Anti-PM-Scl antibodies-positive patients encompass three different groups with distinct prognoses.

OBJECTIVE: To help identify homogeneous subgroups among patients with anti-PM-scleroderma-antibodies (PM-Scl-Abs) positive auto-immune diseases regardless of diagnostic classifications. MATERIAL AND METHODS: This multicentric (four hospitals) retrospective study collected all consecutive patients (from 2011 to 2021) with positive testing for anti-PM-Scl-Abs in a context of CTD. Subgroups of patients with similar clinico-biological phenotypes were defined using unsupervised multiple correspondence analysis and hierarchical clustering analysis of the features recorded in the first year of follow-up. RESULTS: One hundred and forty-two patients with anti-PM-Scl-Abs were evaluated and 129 patients were included in the clustering analysis and divided into three clusters. Cluster 1 (n = 47) included patients with frequent skin thickening, digestive involvement and interstitial lung disease (ILD) with non-specific interstitial pneumonia (NSIP). They were more likely to develop progressive fibrosing ILD. Cluster 2 (n = 36) included patients who all featured NSIP with frequent organizing pneumonia-associated pattern and mechanic's hands. This subgroup had increased risk of relapse and ILD was characterized by a good functional outcome. Cluster 3 (n = 46) was characterized by predominant or isolated musculoskeletal involvement and frequently matched UCTD criteria. Although very frequent among anti-PM-Scl-Abs positive patients, muscle involvement was less discriminating compared with skin thickening and ILD pattern to classify patients into subgroups. CONCLUSION: Anti-PM-Scl-Abs associated auto-immune diseases are segregated into three subgroups with distinct clinical phenotype and outcomes. Skin thickening and NSIP are determinant predictors in segregation of theses populations.

Changes of anti-citrullinated peptide antibodies titers after biologic treatment in patients with rheumatoid arthritis: a systematic literature review and retrospective study.

OBJECTIVES: There is an increasing body of evidence suggesting a direct pathophysiological role of anti-citrullinated peptide antibodies (ACPA) in rheumatoid arthritis (RA), and immunological remission could be a target for treatment. However, data related to the ability of biologics to reduce ACPA titres are contradictory.We aimed to evaluate the changes in ACPA titres after treatment with different biologics in patients with RA. METHODS: As a first step, a systematic review of the literature available on 3 biologics (TNFi, abatacept and rituximab) and ACPA in patients with RA was performed in Pubmed and Cochrane. As a second step, a retrospective study was performed: all RA patients treated with the 3 above-mentioned biologics were identified. To be included in the analysis, patients had to have at least two titres of ACPA (one before and one after biologic treatment) available. ACPA titres were compared before and after treatment in each of the treatment groups. RESULTS: As a result of the literature review, 24 articles were retained confirming that the data on change in ACPA under biologics is contradictory, particularly for abatacept and TNFi. 144 RA patients (79.3% female, mean age: 56 years) were included in the retrospective analysis: 59 patients had received rituximab, 31 abatacept, 55 TNFi. ACPA titres decreased significantly with rituximab but not with abatacept nor TNFi. Modelling of ACPA titres over follow-up confirmed the significant decrease of ACPA over time rituximab. CONCLUSIONS: In this real-life study, ACPA titres only significantly decreased after treatment with rituximab.

Bullous pemphigoid: Three main clusters defining 3 outcome profiles.

BACKGROUND: Bullous pemphigoid (BP) is the most common autoimmune blistering disorder. Its presentation is polymorphic. OBJECTIVE: To investigate different clinical and biological profiles of BP. METHODS: We conducted a retrospective 2-center study including all BP patients seen between January 1, 2015, and February 28, 2021. We performed hierarchical clustering on principal components. RESULTS: Three clusters were identified. Patients in cluster 1 (n = 155) were older than those in clusters 2 (n = 89) and 3 (n = 35; P < .0001), more frequently presented pauci-bullous BP (n = 63 [41%] vs 14 [16%] and 2 [6%], respectively; P < .0001) and had anti-BP230 antibodies in 87% of cases. More than 100 blisters were observed in 14 patients (40%) from cluster 3, versus 3 (2%) from cluster 1 and 0 (0%) from cluster 2 (P < .0001). Frequency of mucosal involvement was higher in cluster 3 (n = 32 [91%, including epiglottis in 40%] vs 11 [7%] and 34 [38%]; P < .0001). In clusters 2 and 3, 70% and 74% of patients had antibodies targeting only BP180. Those in cluster 3 received more lines of systemic treatment and experienced more relapses. LIMITATIONS: Retrospective study without immunoelectron microscopy. CONCLUSION: We identified 3 different BP clusters, including one corresponding to severe BP180+ BP230- BP with features common to mucous membrane pemphigoid.

