Clinical Course, Nosocomial, and Opportunistic Infections Among Kidney Transplant Recipients with COVID-19: A Retrospective Single Center Study

Background: We report the results of an observational study, analyzing the clinical course of kidney transplant patients hospitalized for COVID-19 and comparing it with a control to determine if outcomes, nosocomial, and opportunistic infections were different between groups.

Methods: An observational, retrospective, case-control, single-center study, including a group of kidney transplant adults diagnosed with COVID-19, from March 2020 to April 2022. Transplant patients hospitalized for COVID-19 comprised the cases. The control group consisted of non-transplanted adults, without immunosuppressive treatment, hospitalized for COVID-19, and matched by age, sex, and month at diagnosis of COVID-19. Study variables were collected, including demographic/clinical, epidemiologic, clinical/biological at diagnosis, evolutive, and outcome variables.

Results: Fifty-eight kidney transplant recipients were included. Thirty required hospital admission. Ninety controls were included. Transplant recipients had a higher frequency of intensive care unit (ICU) admission, ventilatory support, and death. The relative risk for death was 2.45. When adjusted by baseline estimated glomerular filtration rate (eGFR) and comorbidity, only the risk for opportunistic infection remained high. Variables independently associated with death were dyslipidemia, eGFR at admission, MULBSTA score, and ventilatory support. Pneumonia by Klebsiella oxytoca was the most frequent nosocomial infection. Pulmonary aspergillosis was the most frequent opportunistic infection overall. Pneumocystosis and cytomegalovirus colitis were more frequent among transplant patients. The relative risk for opportunistic infection in this group was 1.88. Baseline eGFR, serum interleukin 6 level, and coinfection were independently associated with it.

Conclusions: Evolutive course of COVID-19 requiring hospitalization in renal transplant recipients was primarily determined by comorbidity and baseline kidney function. At equal comorbidity and renal function, there were no differences in mortality, ICU admission, nosocomial infection, and hospital stay. However, the risk for opportunistic infection remained high.