Factors Affecting Kidney Functions in One-Year Follow-up After COVID-19 in Kidney Transplant Patients

Background Coronavirus disease (COVID-19) is more severe, and mortality is higher in kidney transplantation (KTx) patients; it is still unclear how renal functions progress and the conditions affecting renal functions in the post-COVID-19 period. We aimed to investigate the changes in kidney functions and the factors affecting this change after COVID-19. Material and Methods Forty-one kidney transplantation patients who were hospitalised for COVID-19 were included in this retrospective study. The patient's personal information, examination, and treatment information regarding their hospitalisation and follow-ups were obtained from the hospital system. Results Patients with elevated serum creatinine in the first year post-COVID had higher baseline proteinuria and systemic immune inflammation index (SII). Proteinuria increased more in patients with a long transplantation period, hypertension, high basal creatinine, and SII. Also, proteinuria was higher in patients who developed AKI during the COVID period. In addition, baseline SII was an independent predictor of the change in serum creatinine and proteinuria. Conclusions We found that patients with signs of increased inflammation, such as high SII were more fragile regarding renal functions. Therefore, the post-COVID-19 follow-up process of KTx patients with COVID-19 should be individualised.