CK-MB Mass-Reject false positive, make the test more "quality"
发布日期：
2024-01-04
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Introduction to the CK-MB Mass Determination


Phosphocreatine kinase

Phosphocreatine kinase Phosphocreatine kinase is mainly found in skeletal muscle, cardiac muscle and brain tissue, and its isoenzyme (CK-MB) is a specific and sensitive indicator ofmyocardial injury. Currently, CK-MB is often detected by enzyme method (immunosuppression method), which is easily interfered by many factors, and the limitations of this method have gradually appeared, with frequent false positives, which brings the risk of misinformation for clinical diagnosis and treatment. The principle of CK-MB mass determination is to use monoclonal antibody technology and chemiluminescence or fluorescence immunity to directly detect the mass concentration of CK-MB, so the shortcoming of the enzyme method can be solved fundamentally.

The health industry standard of the People's Republic of China, WS/T 462-2015: Cardiac Marker Detection and Clinical Application in Coronary Artery Disease and Drinking Heart Failure, suggests that "CK-MB mass assay has a better analytical and diagnostic utility, which is obviously superior to the activity assay". Therefore, when available, the use of latex immunoturbidimetric assay for CK-MB mass is more recommended.




CK-MB Mass-Reject false positive, make the test more

Three advantages of  
M
ass Determination




01


Undisturbed by temperature and storage time

The study confirmed that samples were tested twice a day for five consecutive days, and that the results of the CK-MB mass assay were more stable compared to the CK-MB activity assay, as shown in Figure 1.


CK-MB Mass-Reject false positive, make the test more

Figure 1: Trends of CK-MB mass and activity at room temperature



02


High specificity solves the confusion of inverted CK results

The CK-MB mass detection is based on the direct recognition of CK-MB by monoclonal antibodies, which are specific enough not to be interfered by CK-BB and macro-CK, thus solving the problem of CK inversion; and the adenylate kinase in erythrocytes does not take part in the reaction, so mild hemolysis will not interfere with the results of the test.


03


High diagnostic value

The positive predictive value of CK-MB mass assay for diagnosis of AMI group and myocardial ischemia group with lung infection was 46.424% and 42,86%, respectively, and the negative predictive value was 93.33% and 70.00%, while the positive predictive value of the CK-MB activity assay was only 35.71% and 21.43%, and the negative predictive value was 90.00% and 60.00%, respectively, and the sensitivity and specificity of the mass test were better than the activity assay. Details are shown in the table below:

Diagnostic value of CK-MB mass and activity assays in two groups of ischemic heart disease

CK-MB Mass-Reject false positive, make the test more

Note: Comparison of mass and activity within the CK-MB group





CK~MB activity measurement method and analysis of its impact and clinical relationship with diseases



CK-MB Mass-Reject false positive, make the test more

Study method:

A total of 2,100 patients attending Anyang People's Hospital from December 2010 to February 2012 were selected for the study, and the activities of phosphokinase isoenzyme (CK-MB) and phosphokinase (CK) were measured by immunosuppression method and rate method, respectively. The relationship between the ratio (CK-MB/CK) and the disease spectrum was calculated and the factors influencing the pseudo-elevation of CK-MB activity were analyzed.

CK-MB Mass-Reject false positive, make the test more

Data analysis：

Table 1 Relationship between patients with more than 30% increase in CK-MB/CK and clinical diseases

CK-MB Mass-Reject false positive, make the test more

In the selected cases there were 8 diseases with CK-MB/CK increased more than 30%, among the patients with non-cardiogenic myocardial infarction among them tumor diseases, cardiovascular diseases and tuberculosis patients accounted for the highest 70 cases (67.3%), and the highest incidence of tumor patients was 31 cases (29.8%). There were statistically significant differences between patients with malignant tumors, cardiovascular diseases, and tuberculosis and the degree of increased CK-MB/CK (χ2 =5.226,6.400,5.158, P=0.022,0.011,0.023<0.05), while="" there="" were="" no="" statistically="" significant="" differences="" between="" other="" diseases="" and="" the="" degree="" of="" increased="" ck="" p="">0.05).


