Low levels of renalase, a flavoprotein released by kidneys, has been linked with cytokine release syndrome and disease severity of viral infections. We sought to, 1) identify traditional and novel predictors of mortality for patients hospitalized with COVID-19; and 2) investigate whether renalase independently predicts mortality. In a retrospective cohort study, clinicopathologic data and blood samples were collected from hospitalized COVID-19 patients. Patients were excluded if