Arthritis and bursitis in multiple sclerosis patients treated with interferon‐beta

Abstract

Interferon‐beta (IFN‐β) is a type I interferon used in the management of multiple sclerosis. Therapy with IFN‐β has rarely been associated with the development of autoimmune disorders. We present the cases of two female patients diagnosed with relapsing–remitting multiple sclerosis (RRMS) who developed inflammatory musculoskeletal manifestations, following IFN‐β therapy. The first patient developed a monoarthritis 2 weeks after initiation of IFN‐β, which persisted during the 14 months of therapy and resolved with discontinuation of the medication. The second patient developed both autoimmune thyroid disease and a refractory pre‐patellar bursitis after 50 months of IFN‐β therapy. Our literature review revealed an additional six cases of onset of inflammatory arthritis in MS patients receiving IFN‐β. We review these reports with comparison to our two cases. The role of IFN‐β in inflammatory musculoskeletal disease is unclear. The potential autoimmune complications of this therapeutic agent should be comprehended when monitoring patients receiving such treatment.