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Spring 1994Volume 1, Number 1 |
FDA approval of FK506 (tacrolimus) is eagerly awaited by liver transplant surgeons. At the American Society of Transplant Surgeons in May, 1993, the results of the American randomized trial of tacrolimus for the prevention of liver allograft rejection were presented. With a minimum follow-up of 12 months for all patients, the tacrolimus-based immunosuppressive protocol produced the same one-year patient survival (88%) and one-year graft survival as the cyclosporine-based protocol. Freedom from rejection, however, was significantly higher in the tacrolimus-treated recipients. The use of OKT3 for treatment of steroid-resistant graft rejections was greater in the cyclosporine-treated patients.
Five times as many patients (p<0.0001) had cyclosporine discontinued for unresponsive allograft rejection, but more patients (37 vs. 13, p<0.01) discontinued tacrolimus than cyclosporine because of adverse effects. The incidence of nephrotoxicity, the most important side effect, was exactly the same in the two groups. Infections were more common in cyclosporine-treated patients, probably due to the higher incidence of allograft rejection in this group. It is expected that the safety of tacrolimus will increase as experience with the drug grows and as more reliable methods of monitoring drug levels become available.
On another front, the use of liver transplantation for patients with chronic active hepatitis B has been much debated. Currently, the two-year survival following transplantation in this setting is 53%, which is significantly lower than the 82% two-year survival seen in non-hepatitis B recipients at our institution. Recurrent hepatitis B infection of the transplanted graft poses a serious problem. At the American Society of Transplant Surgeon's meeting in May, Dr. J. Crippin reported a 10% two-year patient survival in a multicenter study of patients retransplanted for recurrent hepatitis B disease. In patients retransplanted for reasons other than recurrent hepatitis B, the corresponding survival was 61%. Retransplantation for recurrent hepatitis B disease is clearly difficult to justify in light of the present donor shortage. Whether liver transplants should be performed for chronic active hepatitis B is still being discussed, but since the survival of these patients does not differ markedly from the average survival (as reported by UNOS) after primary liver transplantation for other indications, the procedure must be considered appropriate. Further studies are needed to identify patients who are particularly prone to recurrent hepatitis B disease.
Göran Klintmalm, MD, PhD
Baylor University Medical Center
Dallas, Texas
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