Immunohematology Chapter 1 Flashcards
Acquired immunity
Response by lymphocytes in response to antigen exposure; response is specific for the stimulating antigen.
Active immunization
Stimulation of antibody production by direct antigen contact.
Agglutination
Clumping of red blood cells or particulate matter resulting from the interaction of the antibody and the corresponding antigen.
Allele
One or more forms of a gene that occupies a specific locus on a chromosome.
Anamnestic response
Antibody response stimulated by secondary exposure to an antigen; the response is accentuated and a rapid rise in antibody is exhibited.
Antibody
Proteins produced in response to stimulation by an antigen and interacts with the stimulating antigen.
Anticoagulant
Chemical substance that prevents or delays the clotting (coagulation) of blood.
Antigen
Biochemical substance recognized as foreign; stimulates an immune response.
Atypical antibodies
Antibodies found either in the serum or on the cells that are unanticipated or not found under normal circumstances.
Autoantibodies
Antibodies directed against one’s own red cell antigens.
Cell-mediated immunity
Immunity involving cellular components such as macrophages, natural killer cells, T lymphocytes, and cytokines.
Chemical mediators
Substances secreted by cells that are then involved in an inflammatory response.
Complement
A series of proteins in the serum that are activated sequentially; following activation, bacterial and red cell lysis may occur.
Cytokines
Chemical mediators that stimulate tissue response to invading pathogens.
Decline phase
Phase of antibody production where the level of detectable antibody is decreasing due to catabolism.
Erythrocyte
Mature red blood cell; cell that transports oxygen and carbon dioxide.
Flocculation
Soluble antigen and soluble antibody combine to “fall out” of solution in flakes.
Foreign
Recognized by the immune system as non-self.
Graft versus host disease (GVHD)
Functional immune cells received from a donor that become engrafted in the recipient; these cells then recognize the recipient as “foreign” and mount an immunologic attack.
Hapten
A small molecule that can elicit an immune response only when attached to a large carrier such as a protein.
Hemagglutination
The clumping of red blood cells; used to visualize antigen-antibody reactions.
Hemolysis
Disruption of the membrane of a red blood cell; results in release of the contents into the plasma.
Human leukocyte antigens (HLA)
Antigens present on leukocytes and tissues. Genes that code for these antigens are part of the major histocompatibility complex (MHC) gene systems.
Humoral immunity
Immune response resulting in the production of antibodies.
Immune antibody
Antibody produced by direct stimulation with an antigen.
Immunogen
Synonym for antigen; substance that prompts the generation of antibodies and can cause an immune response.
Immunoglobulin
Gamma globulin protein found in blood or bodily fluids and used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses.
Immunohematology
Study of blood related antigens and antibodies as applied to situations in blood band and the transfusion service.
Immunology
Study of components and processes of the immune system.
Innate immunity
First line of defense for invading pathogens; cells and mechanisms that defend the host from invasion by other organisms; a non-specific defense.
Lag phase
First phase of an immune response: the level of antibody is not detectable by testing.
Leukocytes
White blood cells
Log phase
Second phase of an immune response; antibody levels steadily increase in a linear fashion.
Lymphocyte
Mononuclear leukocyte that mediates cellular and humoral immunity.
Major histocompatibility complex (MHC)
A group of linked genes on Chromosome 6 that determine the expression of complement proteins and leukocyte antigens.
Mononuclear Phagocytes
Leukocytes involved in phagocytosis and antigen presenting; these include monocytes (circulating cells) and macrophages (fixed cells).
Natural antibody
Antibody produced without known exposure to the antigen.
Passive antibody
Antibody administered to an individual.
Plasma
Liquid portion of whole blood containing water, electrolytes, glucose, proteins, fats, and gases; refers also to the liquid portion of a blood sample collected with an anticoagulant.
Plateau phase
Response phase where antibody production is constant and detectable at stable levels.
Polymorphic
System possessing multiple allelic forms at a single locus.
Polymorphonuclear neutrophil
A granulocytic white blood cell that phagocytizes invading microorganisms to provide protection to the host.
Precipitation
Formation of an insoluble compound when soluble ions in separate solutions are combined. The insoluble compound settles out of solution as a solid. The solid is called a precipitate.
Primary response
Antibody response following initial antigen exposure.
Proenzyme
An inactive enzyme precursor; requires a chemical change to become active.
Prozone phenomenon
Incomplete lattice formation with a lack of agglutination; results from antibody excess in comparison to antigen.
Refractory
Resistant to ordinary treatment.
Rouleaux
Coin like stacking of red cells in the presence of abnormal plasma proteins.
(GGLO) Secondary response (anamnestic response)
Antibody response that follows any antigen exposure other than initial exposure.
Serum
Liquid portion of the blood after coagulation.
Solid phase adherence
Testing method where on component of testing is adhered (attached) to a solid phase such as a microtiter plate; the patient’s sample is added; a final assessment is made by examination of the test wells of the plate.
T cytotoxic (Tc) Cells
A sub-group of lymphocytes that kill other cells.
T helper (Tb) cells
A sub-group of lymphocytes that play an important role in activating and directing other immune cells.
Thrombocytes
Anucleate cell fragments called platelets; these cells play a key role in blood clotting.
Titer
Measurement of antibody strength by testing its reactivity with decreasing amounts of the corresponding antigen; reciprocal of the highest dilution that shows agglutination represents the titer.
Zeta Potential
Difference in charge density between the inner and outer ion cloud surrounding the surface of the red blood cells in an electrolyte solution.
Zone of equivalence
When both reactants are present in amounts to create optimal reaction conditions.
