[Separation and assay of the MB isoenzyme of serum creatine phosphokinase. Results apropos of 152 cases].

MB iso-enzyme of creatine phosphokinase (CPK) was estimated after chromatography. The technique used, Mercer's technique, was simple and rapid. It required 1 ml of serum. The study carried out in 152 subjects showed that CPK was increased (N less than 90 mU/ml). In the group of 104 patients with myocardial infarction (average CPK levels = 829 mU/ml +/- 516), the MB iso-enzyme was found in the serum in significant levels (average level of the MB fraction = 10.9% +/- 5.4). On the other hand, in the control group of 44 patients with various diseases, (CPK = 672 mU/ml +/- 531) the MB iso-enzyme remained low (0.35% +/- 0.44). In two subjects with myocardial infarction, no MB fraction was found. On the other hand, in two patients who died, one from necrotic, prostatic adenocarcinoma, the other from necrotic epidermoid lung cancer, the MB iso-enzyme was significantly increased. The test proposed here, which is applicable in a routine laboratory, seems the most specific of all laboratory examinations available to the clinician for the diagnosis of myocardial infarction.