EFFICACY OF LOW-DOSE OKT3 AS CYTOLYTIC INDUCTION THERAPY IN HEART-TRANSPLANTATION

Background: The need for prophylactic cytolytic treatment in heart tra nsplantation is a controversial issue. Its use, however, might prevent the onset of cellular rejection in the immediate postoperative period , facilitating patient management. It has recently been suggested that the administration of these products at low doses might have the same immunologic impact and would reduce secondary effects and the cost of treatment. Methods: In a nonrandomized retrospective study, we assess ed 45 consecutive patients who underwent orthotopic heart transplantat ion in 1992 and 1993. Six patients who died before receiving the compl ete OKT3 dose were excluded. Twenty-three patients were treated with 5 mg/day doses of OKT3 for 7 consecutive days. Another 16 patients recei ved 2.5 mg of OKT3 for 7 consecutive days. Results: There were no sign ificant differences between the two groups with respect to CD3 counts on days 2 (0.1% +/- 0.3% versus 0.04% +/- 0.25%; p > 0.05) and 6 (0.2% +/- 0.45% versus 0.1% +/- 0.3%; p > 0.05), number of rejection episod es (1.45% +/- 0.8% per year of follow-up versus 1.7% +/- 1.2%, p = 0.6 6), number of infectious complications (8 versus 3, p > 0.05), total m ethylprednisolone dose used to treat rejection crises (3900 +/- 2765 v ersus 3600 +/- 1963 mg; p = 0.71), adverse effects attributed to OKT3 (two versus none), or length of the postoperative hospital stay (36.8 +/- 19 versus 30.2 +/- 20.9 days). Conclusions: As cytolytic induction therapy in heart transplantation, a daily regimen of 2.5 mg of OKT3 f or 7 days achieves the same clinical and immunologic effect as the con ventional 5 mg/day dose. In addition, it results in a considerable red uction in the cost of treatment.