Doctor's aptitude for switching from innovator etanercept to biosimilar etanercept in inflammatory rheumatic diseases: experience from a single French rheumatology tertiary care center.

OBJECTIVES: To describe the switch to biosimilar etanercept (bETN), evaluate factors associated with this switch, and evaluate the efficacy of this switch in a real-life setting METHODS: We included patients, from October 2016 to April 2017, with rheumatoid arthritis (RA) and spondyloarthritis (SpA) who received innovator ETN (iETN) for at least 6 months. After receiving information on biosimilars, all physicians were invited to propose a switch from iETN to bETN. Factors associated with bETN discontinuation were explored by univariate and multivariate analyses. We estimated the proportion of patients still on bETN over time by Kaplan-Meier survival analysis. We assessed serum trough concentrations of iETN and bETN and anti-drug antibodies to ETN. RESULTS: Overall, 183 outpatients were eligible for a potential switch; 94 (51.6%) switched from iETN to bETN. The probability of a switch was greater with an older than younger aged physician (mean [SD] age 50.4 [14.3] with a switch vs 44.8 [11.3] with no switch, p = 0.005) and the physician having a full-time academic position than other position (56.4% with a switch vs 13.5% with no switch, p < 0.001). After a 6-month follow-up, bETN retention rate was 83% (95% CI: 0.76-0.92). The first cause of bETN discontinuation was inefficacy (50%). On multivariate analysis, no factor was independently associated with a bETN switch or discontinuation. Drug trough levels did not significantly differ by discontinuation or continuation of bETN. No patient showed anti-drug antibodies. CONCLUSION: The probability of switching from iETN to bETN was likely related to physician characteristics.

mTOR pathway is activated in endothelial cells from patients with Takayasu arteritis and is modulated by serum immunoglobulin G.

Objectives: Takayasu arteritis (TA) and GCA are large-vessel vasculitides characterized by vascular remodelling involving endothelial cells (ECs) and vascular smooth muscle cells. Mammalian target of rapamycin (mTOR) pathway has been involved in vascular remodelling. We hypothesized that the mTOR pathway was involved in the pathogenesis of large-vessel vasculitis. Methods: We used IF analysis on aortic and temporal artery biopsies from patients with TA and GCA to assess the involvement of the mTOR pathway and searched for antibodies targeting ECs in serum by IIF and cellular ELISA. We evaluated in vitro the effect of purified IgG from patients on mTOR pathway activation and cell proliferation. Results: IF analyses on tissues revealed that both mTORC1 and mTORC2 are activated specifically in ECs from TA patients but not in ECs from GCA patients and healthy controls (HCs). Using IIF and ELISA, we observed higher levels of antibodies binding to ECs in TA patients compared with GCA patients and HCs. Using western blot, we demonstrated that purified IgG from TA patients caused mTORC1 activation in ECs, whereas this effect was not observed with purified IgG from GCA patients or HCs. Purified IgG from TA patients induced a significant EC proliferation compared with to GCA and HC IgG, and this effect was decreased after EC exposure with sirolimus, a specific mTOR inhibitor and PI3K inhibitor. Conclusion: Our results suggest that antibodies targeting ECs drive endothelial remodelling in TA through activation of the mTOR pathway, but not in GCA. Inhibition of the mTOR pathway could represent a therapeutic option in TA.

Neutralizing IFN-γ autoantibodies are rare and pathogenic in HLA-DRB1*15:02 or 16:02 individuals.

