Hepatocyte Transplantation in Man

Recent advances in liver transplantation have caused a serious shortage of donor livers, and a consensus on determining brain death has not been reached by the medical community in several countries, including Japan. To overcome these circumstances, hepatocellular transplantation (HCTX) has been attempted because HCTX requires no vascular anastomosis and donor hepatocytes are easy to obtain from living donors, and easy to preserve for a long time. In many experimental studies on HCTX some promising findings have been obtained, but clinically there has been little progress. Our success with survival of autotransplanted monkey hepatocytes and the development of a preparation of human hepatocytes has renewed interest in clinical HCTX. A multipuncture perfusion method or collagenase perfusion via the umbilical vein enables us to obtain approximately 1 × 108 hepatocytes from partially resected liver (60 g). The clinical trial of HCTX into the spleen was performed in 10 patients in Japan. A CT image, taken 1 mo after HCTX, showed a low density area corresponding to the inoculated site, which suggested that the transplanted hepatocytes survived and possessed hepatocellular function. One patient who sustained hepatic encephalopathy and massive ascites has now returned to work 11 mo after HCTX and hepatic artery ligation. However, there were no definite findings for functional support of damaged livers by HCTX in the spleen. We will review our experiments on HCTX, and describe the current and future aspects of HCTX.