Rheumatoid arthritis induced by alpha-interferon therapy

Interferon (IFN) therapy has been used for the treatment of common diseases such as hepatitis C, myeloproliferative disorders, autoimmune diseases and various types of cancer. Given the biological properties of interferon, it is not surprising that there are a larger number of side effects due to it s use. Although rheumatoid arthritis (RA) is one of the most common autoimm une diseases found in clinical practice, it does not seem to be frequently related to IFN therapy. We report a 40-year-old female patient who, after h igh doses of IFN-alpha therapy for malignant melanoma, developed symmetrica l polyarthritis, with pain and oedema in small and large joints, associated with prolonged morning stiffness. She had positive rheumatoid factor and D R4 HLA phenotype. She was treated with deflazacort (6 mg/day), chloroquine and NSAIDs, with a partial response. In conclusion, although the developmen t of RA after IFN therapy is a rare event, IFN may work as a 'trigger' for such complication, leading to deregulation in the immune cascade in a perso n genetically predisposed.