BACKGROUNDWeakly virulent environmental mycobacteria (EM) can cause severe disease in HLA-DRB1*15:02 or 16:02 adults harboring neutralizing anti-IFN-γ autoantibodies (nAIGAs). The overall prevalence of nAIGAs in the general population is unknown, as are the penetrance of nAIGAs in HLA-DRB1*15:02 or 16:02 individuals and the proportion of patients with unexplained, adult-onset EM infections carrying nAIGAs.METHODSThis study analyzed the detection and neutralization of anti-IFN-γ autoantibodies (auto-Abs) from 8,430 healthy individuals of the general population, 257 HLA-DRB1*15:02 or 16:02 carriers, 1,063 patients with autoimmune disease, and 497 patients with unexplained severe disease due to EM.RESULTSWe found that anti-IFN-γ auto-Abs detected in 4,148 of 8,430 healthy individuals (49.2%) from the general population of an unknown HLA-DRB1 genotype were not neutralizing. Moreover, we did not find nAIGAs in 257 individuals carrying HLA-DRB1* 15:02 or 16:02. Additionally, nAIGAs were absent in 1,063 patients with an autoimmune disease. Finally, 7 of 497 patients (1.4%) with unexplained severe disease due to EM harbored nAIGAs.CONCLUSIONThese findings suggest that nAIGAs are isolated and that their penetrance in HLA-DRB1*15:02 or 16:02 individuals is low, implying that they may be triggered by rare germline or somatic variants. In contrast, the risk of mycobacterial disease in patients with nAIGAs is high, confirming that these nAIGAs are the cause of EM disease.FUNDINGThe Laboratory of Human Genetics of Infectious Diseases is supported by the Howard Hughes Medical Institute, the Rockefeller University, the St. Giles Foundation, the National Institutes of Health (NIH) (R01AI095983 and U19AIN1625568), the National Center for Advancing Translational Sciences (NCATS), the NIH Clinical and Translational Science Award (CTSA) program (UL1 TR001866), the French National Research Agency (ANR) under the "Investments for the Future" program (ANR-10-IAHU-01), the Integrative Biology of Emerging Infectious Diseases Laboratory of Excellence (ANR-10-LABX-62-IBEID), ANR-GENMSMD (ANR-16-CE17-0005-01), ANR-MAFMACRO (ANR-22-CE92-0008), ANRSECTZ170784, the French Foundation for Medical Research (FRM) (EQU201903007798), the ANRS-COV05, ANR GENVIR (ANR-20-CE93-003), and ANR AI2D (ANR-22-CE15-0046) projects, the ANR-RHU program (ANR-21-RHUS-08-COVIFERON), the European Union's Horizon 2020 research and innovation program under grant agreement no. 824110 (EASI-genomics), the Square Foundation, Grandir - Fonds de solidarité pour l'enfance, the Fondation du Souffle, the SCOR Corporate Foundation for Science, the Battersea & Bowery Advisory Group, William E. Ford, General Atlantic's Chairman and Chief Executive Officer, Gabriel Caillaux, General Atlantic's Co-President, Managing Director, and Head of business in EMEA, and the General Atlantic Foundation, Institut National de la Santé et de la Recherche Médicale (INSERM) and of Paris Cité University. JR was supported by the INSERM PhD program for doctors of pharmacy (poste d'accueil INSERM). JR and TLV were supported by the Bettencourt-Schueller Foundation and the MD-PhD program of the Imagine Institute. MO was supported by the David Rockefeller Graduate Program, the Funai Foundation for Information Technology (FFIT), the Honjo International Scholarship Foundation (HISF), and the New York Hideyo Noguchi Memorial Society (HNMS).

Autoinflammation in patients with leukocytic CBL loss of heterozygosity is caused by constitutive ERK-mediated monocyte activation.

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Subacute cutaneous lupus erythematosus induced and exacerbated by proton pump inhibitors.

