Anti-annexin II level in serum correlates with disease manifestations in lupus nephritis

Abstract

BACKGROUND: We have reported that anti-dsDNA antibodies from patients with lupus nephritis could bind to annexin II on the surface of human mesangial cells and mediate downstream inflammatory processes. In this study we investigated the relationship between serum anti-annexin II activity, measured with ELISA, and clinical parameters. METHODS: Serial serum samples from 23 patients with biopsy-proven severe proliferative lupus nephritis were included. Sera from patients with non-lupus renal diseases and healthy subjects were used as controls. RESULTS: A total of 487 serum samples were from patients with lupus nephritis, including 97 during active disease and 390 samples during remission. IgG anti-annexin II activity was significantly higher in patients with lupus nephritis compared with controls (P<0.001). Sero-positivity rate for anti-annexin II IgG was 20.3%, 5.3%, and 3.1% in patients with lupus nephritis, non-lupus glomerular diseases, and healthy controls respectively (P<0.001 for both). Anti-annexin II titre (IgG) correlated with the level of anti-dsDNA antibodies (r=0.26, P<0.001), total IgG (r=0.45, P<0.0001), and serum creatinine (r=0.45, P<0.001), while there was an inverse correlation with C3 level (r=-0.31, P<0.001). In 15 of 23 patients investigated, the levels of anti-annexin II and anti-dsDNA were both higher during active disease than during remission. CONCLUSIONS: The data show that IgG anti-annexin II titre correlates with serological and clinical markers indicating disease activity in lupus nephritis.