Age of onset influences on clinical and laboratory profile of patients with systemic lupus erythematosus.

The present study aims to evaluate differences in clinical and laboratory manifestations and medication use in the different ages of disease onset in patients with systemic lupus erythematosus (SLE). This cross-sectional study consisted of 598 SLE patients (550 female and 48 male), who attended the Rheumatology Clinic of the Hospital de Clínicas de Porto Alegre between 2003 and 2015. Demographic, clinical and laboratory data were collected. The patients were classified into three groups according to their ages at disease diagnosis. Mean age of diagnosis was 33.6 ± 14.3 years, and the median (25th-75th percentile) disease duration was 13 (7-20) years. Among the patients studied, 419 (70%) were adult-onset (aSLE), 90 (14.8%) were late-onset (lSLE) and 89 (14.8%) were childhood-onset (cSLE). The female to male ratio was higher in aSLE (18:1) compared to the other groups (p = 0.001). Arthritis was predominantly found in aSLE (78.5%) when compared with lSLE (57.7%) (p < 0.001). Nephritis was more common in cSLE (60.6%) than in lSLE (26.6%) (p < 0.001). Median (25th-75th percentile) of SLE disease activity index (SLEDAI) was higher in the cSLE group [2 (0-5)] when compared to the lSLE group [0 (0-4)] (p = 0.045). Childhood-onset SLE showed a more severe disease due to the higher incidence of nephritis and needed a more aggressive treatment with immunosuppressive drugs.