BB 1: Genetics, Immuno, Reagents

what inheritance pattern is described below:

• trait appears whenever the allele is present

• e.g., either homozygous or heterozygous

• found in each generation of family in males and females

autosomal dominant

what inheritance pattern is described below:

• must be homozygous genotype to express trait

• both parents must be heterozygous to express trait

autosomal recessive

what inheritance pattern is described below:

• in heterozygous genotype, both alleles are equally expressed

• most common pattern found in human blood groups

codominant

what inheritance pattern is described below:

• male carries trait on X chromosome

• all his daughters will have the trait

• female offspring will have a 50/50 chance of inheriting the trait and is expressed

sex linked dominant

what inheritance pattern is described below:

• male carries trait on X chromosome

• none of a male carrier’s sons will have the trait

sex linked dominant

what inheritance pattern is described below:

• father will always express the trait

• none of his sons will have the trait

sex linked recessive

what inheritance pattern is described below:

• father will always express the trait

• all daughters will be carriers

  • half of her sons will express the trait

  • half of her daughters will get the trait if a rare match to another carrier resulting in homozygous female with the trait being expressed

sex linked recessive

____ is a chromatid containing the genes from the parent and offspring acquire these from each parent.

haplotype

what result of relationship testing refers to the exclusion if paternity when a child has a trait that neither parent demonstrates?

direct exclusion

what result of relationship testing refers to the failure to find an expected marker in a child when the alleged father is apparently homozygous for the gene?

indirect exclusion

in relationship testing, what refers to the gene that should be inherited from the father to prove paternity?

obligatory gene

what is the result of relationship testing:

• child has a trait present that neither parents posses

• child group B: B/O or B/B

• mom group O: O/O

• alleged dad group A: A/A or A/O

direct exclusion

what is the result of relationship testing:

• child lacks a gene that should be inherited from the parent in question

• child Jk(a+b-): Jka/Jka

• mom Jk(a+b-): Jka/Jka

• alleged Jk(a-b+): Jkb/Jkb

indirect exclusion

what is the result of relationship testing:

• when the child has the predictable traits that are expected from the parent in question

inclusion

the following are examples of _____.

• ABO

• Kell

• Rh

• Duffy

• MNSs

• Kidd

RBC antigens

the following are examples of _____.

• PGM1

• Hp

• ACP

• Gc

• ESD

RBC enzymes and serum proteins

the following are examples of _____.

• Gm

• Km

• Am

immunoglobulin allotypes

the following are examples of _____.

• A and B loci

  • class I; CD8 T lymphs

• DR locus

  • class II; CD4 T lymphs

HLA

what law refers to the statistical formula developed to calculate gene frequencies in a population? p² + 2pq + q²

hardy weinberg law

in the hardy weinberg law, in the equation p² + 2pq + q², “p” refers to the ____ allele.

dominant

in the hardy weinberg law, in the equation p² + 2pq + q², “q” refers to the ____ allele.

recessive

which type of class/hypersensitivity category is most commonly dealt with in the blood bank?

II

the ____ refers to the foreign substance that, when entered to the body, elicits the body to form an antibody that defends the body.

antigen

_____ only occurs when the complement (C’) pathway has been completed.

hemolysis

which immunoglobulin type is described below:

• large Ig pentamer

• does not pass placenta

IgM

which immunoglobulin type is described below:

• readily binds complement

• reacts at RT or lower

• usually seen in the first phase of antibody detection testing (e.g., IS)

IgM

which immunoglobulin type is described below:

• small Ig monomer (single Y shaped)

• passes placenta barrier

• reacts at 37°C or at AHG test phase of antibody detection testing / ABS (antibody screen)

IgG

which immunoglobulin type accounts for 80% of Igs present in the sera?

IgG

list the following IgG subtypes from MOST to LEAST readily available to bind complement.

• IgG1, IgG2, IgG3, IgG4

IgG3 > IgG1 > IgG2 > IgG4

primary and secondary/amnestic responses are the 2 phases of the ____.

humoral response

which phase of the humoral response is described below:

• lag time ~5-7 days greater

• IgM antibody is produced 1st, followed by IgG antibody

primary response

which phase of the humoral response is described below:

• lag time ~1-2 days

• IgG antibody is produced

  • often no IgM antibody because this exposure was not the first time the body recognized the antigen

secondary/amnestic response

_____ takes place in a 2 stage process involving:

• sensitization (Ab uptake)

• lattice formation (agglutination)

hemagglutination

_____ is dependent on the activation of binding complement and completion of activation pathway and is considered a “positive reaction.”

hemolysis

which phase of hemagglutination is described:

• binding stage of the antibody to the antigen

sensitization

the following are factors that may influence the _____ reaction phase of hemagglutination:

• serum to cell ratio (aka serum:cell ratio or SC ratio)

• temperature

• time

• pH

• ionic strength

• affinity/Ab uptake

• Ig class

sensitization

the following are factors that may influence the _____ reaction phase of hemagglutination:

• distance between RBCs

• zeta potential

• optimal concentrations of Ab and Ag

  • prozone

  • zone of equivalence

  • postzone

• effect of centrifugation

• size of Ig (IgM v. IgG)

• the # of binding sites on RBC

lattice formation

for hemagglutination, visible agglutination can occur due to the large pentameric shaped molecule and ability to form a lattice if the antibody is ____.

