Interpretation of Hepatitis B Serologic Test Results

 Hepatitis B serologic testing involves measurement of several hepatitis B virus (HBV)-specific antigens and antibodies. See this blog post

Different serologic “markers” or combinations of markers are used to identify different phases of Hepatitis B Virus (HBV infection) and to determine whether a patient has acute or chronic HBV infection, is immune to HBV as a result of prior infection or vaccination, or is susceptible to infection.

Serologic Methods: Counterimmunoelectrophoresis (CIE)

1. Modification of the Ouchterlony method.
2. Unknown bacterial antigen and a known specific antibody move towards each other in an electrical field
3. Most bacterial antigen are negatively charged  (eg. Capsular polysaccharide) in a slightly alkaline environment.
4. When Ag and Ab meet in optimal proportions, a line of precipitation appear within the agar matrix 
5. The entire procedure takes about One hour. 
6. Any antigen for which antisera is available can be tested by CIE Sensivity less than that of particle agglutination (0.01-0.05 mg/ml) of antigen.

Used to detect presence of capsular antigens in CSF of

• H. influenzae
• N. meningitidis
• S. Pneumoniae etc

 CIE is  more expensive than agglutination based tests.
Initial capital outlay for the apparatus
Nee of large quantity of Ag and Ab

Serologic Methods:Agglutination

Serologic Methods: Agglutination
Can be performed in:

• Surface of glass slides: Rapid reading/evaporation
• Test tubes: More sensitive Because of longer incubation

Reagents available commercially


Types

• Identification of an organism with Known antiserum
• Identification of Serum Antibodies with Known antigens.