Table 2 Relationship between the degree of CK-MB/CK increase and gender, age, etc. in the number of selected patients

CK-MB Mass-Reject false positive, make the test more

In terms of gender, there were 51 (49%) males and 53 (53%) females, and there was a significant linear correlation between the degree of CK-MB/CK increase and gender (r=-0.307, P=0.002<0.01); in terms of age, there were 13 patients less than 20 years old, 15 patients aged 20-40 years old, 30 patients aged 40-60 years old, and 46 patients aged 60 years old or above, and there was a significant linear correlation between the degree of CK-MB/CK increase and age (r=-0.329, P=0.001<0.01). There was a significant linear correlation between the degree of CK-MB/CK increase and age (r=-0.329, P=0.001<0.01).

CK-MB Mass-Reject false positive, make the test more

Analysis of factors influencing the false elevation of CK-MB activity:

①For patients with cardiovascular diseases, tumors, immunoinflammatory diseases and other organic pathologies, there is a CK-BB effect in the body. For some patients with little CK-BB effect, the CK-MB activity can be detected by ignoring the content of CK-BB, and then carry out the M-subunit inhibition, and the phenomenon of pseudoincrease in CK-MB activity may not occur, but some tumors, inflammatory diseases or cardiovascular disease patients with an increase in the content of CK-BB in their bodies, which will affect the immunosuppression method to determine the activity of CK-MB.


② The effect of the presence of macro-CK in the patient's body, macro-CK, including macro CK-1 and macro CK-2, macro CK-1 is a macromolecular complex, mainly formed by the CK isoenzyme and autoimmune globulin (IgA or IgG), in the middle-aged and elderly women are more common, macro CK-2 is a mitochondrial CK (CK-MT) polymerization of each other to form a macromolecular polymer of oligomers. When the mitochondria disintegrate, CK-2 enters the bloodstream. CK-MT, unlike the CK-M subunit, cannot be inhibited by anti-M. The presence of increased levels of macro-CK in some patients can affect the activity of CK-MB assay.


③The presence of immunoglobulins or tumor cell-secreted proteins in the patient's body can have an effect on the results of the immunosuppression method, especially common in patients with tumor diseases, and the study concluded that there is a linear correlation between the degree of increase in CK-MB/CK and gender and age (r=-0.307, -0.329, P=0.002,0.001<0.05), and that the older the patient, the greater the degree of increase in CK-MB/CK. The higher the age, the higher the degree of CK-MB/CK increase, which may be related to the age of the patients, immunity and metabolism decrease, cardiovascular diseases, tumors, immuno-inflammatory diseases and other prevalence will increase, CK-MB/CK increase degree is also greater, the male patients are also increased, which may be related to the male patients smoking, drinking, and other bad habits caused by the disease.

CK-MB Mass-Reject false positive, make the test more

Discussion of Results:

The phenomenon of CK-MB/CK increase more than 30% is very high in non-myocardial infarction diseases such as malignant tumors, and there is a phenomenon that causes a false increase in CK-MB activity, and the degree of increase has a linear correlation with gender and age, so the clinical use of immunosuppression should pay attention to the impact of false increase on the detection of disease.

CK-MB Mass-Reject false positive, make the test more

Example display





CK-MB Mass-Reject false positive, make the test more

Due to the influence of the presence of macro CK1 in the patient's body, which interferes with the active assay and causes false positives in the assay, posing a risk of misdirection for clinical diagnosis and treatment, it is recommended to use the CK-MB mass assay.



CK-MB Mass-Reject false positive, make the test more

CK-MB quality method testing reagents and ordering information diagram



CK-MB Mass-Reject false positive, make the test more CK-MB Mass-Reject false positive, make the test more


References：

[1] Mao Y, Poschke I,Kiessling R.Tumour-induced immune suppression: role of inflammatory mediators released by myelomonocytic cells [J].J Intern Med，2014，276(2):154-70.

[2] Peng Shijun. Changes and clinical significance of serum troponin and creatine phosphokinase isoenzymes in patients with acute cerebrovascular disease [J]. Chinese Journal of Practical Neurological Diseases, 2013, 16 (10): 25-27.

[3] Athamneh H,Basnawi A,Siler -Fisher A.CKMB and acutemyocardial infarction in the emergency department[J].J Emerg Med，2013，45(4):617.

[4] Chen Jianyun, Shi Yuling, Li Linhai, et al. Comparative analysis of serum CKMB quality and activity detection results [J]. South China Journal of National Defense Medicine, 2010, 24 (6): 455-456.



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