Measurement of brain-specific creatine kinase isoenzyme activity in serum.

We have modified the columti-chromatographic technique of Mercer (1) to produce a sensitive and rapid separation of serum CK2 and CK3, even at normal total serum CK activity (3).12 However, CKj was not separated from CK2. Here, we report a modification of our method such that all three CK isoenzymes are separated by stepwise elution from a mini-column of diethylaminoethyl-cellulose. CK1 has only been reported in the serum in the rare condition of malignant hyperpyrexia (4). In most other neurological conditions-such as head injuries, strokes, meningitis, and encephalitis-the increased CK activity in serum has been solely attributable to CK3 elevation (5, 6). We have been unable to test our system on cases of malignant hyperpyrexia, and we therefore chose instead to study the serum CK isoenzyme activity of patients who had undergone neurosurgery of the brain.