Abstract: TH-PO111

Urine Anti-PLA2R Antibody Is a Biomarker for Diagnosis and Activity in Idiopathic Membranous Nephropathy

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Author

  • Li, Bing, 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
Background

Detection of the serum anti-PLA2R antibody (sPLA2R-Ab) and the glomerular PLA2R antigen (gPLA2R) has been widely used as a diagnostic tool for idiopathic membranous nephropathy (IMN) and for the evaluation of IMN activity and severity. Since urine samples more directly reflect kidney damage and alterations than blood samples, we evaluated whether urine anti-PLA2R antibody (uPLA2R-Ab) could be utilized as a noninvasive biomarker for IMN.

Methods

In this study, we completed a qualitative analysis through indirect immunofluorescence test (IIFT) and measured uPLA2R-Ab and sPLA2R-Ab concentrations by enzyme-linked immunosorbent assay (ELISA) in 28 patients with biopsy-proven IMN and 12 patients with secondary membranous nephropathy (SMN).

Results

Overall, 64.3% (n=18) of patients with IMN had IIFT-positive sPLA2R-Ab, 67.9% (n=19) of patients with IMN had IIFT-positive uPLA2R-Ab IIFT, and none of the SMN patients had IIFT-positive sPLA2R-Ab or uPLA2R-Ab. The titers of the anti-PLA2R antibody from the IMN patients in the urine (10.72±22.24 RU/mmol, presented as uPLA2R-Ab/urine creatinine) or the serum (107.36±140.93 RU/ml) were higher than those from the SMN patients (0.51±0.46 RU/mmol, p<0.001; 0.008±0.029 RU/ml, p=0.02, respectively). Statistical analyses indicated that there were positive correlations between uPLA2R-Ab and gPLA2R, sPLA2R-Ab or urinary protein and negative correlations between uPLA2R-Ab and serum albumin in patients with IMN.

Conclusion

Our results indicate that uPLA2R-Ab might serve as a biomarker, like sPLA2R-Ab, for IMN diagnosis and that the antibody titer, as measured by ELISA, might reflect IMN activity and severity.

Funding

  • Government Support - Non-U.S.