Test Details
Methodology
Electrochemiluminescence immunoassay (ECLIA)
Result Turnaround Time
1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Confirm and monitor therapy after acute myocardial infarction
Special Instructions
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Footnotes
References
Custom Additional Information
Creatine kinase (CK) is an enzyme, found primarily in muscle and brain tissue, which exists as three dimeric isoenzymes: CK-MM (CK-3), CK-MB (CK-2), and CK-BB (CK-1) − built from subunits designated M and B. The CK-MB isoenzyme, which has a molecular mass of approximately 87 kilodaltons, accounts for 5% to 50% of total CK activity in myocardium. In skeletal muscle, by contrast, it normally accounts for ≤1%, CK-MM being the dominant form, though the percentage can be as high as 10% in conditions reflecting skeletal muscle injury and regeneration (eg, severe exercise, muscular dystrophy, polymyositis).1
CK-MB is one of the most important myocardial markers (in spite of not being altogether cardiac-specific), with well-established roles in confirming acute myocardial infarction (AMI) and in monitoring reperfusion during thrombolytic therapy following AMI.1
In AMI, plasma CK-MB typically rises some four to six hours after the onset of chest pains, peaks within 12 to 24 hours, and returns to baseline levels within 24 to 48 hours. The pattern of serial CK-MB determinations is more informative than a single determination: one CK-MB measurement, even when taken at an appropriate time, cannot definitively confirm or rule out the occurrence of AMI. High levels might reflect skeletal injury rather than myocardial damage. A value within the reference range might be significant if it represents an increase from the patient's baseline level. (Low baseline levels are sometimes encountered in the elderly.) Accordingly, it has been recommended that CK-MB be measured on admission to the emergency room and at intervals thereafter (eg, at three-hour intervals over a six-hour to nine-hour period in patients with nonspecific electrocardiogram changes;1,2 or at six-hour to eight-hour intervals over a 24-hour period and more frequently if thrombolytic therapy has been instituted).1
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Gel-barrier tube (preferred) or red-top tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Stability Requirements
Temperature | Period |
---|---|
Room temperature | 1 day |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
• Male: 0.0−10.4 ng/mL
• Female: 0.0−5.3 ng/mL
Storage Instructions
Room temperature
Patient Preparation
The MB isoenzyme of CK is most commonly elevated in acute myocardial infarction (AMI). In AMI, plasma CK-MB typically rises some four to six hours after the onset of chest pains, peaks within 12 to 24 hours, and returns to baseline levels within 24 to 48 hours. The pattern of serial CK-MB determinations is more informative than a single determination.
Causes for Rejection
Citrate plasma specimen; improper labeling
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
120816 | Creatine Kinase (CK), MB | 13969-1 | 120817 | Creatine Kinase (CK), MB | ng/mL | 13969-1 |
Order Code | 120816 | |||||
Order Code Name | Creatine Kinase (CK), MB | |||||
Order Loinc | 13969-1 | |||||
Result Code | 120817 | |||||
Result Code Name | Creatine Kinase (CK), MB | |||||
UofM | ng/mL | |||||
Result LOINC | 13969-1 |