Immunohematology Lecture - ABO Blood Group Systems

Flashcards covering key vocabulary and concepts related to the ABO blood group system and immunohematology.

Antigen (Ag)

Substances recognized as foreign by the immune system, eliciting immune responses.

Antibody (Ab)

Immunoglobulins developed in response to antigens, produced by activated B lymphocytes.

Heteroantibodies

Antibodies derived from antigens originating from another species (e.g., animal to human).

Alloantibodies

Antibodies made in response to antigens from individuals of the same species, often seen in transfusion reactions.

Autoantibodies

Antibodies directed against the body's own antigens.

Immunoglobulin G (IgG)

A major class of antibodies that is clinically significant and can cross the placental barrier.

Immunoglobulin M (IgM)

A type of antibody that is a pentamer, does not cross the placental barrier, and is effective in agglutination.

ABO System

A blood group system defined by the presence of A and B antigens on the surface of red blood cells.

Formation of Antigens

ABO antigens are formed through the actions of glycosyltransferases that attach specific sugars to red blood cell surfaces.

Type A Antigen

Characterized by the presence of N-acetylgalactosamine and produced by the A gene.

Type B Antigen

Characterized by the presence of D-galactose and produced by the B gene.

Bombay Phenotype

Phenotype characterized by the absence of H antigen and the presence of the genotype hh.

Forward Typing

A blood typing method that detects the presence of antigens using known antibodies.

Reverse Typing

A confirmatory blood test that verifies ABO blood group through the presence of antibodies.

Sephadex Gel Matrix

A gel used in blood typing to separate agglutinates based on size.

Grading of Agglutination

A method of evaluating agglutination ranging from no agglutination (0) to one solid agglutinate (4+).