Clinical trial of 111In-antimyosin antibody imaging, (5)

Indium-111 labeled monoclonal antimyosin antibody (AM MoAb) imagings were performed repeatedly to examine changes of myocardial cell necrosis. Eight patients with myocardial infarction and one patient with myocarditis underwent the first study at 44.2±84.9 days and the second study at 11.2±3.8 months after the onset. Both positive rate and myocardial uptake decreased on the second images, as compared with the first images. Four patients with myocardial infarction had consistent uptake of In-111 AM MoAb, three of whom had recurrent chest pain. For myocarditis, intense uptake at the acute stage disappeared 11 months later. After the second administration of In-111 AM MoAb, human anti-mouse antibody occurred transiently in one patient. Neither subjective nor physical findings were abnormal in any of the patients. Repeat administration of In-111 AM-MoAb was safe, and was thus considered useful in monitoring the treatment of myocardial necrosis and determination of prognosis. (N.K.)