Alemtuzumab preconditioning with tacrolimus monotherapy-the impact of serial monitoring for donor-specific antibody.

BACKGROUND: Antibody preconditioning with tacrolimus monotherapy has allowed many renal allograft recipients to be maintained on spaced weaning. METHODS: Of 279 renal allograft recipients transplanted between March 2003 and December 2004, 222 (80%) had spaced weaning (i.e., reduction of tacrolimus monotherapy dosing to every other day, three times a week, twice a week, or once a week) attempted. Routine monitoring for donor-specific antibody (DSA) was begun in September 2004. Mean follow-up is 34+/-6.5 months after transplantation and 26+/-8.1 months after the initiation of spaced weaning. RESULTS: One hundred and twenty-two (44%) patients remained on spaced weaning. One- and 2-year actual patient/graft survival was 99%/99%, and 97%/96%. Fifty-six (20%) patients experienced acute rejection after initiation of spaced weaning. One- and 2-year actual patient/graft survival was 100%/98%, and 94%/78%. Forty-two (15%) patients with stable renal function had spaced weaning stopped because of the development of DSA, which disappeared in 17 (40%). One- and 2-year actual patient and graft survival was 100% and 100%. CONCLUSION: Adult renal transplant recipients who are able to be maintained on spaced weaning have excellent outcomes. Patients with stable renal function who have reversal of weaning because of the development of DSA also have excellent outcomes. Routine monitoring for DSA may allow patients to avoid late rejection after spaced weaning.