Creatine Kinase (CK), Total Plus Isoenzymes
Also known as: CK Fractionation, CK Isoenzymes, CPK Isoenzymes, Creatine Phosphokinase Isoenzymes
Use
Diagnose myocardial infarction (MI). Three fractions normally may be found, each an isoenzyme:
Special Instructions
State the patient's sex on the test request form. Submit two separate serum aliquots to avoid delays when requesting multiple tests on frozen samples.
Limitations
Exercise, intramuscular injections, myxedema, seizures, prior trauma, surgery, acute MI, and other conditions can lead to increased CK levels without an MI. CK-MB elevations have been noted in non-MI conditions such as myocarditis and extensive rhabdomyolysis. The test is not practical when total CK is very low, although sensitive assays may be useful for the elderly. A single CK isoenzyme examination may be misleading; serial analyses and confirmation with LD isoenzymes are recommended.
Methodology
Other
Biomarkers
LOINC Codes
- 2157-6
- 26020-8
- 15049-0
- 26019-0
- 12187-1
- 15048-2
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL (CK, Total) and 1 mL (Isoenzymes)
Minimum Volume
0.7 mL (CK, Total) and 0.8 mL (Isoenzymes)
Container
Red-top tube or gel-barrier tube
Collection Instructions
Submit two separate serum aliquots.
Patient Preparation
CK is most commonly elevated in acute myocardial infarction (AMI) in which it has its greatest usefulness. Collection of specimen at onset of symptoms to establish baseline values is needed.
Storage Instructions
CK Total aliquot: Maintain at room temperature. Isoenzymes aliquot: Refrigerate at 2°C to 8°C up to 48 hours.
Causes for Rejection
Moderate or excessive hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | CK: 14 days |
| Refrigerated | CK: 14 days, Isoenzymes: 48 hours |
| Frozen | CK: 14 days, Isoenzymes: 14 days |