BACKGROUND: Subacute cutaneous lupus erythematosus (SCLE) can be induced by numerous drugs. We report 3 cases of SCLE induced by proton pump inhibitors (PPIs). OBJECTIVE: To highlight a rare cutaneous side effect induced by a frequently prescribed drug such as a PPI. CASE REPORTS: Case 1 was a 30-year-old man who developed multiple annular plaques over the trunk and lower limbs 1 month after the initiation of pantoprazole. Antinuclear antibodies (ANA) were positive with anti-Ro/SSA and anti-La/SSB antibodies, and histology confirmed the diagnosis. Clinical improvement was achieved 8 weeks after the discontinuation of pantoprazole and the introduction of a treatment combining topical steroids and hydroxychloroquine. Lesions relapsed when pantoprazole was accidentally rechallenged. The second case was a 31-year-old woman, 28 weeks pregnant, who presented erythematous annular plaques over the trunk 7 weeks after starting esomeprazole. ANA and anti-Ro/SSA antibodies were positive, and the histology was compatible with SCLE. Fetal ultrasound was normal. She was treated with topical and oral steroids and hydroxychloroquine. Clinical improvement was achieved 4 weeks after the discontinuation of esomeprazole. The third case was a 57-year-old woman with systemic erythematosus lupus presenting annular and psoriasiform lesions on the trunk for 15 months. She was treated successively with hydroxychloroquine, azathioprine, mycophenolate mofetil and methotrexate with prednisone. A review of her drug history revealed the introduction of omeprazole a few weeks before the first appearance of skin lesions and omeprazole was contraindicated. CONCLUSION: SCLE should systematically be suspected in case of eruption after the introduction of PPI. The risk of fetal cardiac complications is important in pregnant women.

Sialylation levels of anti-proteinase 3 antibodies are associated with the activity of granulomatosis with polyangiitis (Wegener's).

OBJECTIVE: To investigate whether the glycosylation and sialylation levels of anti-proteinase 3 (anti-PR3) antibodies could affect their pathogenicity, and whether these levels could be correlated with the activity of granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: Forty-two serum samples positive for anti-PR3 antibodies from 42 patients with active or weakly active/inactive GPA were included. Anti-PR3 antibodies were assayed by enzyme-linked immunosorbent assay, and their levels of glycosylation and sialylation were assessed by enzyme-linked lectin assay. The glycosylation and sialylation levels of IgG purified from the serum of healthy donors and patients with active, remitted, or weakly active disease were assessed by permethylation and mass spectrometry analysis of glycans, following neuraminidase digestion. The neutrophil oxidative burst induced by purified IgG was assayed by spectrofluorimetry. RESULTS: The mean sialylation ratio of anti-PR3 antibodies was significantly lower in patients with active disease than in patients with weakly active or inactive disease, and this was inversely correlated with the Birmingham Vasculitis Activity Score (BVAS) (P < 0.0001). Similar results were obtained using the BVAS/GPA. The area under the receiver operating characteristic curve for the sialylation ratio of anti-PR3 antibodies, as a test to determine the activity of GPA, was 0.82 (P = 0.0006). The characterization of N-glycans showed a decrease in 2,6-linked sialylated N-glycans and an increase in dHex1 Hex3 HexNAc4 (mass/charge 1,836) agalactosylated structures in purified IgG from patients with active disease compared with controls. The anti-PR3 antibody-induced oxidative burst of neutrophils was inversely correlated with the sialylation levels of anti-PR3 IgG. CONCLUSION: The sialylation level of anti-PR3 antibodies contributes to the clinical activity of GPA, by modulating the oxidative burst of neutrophils induced by these autoantibodies.

Immunogenicity of Rituximab biosimilar GP2013 in chronic inflammatory rheumatic disorders in daily clinical practice.

