Background: Coronavirus disease 2019 (COVID-19) infection is a common infectious disease worldwide. It can increase morbidity and mortality in the kidney transplant (KT) recipients. Favipiravir has been a medication for COVID-19 pneumonia treatment in KT patients. Previous case reports identified Favipiravir may have had nephrotoxicity in general population with COVID-19 infection. We aim to explore short term effect of Favipiravir on kidney function at 1st, 3rd months of KT recipients with COVID-19.
Methods: Propensity score inverse weighting multivariable risk regression was introduced to reduce to the possible bias in baseline characteristics between the two treatment groups, including 68 KT patients with COVID-19. The primary endpoints were rate decline in kidney function at 1st, 3rd months. The estimated glomerular filtration rate (eGFR) between groups were compared by using marginal model with generalized estimating equation (GEE).
Results: Fifty KT patients (73.5%) were treated with Favipiravir. We develop propensity scores including age, gender, body mass index, underlying hypertension, diabetes, and coronary artery diseases, ABDR mismatches, immunosuppressive agents for induction, mycophenolic acid use, calcineurin inhibitors, renin-angiotensin-aldosterone system blockades, duration of transplantation, LRKT status, and numbers of receiving COVID-19 vaccination. The eGFR of Favipiravir group was lower than another at 1st, 3rd months after COVID-19 infection by using propensity score reverse weighting (stabilized) double adjusted GEE with autoregressive one correlation (eGFR different of –11.7 [95% CI {confidence interval} –24.3 to 0.8; P=0.068], –13.2 [95% CI –24.7 to –1.7; P=0.025], and –15.8 [95% CI –27.5 to –4.1; P=0.008] for baseline, 1st month, and 3rd month, respectively).
Conclusions: We demonstrated that Favipiravir might have short term 1- and 3-months nephrotoxic effect. The physicians should closely monitor kidney function when prescribed this medication for the KT recipients.