Serum creatine kinase isoenzyme

CK consists of two subunits, M and B, which are combined into three isozymes, CK-BB, CK-MM and CK-MB. There is another isoenzyme in the mitochondria of cells, called CK-Mt. CK-BB mainly exists in organs such as brain and prostate, CK-MM mainly exists in bone and myocardium, CK-MB mainly exists in myocardium, and most of normal human blood is CK-MM, a small amount of CK-MB, and CK- There are very few BBs. A significant increase in CK-MB in the blood suggests myocardial infarction, which is more capable of determining myocardial damage than the total activity of creatine kinase, and has higher specificity and sensitivity.

Basic Information

Specialist classification: cardiovascular examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Tips: You should sit still for a while before taking blood. If you have muscle damage or fracture, avoid checking. Normal value

1, electrophoresis

CK-MB: <0.05 (CK-MB < 5%).

CK-MM: >0.94 to 0.96 (CK-MM>94% to 96%).

CK-BB: No or trace (CK-BB no or trace).

2, enzyme rate method (37 ° C)

CK-MB: 0 to 18 U/L.

CK-MM: 0 to 18 U/L.

CK-BB: 0U/L.

Clinical significance

1, elevated: acute myocardial infarction (CK-MB>0.03, up to 0.12 ~ 0.38), can also be seen in muscular dystrophy, malignant tumors.

2, thyroid dysfunction, cerebrovascular disease, lung disease, chronic alcoholism, post-operative recovery muscle spasm, cardiac resuscitation, shock, tetanus, skeletal muscle injury equivalent enzyme analysis only found CK-MM type, No DK-MB type, no CK-BB type can be detected.

3, drug injection (chlorpromazine, phenobarbital, penicillin, reserpine phenytoin, adrenaline, polymyxin B) muscle damage can be detected CK-MM type.

High results may be diseases: pediatric heart failure, pediatric myocarditis, pediatric spinal muscular atrophy, pediatric dilated cardiomyopathy, pediatric idiopathic ventricular tachycardia, primary cardiac lymphoma, acute myocardial infarction, painless myocardium Infarction, eosinophilia - myalgia syndrome considerations

1. Sit for a while before taking blood. Avoid muscle injury and fractures.

2, CK-MB began to rise within 3 to 4 hours of myocardial infarction, reached a peak within 12 to 36 hours, and recovered after 3 to 5 days of onset.

3. Muscle trauma or intramuscular injection is only seen in CK-MB elevation.

Inspection process

Immediately after blood collection, the test method is determined by electrophoresis.

Not suitable for the crowd

Avoid muscle damage and fractures.

Adverse reactions and risks

Discomfort: There may be pain, swelling, tenderness, and visible subcutaneous ecchymosis at the puncture site.