Glossary

Author: Glossary

  • Histocompatibility locus antigen

    Any of the multiple antigens present on all nucleated cells in the body that identify the cells as “self.” Immune cells compare these antigens to foreign antigens, which do not match the “self’ and therefore trigger an immune response. These markers determine the compatibility of tissue for transplantation.  

  • Hepatitis B surface antigen

    The glycoprotein found on the surface of the hepatitis B viral envelope. It is the first marker of infection with the hepatitis B virus. If HBsAg is still found in blood samples 6 months after infection with the virus, chronic and potentially contagious infection with hepatitis B is present.  

  • Hepatitis B core antigen

    A protein marker found on the core of the hepatitis B virus (HBV). HBV antigen does not circulate in the blood but is found only in fiver cells infected by HBV. HBcAg stimulates the production of a protective antibody, immunoglobulin M (IgM-anti-HBc), which appears in the blood shortly before the onset of symptoms. Tests for…

  • Hepatitis antigen

    The original term for the Australian antigen, now called hepatitis B surface antigen (HBsAg). Its discovery made possible the differentiation of hepatitis B from other forms of viral hepatitis.  

  • Cross reacting antigen

    An antigen having the ability to react with more than one specific antibody.  

  • Carcinoembryonica antigen

    A molecular marker found on normal fetal cells and in the bloodstream of patients with cancers of the colon, breast, lung, and other organs. Assays for CEA are used both to monitor the effectiveness of treatments for cancer and to provide prognostic information to patients.  

  • Allogeneic antigen

    An antigen that occurs in some individuals of the same species. Examples are the human blood group antigens.  

  • Antigalactic

    Preventing or diminishing the secretion of milk. A substance that reduces or stops the production of milk in a breastfeeding breast.  

  • Antifibrinolysin

    A substance that counteracts fibrinolysis.  

  • Antiestrogen

    A substance that blocks or modifies the action of estrogen.