医学研究：ブタから人間への肝臓移植の評価

The first known transplantation of a gene-modified pig liver to a human recipient diagnosed with brain death is described in a study published in Nature. The procedure was carried out in a person diagnosed with brain death to evaluate the performance of the transplanted organ over a 10-day observation period.

Liver transplantation is the most effective treatment for end-stage liver diseases, but the demand for donor livers far exceeds the supply. Pigs are being considered as an alternative source of organs owing to their compatible physiological functions and size. Advances in gene editing have made it possible to modify pig organs to reduce the risk of rejection and improve compatibility with human recipients. However, the complexity of liver function makes transplantation difficult.

Hai-Long Dong, Lin Wang, Ke-Feng Dou and colleagues transplanted a liver from a Bama miniature pig in which six genes had been edited into a human recipient who was diagnosed with brain death, under the strict supervision of their hospital ethics committee. The gene edits included removal of genes that mediate rejection and the insertion of human transgenes to facilitate compatibility. The authors monitored graft function, blood flow, and immune and inflammatory responses over a period of 10 days. The porcine liver produced bile and porcine albumin, maintained stable blood flow and showed no signs of rejection. Immune responses were controlled with immunosuppressants.

These findings suggest that gene-modified pig livers can survive and function in human bodies, potentially serving as a bridge therapy for patients with liver failure awaiting human donors. However, the study was limited to a 10-day observation period, and only basic liver functions were measured. Further research is needed to evaluate long-term outcomes and the full range of liver functions.