RESUMEN
OBJECTIVE: To determine the frequency of antiparvovírus B19 (B19) antibodies in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and the possible correlation of anti-B19 seropositivity with disease activity and quality of life. PATIENTS AND METHODS: Serum samples from 57 patients with RA, 45 with SLE and 65 healthy controls were used. We applied protocol with clinical data, and the Disease Activity Score 28 (DAS 28), Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Health Assessment Questionnaire (HAQ) indexes. The anti-B19 serology was done by enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean age of patients was 42.74 ± 14.09 years, and of controls was 38.38 ± 13.42 years. 79 patients had active disease (77.5%), and 23 had inactive disease (22.5%). Anti-B19 (IgG) was positive in 49 (86.0%; CI 95% 77.0-95.0) RA patients, 38 (84.4%; CI 95% 73.9-95.0) SLE patients, and 40 (61.5%; CI 95% 49.7-73.4) controls (p = 0.002). Anti-B19 (IgM) was positive in 3 (5.3%; CI 95% 0.0-11.1) RA patients, in 7 (15.6%; CI 95% 5.0-26,2) SLE patients, and in 1 (1.5%; CI 95% 0.0-4.5) control (p = 0.011).There was no correlation of anti-B19 reactivity with disease activity and with DAS 28, HAQ and SLEDAI indexes. CONCLUSION: This study demonstrated that the studied population is exposed to infection by B19, which demands attention with its manifestations, especially among patients at greatest risk, such as those immunosuppressed.