Australia antigen (hepatitis-associated antigen)

Detection of hepatitis B antibody by a single-antibody radioimmunoassay

A radioimmunoassay (RIA) for the measurement of antibody to hepatitis B surface antigen (anti-HB-s) in human and non-human sera is described. The principle is based upon our earlier observation that anti-HB-s and hepatitis B surface antigen (HB-s-Ag) are soluble in 4.5% w/v polyethylene glycol 4000 but that anti-HB-s-HB-s-Ag complex is precipitated. The use of activated charcoal suspended in polyethylene glycol and dextran solution facilitated the separation of this complex by centrifugation, thus improving reproducibility and sensitivity. The test is approx. 3-5000 times as sensitive as counterelectrophoresis. In a survey of a normal blood donor population, with an incidence of approx. 0.1% positive for HB-s-Ag by RIA, 7-8% were found to have anti-HB-s by this method.

Chronic liver disease: differences in autoimmune serological reactions between Australians and Asians

A total of 164 patients from Australia, Ceylon, India, Singapore, and Thailand were studied for the prevalence of autoantibodies associated with "idiopathic" chronic liver disease-namely, antinuclear antibody, smooth muscle antibody, and mitochondrial antibody. The prevalence of these autoantibodies was high among patients from Australia (55%), but was low among patients from Ceylon (14%), India (11%), Singapore (0%), and Thailand (8%). There are variations in types of hepatitis and cirrhosis between races, and this applies particularly to the type associated with autoimmune markers. This may be related to genetic differences that have evolved between peoples of European and Asian descent.

An automated passive haemagglutination technique suitable for the detection of hepatitis B virus antigen and antibody in blood donors

A method is described for preparing purified hepatitis B antigen (HB Ag) viral antigen without density gradient centrifugation. A method for sensitizing human group O red cells with this preparation is given, together with the technical details of an automated passive haemagglutination technique suitable for the mass screening of blood donors for HB virus and anti-HB antibody.