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Objectives: This study aimed to compare the clinical features, damage accrual, and survival of patients with familial and sporadic systemic lupus erythematosus (SLE)., Methods: A multi-ethnic, multinational Latin American SLE cohort was studied. Familial lupus was defined as patients with a first-degree SLE relative; these relatives were interviewed in person or by telephone. Clinical variables, disease activity, damage, and mortality were compared. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. Hazard ratios (HR) were calculated using Cox proportional hazard adjusted for potential confounders for time to damage and mortality., Results: A total of 66 (5.6%) patients had familial lupus, and 1110 (94.4%) had sporadic lupus. Both groups were predominantly female, of comparable age, and of similar ethnic distribution. Discoid lupus (OR = 1.97; 95% CI 1.08-3.60) and neurologic disorder (OR = 1.65; 95% CI 1.00-2.73) were significantly associated with familial SLE; pericarditis was negatively associated (OR = 0.35; 95% CI 0.14-0.87). The SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) were similar in both groups, although the neuropsychiatric (45.4% vs. 33.5%; p  = 0.04) and musculoskeletal (6.1% vs. 1.9%; p  = 0.02) domains of the SDI were more frequent in familial lupus. They were not retained in the Cox models (by domains). Familial lupus was not significantly associated with damage accrual (HR = 0.69; 95% CI 0.30-1.55) or mortality (HR = 1.23; 95% CI 0.26-4.81)., Conclusion: Familial SLE is not characterized by a more severe form of disease than sporadic lupus. We also observed that familial SLE has a higher frequency of discoid lupus and neurologic manifestations and a lower frequency of pericarditis.

Objective: To compare the clinical, laboratory and outcome features of SLE patients with and without Jaccoud's arthropathy (JA) from the Grupo Latino Americano De Estudio del Lupus (GLADEL) cohort., Methods: 1480 patients with SLE [(34 centres, 9 Latin American countries with a recent diagnosis (≤2 years)] constitute the GLADEL cohort. JA was defined as reducible deformity of the metacarpophalangeal axis, without radiographic erosions at any time. Within this cohort, a nested case-control study was carried out. Control was matched for age, gender and centre in a 1:3 proportion. The variables included were: sociodemographic, clinical and immunological features, disease activity, damage and mortality. Comparisons were performed with Wilcoxon and χ 2 tests for continuous and categorical variables, respectively. ORs and 95% CIs and Kaplan-Meier survival curve were estimated., Results: Of 1480 patients, 17 (1.1%) JA patients were identified; 16 (94.1%) of them were women, mean age: 31.0 years (SD 12.0). Five (29.4%) patients presented JA at SLE diagnosis and 12 (70.6%) after. The median follow-up time and all disease features were comparable in both groups except for a higher frequency of pneumonitis in the patients with JA [4 (23.5) vs 1 (2.0); p=0.012; (OR: 15.4; 95% CI 1.6 to 149.6)]. The SLE disease activity index, Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage Index and the Kaplan-Meier survival curve were similar in both groups., Conclusion: JA may tend to appear early in the course of SLE; it seems not to have an impact on disease activity, damage accrual or in survival., Competing Interests: Competing interests: None declared.

Objective: To define whether Amerindian genetic ancestry correlates with clinical and therapeutic variables in admixed individuals with rheumatoid arthritis (RA) from Latin America., Methods: Patients with RA (n = 1347) and healthy controls (n = 1012) from Argentina, Mexico, Chile, and Peru were included. Samples were genotyped for the Immunochip v1 using the Illumina platform. Clinical data were obtained through interviews or the clinical history., Results: Percentage of Amerindian ancestry was comparable between cases and controls. Morning stiffness (p < 0.0001, OR 0.05), rheumatoid factor (RF; p < 0.0001, OR 0.22), radiographic changes (p < 0.0001, OR 0.05), and higher number of criteria were associated with lower Amerindian ancestry after Bonferroni correction. Higher Amerindian ancestry correlated only with weight loss (p Bonferroni < 0.0001, OR 2.85). Increased Amerindian ancestry correlated with higher doses of azathioprine (p < 0.0001, OR 163.6) and sulfasalazine (p < 0.0001, OR 48.6), and inversely with methotrexate (p = 0.001, OR 0.35), leflunomide (p = 0.001, OR 0.16), and nonsteroidal antiinflammatory drugs (p Bonferroni = 0.001, OR 0.37). Only the presence of RF and weight loss were modified after confounders adjustment., Conclusion: Amerindian ancestry protects against most major clinical criteria of RA, but regarding the association of RF with increased European ancestry, age, sex, and smoking are modifiers. Ancestry also correlates with the therapeutic profiles.

Objective: To identify susceptibility loci for rheumatoid arthritis (RA) in Latin American individuals with admixed European and Amerindian genetic ancestry., Methods: Genotyping was performed in 1,475 patients with RA and 1,213 control subjects, using a customized BeadArray containing 196,524 markers covering loci previously associated with various autoimmune diseases. Principal components analysis (EigenSoft package) and Structure software were used to identify outliers and define the population substructure. REAP software was used to define cryptic relatedness and duplicates, and genetic association analyses were conducted using Plink statistical software., Results: A strong genetic association between RA and the major histocompatibility complex region was observed, localized within BTNL2/DRA-DQB1- DQA2 (P = 7.6 × 10(-10) ), with 3 independent effects. We identified an association in the PLCH2-HES5-TNFRSF14-MMEL1 region of chromosome 1 (P = 9.77 × 10(-6) ), which was previously reported in Europeans, Asians, and Native Canadians. We identified one novel putative association in ENOX1 on chromosome 13 (P = 3.24 × 10(-7) ). Previously reported associations were observed in the current study, including PTPN22, SPRED2, STAT4, IRF5, CCL21, and IL2RA, although the significance was relatively moderate. Adjustment for Amerindian ancestry improved the association of a novel locus in chromosome 12 at C12orf30 (NAA25) (P = 3.9 × 10(-6) ). Associations with the HLA region, SPRED2, and PTPN22 improved in individuals positive for anti-cyclic citrullinated peptide antibodies., Conclusion: Our data define, for the first time, the contribution of Amerindian ancestry to the genetic architecture of RA in an admixed Latin American population by confirming the role of the HLA region and supporting the association with a locus in chromosome 1. In addition, we provide data for novel putative loci in chromosomes 12 and 13., (Copyright © 2013 by the American College of Rheumatology.)