Anti-M-type phospholipase A2 receptor antibody diagnosing and monitoring disease activity in idiopathic membranous nephropathy: a single center and retrospective cohort study

Objectives: This study was to investigate the effects of anti-M-type phospholipase A2 receptor (PLA2R) antibody in diagnosing and monitoring the progresssion in idiopathic membranous nephropathy (iMN). Methods: Fifty-six cases with iMN were chosen from October 2009 to November 2015. The control cohorts were patients with hepatitis B virus associated MN (n=17), lupus nephritis related MN (n=19) and non-MN nephrotic syndrome (n=39). The level of serum a-PLA2R antibody (a-PLA2R) was detected by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF). The expression of renal PLA2R and IgG subclasses was examined by indirect immunofluorescence. Results: IMN patients with a-PLA2R negativity more often entered remission (68.4%), whereas positive patients with immunosuppressive therapy achieved remission more frequently than patients with conservative therapy. In a-PLA2R positive patients, antibody titers correlated with nephropathy activity. A-PLA2R combining with renal IgG4-dominant subclasses strength the determination of iMN, and absence of a-PLA2R and renal non-IgG4- dominant subclasses excluded the diagnosis of iMN. Conclusions: A-PLA2R titers are helpful in diagnosing iMN and monitoring the activity of iMN. The multiple-assays of serum a-PLA2R antibody, renal PLA2R and renal IgG4 would enhance the diagnosis of iMN. For MN patients with negative a-PLA2R or negative renal PLA2R, secondary MN is more evidently certain.Guangdong provincial Department of Science and Technology [2014A020212049]SCI(E)ARTICLExiongzy2005@163.com1223351-23362