Liver transplantation using grafts of living donors with isolated unconjugated hyperbilirubinemia: a matched case-control study

Unconjugated bilirubin has shown both cytotoxic and cytoprotective effects, acting as either an oxidant or an antioxidant. Elevated unconjugated bilirubin with otherwise normal, so-called isolated unconjugated hyperbilirubinemia (IUHB), is encountered frequently in living liver donor evaluation. However, the significance of IUHB on transplantation-related outcomes has not been clarified in donors and recipients. Forty-six living donors with IUHB were matched 1:1 with the control donors and 43 recipients who received grafts from donors with IUHB were matched 1:1 with the control recipients. Matched variables included donor/recipient age, residual liver volume, steatosis, cold ischemic time, graft versus recipient weight ratio, the MELD score and others. Donors in the control and IUHB group were comparable regarding the maximum postoperative transaminase concentrations, postoperative complications, and hospital stay. Recipients in the control and IUHB group were comparable regarding primary graft dysfunction, major postoperative complications, long-term ICU/hospital stay, 1-year mortality, and rejection rate, as well as recipient/graft survival rates. Recipients' unconjugated bilirubin concentration at 3 years after transplantation was higher in IUHB group with otherwise comparable liver function. It was concluded that living donor liver transplantation is safe for donors with IUHB and their recipients.