Predictors Of Severe Covid-19 In Kidney Transplant Recipients In The Different Epidemic Waves: Analysis Of The Spanish Registry

SARS-CoV-2 infection has produced high mortality in kidney transplant (KT) recipients, especially in the elderly. Until December 2020, 1011 KT with COVID-19 have been prospectively included in the Spanish Registry and followed until recovery or death. In multivariable analysis, age, pneumonia, and KT performed <= 6 months before COVID-19 were predictors of death, whereas gastrointestinal symptoms were protective. Survival analysis showed significant increasing mortality risk in four subgroups according to recipient age and time after KT (age 6 months, age <65 and time <= 6, age >= 65 and time >6 and age >= 65 and time <= 6): mortality rates were, respectively, 11.3%, 24.5%, 35.4%, and 54.5% (p < .001). Patients were significantly younger, presented less pneumonia, and received less frequently specific anti-COVID-19 treatment in the second wave (July-December) than in the first one (March-June). Overall mortality was lower in the second wave (15.1 vs. 27.4%, p < .001) but similar in critical patients (66.7% vs. 58.1%, p = .29). The interaction between age and time post-KT should be considered when selecting recipients for transplantation in the COVID-19 pandemic. Advanced age and a recent KT should foster strict protective measures, including vaccination.