Blood Bank Chapters 12–14 | ASCP MLT High-Yield Review

High-yield vocabulary flashcards covering Hemolytic Disease of the Fetus and Newborn, donor eligibility and adverse reactions, and infectious disease screening methodologies for the ASCP MLT Blood Bank examination.

Hemolytic Disease of the Fetus and Newborn (HDFN)

A condition in which maternal IgG antibodies cross the placenta, bind to fetal red blood cells, and cause hemolysis or suppress fetal RBC production.

Anti-K

A clinically significant IgG red blood cell antibody that can suppress fetal erythropoiesis in addition to causing red blood cell destruction, whose maternal titers may correlate poorly with fetal disease severity.

ABO HDFN

A form of hemolytic disease that commonly occurs in a group O mother carrying a group A or B fetus; unlike anti-D HDFN, it can occur during a first pregnancy and is typically milder.

Kernicterus

Severe neurological damage resulting from toxic levels of unconjugated bilirubin crossing the immature blood-brain barrier in a newborn.

MCA Doppler (Middle Cerebral Artery Doppler)

A noninvasive ultrasound assessment tool for fetal anemia; a peak systolic velocity exceeding $1.5\,\text{MoM}$ is concerning for moderate-to-severe fetal anemia.

Cordocentesis

Percutaneous umbilical blood sampling performed to directly assess fetal blood parameters, such as hemoglobin or hematocrit, when clinically indicated.

Direct Antiglobulin Test (DAT)

An assay used to detect IgG antibodies and/or complement components that are already bound in vivo to a patient's red blood cells.

Indirect Antiglobulin Test (IAT)

An in vitro assay used to detect unexpected red blood cell antibodies free in serum or plasma using reagent red blood cells.

Rh Immune Globulin (RhIG)

A concentrated solution of human IgG anti-D administered to nonsensitized Rh-negative pregnant individuals to prevent immunization to the D antigen; a standard $300\,\mu\text{g}$ dose covers up to $30\,\text{mL}$ of fetal whole blood or $15\,\text{mL}$ of packed fetal RBCs.

Rosette Test

A qualitative screening test that utilizes anti-D reagent to detect the presence of D-positive fetal red blood cells in maternal Rh-negative circulation.

Kleihauer-Betke (KB) Test

A quantitative acid-elution procedure where fetal hemoglobin (HbF) resists acid elution and stays pink while adult hemoglobin (HbA) elutes to form ghost cells; used to quantify fetomaternal hemorrhage and determine the required number of RhIG vials.

Temporary Deferral

A donor eligibility status indicating that a donor is unable to donate for a specified waiting period or until recovery from a condition, such as low hemoglobin, recent illness, or travel exposure.

Indefinite Deferral

A donor eligibility status in which a donor cannot donate for an unspecified duration without a fixed return date, requiring formal reassessment of eligibility.

Permanent Deferral

A donor eligibility status indicating that an individual is completely disqualified from donating blood under applicable regulatory criteria due to confirmed, non-resolving safety conditions.

Allogeneic Donation

A blood donation collected from a donor intended for transfusion into another, unrelated recipient and entered into the general blood supply following mandatory testing.

Autologous Donation

A blood donation collected from an individual exclusively for their own anticipated future use.

Vasovagal Reaction

A donor collection adverse reaction characterized by pallor, sweating, nausea, dizziness, and fainting; managed by immediately stopping collection, placing the donor supine, and elevating their legs.

Citrate Reaction

An apheresis complication caused by citrate anticoagulant binding ionized calcium, producing symptoms of perioral tingling, finger paresthesia, chills, and muscle cramps.

Preoperative Autologous Donation (PAD)

An autologous blood collection method in which an individual donates units of their own blood weeks before a planned surgical procedure.

Acute Normovolemic Hemodilution (ANH)

An autologous blood preservation technique where whole blood is drawn from a patient immediately prior to surgery while intravascular volume is maintained using crystalloid or colloid replacement fluids.

Intraoperative Cell Salvage

An autologous blood recovery process where blood shed during a surgical procedure is collected, washed or filtered, and reinfused into the patient.

Plateletpheresis

An automated apheresis collection technique specifically designed to harvest platelets from a donor while returning the remaining blood components.

Sandwich EIA

An enzyme immunoassay format in which target antigen is captured between two antibodies, producing a measurable signal that is directly proportional to the amount of antigen present.

Indirect EIA

An enzyme immunoassay format designed to detect patient antibody by allowing it to bind an immobilized antigen on a solid phase, which is subsequently detected by an enzyme-labeled anti-human globulin reagent.

Competitive EIA

An enzyme immunoassay format where patient analyte competes with a labeled reagent target for binding sites; more patient target results in an inverse, reduced signal output.

Nucleic Acid Testing (NAT)

A molecular testing method that amplifies and detects viral genetic material (RNA or DNA), substantially narrowing the diagnostic window period compared to serological testing.

Window Period

The interval between initial exposure or infection with a pathogen and the earliest point at which laboratory assays can detect viral markers, antigens, or antibodies.

Diagnostic Sensitivity

The ability of an assay to correctly identify individuals who truly have the target condition or disease; mathematically defined as $\frac{\text{TP}}{\text{TP} + \text{FN}} \times 100$.

Diagnostic Specificity

The ability of an assay to correctly identify individuals who truly do not have the condition or disease; mathematically defined as $\frac{\text{TN}}{\text{TN} + \text{FP}} \times 100$.

Look-Back Investigation

The formal regulatory process of tracing prior blood donations, blood components, and potentially infected recipients after a donor is found to test positive for a transmissible blood-borne disease such as HIV or HCV.