[Three cases with juvenile rheumatoid arthritis who showed hypocomplementemia related to disease activity].

We encountered three cases of juvenile rheumatoid arthritis which showed a depressed serum complement level during the clinical course. Circulating immune complex and increased secondary fibrinolysis were detected in all cases. The laboratory data suggested the presence of vesculitis. Cutaneous vasculitis was observed by biopsy in 2 cases and abnormal respiratory function in one cases. These 3 cases were in contrast to other 95 JRA cases treated in our department who showed normal serum complement levels. Estimation of serum complement may, therefore be useful to predict the vascular complication and refractoriness to therapy in JRA.