Impact of donor hepatitis C virus on kidney transplant outcomes for hepatitis C positive recipients in the direct acting antiviral era: time to revise the kidney donor risk index?

INTRODUCTION: Kidneys from donors with hepatitis C (HCV) infection are traditionally considered to be at risk for poorer survival outcomes, as reflected in the KDPI. Modern direct acting antivirals (DAAs) may modify this risk. METHODS: Using UNOS data, HCV infected adult first time kidney transplant recipients from 2014-2017 were examined. Graft and patient survival were compared in a propensity matched cohort of recipients of HCV antibody(+) kidneys versus antibody(-) kidneys. Subsequent analysis was performed in a propensity matched cohort of recipients of HCV viremic (RNA positive) vs. HCV naive kidneys. RESULTS: There were 379 recipients each in the matched cohort of recipients of HCV antibody(+) vs. HCV antibody(-) kidneys. Despite a higher KDPI (58.2% for HCV antibody(+) vs. 38.8% for HCV antibody(-)), 1 year patient and graft survival were similar in the HCV(+) and HCV(-) groups (95.4% and 94.9% vs 97.9% and 96.0%, p=0.543 and p=0.834, respectively). There were 200 recipients each in the cohort of recipients of HCV viremic vs. HCV naive kidneys, with the KDPI again higher in the HCV viremic group (56.8% vs 35.2%). Baseline hazard ratios for graft failure (HR 4.69; p=0.009) and death (HR 7.60; p=0.003) were significantly elevated in the viremic group, but crossed 1 at 21 and 24 months, respectively. CONCLUSIONS: In the modern DAA era, calculated likely KDPI overestimates risk kidneys from HCV antibody(+) donors. Donor viremia conveys an early risk which appears to subside over time. These results suggest that it may be time to revise the kidney donor risk index.