Complex-release activity of complement in systemic lupus erythematosus

Complex-release activity (CRA) of complement was measured in 30 systemic lupus erythematosus (SLE) patients by our simple method using peroxidase as an antigen in immune complex. We studied the relationship among CRA and other complement levels, and the influence of CRA on the pathogenesis of SLE was discussed. CRA in SLE was lower than that in normal subjects and correlated with CH 50, ACH 50, C3, C4 and factor B. In some patients with persistent hypocomplementemia, reduced CRA was normalized soon after the administration of corticosteroid. In other patients, CRA correlated with clinical manifestations such as lupus nephritis or skin erythema. These observation suggested that the measurement of CRA might be more useful than that of CH 50 in some SLE patients and that CRA would affect tissue injury due to immune complex.