Immunohematology Review Flashcards

Comprehensive vocabulary flashcards covering immunohematology concepts including antibody responses, blood groups, testing procedures, transfusion reactions, and donor criteria.

Primary Response

The immune response resulting from the first exposure to an antigen, characterized by a lag phase of days to months and initial IgM production.

Anamnestic Response

Also known as a secondary response; the immune response upon subsequent exposure to an antigen, featuring a shorter lag phase of hours and a faster, higher rise in IgG titer.

Isotype Switching

The process where the type of antibody produced switches from IgM to IgG, usually occurring after 2-3 weeks.

IgG Structure

A monomeric immunoglobulin with 2 antigen-binding sites that reacts best at $37^{\circ}\text{C}$ and can cross the placenta.

IgM Structure

A pentameric immunoglobulin with 10 antigen-binding sites that reacts best at $25^{\circ}\text{C}$ or lower and is more effective at inducing agglutination.

Hemolysis

A sign of an antigen-antibody reaction where the union activates complement, destroying the RBC membrane; it requires Ca²⁺.

Agglutination

The most common reaction seen in blood bank testing where antibodies form bridges between antigens on adjacent RBCs.

Mixed Field (mf)

A grading of agglutination characterized by some agglutinated RBCs in a sea of free RBCs.

Zeta Potential

The difference in charge between the negatively charged RBC surface and the cloud of positive ions that surround them.

Low Ionic Strength Solution (LISS)

An enhancement medium that facilitates antibody-antigen interaction by reducing ionic strength, lowering incubation time to 10 minutes.

Polythyleneglycol (PEG)

An additive that increases antibody uptake and is used for detecting and identifying weak IgG antibodies.

Enzymes (ficin, bromelin, papain)

Agents that reduce RBC surface charge by cleaving sialic acid; they destroy M, N, S, Fyᵃ, and Fyᵇ antigens.

Polyspecific Antihuman Globulin

A broad-spectrum serum used in DAT to detect both IgG and C3d.

Direct Antiglobulin Test (DAT)

A test used to detect in vivo sensitization of RBCs by IgG antibody; often used in the investigation of HDN and transfusion reactions.

Indirect Antiglobulin Test (IAT)

A test used to detect in vitro sensitization of RBCs; applied in antibody screens, crossmatches, and RBC phenotyping.

N-acetylgalactosamine

The terminal sugar that determines A antigen specificity.

D-galactose

The terminal sugar that determines B antigen specificity.

Rouleaux

An ABO discrepancy cause that can be resolved using saline replacement technique in reverse grouping.

Acquired B Antigen

A discrepancy usually associated with GI problems or septicemia; resolved by using human anti-B acidified to pH 6.0.

Fisher-Race: D

Corresponds to the Weiner nomenclature symbol Rho.

Fisher-Race: C

Corresponds to the Weiner nomenclature symbol rh'.

Fisher-Race: E

Corresponds to the Weiner nomenclature symbol rh''.

Fisher-Race: c

Corresponds to the Weiner nomenclature symbol hr'.

Fisher-Race: e

Corresponds to the Weiner nomenclature symbol hr''.

Rh Positive Frequency (Whites)

$85\%$.

R⁰ Genotype

A common Rh gene in Blacks ($44\%\text{ frequency}$) characterized by the antigens cDe.

Weak D Testing

Testing required for donors or prenatal patients when the initial Anti-D test is negative.

Kidd Antibodies

Antibodies that are labile in vivo and in vitro and are a common cause of delayed transfusion reactions (anamnestic response).

Anti-I

A cold antibody associated with Mycoplasma pneumoniae infections and cold agglutinin disease.

Anti-i

A cold antibody associated with infectious mononucleosis.

Anti-P

An antibody associated with paroxysmal nocturnal hemoglobinuria.

Antiglobulin Crossmatch

A test of recipient serum and donor RBCs through the IAT phase; required if the recipient has a history of clinically significant antibodies.

Major Crossmatch

A procedure that will detect ABO incompatibility and most antibodies, but will not detect Rh typing errors or ensure normal RBC survival.

Intravascular Hemolytic Reaction

The most serious transfusion reaction, usually due to ABO incompatibility, presenting with fever, shock, DIC, and renal failure.

Febrile Reaction

A transfusion reaction caused by anti-leukocyte antibodies; managed with leuko-poor RBCs and antipyretics.

Anaphylactic Reaction

A rare reaction caused by anti-IgA in an IgA-deficient recipient; requires washed RBCs for future transfusions.

Graft-versus-host Disease (GVHD)

A usually fatal condition where donor T lymphocytes attack the recipient; prevented by irradiation of cellular components.

Rh Immune Globulin (RhIG)

Anti-D derived from human plasma used to prevent D immunization; a standard dose is given for every $15\,\text{mL}$ of D-positive fetal RBCs.

Kleihaur-Betke Test

An acid-elution test used to quantitate fetal bleed; fetal cells resist acid elution and stain pink.

Allogeneic Donor Hemoglobin Requirement

$\ge 12.5\,\text{g/dL}$.

CPDA-1 Shelf-Life

$35\text{ days}$.

Adsol (AS-1) Shelf-Life

$42\text{ days}$.

Cryoprecipitate Contents

Must contain at least $80\,\text{IU}$ of Factor VIII and $150\,\text{mg}$ of fibrinogen.

Fresh Frozen Plasma (FFP) Storage

$\le -18^{\circ}\text{C}$ for $12\text{ months}$.

Blood Bank Refrigerator Temperature

Must be maintained between $1-6^{\circ}\text{C}$.