TACROLIMUS - A SUPERIOR AGENT TO OKT3 FOR TREATING CASES OF PERSISTENT REJECTION AFTER INTRATHORACIC TRANSPLANTATION

Acute myocardial rejection refractory to treatment still contributes s ignificantly to patient death after intrathoracic transplantation. A h istorical series of 25 patients who received OKT3 (5 mg/day for 10 day s) was compared with our current experience with 14 patients treated w ith tacrolimus (0.1 mg/kg/day targeting whole blood concentrations of 13 to 18 ng/ml): all 39 patients having persistent rejection unrespons ive to treatment at the time of conversion. Mean periods of follow-up were 842.9 days and 342.6 days, respectively. Actuarial 1-year patient survival rates were 64.0% and 76.2% for the OKT3 and tacrolimus treat ment groups, with most of the deaths in the OKT3 group occurring early (p = 0.064). Causes of death for patients receiving OKT3 included acu te rejection (n = 5), infection (n = 3), carcinoma (n = 2), multiorgan failure (n = 1), and graft vessel disease (n = 1). The two deaths in the tacrolimus treatment group were the result of infections. Eighty p ercent of patients treated with OKT3 subsequently experienced further rejection episodes, in many cases necessitating methotrexate therapy. In contrast, only one patient (7.1%) from the tacrolimus group was dia gnosed with rejection after conversion (p < 0.001). In conclusion, whe n compared with OKT3 therapy, a switch in baseline immunosuppression f rom cyclosporine to tacrolimus seems to be markedly more effective, as well as being safe for the treatment of persistent acute rejection.