Clinical Course and Factors Correlated with Severe Morbidity and Mortality in Patients with Coronavirus Disease 2019 Undergoing Maintenance Dialysis in Kanagawa, Japan.

Objective Patients undergoing maintenance dialysis are at a higher risk of morbidity and mortality due to severe coronavirus disease 2019 (COVID-19) than the general population. However, longitudinal data regarding this subpopulation of patients are lacking. We therefore examined the prognosis of patients with COVID-19 undergoing maintenance dialysis between 2020 and 2023. In addition, we explored the factors correlated with COVID-19 severity, focusing on the transition thereof throughout the observational period. Methods The primary outcome was the progression to severe or fatal COVID-19. We evaluated the correlation between the primary outcome and baseline demographic and clinical characteristics of patients. Patients undergoing maintenance dialysis who were hospitalized for mild-to-moderate COVID-19 between February 2020 and April 2023 were enrolled at four institutions in Kanagawa, Japan. Results Of the 173 patients, 7 (4.0%) developed severe COVID-19, and 12 (6.9%) died. The severe/death cohort was significantly older, with a higher percentage of unvaccinated patients than the non-severe cohort (58.2% and 25.0%, respectively; p=0.016). Thymus and activation-regulated chemokine levels on admission were lower in the severe/death cohort than in the non-severe cohort, albeit not to a statistically significant degree (148±84 mg/dL and 342±657 pg/mL, respectively; p=0.082). A multivariate logistic regression analysis revealed that the odds ratio for severe morbidity or death was 0.23 (95% confidence interval: 0.07-0.75) for vaccinated patients. Conclusion In patients undergoing maintenance dialysis, the severity rate of COVID-19 is approximately 10%. Vaccination was correlated with a reduced risk of severe COVID-19.