OBJECTIVE: To study in daily practice the risk of immunogenicity of patients treated with the biosimilar rituximab (RTX) GP2013 used for chronic inflammatory rheumatic disorders. METHODS: A prospective monocentric routine care study was carried out between September 2018 and May 2021, including consecutive patients treated with the biosimilar RTX GP2013. Biosamples were taken before each infusion to quantify anti-RTX antibodies (ADAbs) and serum RTX trough levels by ELISA (Lisa Tracker Duo Rituximab, LTR005, Theradiag). RESULTS: 168 GP2013-treated patients were included (129 who switched from originator RTX and 39 originator RTX naïve). The analysis of 602 samples identified 15 patients (8%) with positive ADAbs including 6 and 9 with transient and persistent ADAbs, respectively. The switch from originator RTX to GP2013 did not increase the risk of immunogenicity, with an incidence rate of 0.8 for 100 patient years. The frequency of persistent ADAs was higher in non-RA patients (5/56, 9% vs. 4/112, 3.5%). Patients with positive persistent ADAbs were more frequently non-caucasian (7/9, 78%, vs. 56/159, 35%, p<0.01) and all had detectable circulating B cells (vs. 40% in ADAb-negative patients, P<0.001). ADAb positivity was not associated with disease activity or RTX discontinuation but patients with ADAb titers >100 ng/mL experienced reduced treatment efficacy or severe infusion-related reaction. CONCLUSION: Within the study duration, the immunogenicity of GP2013 is a rare event affecting the pharmacodynamics of RTX. Although development of ADAbs had no impact on treatment discontinuation, possible harmful consequences may be observed in patients with high antibody levels.

Quantification of infliximab and adalimumab in human plasma by a liquid chromatography tandem mass spectrometry kit and comparison with two ELISA methods.

Background: This study compared the performance of plasma infliximab and adalimumab quantification using a commercially available kit (mAbXmise kit) and mass spectrometry readout to that of two ELISA methods in patients treated for inflammatory bowel disease. Methods & results: The mAbXmise method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) was linear from 2 to 100 µg/ml. It was validated according to international guidelines. Regarding cross-validation for infliximab (n = 70), the mean bias with LC-MS/MS assay was approximately threefold higher with the commercial ELISA assay compared with the in-house ELISA (-6.1 vs -1.8 µg/ml, respectively). The mean bias between the LC-MS/MS assay and in-house ELISA was -1.2 µg/ml for adalimumab (n = 35). Conclusion: The LC-MS/MS method is a powerful alternative to immunoassays to monitor concentrations of infliximab and adalimumab.

Preexisting Autoantibodies and Immune Related Adverse Events in Metastatic Urothelial Carcinoma Patients Treated by Pembrolizumab.

INTRODUCTION: Immune checkpoint inhibitor are standard therapy in metastatic urothelial carcinoma. No predictive biomarker of immune related adverse events (iRAE) exists. Antinuclear antibodies (ANA) can be the sign of a subclinical autoimmune condition that could be enhanced by Immune checkpoint inhibitor. We decided to assess the predictive value of baseline autoantibodies and ANA for iRAE in metastatic urothelial carcinoma patients treated with pembrolizumab and explore their prognostic signification. PATIENTS AND METHOD: Data concerning patients treated in our institution between 2015 and 2020 with pembrolizumab for metastatic urothelial carcinoma with available baseline value of ANA and other autoantibodies was collected. ANA with titer >1/80 were defined positive. RESULTS: A total of 68 patients were included. Fifty-five (80%) had ANA >1/80 and among them 21 patients (30%) had ANA >1/160. Seven patients with ANA >160 (33%) presented iRAE vs. 5 patients (10%) in the rest of the population. Presence of ANA >160 was significantly associated with iRAE (P = .029) and limiting toxicity (P = .048) in univariate analysis. iRAE tend to occur earlier, before the third cycle, for patients with ANA >1/160 as compared to rest of the patients (28% vs. 6%, P = .052). Exploratory analysis did not reveal correlation between progression free survival or overall survival and ANA >1/160 in univariate or in multivariate analysis including the Bellmunt score (HR = 0.7, 95%CI [0.38-1.35], P = .5). CONCLUSION: The presence of ANA >1/160 is associated with iRAE and limiting toxicity of pembrolizumab.

Dynamics of circulating calprotectin accurately predict the outcome of moderate COVID-19 patients.

