HCV-positive kidney transplant patients treated with direct-acting antivirals maintain stable medium-term graft function despite persistent reduction in tacrolimus trough levels

BACKGROUND/AIM: Direct-acting antivirals (DAAs) have improved the treatment of HCV-positive kidney transplant recipients (KTRs). However, their medium-term follow-up effects on graft function are conflicting. This study aimed to analyze how the interplay between DAAs, calcineurin inhibitors (CNI), and HCV eradication impacts 12-month kidney graft function. METHODS: This double-center retrospective study with a prospective follow-up enrolled 35 KTRs with HCV treated with DAAs for 12 weeks. We compared three parameters: estimated glomerular filtration rate (eGFR), 24-h proteinuria, and CNI trough levels at three time points: baseline, end of treatment (EOT), and 12 months later. RESULTS: Kidney allograft function remained stable when comparing baseline and 12-month post-treatment values of eGFR (60.7 versus 57.8 ml/min; p = 0.28) and 24-h proteinuria (0.3 versus 0.2 g/24 h; p = 0.15), while tacrolimus (Tac) trough levels underwent a statistically significant decline (6.9 versus 5.4 ng/ml; p = 0.004). Using an ongoing triple Tac-based maintenance therapy as a conservative measure, a dose escalation of Tac was applied only in seven patients. No variation in CyA and mTOR levels was detected. CONCLUSION: DAA therapy is safe and effective in HCV-positive KTRs. It also produces a persistent significant reduction in Tac trough levels that does not influence graft function at 12 months.