cytokeratin 19 fragment

Cytokeratin is the intermediate filament of the cell body and is the main component of the cell structure. It can be divided into 20 different types according to its molecular weight and the two-dimensional two-dimensional electrophoresis. It can be used in normal epithelium, tumor cells and cell culture. Differentiated epithelial cell expression. CYFRA21-1 consists of two monoclonal antibodies to the cytokeratin 19 fragment, the monoclonal antibodies BMl9-21 and KSl9.1, which are acidic cell proteins with a molecular weight of 4 kD. It is mainly distributed in the cytoplasm of monolayer and stratified epithelial tumor cells, and when the cell dies, it is released into the serum as a lysed fragment. Basic Information Specialist classification: Oncology examination classification: immune examination Applicable gender: whether men and women apply fasting: not fasting Tips: Before the examination, the diet is light and alcohol is prohibited. Check for an empty stomach in the morning. Normal value ≤ 3.3 μg / L. Clinical significance (1) The concentration of CYFRA21-1 in serum and pleural effusion of lung cancer patients, especially NSCLC patients, is increased, and its sensitivity increases with the progress of the disease, and is positively correlated with the staging of lung cancer. From a histological point of view, it is more sensitive to squamous cell carcinoma than adenocarcinoma and SCLC. At the same time, CYFRA21-1 is also an independent prognostic factor for the survival and recurrence of lung squamous cell carcinoma. Therefore, CYFRA21-1 detection has a high clinical value for the diagnosis, disease monitoring and efficacy judgment of patients with non-small cell lung cancer. (2) serum CYFlRA21-1 increased can also be found in breast cancer, bladder cancer, biliary tract cancer, pancreatic cancer and other neoplastic diseases, can also be seen in a small number of emphysema, bronchitis, peptic ulcer, liver benign diseases. High results may be diseases: precautions for lung cancer, breast cancer, gallbladder cancer Observing the dynamic monitoring of clinical lung cancer surgery and the efficacy of radiotherapy before and after chemotherapy is an important auxiliary index. Inspection process The method is divided into three steps, namely antigen-antibody reaction, B and F separation, and radioactivity determination. (1) Reaction of antigen with antibody: The specimen (non-labeled antigen), labeled antigen and antiserum are sequentially dosed into a small test tube, and allowed to stand at room temperature (15 to 30 ° C) for 24 hours to fully compete for binding. (2) Separation of B and F: There are various separation techniques, and the precipitation method is commonly used. 1 second antibody precipitation method: also known as diabody method, after the test antigen specifically reacts with the first antibody, the corresponding second antibody is added, so that the formed antigen-first antibody-second antibody complex is co-precipitated. The labeled antigen B is separated from the free antigen F by centrifugation. This method is a specific precipitation, complete separation, low non-specific binding. However, the amount of the second antibody is large and the cost is high. In addition, the serum concentration and the presence or absence of anticoagulants can affect the results to some extent. 2 Polyethylene glycol (PEG) precipitation method: the protein is in an isoelectric point state, and the hydration layer is destroyed to cause protein precipitation. The advantage of this method is that PEG is convenient to prepare, inexpensive, and rapid to separate. The disadvantage is that there are many non-specific precipitates and the separation is incomplete. 3Second antibody-polyethylene glycol precipitation method: This method not only has the advantage of rapid precipitation of PEG method, but also maintains the effect of specific precipitation of second antibody, reduces the amount of second antibody, and reduces the concentration of PEG, so that non-specific precipitation Reduced material. 4 Activated carbon adsorption method: the free part of small molecules is adsorbed by the surface activity of activated carbon. For example, a layer of dextran is coated on the surface of the activated carbon to make a mesh having a certain pore diameter on the surface, thereby allowing small molecules of free antigen or hapten to escape and being adsorbed, while the macromolecular complex is excluded. After the antigen and the antibody are reacted, the dextran-activated carbon is added and allowed to stand for 5 to 10 minutes, so that the free antigen is adsorbed on the activated carbon particles, and the particles are precipitated by centrifugation, and the supernatant contains the labeled antigen. (3) Determination of radioactivity: After separation of B and F, the radioactivity can be measured. There are two types of measuring instruments: a liquid scintillation counter (measuring beta rays) and a crystal scintillation counter (measuring gamma rays). The unit of counting is the number of electrical pulses output by the detector in units of cpm (number of pulses/min). A standard curve is required for each measurement, and the different concentrations of the standard antigen are plotted on the abscissa, and the corresponding radioactivity measured is plotted on the ordinate. The radioactivity may be optionally B or F, and the calculated values ​​B/B+F, B/F or B/B0 may also be used. Specimens should be determined in duplicate, the average value is taken, and the corresponding antigen concentration is detected on the standard curve. Not suitable for the crowd Inappropriate people: Generally there are no people who are not suitable. Adverse reactions and risks Generally no adverse reactions.

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