Experimental and clinical experience with the use of tacrolimus (FK506) in kidney transplantation.

Tacrolimus is a recently developed immunosuppressive agent, based on a mechanism similar to cyclosporin. A broad variety of trials has provided evidence for its efficacy in human liver transplantation. In these trials, the incidence of acute rejection was markedly reduced. The following article reviews recent knowledge regarding clinical and experimental experience with tacrolimus in kidney transplantation. In summary, clinical trials suggested a marked reduction of acute allograft rejections comparable to those observed in liver transplantation. Its efficacy in steroid-resistant rejections is also well documented, while not critically analyzed in a prospective trial. Its effect is independent of the preceding administration of antilymphocyte antibodies. Thus, its use seems warranted even in the presence of steroid-resistant graft rejection, when treatment with antilymphocyte antibodies is contraindicated. Based on preliminary experience with tacrolimus in previous studies of primary immunosuppressive treatment and on the compelling evidence that the drug is effective in rescue therapy, its use as primary immunosuppressive regimen in immunologic high risk patients should now be considered.