procedure. At 15 days after initiation of antibiotic therapy including vancomycin, he developed a purpuric rash of the lower limbs, arthralgia, and macroscopic hematuria. At that time, our patient was already on hemodialysis for end-stage renal disease. Henoch-Schönlein purpura was diagnosed. After a second 15-day course of vancomycin, a second flare of Henoch-Schönlein purpura occurred. Skin biopsies showed leucocytoclastic vasculitis with IgA deposits and eosinophils in the peri-capillary inflammatory infiltrate, suggesting an allergic mechanism. After vancomycin was stopped, we did not observe any further flares. Only five cases of isolated cutaneous vasculitis, one case of lupus-like syndrome and one case of Henoch-Schönlein purpura after vancomycin treatment have been described to date in the literature.</p> <p>Conclusions</p> <p>Clinicians should be aware that systemic vasculitis can be induced by some treatments. Vancomycin is a widely prescribed antibiotic. Occurrence of rare but serious Henoch-Schönlein purpura associated with vancomycin requires its prompt discontinuation.</p

Acute tubulointerstitial nephritis complicating Legionnaires' disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>Legionnaires' disease is recognized as a multi-systemic illness. Afflicted patients may have pulmonary, renal, gastrointestinal tract and central nervous system complications. However, renal insufficiency is uncommon. The spectrum of renal involvement may range from a mild and transient elevation of serum creatinine levels to anuric renal failure requiring dialysis and may be linked to several causes. In our present case report, we would like to draw attention to the importance of the pathological documentation of acute renal failure by reporting a case of a patient with acute tubulointerstitial nephritis complicating Legionnaires' disease.</p> <p>Case presentation</p> <p>A 55-year-old Caucasian man was admitted to our hospital for community-acquired pneumonia complicated by acute renal failure. <it>Legionella pneumophila </it>serogroup type 1 was diagnosed. Although the patient's respiratory illness responded to intravenous erythromycin and ofloxacin therapy, his renal failure worsened, he became anuric, and hemodialysis was started. A renal biopsy was performed, which revealed severe tubulointerstitial nephritis. After initiation of steroid therapy, his renal function improved dramatically.</p> <p>Conclusions</p> <p>This case highlights the importance of kidney biopsies in cases where acute renal failure is a complicating factor in Legionnaires' disease. If the presence of acute tubulointerstitial nephritis can be confirmed, it will likely respond favorably to steroidal treatment and thus irreversible renal damage and chronic renal failure will be avoided.</p

Both Monoclonal and Polyclonal Immunoglobulin Contingents Mediate Complement Activation in Monoclonal Gammopathy Associated-C3 Glomerulopathy

C3 glomerulopathy (C3G) results from acquired or genetic abnormalities in the complement alternative pathway (AP). C3G with monoclonal immunoglobulin (MIg-C3G) was recently included in the spectrum of “monoclonal gammopathy of renal significance.” However, mechanisms of complement dysregulation in MIg-C3G are not described and the pathogenic effect of the monoclonal immunoglobulin is not understood. The purpose of this study was to investigate the mechanisms of complement dysregulation in a cohort of 41 patients with MIg-C3G. Low C3 level and elevated sC5b-9, both biomarkers of C3 and C5 convertase activation, were present in 44 and 78% of patients, respectively. Rare pathogenic variants were identified in 2/28 (7%) tested patients suggesting that the disease is acquired in a large majority of patients. Anti-complement auto-antibodies were found in 20/41 (49%) patients, including anti-FH (17%), anti-CR1 (27%), anti-FI (5%) auto-antibodies, and C3 Nephritic Factor (7%) and were polyclonal in 77% of patients. Using cofactor assay, the regulation of the AP was altered in presence of purified IgG from 3/9 and 4/7 patients with anti-FH or anti-CR1 antibodies respectively. By using fluid and solid phase AP activation, we showed that total purified IgG of 22/34 (65%) MIg-C3G patients were able to enhance C3 convertase activity. In five documented cases, we showed that the C3 convertase enhancement was mostly due to the monoclonal immunoglobulin, thus paving the way for a new mechanism of complement dysregulation in C3G. All together the results highlight the contribution of both polyclonal and monoclonal Ig in MIg-C3G. They provide direct insights to treatment approaches and opened up a potential way to a personalized therapeutic strategy based on chemotherapy adapted to the B cell clone or immunosuppressive therapy

