Serum Antibody and Glomerular Antigen of Antiphospholipase A2 Receptor in Chinese Patients with Idiopathic Membranous Nephropathy

الملخص EN

Background.

M-type phospholipase A2 receptor (PLA2R) is the first autoantigen responsible for idiopathic membranous nephropathy (IMN).

However, serum PLA2R antibody (PLA2R-Ab) can be inaccurate in distinguishing between IMN and secondary membranous nephropathy, while renal PLA2R antigen (PLA2R-Ag) emerges as an ancillary diagnostic.

The present study is aimed at examining the associations between PLA2R-Ab in sera and PLA2R-Ag in kidneys in IMN patients.

Methods.

A total of 93 patients with IMN were retrospectively identified.

Their serum PLA2R-Ab and renal PLA2R-Ag expression levels were determined, and the clinical correlations between these parameters and clinical features were examined.

Results.

The sensitivities of serum PLA2R-Ab and renal PLA2R-Ag for diagnosing IMN were 74.2% and 88.2%, respectively (P<0.001), with poor consistency.

Higher serum PLA2R-Ab levels were correlated to stronger renal PLA2R-Ag expression (P=0.048).

Patients with positive PLA2R-Ab significantly differed from those with negative levels, in terms of proteinuric levels over 24 hours (4.54 vs.

3.46 g/day, P=0.015) and serum albumin (23.28 vs.

27.95 g/L, P=0.038).

Among patients with positive renal PLA2R-Ag, patients with positive PLA2R-Ab had significantly higher 24-hour proteinuria, when compared to patients with negative PLA2R-Ab (4.57 vs.

3.08 g/day, P=0.005).

Among those with positive PLA2R-Ab in sera, their PLA2R-Ab levels were correlated with the estimated glomerular filtration and serum creatinine.

Conclusion.

Serum PLA2R-Ab exhibits a closer correlation with proteinuric severity and renal function, when compared to renal PLA2R-Ag.