Objective: This study evaluated the outcome of liver grafts from ABO incompatible donors, focusing on biliary complications, and compared the results to an ABO compatible control group. Also, the expression of donor ABH antigens in the liver graft was analyzed.
Summary background data: The outcome of liver transplantation using an ABO incompatible graft is still debated. These blood group related (ABH) antigens are known to be expressed not only on the surface of the erythrocytes, but also on the epithelial cells of large bile ducts. Because the biliary epithelium of hepatic allografts may continue to express donor ABH antigens, it may be more susceptible to immunologic bile duct injury after transplantation across the ABO barrier.
Methods: Eighteen ABO incompatible grafts were compared with 18 ABO compatible grafts in patients who were matched according to medical urgency, primary liver disease (PLD), and recipient age. After transplantation, the grafts were analyzed with cholangiography, Doppler ultrasound, or arteriography and liver histology according to protocol. Immunoperoxidase staining for ABH antigens was performed on hepatic tissue.
Results: Biliary complications developed in 82% of the ABO incompatible donors, compared to 6% of the ABO matched controls. Hepatic artery thrombosis occurred in 24%. Cellular rejection was diagnosed in 65% versus only 28% in the control group. The 1-year actuarial graft survival rate was 44% versus 78% in the control group. ABH antigens of the donor were expressed on vascular endothelium and bile duct epithelial cells as long as 150 days after transplant.
Conclusions: Using ABO incompatible allografts, a high incidence of biliary and hepatic artery complications and decreased graft survival in liver transplantation were found. An immunologic injury to the bile duct epithelium and/or to vascular endothelium is suspected.