Calcineurin inhibitors, but not rapamycin, reduce percentages of CD4+CD25+FOXP3+ regulatory T cells in renal transplant recipients.

Background: Immunosuppression in renal transplantation, although manageable in the short-term, is a major hurdle for long-term graft survival. Recently, increased frequencies of CD4CD25 regulatory T cells (Tregs) have been described as an additional mechanism that induces alloimmune tolerance.

Methods: We assessed 64 renal transplant recipients with stable renal function for at least one year.