Test performed on weekdays.
CK isoenzyme analysis is performed by electrophoresis. It is useful in investigating patients with a raised CK where the cause is unclear, and to identify macro CK.
The multiple forms (isoenzymes) of CK result from its being a dimer of two subunits, M (for muscle) and B (for brain). The 3 main isoenzymes are MM (or CK-3, found mainly in muscle, both skeletal and heart), MB (or CK-2, found mainly in heart) and BB (or CK-1, found mainly in brain).
Cardiac muscle has a high proportion of MB (up to 46% of total CK activity compared with <5% in skeletal muscle).
An additional isoenzyme is CK-Mt (mitochondrial CK).
Macro CK refers to high molecular weight forms of CK. , which are cleared more slowly from plasma than normal CK, resulting in a raised plasma level. There are 2 types of macro CK:
Type 1 is is a complex of CK with immunoglobulins; it often occurs in women older than 50 years and is an incidental finding of no significance.
Type 2 macro CK is oligomeric CK-Mt, is found predominantly in severely ill patients with malignancies or liver disease, and carries a poor prognosis.
References
1 Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, 4th Ed (2006)
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Cam Kyle (Clinical Head): CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Leah Ha: LHa@adhb.govt.nz ext. 23427
Dr Samarina Musaad: SamarinaM@adhb.govt.nz ext. 22402
Dr Leo Lam: ChiSingL@adhb.govt.nz ext 22574