Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals

Efficacy and Safety of Epratuzumab in Moderately to Severely Active Systemic Lupus Erythematosus: Results From Two Phase III Randomized, Double-Blind, Placebo-Controlled Trials

OBJECTIVE: Epratuzumab, a monoclonal antibody that targets CD22, modulates B cell signaling without substantial reductions in the number of B cells. The aim of this study was to report the results of 2 phase III multicenter randomized, double-blind, placebo-controlled trials, the EMBODY 1 and EMBODY 2 trials, assessing the efficacy and safety of epratuzumab in patients with moderately to severely active systemic lupus erythematosus (SLE). METHODS: Patients met 654 of the American College of Rheumatology revised classification criteria for SLE, were positive for antinuclear antibodies and/or anti-double-stranded DNA antibodies, had an SLE Disease Activity Index 2000 (SLEDAI-2K) score of 656 (increased disease activity), had British Isles Lupus Assessment Group 2004 index (BILAG-2004) scores of grade A (severe disease activity) in 651 body system or grade B (moderate disease activity) in 652 body systems (in the mucocutaneous, musculoskeletal, or cardiorespiratory domains), and were receiving standard therapy, including mandatory treatment with corticosteroids (5-60 mg/day). BILAG-2004 grade A scores in the renal and central nervous system domains were excluded. Patients were randomized 1:1:1 to receive either placebo, epratuzumab 600 mg every week, or epratuzumab 1,200 mg every other week, with infusions delivered for the first 4 weeks of each 12-week dosing cycle, for 4 cycles. Patients across all 3 treatment groups also continued with their standard therapy. The primary end point was the response rate at week 48 according to the BILAG-based Combined Lupus Assessment (BICLA) definition, requiring improvement in the BILAG-2004 score, no worsening in the BILAG-2004 score, SLEDAI-2K score, or physician's global assessment of disease activity, and no disallowed changes in concomitant medications. Patients who discontinued the study medication were classified as nonresponders. RESULTS: In the EMBODY 1 and EMBODY 2 trials of epratuzumab, 793 patients and 791 patients, respectively, were randomized, 786 (99.1%) and 788 (99.6%), respectively, received study medication, and 528 (66.6%) and 533 (67.4%), respectively, completed the study. There was no statistically significant difference in the primary end point between the groups, with the week 48 BICLA response rates being similar between the epratuzumab groups and the placebo group (response rates ranging from 33.5% to 39.8%). No new safety signals were identified. CONCLUSION: In patients with moderate or severely active SLE, treatment with epratuzumab\u2009+\u2009standard therapy did not result in improvements in response rates over that observed in the placebo\u2009+\u2009standard therapy group