IgM

for hemagglutination, no visible agglutination is observable due to small Y-shaped molecule where a lattice cannot be achieved if the antibody is ____.

IgG

antigen-antibody complexes (pathogen surfaces) enable the start of the ____ pathway for complement.

classical

what components of the classical pathway of complement refer to peptide mediators of inflammation and phagocyte recruitment?

C3a; C5a

what component of the classical pathway of complement punctures the RBC membrane for RBC hemolysis?

C9

rouleux and its increased proteins may cause RBCs to clump and stack resulting in a false ____ result.

positive

what term is commonly used to describe the two cell population of “mixed field agglutination?”

chimera

____ is best describe as an island of agglutinates in a sea of free cells.

mixed field

____ refers to the presence of two different cell populations.

mixed field

what reagent possesses Abs to know specificity?

reagent antisera

what reagent possesses Ags to know specificity?

reagent RBCs

for reagent antisera, ABO anti-A is the color ____.

blue

for reagent antisera, ABO anti-B is the color ____.

yellow

for reagent antisera, ABO anti-A,B is the color ____.

clear

other reagent antisera than ABO is often clear or albumin (yellowish). true or false?

true

what reagent detects IgG and/or C’ on RBCs?

antiglobulin reagent

which antisera refers to several different clones of B cells that secrete antibody?

polyclonal antisera

which antisera refers to single clones of B cells that secrete one antibody?

monoclonal antisera

____ refer to reagents that may:

• enhance antibody uptake (1st stage of agglutination)

• promote direct agglutination (2nd stage of agglutination)

• serve both

antibody potentiators

the following 4 are the major types of ____ used in blood bank:

• BSA: bovine serum albumin

• LISS: low ionic strength solution

• PEG: polyethylene glycol

• polybrene

antibody potentiators

which antibody potentiator is described below:

• 22% albumin

• high molecular weight protein

BSA

which antibody potentiator is described below:

• reduces zeta potential by dispersing some cations surrounding each negatively charged red cell (2nd stage of agglutination)

• increases dielectric constant, defined as a measure of ability to dissipate a charge

BSA

which antibody potentiator is described below:

• does not enhance Ab uptake

• incubated for 30 minutes minimum

• may be an ingredient of another reagent

BSA

which antibody potentiator is described below:

• made of saline, glycine, albumin

  • glycine added to reagent to prevent lysis of RBCs at the low ionic strength

• shorter incubation time (10min minimum; 15-30min can be used)

LISS

which antibody potentiator is described below:

• creates a low ionic environment

  • lowers zeta potential

  • promotes Ab uptake by RBCs (speed, not quantity; 1st stage of agglutination)

• decreased ionic strength (0.3M) of saline (normal saline: 0.15M)

LISS

equal volume of serum and LISS is required. if there is extra serum, test ____ will decrease.

sensitivity

equal volume of serum and LISS is required. if there is extra LISS, nonspecific positive reactions will ____.

increase

which antibody potentiator causes agglutination by adjusting zeta potential between RBCs?

BSA

which antibody potentiator lowers zeta potential and increases the rate of Ab uptake?

LISS

which antibody potentiator concentrates the Ab in the test environment by removing water and is also a low ionic strength solution?

PEG

which antibody potentiator neutralizes the net negative charge of the RBC that causes a rapid Ab uptake to the RBCs and causes nonspecific RBC agglutination?

polybrene

list 2 enzymes that remove negative charges from the RBC membrane to reduce zeta potential.

papain; ficin

which antibody potentiator must you NOT centrifuge for a 37°C reading because the RBCs may aggregate?

PEG

which antibody potentiator is no longer used?

polybrene

what is the antigen specificity for the lectin Dolichos biflorus?

A1

what is the antigen specificity for the lectin Ulex europaeus?

H

AHG reagents aid in the visual hemagglutination of Ab-Ag binding occuring in which Ig Abs?

IgG

____ reagent is an antibody to antibody solution.

AHG

which AHG reagent contains Abs to both IgG and C3?

polyspecific

which AHG reagent is commonly used for DAT?

polyspecific

if a polyspecific AHG is used for a DAT and it is positive, you must retest the DAT using monospecific AHG reagents. true or false?

true

which AHG reagent contains Abs to either IgG or C3 where each item is in its own individual vial?

monospecific

monospecific reagents are used when the polyspecific AHG reagent gives a negative reaction. true or false?

false

which AHG reagent is commonly used specifically for performing the antibody screen?

monospecific

anytime you are using the AHG reagent and you get a ____ result by the tube method, you MUST:

• add Coombs’ control cells/check cells (CC), mix, spin, and read

• the resulting reaction must be positive (2+ or greater)

negative