Role of uremic toxins in the imbalance between endothelial lesion and repair

L'insuffisance rénale chronique (IRC) est associée à une importante morbidité et mortalité cardio-vasculaire, à laquelle participent l'inflammation chronique, le stress oxydant et la dysfonction endothéliale. Les toxines urémiques sont des solutés s'accumulant dans le sérum et les tissus des patients IRC. Parmi elles, les toxines urémiques liées aux protéines sont mal épurées par la dialyse, et ont une toxicité endothéliale démontrée in vitro. Nous avons démontré que l'indoxyl sulfate (IS), une toxine liée aux protéines, induit la production de radicaux oxygénés (ROS) par les cellules endothéliales en culture (HUVEC), par le biais de l'activation de la NADP(H) oxydase, et par une déplétion en glutathion intracellulaire. Ce stress oxydant était induit par des concentrations d'IS rencontrées dans le sérum des patients IRC. Les patients IRC ont un niveau élevé de microparticules endothéliales (MPE), marqueur d'activation et de lésion endothéliale, et un nombre diminué de progéniteurs endothéliaux circulants (PEC), qui représentent les capacités de réparation de l'endothélium lésé. Nous avons souhaité étudier si les toxines urémiques jouaient un rôle dans ce déséquilibre. Chez des patients hémodialysés (HD), nous avons démontré que le nombre de PEC CD34+/CD133+ était inversement corrélé aux taux de 3 toxines urémiques, l'indole-3-acétique acide (IAA, une toxine proche de l'IS) et la ß2 microglobuline. In vitro, l'IAA induit l'apoptose des progéniteurs CD133+, et cet effet est imbibé par l'ajout d'érythropoïétine (EPO) au milieu de culture. Le sérum urémique induit l'apoptose des PEC. Bien que le nombre des PEC soit diminué chez les patients HD par rapport aux contrôles, leur nombre est positivement corrélé à 2 marqueurs de lésion vasculaire : le nombre de MPE, et la rigidité artérielle évaluée par la vitesse de l'onde de pouls aortique. Cela suggère que les PEC restent mobilisables chez les patients HD, en réponse aux lésions vasculaires, peut-être en partie grâce à leur traitement par EPO. En conclusion, les toxines urémiques participent à la dysfonction endothéliale des patients IRC, en augmentant le stress oxydant endothélial et la libération de MPE, et réduisent les capacités de réparation endothéliale en diminuant la survie des PEC.Chronic kidney disease (CKD) is associated with dramatically increased cardio-vascular morbidity and mortality. Not only do traditional risk factors explain this accelerated atherosclerosis, but also chronic inflammation, oxidative stress and endothelial dysfunction. Uremic toxins are solutes accumulating in serum and tissues of CKD patients. Among them, protein-bound uremic toxins are poorly removed by haemodialysis (HD), and have shown deleterious effects on cultured endothelial cells (HUVEC). We showed that indoxyl suphate (IS), a protein-bound toxin, induces reactive oxygen species production in HUVEC, through activation of NAD(P)H oxidase, and intracellular glutathione depletion. This induction of oxidative stress was observed for concentrations of IS found in CKD patients. CKD patients exhibit high levels of endothelial microparticles (EMP), a marker of endothelial lesion, and low levels of endothelial progenitor cells (EPC), originating from bone marrow and implied in endothelial repair. We asked whetehr uremic toxins could play a role in this imbalance. In HD patients, we showed that the number of CD34+/CD133+ EPC was inversely correlated with the serum levels of two uremic toxins, indole-3-acetic acid (IAA, a protein-bound uremic toxin close to IS) and ß2microglobulin. In vitro, IAA induced apoptosis of CD133+ cells, unless erythropoietin was added to the medium. Uremic serum induced EPC apoptosis. Although endothelial progenitor cell number was reduced in CKD patients compared to healthy controls, it was positively correlated with two markers of vascular lesion : the number of EMP in serum, and the pulse wave velocity reflecting arterial stifness. This suggests that EPC can be mobilized in the circulation upon vessel injury, in spite of uremic toxicity, and maybe thanks to erythropoietin treatment in HD patients. In conclusion, uremic toxins induce endothelial dysfunction, assessed by increased endothelial oxidative stress and shedding of EMP, and reduce regeneration capacities of endothelium. They are probably key actors in cardio-vascular risk of CKD patients

