Associação entre presença de factores reumatóides 16M no soro e resposta à terapêutica com agentes inibidores do tnf@ em doentes com artrite reumatóide

AIM To verify if the response to TNFalpha inhibitors is influenced by the presence of IgM rheumatoid factor (RF), in patients with RA. MATERIAL AND METHODS In this study, the patients with the diagnosis of RA treated with TNFa inhibitors followed in our hospital were recruited. A protocol was applied including demographic, clinical and laboratory data, in order to calculate DAS 28. The presence/absence of IgM RF and associated therapies were record. RESULTS Fifty-seven patients, 52 female, with a mean duration of anti-TNFa treatment of 30,9+/-15,9 months were studied. Twenty-four patients were being treated with infliximab, 17 with adalimumab and 16 with etanercept. Forty-one patients had IgM RF detectable in serum (RF positive group). In the RF positive group, the variation of DAS 28 was -1,75 +/- 1,53 vs -1,04 +/- 1,76 in the RF negative group (p=0,135). The mean duration of anti-TNFalpha treatment was similar in both groups (31,9+/-15,9 vs 29,5+/-16,16 months). Patients who were treated with methotrexate presented a higher variation of DAS 28 (-1,87 +/- 1,70 vs -0,80 +/- 1,09; p=0,041) and this variation was dose dependent (p=0,056). CONCLUSIONS Despite needing a replication in a larger cohort, our results suggest that the presence of IgM RF in the serum did not interfere with the response to treatment with TNFalpha inhibitors.