Test Code CKM CK-MB Isoenzyme with Total CK Panel
Specimen and Container/Tube
Specimen Type: Plasma
Preferred Specimen: Li-Heparin Mint Green Top
Other Acceptable specimens: Serum/Gold Top, Serum/Red Top
Volume
Preferred Volume: 0.5 mL
Minimum Volume: 0.2 mL
Specimen Stability
Storage Temperature |
Stability |
Room Temperature |
12 hours |
Refrigerated |
5 hours |
Frozen |
3 months |
Collection Instructions
Collect specimen per standard laboratory collection procedures.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
- Collect specimen per standard collection procedure and send to laboratory immediately.
UCMC Offsite and UC MedLab Outreach Instructions:
- Samples should be centrifuged within 2 hours of collection.
- Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
- Aliquot sample into plastic transport tube containing a minimum of 0.2 mL of specimen.
- Samples must be sent frozen at -20oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are clotted or grossly hemolyzed.
- Specimens that were transported unspun/whole blood and draw time is greater than 6 hours
Reference Values
Test |
Age |
Sex |
Reference Range |
CK-MB |
All |
All |
<9.9 ng/mL |
CK-MB Relative Index |
All |
All |
<3.9% |
Creatine Kinase |
All |
All |
15-59 U/L |
Note: Reference ranges for CK-MB are based on in-house studies performed at the University of Chicago Medicine by the Clinical Chemistry Laboratories per the Roche cobas 8000 modular analyzer e801 System Installation Workbook and the e801 CK-MB product insert. Reference range for Total CK are based on in-house studies, recommendations from Tietz Textbook of Clinical Chemistry, and Roche product literature.
Critical Values
Analyte |
Unit |
Low |
High |
Age |
N/A |
N/A |
N/A |
N/A |
N/A |
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: up to 4 hours
Testing Schedule: 24/7
Clinical Indications
- CK-MB is used as an aid in the diagnosis of myocardial ischemia, e.g. in acute myocarial infarction, myocarditis, etc.
- The determination of CK and CK-isoenzyme activities is utilized in the diagnosis and monitoring of myocardial infarction and myopathies such as the progressive Duchenne muscular dystrophy.
Test Components
- Creatinine Kinase MB Isoenzyme Fraction
- Total CPK
- CK-MB Relative Index (%) is a calculation of (CK-MB Mass Concentration (ng/mL) divided by the Total CK Activity (U/L)) times 100.
Methodology
- Electrochemiluminescence immunoassay (ECLIA) (Roche Diagnostics)
- Spectrophotometric (Activation by NAC) (Roche Diagnostics)
CPT Codes
82553, 82550
LOINC Codes
2157-6
Synonyms/Keyword Search
N/A
Additional Information
- Elevated CK-MB is not specific for MI (myocardial infarction) and may be detected in other disease states. Results should always be assessed in conjunction with patient's medical history, clinical examination and other findings.
- 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.
- Sensitivity of a CK-MB determination is dependent upon the time at which the sample was collected. Follow-up assays are therefore meaningful.
- CK-MB Relative Index is reported as a percentage only and has no other associated units of measure.
- Following injury to the myocardium, such as occurs with acute myocardial infarcation, CK is released from the damaged myocardial cells. In early cases, a rise in the CK-activity can be found just 4 hours after an infarction. The CK-activity reaches a maximum after 12-24 hours and then falls back to the normal range after 3-4 days.
- Cyanokit (hydroxocobalamin) at therapeutic concentrations interferes with the CK result.
- CK varies with physical activity level and race in healthy individuals.
- A test or panel may be ordered only when all components are medically necessary to diagnose or treat an individual patient. If all components are not medically necessary, a less inclusive panel and/or an individual test as appropriate to treat the individual patient should be ordered.
Last Review Date
8/19/2024