Progéniteurs endothéliaux circulants, toxines urémiques et rigidité artérielle chez les patients en hémodialyse chronique

L insuffisance rénale chronique (IRC) entraîne une athérosclérose accélérée. Un dysfonctionnement endothélial, première étape de l athérosclérose, est présent chez les patients IRC. Plusieurs toxines urémiques ont montré un effet délétère sur les cellules endothéliales in vitro. Il est nécessaire de rechercher des marqueurs de dysfonctionnement endothélial in vivo pour démontrer l effet des toxines urémiques. L un de ces marqueurs est le nombre de progéniteurs endothéliaux circulants (PEC), dont la diminution pourrait causer un défaut de réparation endothéliale. Ce travail a pour objectif principal de compter les PEC chez des patients hémodialysés chroniques (HDC) non diabétiques, et de rechercher des corrélations entre le nombre de PEC, les taux de certaines toxines et les marqueurs de lésions vasculaires. Trente-huit HDC sont étudiés. Les PEC sont comptés par 3 méthodes : cytométrie en flux (cellules CD34+, CD133+/CD34+ et KDR+/CD34+), test clonogénique (colony forming unit endothelial cells) et culture cellulaire (cellules angiogéniques circulantes). Les toxines dosées sont l homocystéine, la 2 microglobuline ( 2m), le p-crésol sulfate, l indoxyl sulfate et l indole-3 acétique acide (IAA). Les marqueurs vasculaires étudiés sont la pression pulsée, la vitesse de l onde de pouls aortique (VOP), et l index de pression systolique cheville/bras (IPS). Les résultats montrent une corrélation positive entre le nombre de PEC et la VOP, et une corrélation négative entre le nombre de PEC et les taux de 2m et d IAA. Cette étude établit pour la première fois une relation entre le nombre de PEC et la rigidité artérielle chez les patients HDC. Elle suggère également que certaines toxines urémiques pourraient avoir une influence sur la mobilisation des PEC.Patients with chronic renal failure (CRF) experience accelerated atherosclerosis, which could be partly due to some uremic toxins. Endothelial dysfunction, one of the first steps in atherogenesis, is encountered in CRF patients. Several uremic toxins have shown deleterious effects on endothelial cells in vitro. It is now necessary to search for endothelial dysfunction markers in vivo, and to demonstrate the role of uremic toxins on these markers. One of these markers is represented by endothelial progenitor cells (EPC), because decreased number of EPC can impair endothelial repair. This work aimed to count EPC in non diabetic patients on maintenance hemodialysis (HD), and to find correlations between EPC number and uremic toxins levels, as well as between EPC number and vascular lesions in this population. Thirty-eight patients were studied. EPC were counted by 3 methods: flow cytometry (CD34+, CD133+/CD34+ and KDR+/CD34+ cells), colony forming unit assay (CFU-EC) and in vitro culture (circulating angiogenic cells). The following uremic toxins were measured: homocysteine, 2 microglobulin ( 2m), p-cresol sulfate, indoxyl sulfate and indole-3 acetic acid (IAA). Vascular lesions were evaluated by pulse pressure, aortic pulse wave velocity (PWV) and ankle/arm blood pressure index (AAI). Results showed a strong correlation between EPC number and PWV. Morover, an inverse correlation was shown between EPC number and the levels of 2m and IAA. This study shows for the first time a link between EPC number and arterial stiffness in HD patients. It also suggests that some uremic toxins may influence EPC number.AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Categorization of patients with systemic lupus erythematosus using disease activity, patient-reported outcomes, and transcriptomic signatures

