Changes in Kidney Graft Function in COVID-19 Convalescents

Background: Kidney transplant recipients (KTRs) are at an increased risk of infection with severe acute respiratory syndrome coronavirus 2, with mortality from 13% to over 30%. However, data concerning the influence of COVID-19 on long-term graft function in convalescents is lacking. The aim of this study was to evaluate the influence of COVID-19 on graft function at 6 months after recovery.

Methods: A longitudinal controlled study was conducted in a group of 1058 KTRs. Of 180 patients with COVID-19 in the past, 77 KTRs (45 male) with a mean age 50.57 ± 13.37 years, Charlson Comorbidity Index of 3 (median; interquartile range [IQR], 3-5), Fragility Score of 3 (median; IQR, 3-3), and minimum 6 months after acute COVID-19 were included. The most common symptoms were weakness (75.33%), fever (74.03%), cough (51.95%), and loss of appetite (48.05%). Thirty-three patients were hospitalized; none required invasive ventilation therapy, but 16 required oxygen support. The treatment of COVID-19 included antibiotics (38.96%), thromboprophylaxis (25.97%), and nonsteroidal anti-inflammatory drugs, or paracetamol (25.97%).

Results: The median (IQR) values of serum creatinine 3 months before the onset and 6 months after COVID-19 were 1.25 (0.98-1.86) and 1.26 (1.03-1.78) mg/dL (nonsignificant difference); in strata analysis, there were also no differences with regards to patients with higher and lower comorbidity (3 < Charlson Comorbidity Index < 3) and fragility (3 < Fragility Score < 3). Furthermore, creatinine concentration in KTRs and controls did not differ.

Conclusions: In the group of KTRs with a mild course of COVID-19, no negative impact of the infection on graft function was observed 6 months after transplantation.