Hepatitis D antigen
Hepatitis D virus antigens are present in infected cells and in the periphery. In the early stage of acute infection of hepatitis D virus, the hepatitis D virus antigen can be detected in the blood during the positive period of hepatitis B virus surface antigen for 1 to 2 weeks; the chronic infection can be maintained at a low titer level.Basic Information
Specialist classification: Infectious disease inspection and classification: pathogenic microorganism inspection
Applicable gender: whether men and women apply fasting: fastingAnalysis results:
The negative suggestion was not infected with the hepatitis D virus.
Positive indications are infected with hepatitis D virus.
(1) The visual method brown or yellow is HDAg positive, and colorless is negative.
(2) Colorimetric method using a microplate reader to measure the light absorption value (A) at a wavelength of 492 nm, and calculate the S/N value or threshold value based on the A value of the sample and the average value of the negative control A. Where the sample S/N value is ≥ 2.1 or greater The threshold is positive, and vice versa.
Threshold = negative control A492 mean x 2.1.Clinical significance
The hepatitis D virus antigen is present in the infected liver tissue cells and in the intact virus of the peripheral blood. The HDAG positive in the peripheral blood of the patient indicates that there is replication of the hepatitis D virus in the body and the hepatitis D virus in the blood.Precautions
(1) Because hepatitis D and hepatitis B infection exist at the same time, after peripheral blood is treated with detergent, HBAg and HBcAg may exist at the same time. Therefore, attention should be paid to prevent interference of HBcAg. Therefore, non-labeled substances must be added to the enzyme label. Monoclonal antibodies that specifically neutralize HBcAg are excluded.
(2) Because the amount of antigen in the peripheral blood is small, the serum should not be diluted at least 30 ~ 50μl.
(3) It is best to use the colorimetric method to avoid false positives or false negatives.
(4) Repeat the test for suspected specimens.Inspection process
1, the principle of determination of hepatitis D antigen
The hepatitis D virus antigen is encapsulated by hepatitis B-indicating antigen (HBsAg) and released after being lysed with a detergent (Tween20 or NP40). The immunological principle of antigen-antibody specific binding is applied to the double antibody sandwich enzyme. Detection by immunosorbent assay.
(1) Anti-HDV IgG purified antibody was used for coating.
(2) HRP-anti-HDV antibody.
(3) Anti-HBc monoclonal antibody with neutralizing activity: ELISA titer 1:100, for dilution of HRP-anti-HD.
(4) 10% Tween20.
(5) Other equipment and solutions are the same as above.
3, the operation method
(1) The anti-HDV IgG coated polystyrene plate was diluted with a coating solution, and 100 μl per well was placed at 37 ° C for 1 h at 4 ° C overnight.
(2) After washing 3 times, add 50 μl of serum and negative control serum (negative control serum wells, positive control serum 2 wells) and 10% Tween 2050 μl to each well, mix thoroughly and let stand at room temperature overnight to lyse. The hepatitis B virus surface-encapsulated HBsAg releases the hepatitis D antigen.
(3) After washing 3 times, add 50 μl of HRP-anti-HDV antibody to each well (10 ELISA units of anti-HBc monoclonal antibody in addition to 10% calf serum), and put at 45 ° C for 1 h (or 37 ° C) 2h).
(4) After washing 3 times, add 50 μl of freshly prepared substrate solution to each well, and let the reaction develop in the dark at room temperature for 15 to 30 minutes, then add 25 μl of 2 mol/L H 2 SO 4 per well to terminate the reaction.Not suitable for the crowd
Those who do not have an indication for examination should not do this check.Adverse reactions and risks
Generally no complications and harm.