Muromonab CD3 (Orthoclone OKT3) for the prophylaxis of heart allograft rejection. Hemodynamics and respiratory tolerance

Treatment of transplant rejection with muromonab CD3 (Orthoclone OKT3) may result in haemodynamic instability and pulmonary oedema, which would question its prophylactic use. The aim of this study was to the evaluate haemodynamic and respiratory tolerance of prophylactic treatment of cardiac rejection with OKT3. Prospective clinical study. Twelve patients, whose pulmonary arterial resistances before transplantation were less than 400 dyn.s.cm-5, with haemodynamic and respiratory stability during the 4 hours before OKT3 administration. Patients under preventive haemodynamic support with isoprenaline 0.05 micrograms.kg-1.min-1 and dopamine 3 micrograms.kg-1.min-1. Immunosuppressive treatment with azathioprine 5 mg.kg-1 at d0 and 3 mg.kg-1 at d1 and d2 and with methylprednisolone 720 mg at d0 and 240 mg at d1 and d2. OKT3, 5 mg administered i.v. at d0, d1, d2. Respiratory and haemodynamic variables were recorded prior to (T0), 30 min (T1) and 360 min (T2) after injection of OKT3. Neither clinical nor radiological changes were observed after the OKT3 injections. At d0, T2, the heart rate increased and PaO2 and SaO2 decreased. At d1 and d2, T1, PaO2 decreased, and QS2QT at T1 d2 increased by nearly 3%. OKT3 does not result in major circulatory and haematosis changes, provided patients are selected, especially free of pretransplantation pulmonary hypertension. Prior to the treatment with OKT3, they should be in a satisfactory haemodynamic and respiratory status and receive high doses of corticosteroids.