Anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus and lupus nephritis.

This study aims to investigate the role of Antineutrophil cytoplasmic antibodies (ANCA) in patients with new-onset systemic lupus erythematosus (SLE). Sixty SLE patients, 28 of whom had lupus nephritis (LN), and 60 normal controls were enrolled; Serum ANCA was measured by enzyme linked immunosorbent assay (ELISA). The clinical and laboratory parameters of the patients were also recorded. Results show that twenty SLE patients were seropositive for ANCA, which was significantly higher than in normal controls. LN patients had significantly higher positive rate of ANCA than patients without nephritis. Compared with ANCA-negative patients, the ANCA-positive patients had significantly higher incidence of nerves system disorder, myocarditis, renal involvement and serositis. The positive rate of gamma-globulin, anti-dsDNA and anti-Sm antibodies were significantly higher in ANCA-positive patients. Elevated IgG and ESR, decreased serum C3/C4 appeared more often in ANCA-positive patients. In addition, serum ANCA level correlated positively with disease activity. Taken together, ANCA might be used as a potential complementary parameter to differentiate LN from SLE without nephritis. In addition, ANCA may serve as a useful marker of the disease activity of SLE.