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Test Code CKM CK-MB Isoenzyme with Total CK Panel

Important Note

This test may be affected by biotin interference. Patients on high dose biotin (5mg/day or more) should not have samples drawn until at least 24 hours after the last biotin administration.

Specimen and Container/Tube

Specimen Type: Plasma

Preferred Specimen: Li-Heparin Mint Green Top

Other Acceptable specimens: Serum/Gold Top, Serum/Red Top

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

CPT Codes

82553, 82550

LOINC Codes

2157-6

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. 

 

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.

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.

Methodology

  • Electrochemiluminescence immunoassay (ECLIA) (Roche Diagnostics)
  • Spectrophotometric (Activation by NAC) (Roche Diagnostics)

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.

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

Last Review Date

8/19/2024