Predictors of disease severity and outcome of hospitalized renal transplant recipients with COVID-19 infection: a systematic review of a globally representative sample

Introduction. COVID-19 presents a special challenge to the kidney transplant population.Methods. A systematic review of articles that examined COVID-19 in kidney transplant recipients was performed. Patients' demographics, clinical, laboratory and radiological presentations, immunosuppression modification, and COVID-19 specific management were abstracted and analyzed. COVID-19 severity was classified into mild, moderate, and severe. Disease outcome was classified by whether the patient was discharged, still hospitalized, or died.Results. 44 articles reporting individual data and 13 articles reporting aggregated data on 149 and 561 kidney transplant recipients respectively with COVID-19 from Asia, Europe and America fulfilled all inclusion and exclusion criteria. Among studies reporting case specific data, 76% of cases had severe disease. Compared to patients with mild/moderate disease, patients with severe disease had higher CRP, LDH, Ferritin, D-dimer and were more likely to have bilateral lung involvement at presentation and longer time since transplantation (P < 0.05 for all). Recipients' age, gender and comorbidities did not impact disease severity. Patients with severe disease had a more aggressive CNI reduction and more antiviral medications utilization. Outcome was reported on 145 cases, of those 34 (23%) died all with severe disease. Longer duration from transplant to disease diagnosis, hypoxia and higher LDH were associated with mortality (P < 0.05). Different immunosuppression reduction strategies, high dose parenteral corticosteroids use and various antiviral combinations did not demonstrate survival advantage. Similar finding was observed for studies reporting aggregated data.Conclusion. COVID-19 in kidney transplant patients is associated with high rate of disease severity and fatality. Higher LDH and longer time since transplantation predicted both disease severity and mortality. None of the COVID-19 specific treatment correlated with, or improved disease outcome in kidney transplant recipients.