Serum creatine kinase isoenzymes in Duchenne muscular dystrophy

Creatine kinase isoenzymes in sera of 51 patients with Duchenne muscular dystrophy were separated on a micro-column of DEAE Sephadex A-50. MB isoenzyme was detected in the sera of 32 cases (63%). MB percentage of total creatine kinase activity correlated significantly with urinary creatine/creatinine ratio in the early stages of the disease. No close relationship between MB levels and ECG findings was observed. The origin of serum MB in Duchenne dystrophy is discussed.