Serum anti-PLA2R antibodies and PLA2R1 gene polymorphisms in a sample of Iraqi patients with membranous nephropathy

Background/Aim: Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults. Anti-phospholipase A2 receptor (anti-PLA2R) antibodies and PLA2R1 variants are associated with primary MN, but data from Iraq are limited. This study compared biochemical parameters, serum anti-PLA2R levels and PLA2R1 variants in Iraqi patients with MN and healthy controls.Methods: Laboratory measurements were reported for 50 patients with MN undergoing maintenance haemodialysis and 50 apparently healthy controls. Patient samples were collected before dialysis at Al-Kindy Teaching Hospital, Baghdad, Iraq. Complete blood count and biochemical parameters were measured using automated analysers and serum anti-PLA2R levels were measured by sandwich enzyme-linked immunosorbent assay. DNA from 25 patients and 25 controls was analysed by polymerase chain reaction and sequencing.Results: Patients had lower serum albumin, calcium, iron and haemoglobin and higher creatinine, urea, alkaline phosphatase, phosphate, ferritin, biliru-bin and anti-PLA2R levels (all p < 0.05). Anti-PLA2R levels differed between groups (p < 0.001), with an area under the receiver operating characteristic curve of 1.000, but were not significantly correlated with creatinine (r = -0.12, p = 0.411). The 33,988 (G>A) variant had a reported odds ratio (OR) of 6.78 (p = 0.041), while 34,046 (G>A) had an OR of 0.07 (p < 0.001). No significant asso-ciation was found at 33,861 or 34,254. In the multivariable model, anti-PLA2R level had the largest reported OR (17.6; p < 0.001).Conclusion: Serum anti-PLA2R levels showed strong discrimination be-tween patients and healthy controls in this dataset. Associations with selected PLA2R1 variants warrant further investigation before clinical or causal conclu-sions are drawn.