Viral hepatitis and the Australia-SH antigen

Hepatocellular carcinoma: paradigm of preventive oncology

Morbidity and mortality from hepatocellular carcinoma (HCC), which is primarily caused by hepatitis B virus or hepatitis C virus, can be prevented. Public health interventions have eliminated transfusion transmission of these viruses and, in endemic countries with effective hepatitis B virus vaccination programs, have greatly reduced incident hepatitis B virus infections (and HCC) in children. Antiviral treatment can eliminate detectable hepatitis C virus in 50%-80% of chronically infected patients, presumably reducing their risk of cancer. HCC survival rates remain universally poor, but early detection and treatment in developed countries has improved survival in selected patients. Despite these advances, worldwide HCC rates remain high, and additional preventive efforts are needed. The most important opportunity is wider distribution of hepatitis B virus vaccine in endemic areas. Development of an HCV vaccine, improved antiviral therapies, and better methods for HCC detection would also help decrease morbidity and mortality from HCC. HCC prevention efforts provide a paradigm for preventive oncology in cancers of viral etiology.

Hepatitis A: old and new

The hepatitis A virus (HAV), a picornavirus, is a common cause of hepatitis worldwide. Spread of infection is generally person to person or by oral intake after fecal contamination of skin or mucous membranes; less commonly, there is fecal contamination of food or water. Hepatitis A is endemic in developing countries, and most residents are exposed in childhood. In contrast, the adult population in developed countries demonstrates falling rates of exposure with improvements in hygiene and sanitation. The export of food that cannot be sterilized, from countries of high endemicity to areas with low rates of infection, is a potentially important source of infection. After ingestion and uptake from the gastrointestinal tract, the virus replicates in the liver and is excreted into the bile. Cellular immune responses to the virus lead to destruction of infected hepatocytes with consequent development of symptoms and signs of disease. Humoral immune responses are the basis for diagnostic serologic assays. Acute HAV infection is clinically indistinguishable from other causes of acute viral hepatitis. In young children the disease is often asymptomatic, whereas in older children and adults there may be a range of clinical manifestations from mild, anicteric infection to fulminant hepatic failure. Clinical variants include prolonged, relapsing, and cholestatic forms. Management of the acute illness is supportive, and complete recovery without sequelae is the usual outcome. Research efforts during World War II led to the development of passive immunoprophylaxis. Pooled immune serum globulin is efficacious in the prevention and attenuation of disease in exposed individuals. More recently, active immunoprophylaxis by vaccination has been accomplished. Future eradication of this disease can now be contemplated.

Produção de interferon ou substância semelhante em culturas EB3 inoculadas com soros humanos contendo antígeno Austrália

Culturas de células EB3, quando inoculadas com soros humanos contendo antígeno Austrália, produzem interferon ou substância semelhante em títulos significativamente mais elevados do que as culturas controle, não inoculadas. As culturas de células EB3 inoculadas com soros humanos negativos para o antígeno Austrália comportam-se de modo idêntico às culturas controle, no que respeita aos títulos de interferon, ou substância semelhante. Sugere-se a possibilidade daquele efeito poder servir de indicador de uma possível interação entre as células EB3 e o antígeno Austrália.

Australia antigen and antibody in British patients with leprosy

Seventy-five sera collected from leprosy patients in England were tested for Australia antigen and antibody. Australia antigen was detected in only two patients with lepromatous leprosy and in one patient with borderline pure leprosy. Antibody to Australia antigen was found in one patient with lepromatous leprosy. These findings differ from previous reports and it is suggested that the frequency of Australia antigen in lepromatous leprosy is a function of the incidence of this antigen in the general population rather than increased genetic susceptibility to chronic infection.

Australia antigen as a marker of propagation of the serum hepatitis virus in liver cultures

ATTEMPTS to isolate the human hepatitis viruses in tissue culture have resulted in a collection of “hepatitis-candidate” viruses, none of which has since been shown to be the causal agent of human hepatitis¹. The discovery of Australia antigen provided a specific serological marker of infection with or carriage of the serum hepatitis virus, although the nature of the antigen remains unsettled².

Autoantibodies and the hepatitis-associated antigen in acute infective hepatitis

In 39 unselected patients with acute infective hepatitis diagnosed on clinical, epidemiological, and pathological findings, smooth muscle (S.M.) antibody was found in 87% and hepatitis-associated antigen in 33%. The incidence of S.M. antibody was highest during the first month after the onset of symptoms, and the antibody was preponderantly IgM at this stage.S.M. antibody and hepatitis-associated antigen occurred independently, and unlike hepatitis-associated antigen, which was strongly associated with possible parenteral exposure to infection, the incidence of S.M. antibody was not related to the presumed mode of exposure. It is concluded that production of S.M. antibody is more directly related to liver cell damage than to the presence of hepatitis-associated antigen in the serum.

Presence of particles other than the Australia-SH antigen in a case of chronic active hepatitis with cirrhosis

Examination of serum specimens from a patient with chronic active hepatitis proved negative to the Australia-SH antigen by immunodiffusion and by complement fixation. Because the sera were anticomplementary they were examined with the electron microscope, and virus-like structures similar to members of the coronavirus group were identified. The possible significance of this finding in human serum and its relation to mouse hepatitis virus are discussed.A sample of the serum pool containing the MS-1 agent was found negative when examined by immunodiffusion, complement fixation, and electron microscopy. The possible lack of immunological identity between infectious and serum hepatitis is discussed.

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

This chapter discusses the discovery, characterization, immunology, and etiological significance of “Australia antigen (Au),” a new antigenic specificity appearing in the serum of patients with serum hepatitis, and carried on characteristic lipoprotein particles. In addition to its original name, given before its relationship to viral hepatitis became known, the antigen has also been given the designations, including Au(1) , SH antigen, Au/SH antigen, hepatitis antigen, and hepatitis-associated antigen (HAA). The synthesis of Au antigen, and its appearance in the serum, is specifically associated with infection by the causal agent of the SH type of viral hepatitis. The chapter discusses properties of the antigen, and of the particles which carry the Au specificity. It also discusses various serological techniques for Au antigen, such as two-dimensional double immunodiffusion (ID), complement fixation (CF), immunofluorescence (IF), reversed passive hemagglutination (RPHA) of antibody-coated red cells, immune electron microscopy (IEM), immunoelectroosmophoresis (IEOP), and radioimmunoassay (RIA).