Two elderly cases of familial mediterranean fever with rheumatoid arthritis.

Familial Mediterranean fever (FMF) is a genetic autoinflammatory disorder that usually develops before 20 years of age and is characterized by periodic fever with serositis and arthritis. Both FMF and rheumatoid arthritis (RA) involve arthritis; however, their coexistence is rare. We describe two RA patients with an MEFV mutation in exon 2, who were diagnosed with FMF at an age of over 50 years. We also discuss the possibility that MEFV mutations could modulate RA disease activity.