Tacrolimus for steroid-resistant liver rejection in children

Eighteen pediatric liver transplant recipients were converted from cyclosporine-based immunosuppression to tacrolimus for refractory rejection episodes affecting 21 grafts. Before conversion, steroid boluses were applied to all episodes followed by OKT3 monoclonal antibodies in 3 of them. Baseline biopsy showed cellular rejection in 18 patients and ductopenia in 3 cases. Thirteen episodes initiated within the first 2 postoperative weeks, and 8 occurred beyond the 21st day. A previous steroid-responsive episode of rejection was noted in 4 patients. Tacrolimus was administered by the oral route to obtain trough blood levels in the range 6-15 ng/ml. Reversal of rejection was obtained in 15 patients (71.4%). Complete normalization of liver function tests was achieved in 10 out of 12 patients who were followed for more than 6 months. A refractory evolution affected 6 patients (28.5%). Significant factors predictive for tacrolimus-resistant rejection were identified as ductopenia on baseline biopsy, previous episodes of acute rejection, late onset rejection (beyond 21st posttransplant (day), and a longer time of evolution of rejection prior to conversion.