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Biomedical subjects

R Gerety

Publications and source records attributed to R Gerety.

7 recordsLinked to original sources
PubMed1987

Cytotoxic T-cell responses to the nucleocapsid proteins of HBV in chronic hepatitis. Evidence that antibody modulation may cause protracted infection.

The nucleocapsid antigens (HBc and HBe) are present on the membranes of HBV-infected hepatocytes from HBV carriers. In autologous cytotoxicity experiments we demonstrate that cytotoxic T cells sensitised to the nucleocapsid proteins of hepatitis B are present in HBe antigen-positive HBV carriers with chronic hepatitis and can be blocked by monoclonal anti-HBc and anti-HBe. Passive immunisation of chimpanzees with monoclonal anti-HBc and anti-HBe offers no protection against HBV infection but in both cases leads to an unusually prolonged hepatitis probably by modulation of HBc and HBe antigen display on the hepatocytes. High-titre anti-HBc in the circulation of HBe antigen-positive patients probably modulates the former protein making HBe the important target antigen for cytotoxic T cells mediating liver damage in chronic carriers. These data also support the hypothesis that passive transfer of IgG anti-HBc across the placenta may be one major factor promoting development of persistent infection in neonates infected from carrier mothers.

Animals↗
PubMed1979

[Hepatitis A of children. Seroepidemiological study among French urban population (author's transl)].

A prevalence survey of hepatitis A antibody (anti-HAV) was conducted among 145 children living in the area of Tours (France). Thirty-four per cent of children's sera was found anti-HAV positive when tested by both immune adherence hemagglutination assay (IAHA) and specific radio-immunoassay (RIA). The prevalence of anti-HAV among infants less than one year and children between 1 to 5 years, was 35 per cent and 15 per cent respectively. From 6 years old, the prevalence of anti-HAV increased abruptly and reached 47 per cent in the 11 to 15 age group. Anti-HAV titers as measured by IAHA also increased according to age. In this study, the prevalence of anti-HAV was not related to sex, history of past surgery and/or blood transfusions. Only 12 per cent of children with anti-HAV positive test had history of jaundice. These results show that, in France, primary contact with hepatitis A virus (HAV) appear early in childhood, at school age, and that in children more than 80% of HAV infections remain asymptomatic.

Adolescent↗
PubMedDate not supplied

HLA class I antigens on the hepatocyte membrane during recovery from acute hepatitis B virus infection and during interferon therapy in chronic hepatitis B virus infection.

In a chimpanzee model of acute type B hepatitis, at the time of onset of hepatitis B virus replication and before the development of immunity to hepatitis B virus, interferon is present in the plasma. This is followed by an increase in the display of HLA class I, but not class II proteins, on the hepatocyte membrane. In chronic hepatitis B virus infection, there is a low density of HLA class I protein display on the infected hepatocyte. Administration of alpha-interferon enhances HLA display and in many cases is followed by a transaminase elevation, seroconversion of HBe antigen to antibody and disappearance of hepatitis B virus DNA from serum, changes implying clearance of infected hepatocytes. Successful response to interferon therapy may be predicted by a rapidly rising serum beta 2-microglobulin, a component of the HLA class I molecule, during the first 2 weeks of therapy, before the rise in transaminases.

Acute Disease↗