BACKGROUND: Severe COVID-19 is associated with a high circulating level of calprotectin, the S100A8/S100A9 alarmin heterodimer. Baseline calprotectin amount measured in peripheral blood at diagnosis correlates with disease severity. The optimal use of this biomarker along COVID-19 course remains to be delineated. METHODS: We focused on patients with a WHO-defined moderate COVID-19 requiring hospitalization in a medical ward. We collected plasma and serum from three independent cohorts (N = 626 patients) and measured calprotectin amount at admission. We performed longitudinal measures of calprotectin in 457 of these patients (1461 samples) and used a joint latent class mixture model in which classes were defined by age, body mass index and comorbidities to identify calprotectin trajectories predicting the risk of transfer into an intensive care unit or death. FINDINGS: After adjustment for age, sex, body mass index and comorbidities, the predictive value of baseline calprotectin in patients with moderate COVID19 could be refined by serial monitoring of the biomarker. We discriminated three calprotectin trajectories associated with low, moderate, and high risk of poor outcome, and we designed an algorithm available as online software (https://calpla.gustaveroussy.fr:8443/) to monitor the probability of a poor outcome in individual patients with moderate COVID-19. INTERPRETATION: These results emphasize the clinical interest of serial monitoring of calprotectin amount in the peripheral blood to anticipate the risk of poor outcomes in patients with moderate COVID-19 hospitalized in a standard care unit. FUNDING: The study received support (research grants) from ThermoFisher immunodiagnostics (France) and Gustave Roussy Foundation.

Selective oxidation of DNA topoisomerase 1 induces systemic sclerosis in the mouse.

Systemic sclerosis (SSc) is a connective tissue disorder of great clinical heterogeneity. Its pathophysiology remains unclear. Our aim was to evaluate the relative roles of reactive oxygen species (ROS) and of the immune system using an original model of SSc. BALB/c and immunodeficient BALB/c SCID mice were injected s.c. with prooxidative agents (hydroxyl radicals, hypochlorous acid, peroxynitrites, superoxide anions), bleomycin, or PBS everyday for 6 wk. Skin and lung fibrosis were assessed by histological and biochemical methods. Autoantibodies were detected by ELISA. The effects of mouse sera on H(2)O(2) production by endothelial cells and on fibroblast proliferation, and serum concentrations in advanced oxidation protein products (AOPP) were compared with sera from patients with limited or diffuse SSc. We observed that s.c. peroxynitrites induced skin fibrosis and serum anti-CENP-B Abs that characterize limited SSc, whereas hypochlorite or hydroxyl radicals induced cutaneous and lung fibrosis and anti-DNA topoisomerase 1 autoantibodies that characterize human diffuse SSc. Sera from hypochlorite- or hydroxyl radical-treated mice and of patients with diffuse SSc contained high levels of AOPP that triggered endothelial production of H(2)O(2) and fibroblast hyperproliferation. Oxidized topoisomerase 1 recapitulated the effects of whole serum AOPP. SCID mice developed an attenuated form of SSc, demonstrating the synergistic role of the immune system with AOPP in disease propagation. We demonstrate a direct role for ROS in SSc and show that the nature of the ROS dictates the form of SSc. Moreover, this demonstration is the first that shows the specific oxidation of an autoantigen directly participates in the pathogenesis of an autoimmune disease.

Lupus Anticoagulant Single Positivity During the Acute Phase of COVID-19 Is Not Associated With Venous Thromboembolism or In-Hospital Mortality.

