ABSTRACT
Membranous nephropathy (MN) imposes a substantial burden of illness and death. However, a systematic assessment of the impact of the COVID-19 pandemic on MN incidence has not yet been conducted. This research is an observational cohort study conducted retrospectively. The kidney biopsy results of two medical institutions, including our hospital, were reviewed for the period between January 2016 and May 2023. Relevant statistical analysis of different glomerular diseases was performed based on the corresponding pathological diagnoses. The aim was to compare the incidence changes of different glomerular diseases before and during the COVID-19 pandemic. Our focus was on investigating the changes in the incidence rate of MN and attempting to uncover the causal effects between varying degrees of COVID-19 and MN utilizing bidirectional Mendelian randomization (MR) using GWAS data from European and Asian ancestry. We found that the incidence of MN decreased by 3.6% during the COVID-19 pandemic compared to the period before the onset of the COVID-19 pandemic(P = 0.026). However, after Bonferroni correction, the change in incidence did not reach a significant p-value(P > 0.05/2), and the overall incidence of glomerular diseases did not show a significant change (P = 0.364). Additionally, the Mendelian randomization analysis indicated no significant causality between COVID-19 (critical illness, susceptibility, severe infection, hospitalization, and severity) and MN (no significance, PBonferroni>0.05).The results of this preliminary study suggest that the incidence rate of MN remained relatively stable during the COVID-19 pandemic. Furthermore, our genetic perspective Mendelian randomization analysis has furnished additional evidence contradicting any causal relationship between varying degrees of COVID-19 infection and MN.