"Role of kidney function and concentrations of BAFF, sPD-L1 and sCD25 on mortality in hospitalized patients with COVID-19".

BACKGROUND: Chronic kidney disease (CKD) is a recognized risk factor for severe complications in COVID-19. Our objective was to analyze the association between kidney function / T and B lymphocyte modulatory factors and risk of mortality in COVID-19 patients. METHODS: In-hospital and 30-day mortality were analyzed in COVID-19 patients (n = 110). Plasma levels of selected T and B cell modulators were analyzed and correlated to mortality risk. A subgroup of sex- and eGFR-matched COVID-19 patients was compared to CKD patients without infection and healthy subjects. RESULTS: COVID-19 patients who died in hospital and within 30 days had significantly higher BAFF and sCD25 plasma levels than survivors. In logistic regression models patients with high BAFF, sCD25 and sPD-L1 levels had significantly higher risk of both in-hospital and 30-day mortality while there was no association to eGFR. In the subgroup analysis, a higher level of BAFF, IFN-α, sCD25, sPD-L1 and a lower level of sCD40L was observed in COVID-19 patients compared to the CKD group with corresponding kidney function. CONCLUSIONS: We demonstrate that kidney function and concentrations of BAFF, sCD25 and PD-L1, independent of previously recognized risk factors; age, male gender, and leukocytosis are associated with risk of in-hospital and 30-day mortality in patients with COVID-19. These data indicate the significance of adaptive immune system modulators in COVID-19 and motivate further analysis to identify new potential prognostic and therapeutic approaches.