A previous trial in renal transplantation comparing sirolimus (rapamycin) to cyclosporine (CsA) in a triple-drug therapy regimen with azathioprine and corticosteroids found that the incidence of acute rejection was similar (approximately 40%) with a trend for better renal function with sirolimus. Controlling cells were contained only in the CD25+ fraction, as equal numbers of CD25″CD4+ T cells were unable to control dismissal. This pretreatment strategy led to increased look of CD122 by the CD25+CD4+ T cells.

The cytotoxic T cell and cytotoxic lymphocyte ancestors were shown to be Lyt-3 and these could be useless from sensitized Lyt-1 populations that mediated graft rejection. The action of peripheral blood stem cells with CAMPATH-1H is a simple and effective method for reducing T cells which may be applicable to both autologous and allogeneic transplants from related or unrelated donors. Special advantages of this methodology are the simultaneous reduction of donor B cells and the concomitant infusion of CAMPATH-1H to deplete residual recipient T cells and thus prevent graft rejection.