Supplementary Material for: Serum Phospholipase A2 Receptor Antibody is Associated with Thrombogenesis in Primary Membranous Nephropathy: A Systematic Review and Meta-analysis

Background: Primary membranous nephropathy (PMN) is a leading cause of nephrotic syndrome in adults and is associated with an increased risk of thromboembolic events. The anti–serum phospholipase A2 receptor antibody (anti-PLA2R Ab) is highly specific for PMN, correlate with immunological disease activity, and evidence suggests that it may contribute to a prothrombotic state. This systematic review and meta-analysis aims to further explore the potential association between serum anti-PLA2R Ab and thromboembolic events in patients with PMN and investigate whether they may serve as a potential biomarker for thrombogenesis.
Methods: PubMed, Embase and Cochrane databases were systematically searched for studies that investigated the presence of anti-PLA2R Ab as a potential risk factor for thrombogenesis in patients with PMN. Odds ratios (OR) and mean differences (MD) with 95% confidence intervals (CI) were pooled across studies. Heterogeneity was evaluated using I2 statistics.
Results: We included seven studies involving 1,162 patients; mean age was 53 years. Patients with anti-PLA2R Ab had significantly higher odds of thromboembolism compared to those without anti-PLA2R Ab (OR 1.52; 95% CI 1.10, 2.09; p=0.01). Patients diagnosed with thromboembolism exhibited significantly lower serum albumin levels compared to those without thromboembolism (p=0.003), but there were no statistical differences in proteinuria (p=0.18), or age (p=0.90) between patients with and without thromboembolism. Proteinuria (p=0.59), serum creatinine (p=0.77), or estimated glomerular filtration rate (p=0.59) did not differ between anti-PLA2R Ab positive and negative patients. However, total cholesterol levels were higher in patients with positive anti-PLA2R Ab (p<0.0001).
Conclusion: There was a significant association between the presence of anti-PLA2R Ab and the risk of thromboembolism in patients with PMN, supporting their potential use as a biomarker for thrombogenesis in this population.