Effects of a Tolerance Induction Protocol in Renal Allograft Recipients — the Ahmedabad Experience

Abstract

The most interesting recent development in transplantation immunobiology is the clinical implementation of tolerance induction. We report our experience of megadose hematopoietic stem cell transplantation with non-myeloablative minimum conditioning in renal allograft recipients. This was a retrospective, single-center study of 159 renal allograft biopsies from two groups of patients: one group underwent a tolerance induction protocol (TIP) before renal transplantation; the other underwent renal transplantation directly. Biopsies were classified into two subgroups to differentiate between acute and late rejection: 127 biopsies, comprising 64 from patients who underwent a TIP and 63 from controls, performed within 180 days after transplantation; and 32 biopsies, comprising 26 from patients who underwent a TIP and six from controls, performed 180 days after transplantation. All patients received cyclosporine 7 mg/kg/day, tapered to 3 mg/kg/day 3 months after transplantation, and subsequently continued at the latter dosage. There was markedly less immunologic injury (i.e. generally fewer and milder rejection episodes) evident in biopsies from patients who underwent TIP than in biopsies from controls. Cyclosporine toxicity was considerably greater in patients from the TIP versus control group (82.9% vs 40.6%). TIP protects renal allografts from immunologic injury and has an unexplained cyclosporine-sparing effect.