CK Isoenzymes (CKISO, CK Isoforms)
| Category | Biochemistry >> Proteins |
|---|---|
| Test background |
Human enzyme creatine kinase is composed of two subunits, M (muscle) & B (brain) arranged into dimers giving rise to three possible isoenzymes: MM, MB & BB. |
| Clinical Indications |
The primary use of CK isoenzyme analysis is the identification of Macro CK Type 1 (a CK–immunoglobulin complex) or Macro CK Type 2 (mitochondrial CK) in individuals with a persistently raised total CK without obvious heart or muscle disease. Although CKMB > 5 % may be indicative of acute myocardial infarction, Troponin is a sensitive and specific marker of cardiac damage and CK isoenzyme analysis is now not routinely indicated for this purpose. |
| Reference range | CK Isoenzymes is a semi-qualitative test with interpretation provided. Analysis identifies which isoenzyme(s) are responsible for the elevation in total CK as well as detection of type 1 or type 2 macro-CKs. |
| Sample & container required | Serum |
| Sample volume | 100 µL (all samples require total CK measurement: if referring from another laboratory please ensure that there is sufficient sample or you have provided your laboratory result on the request form). |
| Transport storage | Stable at 2-8°C for 72 hours. Please freeze pending dispatch for analysis. Sample can be sent by first class post. |
| Turnaround time | 4-6 Weeks |
| Notes | Please include the Total CK result on the request if available. Specimens containing inhibitors of CK activity e.g. heparin, EDTA, citrate, fluoride or iodoacetate are unsuitable. |