Glossary IJK

• Idiotype: The variable portion of light and heavy immunoglobulin chains that is unique to a particular immunoglobulin molecule
• IgM anti - HBc: Antibody that is the first to appear in hepatitis B infection
• Immature B cell: A phase in the growth of B cells characterized by the appearance of complete immunoglobulin M (IgM) antibody molecules on the cell surface
• Immediate hypersensitivity: Reaction to an allergen that occurs in minutes and can be lifethreatening
• Immune adherence: The ability of phagocytic cells to bind complement - coated particles
• Immune checkpoint inhibitors: Monoclonal antibodies that enhance patients’ T - cell responses to tumors by blocking inhibitory pathways that inactivate T cells; examples include antibodies to CTLA - 4, PD - 1, and PD - L1
• Immunity: The condition of being resistant to infection
• Immunization: The process by which immunity is acquired
• Immunoblotting: A technique used to identify antibodies to complex antigens
• Immunochromatography: A rapid technique in which the analyte is applied at one end of a strip and migrates toward the distal end, where the results can be visualized in minutes
• Immunodeficiencies: Inherited or acquired disorders in which a part of the body’s immune system is missing or dysfunctional
• Immunoediting: The ability of tumor cells to escape immune surveillance through suppression of immunogenicity
• Immunofixation electrophoresis (IFE): A semiquantitative gel precipitation technique in which proteins are first separated by electrophoresis, then incubated with antibodies to individual proteins that are added directly to the gel surface; used commonly to identify monoclonal immunoglobulins
• Immunofluorescence assay (IFA): Test used to identify cellular antigens or antibodies to those antigens using an antibody with a fluorescent tag
• Immunogen: Any substance that is capable of inducing an immune response
• Immunogenicity: The ability of an immunogen to stimulate a host response
• Immunoglobulin (Ig): Glycoproteins in the serum portion of the blood that are a major component of humoral immunity
• Immunohistochemistry: The use of labeled antibodies to directly detect tumor markers in tissue
• Immunologic diversion: A mechanism by which parasites enhance their survival in the host by inducing the production of proteins that divert the attention of the immune system
• Immunologic subversion: A mechanism by which parasites can avoid the effector mechanisms of the immune response by producing proteins that act as homologues of various components of the immune system
• Immunologic tolerance: A state of immune unresponsiveness directed against a specific antigen
• Immunology: The study of the reactions of a host when foreign substances are introduced into the body
• Immunometric assay: An immunoassay in which antibody to the target antigen is bound to the solid phase; also known as a capture or sandwich immunoassay
• Immunophenotyping: Identifying cells according to their surface antigen expression
• Immunoprophylaxis: The use of immunization to prevent disease.
• Infectivity: An organism’s ability to establish an infection; the proportion of individuals exposed to a pathogen through horizontal transmission (i.e., person-to-person contact) who will become infected
• Indirect ELISAs: Enzyme immunoassays that detect an antibody in the test sample using a labeled antibody reagent
• Intrinsic parameter: Light-scattering properties that are a part of the cell, such as size and granularity
• Indirect antiglobulin test (IAT): A laboratory method that detects in vitro binding of antibody to red blood cells (RBCs); it is used in the crossmatching of blood to prevent a transfusion reaction
• Interferons (IFNs): Cytokines produced by T cells and other cell lines that inhibit viral synthesis or act as immune regulators.
• Inflammatory myopathies (IMs): A group of systemic autoimmune diseases characterized by chronic inflammation of the skeletal muscles and progressive muscle weakness
• Infection control: Procedures used to control and monitor infections occurring within health-care facilities
• Invariant chain: A protein that associates with human leukocyte antigen (HLA) class II antigens shortly after they are synthesized to prevent interaction of their binding sites with any endogenous peptides in the endoplasmic reticulum
• Indirect immunofluorescence (IIF) assay: A technique to identify antigen by using two antibodies: one that is specific to the antigen and a second that is an anti - human immunoglobulin with a fluorescent tag
• Isograft (syngeneic graft): Graft that involves the transfer of tissue between two genetically identical members of the same species
• Innate lymphoid cell (ILC): Family of cells that contribute to innate immunity and tissue remodeling; ILCs develop from the common lymphoid progenitor and have lymphoid morphology but do not possess antigen-specific receptors
• Indirect allorecognition: Pathway by which the immune system recognizes foreign human leukocyte antigen (HLA) proteins on a donor graft; it involves the uptake, processing, and presentation of foreign HLA proteins by the recipient’s antigen - presenting cells (APCs) to recipient T c ells to produce antibodies and cell - mediated responses against the graft
• Interleukin (IL): A group of cytokines produced by leukocytes and other cells that regulate adaptive immune responses and the inflammatory process
• Indigenous microbiota: Symbiotic microorganisms that reside on and colonize the surfaces of an individual, also known as normal flora
• Inflammasome: A protein oligomer that contains caspase enzymes and other proteins associated with apoptosis; it may be defective in some autoinflammatory disorders