Complexes of Creatine Kinase MM and Immunoglobulin A

Abstract

Isoenzymes of creatine kinase (CK) with irregular electrophoretic mobility were found in sera from 5 patients. Enzyme immunoelectrophoresis and electroimmunofixation revealed that these unusual isoenzymes were complexes of CK and IgA. Light chain of CK linked IgA was lambda type.
The native CK isoenzymes in the complexes were identified as CK-MM, since apparent Michaelis constant values of the complexes were similar to that of CK-MM. It is interesting that all donor patients were elder and had malignant tumors near the terminal stage.