Increased RAHA titer and interleukin-6 levels in the synovial fluid in a patient with polymyalgia rheumatica.

We report a patient with polymyalgia rheumatica (PMR) accompanied by an increased Rheumatoid Arthritis Hemagglutinin Test (RAHA) titer and interleukin-6 level in the synovial fluid. A 60-year-old female was admitted because of polymyalgia, a body temperature of 39.2 degrees C, and an erythrocyte sedimentation rate increased to 94 mm/h. Since a muscle biopsy failed to show a specific finding, she was diagnosed as PMR. The titer of RAHA and the interleukin-6 level were increased only in the synovial fluid; prednisolone treatment decreased both. The present case raised the possibility that a similar mechanism in rheumatoid arthritis may involve the development of synovitis in PMR.