Clinical Significance

Creatine kinase (CK) is a dimeric enzyme occurring in four different forms: a mitochondrial isoenzyme and the cytosolic isoenzymes CK‑MM (skeletal muscle type), CK‑BB (brain type) and CK‑MB (myocardial type). 

The determination of CK and CK‑isoenzyme activities is utilized in the diagnosis and monitoring of myocardial infarction and myopathies such as the progressive Duchenne muscular dystrophy. Following injury to the myocardium, such as occurs with acute myocardial infarction, CK is released from the damaged myocardial cells. In early cases, a rise in the CK‑activity can be found just 4 hours after an infarction. The CK activity reaches a maximum after 12‑24 hours and then falls back to the normal range after 3‑4 days. 

_{Source: Roche Cobas CK Method Sheet Version 3.0 2023-12}