Rheumatoid arthritis in a patient with cystic fibrosis: challenging treatment options.

A 26-year-old Caucasian male patient with a history of cystic fibrosis presented with a 6-month history of diffuse joint pain and swelling. He was found to have active synovitis in bilateral wrists and proximal interphalangeal joints of the hands on physical examination. He was diagnosed with seropositive rheumatoid arthritis since he had positive anti-cyclic citrullinated peptide antibodies and erosions on hand and foot X-rays. The patient has responded well to abatacept which may have less infection risk compared with other biological therapies.