Australia (hepatitis-associated) antigen: physicochemical and immunological characteristics

T-lymphocytes and hepatitis B serology

The incorporation of 14C-thymidine by peripheral blood lymphocytes stimulated by phytohemagglutinin (PHA) and the proportion and absolute number of E-rosettes were determined in 28 prostitutes and the results were correlated with hepatitis B virus (HBV) serology. Women were tested for hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs) as well as for antibody to the hepatitis B core antigen (anti-HBc). It was found that women who were carriers of HBsAg had significantly lower incorporation of 14C-thymidine (median value 14451 counts per minute-cpm) compared to women positive for anti-HBc but negative for the other two markers (median value 28590 cpm) as well as to women negative for all the tested markers (median value 30600 cpm). No significant difference was found among the three groups studied with respect to either the absolute number or the percentage of E-rosettes. The results indicate that the presence of anti-HBc alone, is not related to the responsiveness of lymphocytes to PHA.

Seroepidemiological study of HBV infections in Athens, Greece

A seroepidemiological survey of a sample-roughly representative by age and sex - of 2744 persons of the Greater Athens area revealed that hepatitis B virus (HBV) infections are highly endemic in Greece. Hepatitis B surface antigen (HBsAg) was detected in 72(2-6%) of them. The subtype was identified in 70 of the 72 carriers, and 69 were ay; the other was ad. Determinant w was present in all 61 that were capable of being typed further, and a23y(w) was twice as common as a11y(w). Antibody to HBsAg (anti-HBs) was found in 514 (18-7%) persons. The prevalence of the HBsAg rose rapidly with age, reaching peak values (5-3%) at 20-29 years, while anti-HBs reached its highest value (42-1%) in older age groups (50-59 years). The frequency of HBsAg was significantly higher in males (3-4%) than in females (1-5%). The percentage of infected persons who become chronic HBsAg carriers (12-3%) was found higher than in other developed populations. It was also found higher in children (25%) than in adults (5-5%) and in males (14-6%) than in females (8-1%). These data indicate that HBV infection in early life is a major risk factor in the development of HBsAg carriers and support the hypothesis that males are more likely to become HBsAg carriers than females.

Hepatitis B surface antigen: regional variation in sub-type ratio in the Canadian Red Cross donor population

A total of 344 sera positive for hepatitis B surface antigen from volunteer blood donors at several Canadian Red Cross centres were subtyped for ad and ay specificity by counterelectrophoresis. Of the 50 sera from Toronto 21 (42%) were ad and 29 (58%) were ay; of the 95 from Montreal 82 (86%) were ad and 13 (14%) were ay; of the 199 from Quebec 179 (90%) were ad and only 20 (10%) were ay. The w and r specificities were also determined in 125 of the samples: 123 were w; the 2 samples of r specificity were from Toronto. On the other hand, among 45 sera from patients with acute hepatitis type B in Quebec 13 (29%) were ad and 33 (71%) ay.

Comparative biophysical studies of hepatitis B antigen, subtypes adw and ayw

Comparative biophysical and biochemical analyses were performed on purified preparations of hepatitis B antigen (HBs Ag) subtypes adw and ayw, including isoelectric pH evaluations, analysis of the different morphological forms, molecular weight determinations, and analysis of the polypeptides by polyacrylamide gel electrophoresis, Both HBs Ag-positive plasma and purified HBs Ag were analyzed by electrofocusing in a sucrose ampholyte gradient. Four distinct populations of HBs Ag with a pH range of 4.5 plus or minus 0.1 to 5.4 plus or minus 0.1 for unfractionated plasma samples and 3.9 plus or minus 0.05 to 4.9 plus or minus 0.05 for purified samples were detected in both adw and ayw preparations. Electron microscopic studies of each population of purified HBs Ag revealed 19- to 27-nm spheres in each fraction. Purified material labeled with 125I by the chloramine-T method behaved as one major population with an isoelectric pH value of 3.9 plus or minus 0.1. Purified adw preparations revealed a major population with a molecular weight of 3.7 times 10-6 and a second one of 4.6 times 10-6. Purified preparations of ayw contained one population with a molecular weight of 4.6 times 10-6. Polyacrylamide gel electrophoretic analysis of purified HBs Ag revealed nine polypeptides for ayw and seven for adw particles. These studies indicate that purified preparations of HBs Ag are heterogeneous and that distinct differences can be detected between the two subtypes.

Essential malignant hypertension with renal failure and persistent Australia-antigenaemia

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Biophysical and biochemical heterogeneity of purified hepatitis B antigen

Hepatitis B antigen of the D (a+, d+, y-) subtype was purified from plasma of apparently healthy persons and from hepatitis patients. The original samples contained 20- and 42-nm particles and tubular forms (20-nm diameter). Ultracentrifugation during the purification procedure yielded pellets which were then treated at pH 2.4. Both the large, 42-nm Dane particles and the tubular forms were lost during the acid treatment of the pelleted particles, yielding a preparation containing a mixture of particles approximately 20 and 25 nm in diameter. This difference in size was substantiated in that two distinct molecular weights were calculated from high-speed equilibrium data, 3.6 x 10(6) and 4.5 x 10(6). Further heterogeneity was observed in that hepatitis B antigenic activity was present in purified particles with an isoelectric pH of 4.0 and also in those with a pH of 4.4. No significant differences were observed in the gross amino acid composition of purified antigen obtained from plasma of three different persons. (125)I-labeled, purified antigen was found to contain six distinct polypeptides with molecular weights ranging from 10,000 to 39,000.

Production of potent anti-Australia antigen sera of high specificity and sensitivity in goats

Potent antisera of high specificity and sensitivity were produced, in goats, to purified Australia antigen (Au). The antigen was prepared by one of three methods: (i) pelleting, low pH treatment, isopycnic centrifugation two times in CsCl, and rate zonal centrifugation in sucrose; (ii) same as procedure i, with the exception of the low pH treatment; or (iii) twice banding in CsCl by using a BXIV batch-type zonal centrifuge rotor with subsequent preparative Pevikon electrophoresis. The goat anti-Au sera contained high levels of precipitating antibody as tested by immunodiffusion in agar gel and discontinuous counterimmunoelectrophoresis (DCIE) as well as specific complement-fixing antibody and could be used for routine screening of sera for Au without prior adsorption with Au-negative normal human serum (NHS). Identification of 66 of 70 positive specimens (94.3%) in a panel of 98 coded sera (49 duplicates) with 100% reproducibility was made by using one of the goat anti-Au sera at a dilution of 1:16 in the DCIE method. No false positives were recorded. Low levels of antibody against NHS components were effectively removed by a single adsorption with glutaraldehyde cross-linked NHS.

Electron microscopic observations and speculations on Australia antigen

The use of the electron microscope has simplified methods of detection of Australia antigen in carriers of serum hepatitis, in patients suffering from the disease and those with persistent hepatitis.

Basic studies on the nature and properties of Australia antigen, using the electron microscope, are described.