LESSON 1: INTRODUCTION/ DEFINITION OF TERMS Flashcards
is the study of blood group antigens and antibodies, HLA antigens and antibodies, pretransfusion testing, identification of unexpected alloantibodies, immune hemolysis, autoantibodies, drugs, blood collection, blood components, cryopreservation of blood, transfusiontransmitted viruses, tissue banking and organ transplantation, blood transfusion practice, safety, quality assessment, records, blood inventory management, and blood usage review.
Immunohematology
: foreign molecules that bind specifically to an antibody or a T-cell receptor
Antigen
: cells or tissue from a genetically different individual
Allogeneic
: cells or tissue from self
Autologous
: small-molecular-weight particle that requires a carrier molecule to be recognized by the immune system
Hapten
: study of blood group antigens and antibodies
Immunohematology
: lymphocytes that mature in the bone marrow, differentiate into plasma cells when stimulated by an antigen, and produce antibodies
B lymphocytes (B cells)
: lymphocytes that mature in the thymus and produce cytokines to activate the immune cells including the B cell
T lymphocytes (T cells)
: secreted proteins that regulate the activity of other cells by binding to specific receptors
Cytokines
They can increase or decrease cell proliferation, antibody production, and inflammation reactions.
Cytokines
: B cells produced after the first exposure that remain in the circulation and can recognize and respond to an antigen faster.
Memory B cells
: antibody-producing B cells that have reached the end of their differentiating pathway.
Plasma cells
: sites on an antigen that are recognized and bound by a particular antibody or T-cell receptor (also called epitopes)
Antigenic determinants
: single antigenic determinants; functionally, they are the parts of the antigen that combine with the antibody.
Epitopes
: family of cells or organisms having genetically identical constitution.
Clone
: antigen in its role of eliciting an immune response.
Immunogen
: simple sugars, such as monosaccharides and starches (polysaccharides).
Carbohydrates
: fatty acids and glycerol compounds.
Lipids
is an antigen that provokes the immune response.
immunogen
Not all (?) are immunogens.
antigens
: glycoprotein (immunoglobulin) that recognizes a particular epitope on an antigen and facilitates clearance of that antigen.
Antibody
: antibody; glycoprotein secreted by plasma cells that binds to specific epitopes on antigenic substances.
Immunoglobulin
: larger polypeptides of an antibody molecule composed of a variable and constant region
Heavy chains
five major classes determine the isotype of an antibody.
Heavy chains
: smaller polypeptides of an antibody molecule composed of a variable and constant region
Light chains
two major types of light chains exist in humans (?).
kappa and lambda
: one of five types of immunoglobulins determined by the heavy chain: IgM, IgG, IgA, IgE, and IgD.
Isotype
: one of the two types of light chains that make up an immunoglobulin.
Kappa chains
: one of the two types of light chains that make up an immunoglobulin.
Lambda chains
: amino-terminal portions of immunoglobulins and T-cell receptor chains that are highly variable and responsible for the antigenic specificity of these molecules.
Variable regions
: non-variable portions of the heavy and light chains of an immunoglobulin.
Constant regions
: variable part of an antibody or T-cell receptor; the antigen-binding site.
Idiotope
: portion of the immunoglobulin heavy chains between the Fc and Fab region
Hinge region
provides flexibility to the molecule to allow two antigen-binding sites to function independently.
Hinge region
: red cell destruction by phagocytes residing in the liver and spleen usually facilitated by IgG opsonization.
Extravascular hemolysis
: number of epitopes per molecule of antigen.
Valency
: red cell lyses occurring within the blood vessels usually by IgM activation of complement.
Intravascular hemolysis
: having a combining power of two.
Bivalent
: condition caused by destruction of fetal or neonatal red cells by maternal antibodies.
Hemolytic disease of the fetus and newborn
: immune response induced by initial exposure to the antigen.
Primary immune response
is necessary to detect antigen-antibody complexes involving IgG antibodies in vitro.
antiglobulin test method
: process of somatic mutations in the immunoglobulin gene causing the formation of variations in the affinity of the antibody to the antigen.
