Hypocomplementemia in Rheumatoid Arthritis

Abstract

Abstract Hypocomplementemia has rarely been noted in patients with rheumatoid arthritis (RA). Eleven of 250 patients studied consecutively were found to have serum complement levels below the normal range. These 11 patients, as a group, had more severe disease, including greater functional impairment and more frequent positive latex tests and subcutaneous nodules, than did patients with rheumatoid arthritis and normal or elevated complement levels. Episodes of hypocomplementemia usually were associated with an acute flare of multiple joints, vasculitis or rheumatoid pleuritis. It is evident that RA is not necessarily associated with normal or elevated CH 50 levels. In fact, severe RA, with marked destructive changes and multiple complications, is sometimes associated with markedly low CH 50 levels.