Characterization of a Portuguese population with systemic lupus erytematosus

UNLABELLED: To characterize systemic lupus erythematosus (SLE) in Portuguese patients and to identify differences in diseases expression related to sex and ethnicity. PATIENTS AND METHODS: Retrospective cohort analysis of patients with SLE followed at five Rheumatology Departments between 1976 and 2006. Demographic data, diseases manifestations, medications used, co morbidity and damage scores were recorded. RESULTS: Five hundred forty four patients were studied, 93% female, 89% Caucasians, with an average age at disease diagnosis of 35 years. The most frequent clinical features were musculoskeletal (91%), cutaneous and mucous membrane (90%) and the hematological involvement (58%). Renal diseases and serositis occurred more often in males while myositis was more common in black patients. Immunological features included the presence of anti-nuclear antibodies in 99% of the patients, anti-DNA (76%) anti-SSA (33%), anti-SSB (20%), anti-RNP (26%), anti-Sm (22%), anticardiolipine (31%) and lupus anticoagulant (21%). Anti-SSA, anti-RNP, and anti-Sm antibodies were significantly more prevalent among black patients. The presence and severity of damage measured by SLICC/ACR was similar between sexes and ethnicities. In multivariate analyses diseases duration and the presence of hypertension showed a positive association, while educational and antimalarials were negatively associated with the presence of damage. CONCLUSION: In this cohort of Portuguese patients SLE present clinical features similar to those observed in other predominantly Caucasian populations, albeit a higher prevalence of anti-RNP and anti-Sm antibodies was observed. Some particular features were associated with male sex and African ethnicity. Some socio-demographic and clinical variables were associated with damage accrual.