Trends in adult post-kidney transplant immunosuppressive use in Australia, 1991-2005

Aim: Kidney transplant outcomes have improved over the past 15 years, partly due to improvements in immunosuppression. We used data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry to examine trends in immunosuppressive use post transplant. Methods: All adult (recipient age 16+ years) kidney-only transplants performed in Australia from April 1991 to December 2005 were followed to graft loss or December 2005. Immunosuppressive use at induction, 1, 3 and 5 years post transplant were analysed by transplant cohort. Results: Calcineurin-inhibitors (CNI) were used in most recipients for induction and maintenance immunosuppression, with increasing tacrolimus use. Induction cyclosporin dose increased since 2001 (from 5.8 to 7.9 mg/kg per day), but maintenance cyclosporin and tacrolimus dose decreased (from 3.8 to 3.0 mg/kg per day cyclosporin at 1 year post transplant). CNI-free induction increased since 2002 (from 1.4% to 8.4%), while CNI-free maintenance increased throughout the study period. Mycophenolates were the predominant antimetabolite used. Steroid-free maintenance decreased (from 22.7% to 8.7% at 1 year post transplant), as did median prednisolone doses (from 0.12 to 0.09 mg/kg per day at 1 year post transplant). Sirolimus or everolimus are increasingly used for CNI-sparing rather than as antimetabolites substitutes. OKT3 or antithymocyte globulin induction decreased, while anti-CD25 antibody usage increased from 9.5% to 57.1% since 2000. Conclusion: There is a trend to more potent induction immunosuppression with tacrolimus, mycophenolates and anti-CD-25 antibodies, but with CNI avoidance or minimization during maintenance phase. While steroid avoidance/cessation decreased, maintenance steroid dose has also decreased. Anti-CD25 antibodies are now used in > 50% of recipients.