Commonly, organs that test positive for hepatitis C virus (HCV) are discarded due to the risks associated with the infecting a patient with the virus. 
However, the development of highly-effective direct-acting antivirals (DAAs) for HCV may allow hospitals to significantly cut down on wait times for liver transplants. A new report published by Hepatology found that DAAs may allow HCV-negative patients to receive a liver from an HCV-positive donor without causing harm.
"The availability of donor livers continues to be the limiting factor in increasing the number of liver transplant surgeries," said corresponding author Jagpreet Chhatwal, PhD. "Our study shows that transplanting HCV-positive livers into HCV-negative patients and treating with new antivirals can reduce waiting time to transplant and improve overall life expectancy."
The availability of DAAs for HCV-positive recipients has resulted in cure rates higher than 90% after transplantation, leading to high rates of transplant success, according to the study.
DAAs have also reduced the number of HCV-positive patients who require a transplant, meaning that more livers are transplanted in patients with other conditions, according to the authors. Additionally, the opioid epidemic has led to a boom in the prevalence of HCV-positive donors who are typically young and healthy.
The aforementioned factors have resulted in increased interest in the possibility of transplanting infected livers into HCV-negative patients.
The team of researchers developed a virtual trial in which they simulated the lives of HCV-negative patients on a waiting list for a liver transplant. The authors compared the outcomes of patients who waited for an HCV-negative liver and those who accepted any liver.
"By simulating a virtual trial, we could assess the benefits and risks of transplanting HCV-positive organs into HCV-negative patients without putting patients at risk,” said Co-lead author Sumeyye Samur, PhD. “Our study can thus inform efficient design of future trials and clinical practice in liver transplantation."
Factors such as waiting time based on disease severity and location, the supply of donor organs, risk of complications from an HCV-positive organ, and efficacy of post-transplant DAA treatment were accounted for, according to the authors.
The analysis showed that accepting an HCV-positive liver outweighed the potential risk of waiting for an uninfected liver in a majority of patients, according to the study.
The breadth of the benefits varied based on disease severity, as measured by the MELD score that ranges from 6 to 40, with higher scores corresponding to a more serious condition. The authors noted that patients with a score as low as 12 can be considered for a transplant, but the average is 28.
HCV-negative patients with a MELD score of at least 20 were observed to benefit from receiving an infected liver and receiving antiviral therapy after transplant, according to the study.
"Prior to the availability of DAA drugs, the risks of transplanting HCV-positive livers into HCV-uninfected recipients were felt to be prohibitively high and not justifiable," said co-author Raymond Chung, MD. "Every patient has extensive discussions with their care providers during the transplant listing process, part of which includes discussing the potential of accepting a 'high-risk' donor organ, such as one that tests positive for HCV. More clinical studies evaluating the use of HCV-positive donor livers and the efficacy and optimal treatment duration for antiviral drugs will be needed before this approach can be widely applied."
Patients who benefited the most were those with scores of 28 living in areas most affected by the opioid epidemic, which have the highest concentration of HCV-positive donors, according to the study. The authors caution that while the opioid epidemic has led to more organ donations, the overall trend is negative.
Additional studies are needed to determine the cost-effectiveness of this approach because DAAs are costly, according to the authors.
"DAA treatment is expensive and is only covered by insurers for patients with documented HCV infection,” said co-author Emily Bethea, MD. “If we hope to expand future coverage to HCV-negative patients on the transplant waiting list, we will need data on the cost-effectiveness of preemptive antiviral therapy to help payers recognize the importance and long-term success of this approach."