Creatine kinase, MM form
CKMM is a very important constituent of active muscle, and it has been shown to increase with prolonged exercise3. Also, when measuring total CK or just serum CK in normal serum, it is really CKMM that is being measured since it accounts for the vast majority of CK activity normally found in serum from healthy adults.
Significant levels of CKMM activity are also found in cardiac muscle and therefore a large increase in total CK was once used as a tool in the diagnosis of acute myocardial infarction (AMI). Once the CK isoenzymes were elucidated and isoenzyme tests became available, CKMB quickly became the marker of choice for AMI, only to be surpassed later by the cardiac troponins.
However where CKMM (usually just measured as total CK) still has an important role to play is in pathologies of skeletal muscle including the diagnosis, monitoring and assessment of carrier status of muscular dystrophy. CKMM also plays a useful role in diagnosis, prognosis and treatment monitoring of muscle diseases such as polymyositis, dermatomyositis and in ruling out others such as polymyalgia rheumatica.
- Sample of blood serum
- We perform the test in 24 hours from sampling