Kidney Week

Abstract: TH-PO111

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

Session Information

• Clinical/Diagnostic Renal Pathology and Lab Medicine - I
  November 02, 2017 | Location: Hall H, Morial Convention Center
  Abstract Time: 10:00 AM - 10:00 AM

Category: Glomerular

• 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Author

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

Bing Li,

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.