ASSOCIATION BETWEEN ONGOING ANTI-CLQ ANTIBODY-PRODUCTION IN PERIPHERAL-BLOOD AND PROLIFERATIVE NEPHRITIS IN PATIENTS WITH ACTIVE SYSTEMIC LUPUS-ERYTHEMATOSUS

The aim of this study was to compare ongoing production of anti-Clq an tibodies (anti-Clq) in peripheral blood with serum anti-Clq levels in patients with systemic lupus erythematosus (SLE), especially in patien ts with nephritis. Using the ELISPOT technique for the detection of Ig G and IgA anti-Clq production, 21 patients with active SLE were invest igated. ELISAs for IgG and IgA anti-Clq were compared with the ELISPOT results. Six of the patients were found to have proliferative nephrit is (WHO grade III/IV) confirmed by renal biopsy. High numbers of IgG a nti-Clq spot-forming cells (SFC), defined as >20/10(5) plated peripher al blood mononuclear cells (PBMC), were exclusively observed in patien ts with proliferative nephritis (P < 0.0001). Serum levels of IgG anti -Clq were significantly increased in patients with proliferative nephr itis (P = 0.039). High ongoing IgG anti-Clq production was observed in all patients with proliferative nephritis, which may be a contributor y factor in the pathogenesis of this disorder. The detection of IgG an ti-Clq production may be valuable in the clinical investigation of pat ients with suspected SLE nephritis.