Our main finding in the present study is that kidney function and factors that are partly involved in B cell activation (BAFF), T cell activation (sCD25) and suppression (sPD-L1), apart from previously recognized risk factors; age, male gender, leukocytosis, and high neutrophil-to-lymphocyte ratio are associated with risk of mortality and add important predictive information in hospitalized patients with COVID-19. Here, SPDL1 is linked to COVID-19.