Correlation of Anti-Phospholipase A2 Receptor Antibody Level with Disease Activity in Patients with Idiopathic Membranous Nephropathy

Background: Anti phospholipase A2 receptor (PLA2R) antibody detection in serum is a non-invasive, cost effective diagnostic test for idiopathic membranous nephropathy (iMN) precluding the need for a renal biopsy. Extensive research has demonstrated a strong correlation between serum anti-PLA2R antibodies and disease activity but no prior study has been conducted in Pakistan on this important aspect of iMN. Objective: To ascertain the relationship between anti-PLA2R antibodies and disease activity in patients with biopsy proven iMN. Methods: This cross sectional study was conducted atNephrology Department, Mayo Hospital, Lahore from February to October, 2023. Clinical data of individuals with nephrotic syndrome, age >14 years were obtained upon enrollment in the study. Renal biopsy of patients was done and specimen sent for histopathology. The study encompassed eightythree patients diagnosed with iMN, while the remaining individuals were excluded. Serum levels of anti-PLA2R antibodies of 83 patients with iMN were assessed. Results: Out of 83 patients, 51 (61%) tested positive for anti-PLA2R antibody, while 32 (39%) were negative. The mean age of patients was 31.80 +/- 11.71 years. A significant positive relationship was identified between anti-PLA2R level and 24hour urinary protein (r=0.535, p<0.001), Low density lipoprotein (r=0.357, p<0.05). A significant negative relationship was found between anti-PLA2R level and albumin level (r=-0.440, p<0.001). Conclusion: Anti-PLA2R antibody levels showed strong correlation with the clinical parameters reflecting the disease activity in iMN. In iMN, the sensitivity of anti-PLA2R antibody was determined to be moderate.