Serum CK

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Test

To detect and monitor muscle damage and to help diagnose conditions associated with muscle damage

When this test is required

Measurement of CK is requested in people who have sustained severe muscle trauma, particularly from crush injuries, burns or electrocution, and are likely to develop rhabdomyolysis.CK may also be requested in those who develop symptoms or signs of less severe muscle damage after being immobile for a long time on a hard surface, for example during an operation or after a stroke, drugs or alcohol following very severe exercise after a fit during a severe infection while taking certain medicines, for example a statin to lower cholesterolRhabdomyolysis is likely if the urine develops a reddish-brown colour and gives a positive dip-stick test for blood. (Myoglobin, a red protein released from damaged muscle, reacts with the dip-stick in the same way as haemoglobin from blood cells.) The excretion of myoglobin by the kidney can potentially cause kidney failure.Blood concentrations of CK (or its CK-MM isoenzyme) are also requested as a first step in the diagnosis of muscular dystrophy in infants or children who have difficulty walking have difficulty standing have difficulty lifting weights need help climbing stairsThe test may subsequently be used to screen family members.

What the Test Detects

This test measures the amount of creatine kinase (CK) in the blood. CK is an enzyme found in the heart muscle, brain tissue, skeletal muscle and other tissues. Increased amounts are released into the bloodstream when there is muscle damage. CK occurs in three major forms, called isoenzymes: CK-MB (found mostly in heart muscle) CK-BB (found mostly in brain tissue) CK-MM (found in skeletal muscles)See MoreSee Less

Preparation for the Test

None

Sample Requirements

A blood sample taken from a vein in the arm

Additional Notes

For the detection of heart muscle damage, myocardial infarction, changes in serum CK and its heart tissue (MB) isoenzyme have been largely replaced by the more heart specific nonenzymatic markers, cardiac troponin I or T.People who have greater muscle mass have higher normal CK levels. For example, a young fit male will have more muscle mass than an elderly female and hence a higher CK concentration. Normal exercise such as running or cycling and drug injections into muscle can increase CK concentrations.CK concentrations have been found to be normally higher in black race populations.

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