Aim: The use of interleukin-2 receptor antibody (IL-2Ra) induction has been associated with reduced rejection rates in renal transplant recipients. However, the effect of IL-2Ra induction on graft and patient outcomes in renal transplant recipients with differing immunological risk remains unclear.
Methods: Using Australia and New Zealand Dialysis and Transplant Registry, renal transplant recipients in Australia between 1995 and 2005 were included. Recipients were stratified into low immunological risk (primary grafts with < or = 2 human leucocyte antigen (HLA)-mismatches and panel-reactive antibody (PRA) < 10%) or intermediate immunological risk (subsequent grafts or >2 HLA-mismatches or PRA > 25%) recipients. Recipients receiving T-cell depletive induction therapy or steroid and/or calcineurin-free inhibitor regimens were excluded. Outcomes analysed included the presence of rejection at 6 months, estimated glomerular filtration rate at 1 and 5 years, graft and patient survival.
Results: 218 of 1220 (18%) low-risk and 883 of 3204 (28%) intermediate-risk recipients received IL-2Ra. In intermediate-risk recipients, IL-2Ra induction was associated with a 26% reduction in the incidence of acute rejection; but this benefit was restricted only to recipients initiated on cyclosporine-based immunosuppressive regimens. In contrast, the use of IL-2Ra in low-risk recipients was not associated with reduced rejection risk. There was no association between IL-2Ra induction and other graft or patient outcomes in both low- and intermediate-risk recipients.
Conclusion: This registry analysis suggests that IL-2Ra induction may be associated with a reduction in rejection risk in cyclosporine-treated intermediate immunological risk recipients, but not in low-risk renal transplant recipients.