Affinity maturation
B cells with the highest affinity are (?), and the resulting antibody is stronger.
“selected” for the best fit
: immune response induced after a second exposure to the antigen, which activates the memory lymphocytes for a quicker response.
Secondary immune response
: secondary immune response.
Anamnestic response
Multiple stimulations of the immune system with the same antigen produce antibodies with increased binding strength as a result of affinity maturation.
Anamnestic response
: complex of one or more antibody molecules bound to an antigen.
Immune complex
: strength of the binding between a single antibody and an epitope of an antigen.
Affinity
: overall strength of reaction between several epitopes and antibodies
Avidity
depends on the affinity of the antibody, valency, and noncovalent attractive forces.
Avidity
: compounds containing carbohydrate and protein molecules.
Glycoproteins
: compounds containing carbohydrate and lipid molecules.
Glycolipids
: visible clumping of particulate antigens caused by interaction with a specific antibody.
Agglutination
: antibodies with specificities other than self
Alloantibodies
stimulated by transfusion or pregnancy.
Alloantibodies
: test to determine the presence of alloantibodies.
Antibody screen test
: referring to a reaction within the body.
In vivo
: group of serum proteins that participate in an enzymatic cascade, ultimately generating the membrane attack complex that causes lysis of cellular elements.
Complement system
: C5 to C9 proteins of the complement system that mediate cell lysis in the target cell.
Membrane attack complex
: lysis or rupture of erythrocytes.
Hemolysis
: activation of complement that is initiated by antigen-antibody complexes.
Classical pathway
: activation of complement that is initiated by foreign cell-surface constituents.
Alternative pathway
: complement split products (C3a, C4a, and C5a) that mediate degranulation of mast cells and basophils, which results in smooth muscle contraction and increased vascular permeability.
Anaphylatoxins
: products such as histamines released by basophils, mast cells, and platelets that act on the endothelium and smooth muscle of the local vasculature.
Vasoactive amines
: movement of cells in the direction of the antigenic stimulus.
Chemotactic
: substance (antibody or complement protein) that binds to an antigen and enhances phagocytosis.
Opsonin
: molecules on the cell surface that have a high affinity for a particular ligand.
Receptors
: system of mononuclear phagocytic cells, associated with the liver, spleen, and lymph nodes, that clears microbes and damaged cells.
Mononuclear phagocyte system
: reaction in an artificial environment, such as in a test tube, microplate, or column.
In vitro
: binding of antibody or complement components to a red cell.
Sensitization
: combination of antibody and a multivalent antigen to form cross-links and result in visible agglutination.
Lattice formation
: ratio of antigen on the red cell to antibody in the serum.
Serum-to-cell ratio
: interpretation of agglutination reactions immediately after centrifugation and without incubation.
Immediate-spin
: electrostatic potential measured between the red cell membrane and the slipping plane of the same cell.
Zeta potential
: number of binding sites of multivalent antigen and antibody are approximately equal.
Zone of equivalence
: excess antibody causing a false-negative reaction.
Prozone
: excess antigen causing a false-negative reaction.
Postzone
: fluid above cells or particles after centrifugation.
Supernatant
: unresponsiveness to platelet transfusions owing to HLA-specific or plateletspecific antibodies or platelet destruction from fever or sepsis.
Refractoriness
is measured by posttransfusion platelet counts.
Responsiveness
: set of linked genes inherited together because of their close proximity on a chromosome.
Haplotype
: different forms of a gene present at a particular chromosomal locus.
Alleles
: genetic system that expresses several possible alleles at specific loci on a chromosome.
Polymorphic
: antibody destruction of a newborn’s platelets caused by antibodies formed from prior pregnancies and directed to paternal antigens.
Neonatal alloimmune thrombocytopenia
: antibodies with specificities other than self; stimulated by transfusion or pregnancy.
Alloantibodies
: antibody destruction of platelets after transfusion.
Posttransfusion purpura
