Role of anti-phospholipase A2 Receptor antibodies in patients with membranous nephropathy: A prospective study on Indian cohort

Abstract

Context: A search for a cause for membranous nephropathy (MN) is crucial to determine its treatment and management. Primary MN was a diagnosis of exclusion until the discovery of the target antigen, phospholipase A2 receptor (PLA2R). Lack of published data from the Indian population prompted this prospective study to determine the sensitivity and specificity of circulating anti-PLA2R antibodies in MN patients by using cell-based indirect immunofluorescence test (IIFT) and correlating with clinical–histopathology features and response to treatment. Settings and Design: This was a cross-sectional prospective study. Materials and Methods: MN cases (n = 34) diagnosed by renal biopsy and IIFT were evaluated along with 10 controls for serum anti-PLA2R antibodies using IIFT on biochip containing HEK 293 cell lines transfected with cDNA coded for PLA2R in this cross-sectional prospective study and simultaneously investigated to find the cause for MN. Positive cases treated with the Ponticelli regimen were followed up for 6 months with repeat testing for PLA2R. Statistics were performed using Statistical Package for Social Sciences version 18 (IBM). P < 0.05 considered significant. Statistical parameters were analyzed using the Chi-square test. Results: Anti-PLA2R antibodies-positive MN (primary MN) cases (n = 20) had higher 24-h proteinuria (10.09 ± 2.46 g) with 25% cases showing mesangial hypercellularity and basement membrane thickening in all (100%), while 50% of secondary MN cases showed mesangial hypercellularity with 7.17 ± 3.8 g of proteinuria. The sensitivity, specificity, and accuracy rate of anti-PLA2R antibodies for a diagnosis of primary MN were 70%, 100%, and 82%, respectively. Conclusion: Anti-PLA2R antibody in serum is a good reliable noninvasive diagnostic biomarker for primary MN and for monitoring its disease activity.

Keywords

• anti-pla2r antibody
• indirect immunofluorescence test
• membranous nephropathy
• podocyte