A randomized trial of three renal transplant induction antibodies: early comparison of tacrolimus, mycophenolate mofetil, and steroid dosing, and newer immune-monitoring.

BACKGROUND

New trends in immunosuppression in clinical transplantation include the use of antibody induction agents in protocols that emphasize reduction or avoidance of steroids and calcineurin inhibitors.

METHODS

In a randomized trial using three different antibody induction agents in 90 first renal transplant recipients from cadaver donors, group A received Thymoglobulin, group B received Alemtuzumab, and group C received Daclizumab. Maintenance immunosuppression included tacrolimus and mycophenolate in all three arms, and methylprednisolone in groups A and C only (standard clinical institutional practice). The targeted trough level of tacrolimus was between 8 and 10 ng/mL for groups A and C, respectively, with a targeted mycophenolate dose of 1 g twice daily. However, in group B, the target tacrolimus trough level was 4 to 7 ng/mL to reduce long-term nephrotoxicity, with 500 mg twice-daily doses of mycophenolate, without steroid maintenance.

RESULTS

In this 15-month median postoperative interval report, there were no notable differences in demographics and patient and graft survivals. Acute rejection rates at 1 year were equivalent, that is, 5 of 30 in all three groups (16.6%). In group B, there was slightly lower renal function at 1 month, but no difference at 1 year. There was also significantly more leukopenia, but a greater percentage of T-regulatory cells and number of Fox-P3 mRNA copies by flow cytometry and semiquantitative polymerase chain reaction analysis, respectively, in group B.

CONCLUSIONS

This preliminary analysis indicates that 80% of the patients in group B remained steroid-free 1 year postoperatively, with lower tacrolimus trough levels and no difference in other adverse events.