Risk factors for relapse and aggravation in membranous nephropathy after COVID-19 infection.

Background: Relapse of membranous nephropathy (MN) and other glomerular diseases has been observed after COVID-19 infection. The risk factors contributing to disease progression in MN patients after contracting COVID-19 remain unclear.

Methods: This retrospective study included 656 consecutive patients with biopsy-proven primary MN who received treatment and were regularly followed up for over six months. Logistic regression analyses were conducted to identify risk factors for disease progression.

Results: Among the cohort, 555 patients (84.6%) contracted COVID-19 from November 11th, 2022, to February 22nd, 2023. Of them, 112 patients (20.2%) experienced a > 50% increase in proteinuria, including 30 patients (5.4%) who experienced nephrotic syndrome relapse. Sixteen patients (2.9%) showed immune aggravation with elevated anti-PLA2R antibody levels, and five patients (0.9%) had immune relapse characterized by antibody reoccurrence. Kidney dysfunction, defined as an eGFR reduction > 30% from baseline, occurred in 10 patients (1.8%), with two patients (0.4%) progressing to ESKD. Four patients (0.7%) died of respiratory failure. Overall, 132 patients (24.0%) experienced disease progression after COVID-19 infection. Multivariate logistic regression identified longer fever duration (OR 1.118, 95% CI 1.029-1.356, P = 0.018), withdrawal of immunosuppressants and/or steroids (OR 2.571, 95% CI 1.377-4.799, P = 0.003) and extended drug cessation (OR 1.113, 95% CI 1.045-1.186, P = 0.001) as independent risk factors for MN progression.

Conclusions: These findings suggest prompt antiviral treatment and minimizing the duration of immunosuppressant withdrawal to optimize kidney outcomes in MN patients with COVID-19.