Autoantibodies in leprosy patients, with and without joint involvement, in the state of Amazonas

Objective: Determine the frequency of rheumatoid factor (IgM-RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP), antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies (ANCA), anticardiolipin antibodies (aCL), and anti-β2 glycoprotein I antibodies (anti-β2GPI) in leprosy patients, with and without joint involvement, and to evaluate the possible association among those antibodies and articular manifestations, clinical type, reactional episodes, polychemotherapic treatment (PCT), and discharge from PCT. Patients and methods: One hundred and fifty-eight leprosy patients were divided in two groups of 73 patients (Group I) and 82 patients (Group II). Group III was composed of 129 healthy individuals. Methods: Semi-quantitative latex agglutination test for IgM-RF, indirect immunofluorescence for ANA and ANCA, and ELISA for anti-CCP, aCL, and anti-β2GPI. Results: Fifty-six (35.4%) of 158 leprosy patients had lepromatous leprosy (LL). The frequency of anti-CCP, RF, and ANA antibodies in Groups I and II was similar to that of Group III. Antineutrophil cytoplasmic antibodies were not detected in any patient. Anticardiolipin antibodies were more frequent in leprosy patients (Groups I and II) than in control group (15.8% vs. 3.1%; P < 0.001), and differences between Groups I and II (P = 0.67) were not observed. Anti-β2GPI antibodies were also more common in leprosy patients than in control group (46.2% vs. 9.4%; P < 0.001), without differences between Groups I and II. A predominance of IgM isotype over IgG isotype was observed both for aCL (88% vs. 16%; P = 0.001) and anti-β2GPI (97.3% vs. 12.3%; P < 0.001). Patients did not present manifestations suggestive of vascular thrombosis. Conclusion: The frequency of aCL and anti-β2GPI antibodies was significantly increased in leprosy patients than in healthy individuals. However, positivity to other autoantibodies was similar to that observed in the control group. An association between autoantibodies and joint involvement, reactional episodes, polychemotherapic treatment, discharge, and clinical type of leprosy was not observed, except for aCL antibodies, which were more frequent in lepromatous leprosy.