Association between immune cell subtypes and membranous nephropathy: A bidirectional Mendelian randomization study

Prior studies have explored the contribution of immune cells in membranous nephropathy (MN). This study utilized Mendelian randomization (MR) to further explore 731 immune cell subtypes on MN, offering robust evidence for their causality. Genetic information for 731 subtypes of immune cells and MN was obtained from genome-wide association studies. Inverse variance weighting (IVW) was employed as the primary analytical method. To reinforce the findings, additional methods, MR-Egger, weighted median, and weighted mode, were employed, along with sensitivity analyses to ensure robustness and stability. Using the IVW method, MR analysis identified significant positive correlations between 17 immune cell subtypes and MN (P < .05, OR > 1) and negative correlations for 29 subtypes (P < .05, OR < 1). In the reverse MR analysis, MN exhibited positive associations with 2 subtypes (P < .05, OR > 1) and negatively correlated with another 4 subtypes (P < .05, OR < 1). None of these associations showed signs of horizontal pleiotropy (P > .05). This extensive bidirectional two-sample MR analysis provides insights into the complex causal links between certain immune subtypes and MN, underscoring the sophisticated interactions between components of the immune system and MN.