Reactivation of serum creatine kinase isoenzyme BB in patients with malignancies.

Reactivation of serum creatine kinase isoenzyme BB (CK-BB) with 2-mercaptoethanol and EDTA increased the electrophoretic detection rate of CK-BB from 34% to 78% in 58 hospitalized patients with various malignancies. Patients with solid tumors showed the largest and patients with hematologic malignancies the smallest percentage increase in CK-BB after reactivation. For serum from 50 hospitalized patients without cancer, reactivation resulted in detectable CK-BB in two patients; the CK-BB band was never seen in 15 healthy adults. For reasons unknown, five of eight patients with senile dementia of the Alzheimer's type showed CK-BB in serum after reactivation, as did two of five patients suspected of having this disorder. Serum CK-BB may be a useful tumor marker if reactivation with a thiol and EDTA is used immediately after collection.