Clinical, autoimmune and demographic profile in systemic lupus erythematosus (SLE) patients from southern Brazil

With the purpose of determining the association of clinical, autoimmune and demographic features, a group of 90 SLE patients from Southern Brazil were investigated. At diagnosis, 24% of them were under 20 years, 63% were between 20 and 40 years and 13% were older than 40 years. According to the ethnic background, there were 66% Brazilian-white patients, 21% Caucasians and 13% Mullatos/Blacks. Antinuclear antibodies (ANA) were present in 98%, anti-ds-DNA in 56% and anti-Sm in 31% of the patients. Anti-ds-DNA were more prevalent in the Caucasians (79%), while anti-Sm were increased in the Mullatos/Blacks (58%, p < 0.02) as compared to the white patients (Brazilian-whites = 22% and Caucasians = 42%). Neurologic involvement had lower prevalence in the group of Mullato/Black patients (8%) than in the Brazilian-whites (32%) and Caucasians (31%). Serositis was present in 51% of the Brazilian-whites, in 21% of the Caucasians and in 41% of the Mullatos/Blacks. On the other hand, the Mullato/ Black group had an increased prevalence of vasculitis (50%) and none of them presented with Raynaud's phenomenon. Younger patients at diagnosis presented higher frequency of renal involvement (p < 0.05), anti-ds-DNA positivity (p < 0.02) and more severe disease (p < 0.07), and in those patients diagnosed after age 40, 33% presented with Raynaud's phenomenon (p < 0.05). Regarding the anti-ds-DNA positivity, 78% of the patients had renal involvement (p < 0.01 RR 2.2) and 66% severe disease (p < 0.05). These results might be important in assessing clinical subsets and may aid individualized management of Brazilian SLE patients. Also, they may corroborate the need for special attention to racial composition in clinical and immunogenetic studies.