Association of The Autoantibodies to M-Type Phospholipase A2 Receptor Titer with Clinical Characteristics and Outcome of Patients with Primary Membranous Nephropathy – 5-Year Follow up Study

Abstract

Introduction: primary membranous nephropathy (pMN) is glomerulopathy caused in the majority of cases by autoantibodies to Phospholipase-A2 receptors (PLA2R-AB). This study aimed to evaluate the clinical course and outcomes of the patients with pMN regarding PLA2R-AB status. Patients and methods: 32 patients (21 males, 11 females) with renal biopsy-proven pMN were included in the study. PLA2R-AB (ELI SA method) and outcomes (defined according to KDIGO) were evaluated after 21 and 64 months of follow-up in 28 patients. Results: 19 patients had positive PLA2R-AB (>20 RU /ml) (59.3%), with median titer of 97 (21-1418 RU /ml). The rate of remission in low PLA2R-AB titer group ( 200 RU /ml) (90% vs. 50%, p=0.045), and after 64 months the difference was not significant (80% vs. 50%, p=0.210). The relapse rate after 64 months was higher in the high PLA2R-AB group (87% vs. 63%). Multivariant linear regression found serum creatinine (ß=0.682, p<0.001) and PLA2R-AB (ß=0.527, p<0.001) as significant predictors for kidney function at the end of follow-up. Conclusion: higher titers of PLA2R-AB are related to worse kidney function outcome, higher 24-hour proteinuria, and a higher number of relapses in patients with pMN.

Keywords

• Membranous nephropathy
• M-type phospholipase A2 receptor
• Autoantibodies
• Glomerulonephritis