What is an immunohistochemical test?

The article was written by MSc Tran Quynh Trang - Doctor of Biochemistry, Laboratory Department - Vinmec Times City International General Hospital

Methods for detecting antigen-antibody complexes are collectively known as immunoassays. Through determining the amount of immune complex formed after the reaction to calculate the concentration of the substance to be measured.

The tests used are based on the body's immune system: To fight germs, foreign substances that enter the body, the immune system produces antibodies. Antibodies are proteins that can bind to a specific germ or substance, like a key that fits into a specific keyhole. Antibodies capture germs or foreign substances, neutralize them, and attract other immune cells.
Immunoassays are used in laboratories by creating artificial antibodies precisely matched to substances or pathogens. When these antibodies come into contact with a blood, urine or stool sample, they bind to a suitable substance or pathogen if found in the sample.
Immunoassay methods:
Turbidimetric immunoassay Chemoluminescence immunoassay Electroluminescent immunoassay

Vinmec Times City International General Hospital is currently using all three methods above.
Turbidity immunoassay is applied in the quantification of substances with molecular weight not too small such as: CRP, IgA, IgG, IgM, Microalbumine, Prealbumin...
Chemoluminescent immunoassay, Now practical and proven technology is more accurate test results, wide measuring range, no need to dilute samples and more sensitive than conventional colorimetric ELISA, EIA, FEIA methods and does not require long incubation. Chemiluminescent immunoassays are used to analyze many compounds of importance such as pharmaceuticals, hormones and other sex markers.
Electroluminescence immunoassay, using three kinds of principles: sandwich principle, competition principle and bridging principle.
In which, the competition principle is used to analyze substances with extremely small sizes such as FT3, FT4, Cortisol, Testosterone, Estradiol, Progesterone ...

The sandwich principle: for the analysis of substances with larger sizes such as: TSH, FSH, LH, PSA, AFP, CA 19-9, CA 15-3 ...
The bridging principle helps in the detection show antibodies in the test sample such as: IgG, IgM, IgA ...

Immunoassays are widely used, including:
Allergy testing : to detect antibodies against allergens such as pollen, flowers, grass or certain foods.

Currently, Vinmec Times City hospital has been successfully carrying out 36 allergen tests, which can find at the same time common causes of diseases such as shrimp, beef, mold, house dust...
Phat Phat Bacterial infection: In patients with bacterial tonsillitis, the ASLO test allows the identification and quantification of anti-streptolysin O antibodies in the patient's body. With this antibody detection, it helps to prove that the patient has or has ever had a streptococcal infection. In addition, the ASLO test is also useful to correctly identify glomerulonephritis, joint pain due to group A streptococcus or other causes. Diagnosing heart attacks and blood clots: Immediately after a heart attack or if someone has a blood clot, higher levels of a certain protein are found in the blood. Troponin T, with a half-life of about 2 hours, can be increased in plasma for the first 3 to 4 hours after acute myocardial infarction and for up to 2 weeks, so it can be indicated in cases of diagnosis and monitoring. acute coronary syndrome. CK-MB may be used more usefully than Troponin in monitoring of re-infarction or prolonged infarction because the elevation of CK-MB level lasts only 2 to 3 days after myocardial infarction, whereas the elevation of Troponin lasts only 2 to 3 days after myocardial infarction. may take up to 14 days. Thus, if the myocardial infarction recurs early, the CK - MB that has decreased immediately increases, and if the myocardial infarction lasts, after 3 days, the CK - MB activity is still high. CRPhs is not only a biomarker of inflammation but also a factor directly involved in the process of atherosclerosis. The CDC and AHA have recommended the following guidelines for assessing future risk of cardiovascular disease: CRPhs < 1 mg/L: low risk, 1–3 mg/L: moderate risk, > 3 mg /L: high risk.

Cancer screening test: With advanced immunoassay techniques can detect cancer markers. In gastrointestinal cancer: AFP is increased in liver cancer, germ cell cancer. CEA increases in gastrointestinal cancers such as esophageal, liver, pancreatic, colorectal, ovarian, uterine... CA 125 has a role in ovarian cancer diagnosis, checking the success of ovarian cancer. treatment process. Although SCCs are not very suitable for screening for squamous cell carcinoma because of their relatively low specificity and sensitivity, they are the optimal test for monitoring disease progression and can evaluate the progression of the disease. Treatment response of primary and recurrent squamous cell carcinoma. High CA 15-3 is often used to monitor response to treatment and recurrence of breast cancer. Urinalysis: If sugar, blood, protein, or inflammatory cells are found in the urine, it could be a sign of diabetes, a urinary tract infection, or kidney damage.

Pregnancy in women: Beta HCG is performed to check the concentration of HCG in the blood or urine. Help diagnose pregnancy or not, use to find ectopic pregnancy, use this test in combination with other screening tests to look for fetuses at increased risk of birth defects no, for example Down syndrome. Rapid drug testing: The test detects hallucinogenic drugs such as ecstasy, marijuana, cocaine, and certain psychoactive drugs, including synthetic drugs, morphine or sleeping pills. Thereby, it can be seen that immunohistochemical tests are increasingly being applied in the medical field. Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading doctors, modern equipment and technology, but also stands out for its examination and consulting services. and comprehensive, professional medical treatment; civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests here can be completely assured of the accuracy of test results.

Customers can directly go to Vinmec Health system nationwide to visit or contact the hotline here for support.
MORE:
Commonly used immunoassays Anti-Cardiolipin IgG Antibody Tests Allergy Diagnostic Tests