Clinical significance of detection for anti-M-type phospholipase A2 receptor antibody in elderly patients with membranous nephropathy

Abstract

Objective To detect serum level of anti-M-type phospholipase A2 receptor (PLA2R) antibody in elderly patients with idiopathic membranous nephropathy (IMN) and to explore its clinical significance in IMN disease. Methods A total of 134 patients with renal biopsy-proved glomerular diseases were enrolled in this study, including 42 elderly cases with IMN, 45 non-elderly cases with IMN, 19 elderly cases with minimal change nephropathy (MCN), 12 elderly cases with IgA nephropathy (IgAN), 8 elderly cases with hepatitis B-associated membranous nephropathy (HBV-MN) and 8 elderly cases with focal segmental glomerulosclerosis (FSGS). Western blotting was used to detect serum anti-PLA2R antibody and the correlation of anti-PLA2R antibody with laboratory parameters in elderly IMN patients was analyzed. Results The elderly and non-elderly patients with IMN showed that the positive rate of anti-PLA2R antibody was 71.4% and 73.3%, respectively (P>0.05). The positive rate of anti-PLA2R antibody in elderly IgA nephropathy, HBV-MN and MCN patients was 16.7%, 12.5% and 5.3% respectively. Anti-PLA2R antibody was not detected in serum from elderly FSGS patients. The positive rates of serum anti-PLA2R antibody were significantly higher in both elderly and non-elderly IMN patients than in elderly patients with secondary MN and other types of glomerlonephritis (P<0.01). Furthermore, anti-PLA2R autoantibody level was positively correlated with 24-hour urine protein level and negatively correlated with the concentration of serum albumin in elderly patients with IMN (P<0.01). Conclusions Anti-PLA2R antibody is a sensitive serological marker of IMN. Detection for anti-PLA2R antibody might be helpful for the diagnosis of both elderly and non-elderly IMN and for the monitor of IMN disease severity. Key words: Glomerulonephritis, membranous; Phospholipase A2; Antibodies, antiphospholipid