This assay is intended for the quantitative determination of CK-MB in human serum and plasma. Creatine kinase (CK) is a dimeric enzyme which occurs in 4 different forms: a mitochondrial isoenzyme and the cytosolic isoenzymes CK-MM (muscle type), CK-BB (brain type) and CK MB (muscle-brain type). CK-MB is an important biomarker of acute myocardial infarction and other causes of myocardial injury, such as heart failure and myocarditis. CK-MB is detectable in the blood about 3-8 hours after the onset of cardiac symptoms and can remain detectable over a lengthy period of time, depending on the course of the condition. CK-MB may also appear in other clinical conditions, e.g. in rhabdomyolysis and stroke. Within the scope of laboratory diagnostics, the determination of total CK, troponin T and/or myoglobin can contribute to the differentiation of these clinical pictures. Because of their higher sensitivity and specificity, cardiac troponins, measured by high-sensitivity assays, are the preferred biomarkers to define myocardial infarction, and if a troponin assay is not available, the best alternative is CK-MB measured by a mass assay.
