Immunohematology and Blood Banking Flashcards

Vocabulary flashcards covering key terms in basic genetics, blood group systems, blood preservation, donor selection, apheresis, pre-transfusion testing, and transfusion reactions based on the lecture notes.

Dosage Effect

The phenomenon where a homozygous genotype expresses more antigen on red blood cells than a heterozygous genotype.

Genotype

The total genetic composition of an individual, representing maternally and paternally derived genes.

Phenotype

The detectable or physically expressed characteristics of an individual's genes.

Heterochromatin

Chromatin regions that stain as dark bands during chromosome analysis.

Achromatin

Chromatin regions that stain as light bands, consisting of highly condensed regions that are usually not transcriptionally active.

Eurochromatin

The swollen form of chromatin in cells that is considered to be more active in the synthesis of RNA for transcription.

Transcription

The cellular process by which one strand of duplex DNA is copied into RNA.

Translation

The cellular process by which RNA transcripts are turned into proteins and peptides, the functional molecules of the cell.

Meiosis

The process of cell division unique to gametes (ova and sperm) that produces four unique daughter cells with genetic variability.

Mitosis

The process of replication in nucleated body cells (except ova and sperm cells).

Amorph

A silent gene (such as the O gene) that does not produce a detectable antigen product.

Bombay Phenotype (Oh)

A rare blood group phenotype characterized by the absence of H, A, and B antigens due to inheriting a homozygous recessive mutation in the FUT1 gene ($hh$ genotype).

Secretor Status

The condition governed by SeSe or Sese genes in which an individual expresses soluble ABH antigens in body secretions such as saliva.

Chimerism

The presence of two distinct cell populations within a single individual, naturally occurring in twins and rarely found otherwise.

Wharton's Jelly

A viscous mucopolysaccharide material present on cord blood cells that can cause false red blood cell aggregation during testing.

Cis AB Phenotype

A rare genetic condition where both A and B genes are inherited on a single chromosome from one parent, resulting in offspring inheriting three ABO genes instead of two.

Rhnull Syndrome

A rare condition in which red blood cells lack all Rh system antigens ($---/---$), leading to mild compensated hemolytic anemia and stomatocytosis.

Compound Antigen

An antigen expressed on the RBC membrane only when two specific alleles are inherited on the same haplotype, such as the f antigen ($ce$).

RBC Storage Lesion

The cumulative biochemical changes that occur when blood is stored in a liquid state, including decreased ATP, $2,3\text{-DPG}$, and pH, and increased plasma potassium and lactic acid.

Deglycerolization

The process of removing glycerol cryoprotectant from thawed red blood cells by washing with decreasing concentrations of saline before transfusion.

Transfusion-Related Acute Lung Injury (TRALI)

An acute, life-threatening transfusion reaction caused by donor anti-leukocyte antibodies, presenting with severe hypoxemia and non-cardiogenic pulmonary edema within 6 hours of transfusion.

Transfusion-Associated Circulatory Overload (TACO)

A non-immunologic transfusion complication caused by excessive volume or rapid infusion, resulting in acute congestive heart failure and pulmonary edema.

Zeta Potential

The difference in charge density between the inner and outer layers of the ionic cloud surrounding red blood cells in suspension, causing mutual repulsion.

Major Crossmatch

Serologic testing in which donor red blood cells are mixed with recipient serum or plasma to detect ABO incompatibility and unexpected antibodies.

Minor Crossmatch

Serologic testing in which donor serum or plasma is mixed with recipient red blood cells.

High Titer, Low Avidity (HTLA) Antibodies

Antibodies that react weakly at high dilutions of serum and exhibit faint agglutination strength regardless of concentration.

Polyagglutination

A condition where modified red blood cells are agglutinated by a large proportion of normal, ABO-compatible adult human sera.

Autologous Donation

The process wherein an individual donates their own blood for anticipated personal use during a future procedure or surgery.

Therapeutic Plasma Exchange (TPE)

An apheresis procedure that removes patient plasma containing pathologic substances and replaces it with replacement fluids.