Serum adenosine deaminase

The adenosine deaminase (ADA) system is named adenosine aminohydrolase, which mainly catalyzes adenosine and deoxyadenosine, produces hypoxanthine and ammonia, and is one of the important enzymes for adenylate catabolism. ADA is widely distributed in various tissues of the human body, with the highest content of mucosa and spleen in the small intestine, followed by liver, kidney, bone and skeletal muscle. In intracellular ADA is mainly localized in the cytoplasm, and ADA activity in leukocytes is higher than that in red blood cells.

Basic Information

Specialist classification: Digestive examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Tips: After 8 pm on the day before the medical examination, you should fast, so as not to affect the next day's test. Normal value

1. Enzyme rate method (37 ° C) healthy adults 7.7-19.3 U / L.
2. Spectrophotometry <25U.
3, colorimetric healthy adults are 5 ~ 25U / ml.

Clinical significance

The ADA activity assay is mainly used for the diagnosis and differential diagnosis of hepatobiliary diseases, and is also used for the auxiliary diagnosis of diseases such as tuberculosis.

1, liver and gallbladder disease acute viral hepatitis, chronic active hepatitis, liver cirrhosis and liver cancer and other liver diseases ADA activity increased to varying degrees, with cirrhosis most obvious. Simultaneous determination with ALT is more valuable in determining the degree of recovery of hepatocytes. In the case of obstructive jaundice, ADA activity is rarely increased, which contributes to the identification of jaundice.

2, typhoid fever, infectious mononucleosis, rheumatic fever, hemolytic anemia, leukemia and some tumor patients can also increase serum ADA activity.

3, ADA activity in tuberculous pleural effusion is significantly higher than cancerous and non-inflammatory effusion, and pleural ADA activity and its ratio >1. Therefore, serum ADA and pleural ADA activity and their ratio determination are important for identifying the nature of effusion.

4, tuberculous meningitis cerebrospinal fluid ADA activity is significantly higher than purulent meningitis, viral meningitis, cerebral hemorrhage, cerebral infarction, brain trauma and so on.

Low results may be diseases: tuberculous meningitis, severe combined immunodeficiency, high cirrhosis results may be diseases: cirrhosis of the elderly, Haemophilus influenzae pneumonia, serious combined immunodeficiency disease considerations

1, 0.01mol / L hypochlorous acid solution can be diluted with anti-Fomin solution, the active chlorine content can be calibrated according to the following method: take 2ml of Antefumin liquid, about 20ml of distilled water, 3g of potassium iodide, add glacial acetic acid after dissolution 5ml, with soluble starch (1g / L) as an indicator, titrated with 0.1mol / L sodium thiosulfate, according to its dosage, calculate the concentration of active chlorine in the Anfufu liquid.

2. Replace chloramine T with sodium hypochlorite, and the former has a high effective chlorine concentration and a long reagent storage time. The formula is: NaOH 0.5g, Na2HPO4·12H2O5.37g, chloramine T100mg, add water to 100ml. It can be stored in a brown bottle for 1 year.

3. The distilled water used in the reagents should be deionized water or boiled to reduce the absorbance of the blank tube.

4. The above unit is multiplied by 1.19 to be converted into the international unit concentration (U/L), based on: unit × 1000 / (60 × 14).

5, red blood cells contain a lot of ADA activity, so avoid using hemolysis specimens.

Inspection process

Detection operation: Operate according to Table 1.

Mix well, water bath at 37 ° C for 30 min, at 640 nm, zero with distilled water, read the absorbance of each tube.

Not suitable for the crowd

Inappropriate people: Generally there are no people who are not suitable.

Adverse reactions and risks

1. Infection: Pay attention to aseptic operation when collecting blood, avoid contamination of water and other parts at the blood collection site to avoid local infection.
2, bleeding: after the blood is given a full compression time, especially coagulopathy, bleeding tendency, to avoid local subcutaneous oozing, bruising and swelling.