Estimated Impact of Hepatitis C Positive Lung Donor Utilization on US Donor Lung Supply

Abstract

Purpose The advent of highly effective direct-acting antiviral agent (DAA) medications for hepatitis C virus (HCV) has led to reports of safe and acceptable short-term outcomes in recipients of HCV+ donor lungs. While further work is needed to establish the safety and optimal DAA protocols for transplanting HCV+ donor lungs, the potential impact of using HCV+ donor lungs to increase the donor lung supply within the United States is unclear. The aim of this study was to estimate the potential number of acceptable HCV lung donors within the United States. Methods All potential donors within the United States between March 1, 2015 and February 28, 2018 were identified from Scientific Registry of Transplant Recipients data and further classified by their HCV antibody and nucleic acid testing results into 4 categories: HCV-, HCV+ viremic, HCV+ non-viremic, and HCV undetermined. A prediction model of donor lung use within non-HCV positive donors was derived using conditional random forest methods and then applied to HCV+ donors. The number of observed and predicted HCV+ donors was calculated and further stratified by HCV viremia status and Organ Procurement and Transplantation Network (OPTN) region. Results There were 29,481 potential donors during the study period including 2,054 (7.0%) HCV+ donors (676 non-viremic and 1,378 viremic). HCV+ donors more frequently died from anoxia secondary to drug intoxication, had a greater frequency of cigarette use exceeding 20 pack/years, and had lower median lung PaO2 as compared to non-HCV donors. The lung donor prediction model had a sensitivity of 65.6% and a specificity of 92.6%. During the 3-year study period, there were 248 HCV+ lung donors (75 non-viremic and 173 viremic) estimated as acceptable for lung transplant as compared to an actual 82 HCV+ donors utilized for lung transplant. This translates to an estimated net increase of 166 transplants (55/year). The greatest increase was seen in OPTN regions 2, 3, 10, and 11. Conclusion This study estimates an annual increase of 55 lung transplants through the use of HCV+ lung donors. This is a conservative estimate given the high specificity but low sensitivity of the donor prediction model, and therefore the actual impact is likely greater. The potential impact varies by OPTN region and transplant centers within some regions are likely to see a greater impact from developing DAA protocols for HCV+ donor lung use.