Purpose: This study aimed to assess changes in renal function during the acute disease and up to three months after the onset of symptoms among kidney transplant patients surviving COVID-19.

Methods: This ongoing single-center observational prospective study included kidney transplant recipients diagnosed between March 2020 and May 2021 and survived the first 28 days. Before diagnosis, baseline renal function was defined as the mean of the last three creatinines. The follow-up period was three months. We used a one-way ANOVA test to compare the mean eGFR in baseline, 28 days, and three months after COVID-19. The CKD-EPI equation was used to estimate GFR.

Results: Among the 787 patients, the mean age was 48.5 years, 59.3% were male, and 68.0% were white. Comorbidities such as hypertension, diabetes, and cardiopathy were present in 70.4%, 25.3%, and 3.9%, respectively. The mean body mass index was 26.9 kg/m², and baseline GFR was 51,9 ± 20.1 ml/min/1.73m². Immunosuppression was reduced by 27.1% and suspended in 9.5% of cases. In 30.3% of the patients, acute kidney injury occurred, 7.8% needed dialysis support, and 2.5% had graft loss. There was a decline in renal function at 28 days (50.0 ± 22.1 ml/min/1.73m²; p<0.001) and 3 months (47.3 ± 21.0 ml/min/1.73m²; p<0.001) after COVID-19. Among the patients, 47.3% did not return to baseline eGFR values within three months, and 19.9% reduced renal function at least 25%.

Conclusions: COVID-19 does impact early renal function decline in KTR. These data reassure that KTR represents a group that benefits from early access to effective preventive strategies.