Alemtuzumab induction and antibody-mediated kidney rejection after simultaneous pancreas-kidney transplantation.

BACKGROUND

The best induction agent for simultaneous pancreas-kidney transplantation (SPKT) remains the subject of debate. Alemtuzumab is effective in preventing acute cellular rejection (ACR) in SPK recipients and has been used to prevent antibody-mediated rejection (AMR) in sensitized kidney transplant candidates.

METHODS

A retrospective cohort study was performed including 136 SPK recipients receiving maintenance immunosuppression with tacrolimus, mycophenolic acid prodrugs, and prednisone. Two groups were compared: those who received induction with alemtuzumab (n=97) and those induced with basiliximab (n=39).

RESULTS

Kidney ACR was more frequent in SPKT induced with basiliximab (2-year 12.8% vs. 3.1%, P=0.04), but the incidence of AMR was similar (2-year 18% with basiliximab vs. 13.8% with alemtuzumab, P=NS). Kidney rejection was associated with clinical pancreas rejection in 70% of cases, without differences between the groups. Postrejection kidney graft survival was similar in both groups (2-year basiliximab/alemtuzumab 94.7%/91.2%), but death-censored kidney graft survival was lower with alemtuzumab (100%/91.2%, P=0.056). In the basiliximab group, the predominant cause of kidney loss was death-with-function, whereas in the alemtuzumab group AMR accounted for all losses. Pancreas graft survival was similar in both groups, yet more pancreas losses due to acute rejection occurred in alemtuzumab-treated patients (4 vs. 1).

CONCLUSIONS

Kidney AMR is more common than ACR in SPKT recipients treated with alemtuzumab, tacrolimus, mycophenolic acid, and steroids. ACR is better prevented by alemtuzumab than basiliximab, but no relevant difference is found in prevention of AMR. Despite the high incidence of AMR, survival rates are excellent in both groups.