Magnitude of Viremia after Heart and Lung Transplantation from HCV Viremic Donors and Time to Clearance Based on Timing of Starting Therapy Post-Transplantation

Abstract

Thoracic organ transplantation from Hepatitis C (HCV) viremic donors is a promising strategy due to curative therapies for HCV. Currently, there is no consensus on the best time to initiate HCV therapy relative to time of transplantation. We assessed the difference in magnitude of viremia and time to clearance in recipients of heart (HT) and lung (LT) transplant, based on timing of starting antiviral HCV therapy. From January 2018 to October 2019, 42 patients received thoracic organs from viremic donors. All recipients were treated with Mavyret (glecaprevir/pibrentasvir) for 8 weeks. HT recipients received therapy at the time of detectable viremia, while LT recipients were preemptively treated within 3 days post-transplant. HCV viral load was monitored by RT-PCR. 23 patients received HT (mean age 59 ± 9 years) and 19 patients received LT (mean age 60 ± 9 years). HCV serologic testing was performed in HT recipients at a mean of 7 ± 1 days and in LT recipients at a mean of 4 ± 3 days post-transplant. At the time of testing, all HT and 14 LT patients had detectable viremia. Five LT patients never developed viremia. The mean viral load f HT was 4.5 logIU/mL and for LT was 1.6 logIU/ml. Viremia clearance was obtained at a mean of 28 ± 13 days in HT and 21±11 days in LT recipients (p=0.13) (Fig). The mean time to HCV antibody (AB) clearance was 130 ± 145 days in HT and 225 ± 103 days in LT recipients (p=0.058). There was no correlation between the 2 groups in either the duration of viremia or HCV AB clearance. Our study suggests that the magnitude and conversion to detectable viremia depends on the time of initiation of HCV therapy relative to time of transplant with complete conversion to HCV viremia in the HT group. Interestingly, there was no significance in time to viremia or HCV AB clearance between the two groups. This may be an organ specific response, but larger sample size studies need to be conducted to define the optimal time of starting HCV therapy.