Macro creatine kinase type 2: a marker of myocardial damage in infants?

The case histories of two children (aged two months) affected by myocarditis showing an atypical band of serum creatine kinase (EC 2.7.3.2; CK) in the CK isoenzyme electrophoretic pattern are reported. The electrophoretic mobility on cellulose acetate of the atypical iso-CK band and its greater relative molecular mass, the lack of binding with immunoglobulins and the result of CK-BB determination by RIA, allowed us to identify the band with an oligomeric form of the mitochondrial isoenzyme. One child died 2 days after admission, while in the other it was possible to demonstrate reduction and disappearance of the atypical band in concomitance with a marked clinical improvement. Our findings suggest that the oligomeric form of mitochondrial-CK is released in conditions of serious heart muscle damage, and that it may be an indicator of myocardial cellular necrosis in pediatric patients. © 1985.