Glossary of Terms Used in Primary Immunodeficiency Disease
antibody-protein that is part of the body's immune system; it is produced in response to substances, usually foreign, known as antigens (see below). The binding of antibody to foreign substances facilitates their destruction.
antigen-a substance recognized as foreign by the immune system.
autoimmunity-the condition in which the immune system mistakenly attacks and damages the body's own cells and tissues; this immune reaction is the basis of a variety of autoimmune diseases including diabetes, rheumatoid arthritis, and systemic lupus erythematosus, among others.
bone marrow-blood-like material located in the central cavities of bones. Bone marrow is the source of all blood cells.
complement-a series of proteins that work together to kill foreign cells like bacteria and viruses.
gene-a unit of genetic material (DNA). A gene may be defined in different ways as follows:
pattern of inheritance-a segment of DNA that is transmitted, intact, from parent to offspring;
structur-a segment of DNA encoding a protein molecule;
function-a segment of DNA that contains the information for a specific function;
dominant-where the gene from one parent confers a trait;
recessive-where both genes at a locus are required to confer a trait.
gene therapy-treatment of genetic diseases by providing the correct or normal form of the abnormal gene causing a $isease.
genetic disease-a disease due to an abnormal condition of one or more genes. Although most diseases have some genetic component, the term genetic disease is usually applied to those cases where one or two genes determine the disease, such as sickle cell anemia, Tay-Sachs disease, and cystic fibrosis.
HLA (human leukocyte antigens)-the transplantation antigens (i.e., the antigens that are the major targets of immune rejection) of humans. These molecules have a role in regulating the immune response in general.
immune response-the reaction of the immune system to foreign substances.
immunocompetent-capable of developing an immune response.
immunodeficiency-the lack of an adequate or normal immune response. Immunodeficiency can be:
primary-intrinsic, not due to another illness or agent;
secondary-due to another illness or agent, e.g., human immunodeficiency virus, cancer, chemotherapy, etc.;
combined-deficiencies of both killer T lymphocytes and antibodies.
immunologic disease-a disease due to a dysfunction of the immune system. These are the autoimmune, allergic, and immunodeficiency diseases.
leukocyte-a white cell of the blood.
phagocytes-white blood cells called neutrophils and macrophages that engulf and kill foreign invaders like bacteria and viruses.
protein-a type of organic compound that is one of the major components of cells and tissues.
rejection (graft)-the immunological response to transplanted tissues or organs; if rejection is not controlled, it will eventually lead to graft failure or graft-versus-host disease.
transplantation-transfer of cells, tissues, or organs from one area of the body to another or from one organism to another.
X-linked-boys inherit an X chromosome with a defective gene from their mother, and since it is their only X chromosome, they develop the disease.
