Geographic Variation in the Utilization of HCV-viremic Donors into HCV-negative Recipients

Abstract

We read with great interest the article by Cotter et al1 in which they identified that the practice of liver transplantation (LT) from hepatitis C virus (HCV)-viremic donors to HCV-negative recipients (D HCV+/R−) has increased with notable geographic variation. While the authors should be congratulated on a substantial effort, we wish to place emphasis on several points to place their studies in the proper context. First, the geographic variation is driven by a variety of factors. As the authors described, the rate of acute HCV infections in each geographic region appeared to be concordant with the practice of D HCV+/R−. However, that alone does not account for the variation in geographic utilization. Da et al2 reported a regional difference of 59.7% to 84.2% in conversion rates of HCV donors from the potential to actually used donors, likely reflective of regional experience and institutional policies. In addition, marginal grafts in LT such as those from old donors3 and donation after circulatory death (DCD)4 are known to show geographical and center differences in their utilization. The geographical variation in the practice of D HCV+/R− likely derives from a combination of these factors. Second, “racial disparity” in the practice of D HCV+/R− is prone to be influenced by several factors. The proportion of Caucasian recipients in the D HCV+/R− was significantly higher than other ethnic groups, which “raises the possibility of racial disparity” in authors’ study.1 However, additional demographics are important to take into consideration. The proportions of Caucasians as donors, not only as recipients, in the D HCV+/R− group was significantly higher, which could arise from the geographic variation. In addition, this study examined recipients without evidence of HCV infection. Liver disease cause varies on the waiting list by race: Caucasians make up 93.2% of HCV− LT candidates, whereas African Americans account for 79.8%.5 These characteristics could have influenced the differences of race in the D HCV+/R− practice. Nonetheless, more research is warranted to explore this important observation. Finally, there seems to be a causal relationship between the practice of D HCV+/R− and median Model for End-Stage Liver Disease (MELD) scores. The highly utilizing regions are “among the regions with the lowest median MELD scores.” Among the regions with the lowest rates of the D HCV+/R− practices, “regions 4 and 7 have many of the states with higher waitlist mortality rates.” The authors conclude that higher utilization of D HCV+/R− may improve waitlist mortality and decrease median MELD scores. However, the practice of using other marginal grafts showed different patterns. The majority of elderly donors were used in region 9, where waiting times and MELD scores are among the highest.3 Region 4 has significantly increased the DCD LT utilization.4 These results suggest that factors other than the practice of marginal grafts also play a role in median MELD scores and waiting list mortality. Despite these critiques, LT from HCV-viremic donors is a promising strategy to expand donor pool. Further detailed investigations in long-term outcomes and patient selection criteria would be helpful to further advance the practice of LT from HCV-viremic donors.