Antibody Screening and Identification Lecture Review

Comprehensive vocabulary flashcards covering antibody types, testing phases, reagents, and the process of antibody screening and identification in immunohematology.

IgM

The immunoglobulin that gives the strongest agglutination to saline and typically reacts at ambient temperature (22-24°C).

Alloantibodies

Antibodies produced after exposure to nonself (foreign) components, often through transfusion, transplantation, or pregnancy.

Autoantibodies

Antibodies produced in response to self-antigens, directed against the individual's own red cells.

Naturally-occurring alloantibody

An antibody produced through exposure to the environment rather than through red cell exposure.

Passive immunity

The type of immunity acquired when antibodies are produced in one individual and transmitted to another via plasma-containing blood components.

Immediate spin (IS)

The testing phase where reactants are centrifuged immediately at room temperature to detect IgM antibodies.

Thermal Phase (TP)

A testing phase involving incubation at 37°C where IgG antibodies typically react.

AHG (Antihuman Globulin)

A reagent used to act as a bridge between antibodies sensitizing red cell antigens; used specifically to detect incomplete or non-agglutinating IgG antibodies.

Clinically significant alloantibodies

Antibodies (mostly IgG in nature) that cause decreased RBC survival by reacting at 37°C or the AHG phase, leading to hemolysis.

AABB

Standards for Blood Banks and Transfusion Services; requires antibody screening and identification for pre-transfusion testing.

Potentiators (Enhancement Media)

Reagents such as LISS, PEG, and albumin added to the test system to shorten incubation time and facilitate antibody-antigen attachment.

PEG

The most used and preferred enhancement reagent for shortening reaction time in antibody screening.

Coombs Check Cells (CC)

D-positive RBCs coated with anti-D IgG used to confirm that AHG reagent was added and is functioning properly in negative reactions.

Group O cells

The type of red cells used for reagent screen cells to ensure no interference from A or B antigens.

Dosage Effects

A phenomenon where antibodies react stronger to antigens that are homozygously expressed compared to those that are heterozygously expressed.

Homozygous

A state where an individual has inherited a double dose of a gene allele, such as Jk(a+b-).

Heterozygous

A state where an individual has inherited different alleles, such as Jk(a+b+), resulting in a single dose of each antigen.

Autocontrol (AC)

A testing procedure where the patient's serum is reacted with their own red cells to determine if autoantibodies are present.

High-prevalence antigen (HPA)

Antigens present in the majority of the population; antibodies against these are rare due to infrequent exposure.

Low-prevalence antigen (LPA)

Rare antigens that are present in a very small percentage of the population.

Anti-U

An antibody to a rare phenotype in the MNS blood group system specifically found in African populations.

Rule of Three

A standard for antibody identification requiring that the suspected antibody reacts positively with 3 cells and negatively with 3 cells for statistical significance.

Exclusion

The process of eliminating suspected antibodies by examining ID cells that show negative reactions across all testing phases.

Neutralization

The process of using specific substances, such as Hydatid Cyst Fluid for anti-P1, to remove antibody interferences and confirm antibody identity.

Rouleaux

A false-positive agglutination appearance, common in patients with Multiple Myeloma, which can be dispersed by adding 2-3 drops of NSS.