OBJECTIVE: The clinical relevance of antiphospholipid antibodies (aPLs) in COVID-19 is controversial. This study was undertaken to investigate the prevalence and prognostic value of conventional and nonconventional aPLs in patients with COVID-19. METHODS: This was a multicenter, prospective observational study in a French cohort of patients hospitalized with suspected COVID-19. RESULTS: Two hundred forty-nine patients were hospitalized with suspected COVID-19, in whom COVID-19 was confirmed in 154 and not confirmed in 95. We found a significant increase in lupus anticoagulant (LAC) positivity among patients with COVID-19 compared to patients without COVID-19 (60.9% versus 23.7%; P < 0.001), while prevalence of conventional aPLs (IgG and IgM anti-ß2 -glycoprotein I and IgG and IgM anticardiolipin isotypes) and nonconventional aPLs (IgA isotype of anticardiolipin, IgA isotype of anti-ß2 -glycoprotein I, IgG and IgM isotypes of anti-phosphatidylserine/prothrombin, and IgG and IgM isotypes of antiprothrombin) was low in both groups. Patients with COVID-19 who were positive for LAC, as compared to patients with COVID-19 who were negative for LAC, had higher levels of fibrinogen (median 6.0 gm/liter [interquartile range 5.0-7.0] versus 5.3 gm/liter [interquartile range 4.3-6.4]; P = 0.028) and C-reactive protein (CRP) (median 115.5 mg/liter [interquartile range 66.0-204.8] versus 91.8 mg/liter [interquartile range 27.0-155.1]; P = 0.019). Univariate analysis did not show any association between LAC positivity and higher risks of venous thromboembolism (VTE) (odds ratio 1.02 [95% confidence interval 0.44-2.43], P = 0.95) or in-hospital mortality (odds ratio 1.80 [95% confidence interval 0.70-5.05], P = 0.24). With and without adjustment for CRP level, age, and sex, Kaplan-Meier survival curves according to LAC positivity confirmed the absence of an association with VTE or in-hospital mortality (unadjusted P = 0.64 and P = 0.26, respectively; adjusted hazard ratio 1.13 [95% confidence interval 0.48-2.60] and 1.80 [95% confidence interval 0.67-5.01], respectively). CONCLUSION: Patients with COVID-19 have an increased prevalence of LAC positivity associated with biologic markers of inflammation. However, LAC positivity at the time of hospital admission is not associated with VTE risk and/or in-hospital mortality.

Effects of successive switches to different biosimilars infliximab on immunogenicity in chronic inflammatory diseases in daily clinical practice.

OBJECTIVE: To evaluatre the risk of immunogenicity in patients with chronic inflammatory diseases who experienced successive non-medical swiches to different biosimilars infliximab. PATIENTS AND METHODS: Observational study over a 3-year observation period assessing the risk of immunogenicity in i) patients in maintenance therapy with innovator infliximab who were successively switched to CT-P13, then to SB2 (cohort-1) and ii) biologic-naive patients initiated with CT-P13 before being switched to SB2 (cohort-2). A propotion meta-analysis was also performed, integrating our results to 16 additional studies. RESULTS: Cohort-1 included 265 patients who switched to CT-P13, and 140 patients were subsequently switched to SB2. Among the 235 anti-drug antibody (ADA)-free patients at baseline, 20 patients (8.5%) developed ADA over the 3-year observation period (rate of 3 for 100 patient years). Cohort-2 included 44 patients, of whom 29 subsequently switched to SB2. A total of 11 patients (25%) developed ADA within 3 years (rate of 14 for 100 patients years). We found no influence of the number of biosimilars infliximab received on ADA deveopment in both cohorts. The risk of treatment discontinuation was significantly higher in patients with positive ADA in both cohorts. The meta-analysis including our data exposed an incidence of immunogenicity of 4.7% (95% CI 3.5-6.1%) after the switch from innovator infliximab to biosimilar infliximab and 21.1% (95% CI 13.1-30.3%) in patients initiating biosimilar infliximab. CONCLUSION: Immunogenicity was not favored by successive non-medical switches to biosimilars infliximab in our study, but was associated with treatment discontinuation.

Hydroxychloroquine levels in patients with systemic lupus erythematosus: whole blood is preferable but serum levels also detect non-adherence.

