immune
[ĭ-mūn´]1. being highly resistant to a disease because of the formation of humoral antibodies or the development of immunologically competent cells, or both, or as a result of some other mechanism, as interferon activities in viral infections.
2. characterized by the development of humoral antibodies or cellular immunity, or both, following antigenic challenge.
3. produced in response to antigenic challenge, as immune serum globulin.
immune response the reaction to and interaction with substances interpreted by the body as not-self, the result being humoral and cellular immunity. Called also immune reaction. The immune response depends on a functioning thymus and the conversion of stem cells to B and T lymphocytes. These lymphocytes contribute to antibody production, cellular immunity, and immunologic memory.
Disorders of the Immune Response. Pathologic conditions associated with an abnormal immune response (immunopathy) may result from (1) immunodepression, that is, an absent or deficient supply of the components of either humoral or cellular immunity, or both; (2) excessive production of gamma globulins; (3) overreaction to antigens of extrinsic origin, that is, antigens from outside the body; and (4) abnormal response of the body to its own cells and tissues.
Those conditions arising from immunosuppression include agammaglobulinemia (absence of gamma globulins) and hypogammaglobulinemia (a decrease of circulating antibodies). Factors that may cause or contribute to suppression of the immune response include (1) congenital absence of the thymus or of the stem cells that are precursors of B and T lymphocytes; (2) malnutrition, in which there is a deficiency of the specific nutrients essential to the life of antibody-synthesizing cells; (3) cancer, viral infections, and extensive burns, all of which overburden the immune response mechanisms and rapidly deplete the supply of antigen-specific antibody; (4) certain drugs, including alcohol and heroin, some antibiotics, antipsychotics, and the antineoplastics used in the treatment of cancer.
Overproduction of gamma globulins is manifested by an excessive proliferation of plasma cells (multiple myeloma). hypersensitivity is the result of an overreaction to substances entering the body. Examples of this kind of inappropriate immune response include hay fever, drug and food allergies, extrinsic asthma, serum sickness, and anaphylaxis.
Autoimmune diseases are manifestations of the body's abnormal response to and inability to tolerate its own cells and tissues. For reasons not yet fully understood, the body fails to interpret its own cells as self and, as it would with other foreign (not-self) substances, utilizes antibodies and immunologically competent cells to destroy and contain them.
Those conditions arising from immunosuppression include agammaglobulinemia (absence of gamma globulins) and hypogammaglobulinemia (a decrease of circulating antibodies). Factors that may cause or contribute to suppression of the immune response include (1) congenital absence of the thymus or of the stem cells that are precursors of B and T lymphocytes; (2) malnutrition, in which there is a deficiency of the specific nutrients essential to the life of antibody-synthesizing cells; (3) cancer, viral infections, and extensive burns, all of which overburden the immune response mechanisms and rapidly deplete the supply of antigen-specific antibody; (4) certain drugs, including alcohol and heroin, some antibiotics, antipsychotics, and the antineoplastics used in the treatment of cancer.
Overproduction of gamma globulins is manifested by an excessive proliferation of plasma cells (multiple myeloma). hypersensitivity is the result of an overreaction to substances entering the body. Examples of this kind of inappropriate immune response include hay fever, drug and food allergies, extrinsic asthma, serum sickness, and anaphylaxis.
Autoimmune diseases are manifestations of the body's abnormal response to and inability to tolerate its own cells and tissues. For reasons not yet fully understood, the body fails to interpret its own cells as self and, as it would with other foreign (not-self) substances, utilizes antibodies and immunologically competent cells to destroy and contain them.
immune system a complex system of cellular and molecular components whose primary function is distinguishing self from nonself and defense against foreign organisms or substances; see also immune response. The primary cellular components are lymphocytes and macrophages, and the primary molecular components are antibodies and lymphokines; granulocytes and the complement system are also involved in immune responses but are not always considered part of the immune system per se. 
Major organs and tissues of the immune system in the child. From McKinney et al., 2000.
immune complex disease local or systemic disease caused by the formation of circulating antibody-antigen immune complexes and their deposition in tissue, due to activation of complement and to recruitment and activation of leukocytes in type III hypersensitivity reactions.
response
[re-spons´]any action or change of condition evoked by a stimulus.
acute phase response a group of physiologic processes occurring soon after the onset of infection, trauma, inflammatory processes, and some malignant conditions. The most prominent change is a dramatic increase of acute phase proteins in the serum, especially C-reactive protein. Also seen are fever, increased vascular permeability, and a variety of metabolic and pathologic changes.
anamnestic response the rapid reappearance of antibody in the blood following introduction of an antigen to which the subject had previously developed a primary immune response.
auditory brainstem response ABR; a special hearing test that tracks the nerve signals arising in the inner ear as they travel along the auditory nerve to the brain region responsible for hearing. A small speaker placed near the ear makes a clicking sound, and special electrodes record the nerve signal as it travels. The test can determine where along the nerve there is a lesion responsible for sensorineural hearing loss. It is often used for individuals with such loss in just one ear; this is often caused by a benign tumor along the auditory nerve, but if the ABR reading is normal in a given region, the chances of there being a tumor there are small. This test can also be used on infants since it requires no conscious response from the person being tested.
autoimmune response the immune response in which antibodies or immune lymphoid cells are produced against the body's own tissues. See also autoimmune disease.
conditioned response see conditioned response.
dysfunctional ventilatory weaning response a nursing diagnosis adopted by the North American Nursing Diagnosis Association, defined as inability of a patient to adjust to lowered levels of mechanical ventilator support, which interrupts and prolongs the process of weaning. See also mechanical ventilatory weaning.
galvanic skin response the alteration in the electrical resistance of the skin associated with sympathetic nerve discharge.
immune response see immune response.
inflammatory response the various changes that tissue undergoes when it becomes inflamed; see inflammation.
post-trauma response former name for the nursing diagnosis post-trauma syndrome.
reticulocyte response increase in the formation of reticulocytes in response to a bone marrow stimulus.
triple response (of Lewis) a physiologic reaction of the skin to stroking with a blunt instrument: first a red line develops at the site of stroking, owing to the release of histamine or a histamine-like substance, then a flare develops around the red line, and lastly a wheal is formed as a result of local edema.
unconditioned response an unlearned response, i.e., one that occurs naturally, in contrast to a conditioned response.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
an·ti·gen (Ag),
(an'ti-jen),Any substance that, as a result of coming in contact with appropriate cells, induces a state of sensitivity or immune responsiveness and that reacts in a demonstrable way with antibodies or immune cells of the sensitized subject in vivo or in vitro. Modern usage tends to retain the broad meaning of antigen, employing the terms "antigenic determinant" or "determinant group" for the particular chemical group of a molecule that confers antigenic specificity.
See also: hapten.
See also: hapten.
Synonym(s): immunogen
[anti(body) + G. -gen, producing]
Farlex Partner Medical Dictionary © Farlex 2012
immunogen
Any substance that can elicit an immune response. An antigen.Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
immunogen
a substance that is capable of provoking an IMMUNE RESPONSE.Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005