International audienceObjective Patients with systemic lupus erythematosus (SLE) display symptoms that are not always related to disease activity and may distort clinical trial results. Recently, a clinical categorization based on the presence of type 1 (inflammatory manifestations) and/or type 2 (widespread pain, fatigue, depression) symptoms has been proposed in SLE. Our aim was to develop a type 2 score derived from the Short-Form health survey (SF-36) to categorize SLE patients and to compare immunological and transcriptomic profiles between groups.Method Seventeen items from the SF-36 were selected to build a type 2 score for 50 SLE patients (100 visits; LUPUCE cohort), and the SLEDAI was used to define type 1 symptoms. Patients were categorized into four groups: minimal (no symptoms), type 1, type 2, and mixed (both type 1 and type 2 symptoms). Clinical, immunological, and transcriptomic profiles were compared between the groups.Results Type 2 scores ranged from 0 to 31, with a cutoff value of 14 (75th percentile). The sample categorization was minimal in 39%, type 1 in 37%, and type 2 in 9%, and mixed in 15%. Type 2 patients were older than minimal patients and had a longer disease duration than type 1 and mixed patients. Immunological data and modular interferon signatures did not differ between the groups.Conclusion Patients with SLE can be categorized into four clinical groups using the SLEDAI score and our SF-36-derived type 2 score. This categorization is non-redundant with immunological or transcriptomic profiles and could prove useful to stratify patients in clinical trials

Weaning Maintenance Therapy in Lupus Nephritis: For Whom, When, and How?

International audienceLupus nephritis (LN) is one of the main determinants of the severity of systemic lupus erythematosus (SLE). LN flares can lead to organ damage with chronic kidney disease (CKD) or even end-stage kidney disease (ESKD) and impair patients' survival. The "treat-to-target" strategy, which aims at obtaining and maintaining remission or low disease activity of SLE to alleviate symptoms and prevent organ damage, also refers to the control of residual activity in the kidney. But damage in SLE can also come from treatments, and toxicities related to long-term use of treatments should be prevented. This may contribute to the frequent nonadherence in patients with SLE. The de-escalation or even weaning of treatments whenever possible, or "think-to-untreat" (T2U) strategy, is to be considered in patients with LN. This possibility of treatment weaning in LN was explored in retrospective cohorts, on the basis of long-term clinical remission. It was also proposed prospectively with a kidney-biopsy-based approach, combining clinical and pathologic remission to secure treatment weaning. The WIN-Lupus trial was the first randomized controlled trial comparing the continuation to the discontinuation of maintenance immunosuppressive therapy (IST) after 2 to 3 years in patients with LN in remission. It showed a higher risk of severe SLE flares in patients who discontinued treatment, but also a possibility of weaning without flare in some patients, who need to be better identified. We propose here a narrative review of the available literature on the weaning of treatment in LN and discuss how to secure a T2U strategy

Unsupervised clustering analysis of data from an online community to identify lupus patient profiles with regards to treatment preferences

International audienceObjective: Lupus is a chronic complex autoimmune disease. Non-adherence to treatment can affect patient outcomes. Considering patients' preferences into medical decisions may increase acceptance to their medication. The PREFERLUP study used unsupervised clustering analysis to identify profiles of patients with similar treatment preferences in an online community of French lupus patients. Methods: An online survey was conducted in adult lupus patients from the Carenity community between August 2018 and April 2019. Multiple Correspondence Analysis (MCA) was used with three unsupervised clustering methods (hierarchical, kmeans and partitioning around medoids). Several indicators (measure of connectivity, Dunn index and Silhouette width) were used to select the best clustering algorithm and choose the number of clusters. Results: The 268 participants were mostly female (96%), with a mean age of 44.3 years 83% fulfilled the American College of Rheumatology (ACR) self-reported diagnostic criteria for systemic lupus erythematosus. Overall, the preferred route of administration was oral (62%) and the most important feature of an ideal drug was a low risk of side-effects (32%). Hierarchical clustering identified three clusters. Cluster 1 (59%) comprised patients with few comorbidities and a poor ability to identify oncoming flares; 84% of these patients desired oral treatments with limited side-effects. Cluster 2 (13%) comprised younger patients, who had already participated in a clinical trial, were willing to use implants and valued the compatibility of treatments with pregnancy. Cluster 3 (28%) comprised patients with a longer lupus duration, poorer control of the disease and more comorbidities; these patients mainly valued implants and injections and expected a reduction of corticosteroid intake. Conclusions: Different profiles of lupus patients were identified according to their drug preferences. These clusters could help physicians tailor their therapeutic proposals to take into account individual patient preferences, which could have a positive impact on treatment acceptance and then adherence. The study highlights the value of data acquired directly from patient communities