BACKGROUND: Hydroxychloroquine (HCQ) levels can be measured in both serum and whole blood. No cut-off point for non-adherence has been established in serum nor have these methods ever been compared. The aims of this study were to compare these two approaches and determine if serum HCQ cut-off points can be established to identify non-adherent patients. METHODS: HCQ levels were measured in serum and whole blood from 573 patients with systemic lupus erythematosus (SLE). The risk factors for active SLE (SLEDAI score > 4) were identified by multiple logistic regression. Serum HCQ levels were measured in 68 additional patients known to be non-adherent, i.e. with whole-blood HCQ < 200 ng/mL. RESULTS: The mean (± SD) HCQ levels were 469 ± 223 ng/mL in serum and 916 ± 449 ng/mL in whole blood. The mean ratio of serum/whole-blood HCQ levels was 0.53 ± 0.15. In the multivariate analysis, low whole-blood HCQ levels (P = 0.023), but not serum HCQ levels, were independently associated with active SLE. From the mean serum/whole-blood level ratio, a serum HCQ level of 106 ng/mL was extrapolated as the corresponding cut-off to identify non-adherent patients with a sensitivity of 0.87 (95% CI 0.76-0.94) and specificity of 0.89 (95% CI 0.72-0.98). All serum HCQ levels of patients with whole-blood HCQ below the detectable level (< 20 ng/mL) were also undetectable (< 20 ng/mL). CONCLUSIONS: These data suggest that whole blood is better than serum for assessing the pharmacokinetic/pharmacodynamic relation of HCQ. Our results support the use of serum HCQ levels to assess non-adherence when whole blood is unavailable.

[Stability study and external quality assessment scheme implementation for complement components dosage on EDTA plasma]. / Étude de stabilité et mise en place d'un contrôle de qualité externe pour les dosages du complément sur plasma EDTA.

Although the use of EDTA-containing collection tubes is known to stabilize the complement analytes and to make the results more reliable, no external quality assessment (EQA) scheme based on EDTA plasma samples is available to date in France. Consequently, a number of clinical laboratories currently participate to EQA program on samples whose matrix is different from their routine practice. The aim of this work was to offer a new external quality assessment scheme, as an inter-laboratory exchange (ILE). The ILE samples come from pooled EDTA plasmas of healthy subjects and are diluted to obtain distinct control levels. The protocol has been validated on CH50, C3, C4 and C1-inhibitor measurements, through: (i) a stability study of post-centrifugation storage of EDTA plasma samples at room temperature, 4̊C and -20̊C; (ii) the demonstration of the linearity of the dilution steps; and (iii) a stability study of the diluted samples. Our results demonstrate a four-weeks stability of the ILE samples prepared and stored according to our protocol. Those results are compatible with the ILE implementation constraints, and the program has been implemented in January 2018. The one-year ILE implementation experience is also presented. The newly implemented ILE will be useful for the accreditation of the complement activity of French laboratories using EDTA plasma samples.

Systematic switch from innovator infliximab to biosimilar infliximab in inflammatory chronic diseases in daily clinical practice: The experience of Cochin University Hospital, Paris, France.

OBJECTIVE: To investigate effectiveness of systematic switching treatment from innovator infliximab to biosimilar infliximab, and its associated factors. METHODS: In this prospective observational study, all adult patients receiving maintenance therapy with innovator infliximab in Cochin University Hospital were systematically switched to biosimilar infliximab. Effectiveness was assessed by the retention rate of biosimilar infliximab at the time of the third infusion. Sensitivity analyses for effectiveness included changes of disease activity parameters and infliximab trough levels between baseline and the last visit as well as the occurrence of adverse events leading to drug discontinuation. Factors associated with biosimilar infliximab discontinuation at the last visit were explored. RESULTS: A total of 260 patients fulfilled the inclusion criteria, including 31 rheumatoid arthritis (RA), 131 axial spondyloarthritis (axSpA) and 64 inflammatory bowel diseases. The retention rate was 85% (221/260 patients) at the time of the third biosimilar infusion. Between baseline and the last visit (mean follow-up of 34 weeks), 59 patients (23%) discontinued biosimilar infliximab, mainly due to experienced inefficacy (n = 47, 80%). No clinical or biological factors were associated with biosimilar discontinuation. No serious adverse events occurred. No change in objective disease activity parameters or infliximab trough levels was detected. However, a significant increase of BASDAI (2.94 ± 2.20 vs. 3.18 ± 2.21, P = 0.046, before vs. after switch, respectively) was observed in patients with axSpA. Innovator infliximab was re-established in 47/59 patients (80%). CONCLUSION: No changes in drug trough levels or objective parameters were observed after the systematic switch to biosimilar infliximab in a real clinical practice setting. Only changes in patient-reported outcomes were observed, suggesting attribution effects rather than pharmacological differences.