ABO/Rh/Genetics

Question 1

What naturally occurring antibody always appears in the serum of an Rh positive individual?

Answer 1

None

very rarely anti-E or anti-Cw

Question 2

Purpose of washing red blood cells

Answer 2

Eliminates serum proteins

Question 3

What happens when a patient receives multiple units of compatible blood type different from their own?

Answer 3

Patient may show mixed cell populations

May temporarily type as Rh negative

Question 4

What other reaction is interpreted as a positive reaction if using serum (not plasma)?

Answer 4

Hemolysis

Question 5

Where are the red cell antigens found?

Answer 5

Surface of the red cell

Question 6

Homozygous

Answer 6

Identical alleles are inherited at a given locus

Ex. cc

Question 7

Genotype

Answer 7

The actual genes on the chromosome

Ex. AO

Question 8

Phenotype

Answer 8

The expression of the genotype

Ex. A

Question 9

Prozone

Answer 9

Excess antibody which discourages or stops the bridging between antibody-antigen complex to form agglutination

Question 10

Dominant

Answer 10

A trait or characteristic that will be expressed even though it is on only one of a chromosome pair
Ex. A

Question 11

Recessive

Answer 11

A gene that will not be expressed if its dominant allele is present, it will be expressed in homozygous state only
Ex. O

Question 12

Cis

Answer 12

Alleles on the same chromosome

Ex. DCe/dce

Question 13

Trans

Answer 13

Alleles on different chromosomes

Dce/DCe

Question 14

Heterozygous

Answer 14

Two different alleles - one on each individual chromosomes

Ex. Fya and Fyb

Question 15

Paragloboside

Answer 15

Precursor for H antigen

Question 16

Paragloboside + fucose

Answer 16

H antigen (precursor for A and B)

Question 17

4+ agglutination reaction

Answer 17

One large agglutinant

Question 18

3+ agglutination reaction

Answer 18

Several large agglutinants

Question 19

2+ agglutination reaction

Answer 19

small agglutination with clear backround

Question 20

1+ agglutination reaction

Answer 20

fine agglutination with red background

Question 21

Causative agent of intravascular transfusion reaction

Answer 21

IgM antibody that has a broad thermal range of activity

Question 22

Consequence of intravascular transfusion reaction

Answer 22

Complement proceeding to lysis of donor RBCs (intravascular hemolysis)

Question 23

Causative agent of extravascular transfusion reaction

Answer 23

IgG antibody

Question 24

Consequence of extravascular transfusion reaction

Answer 24

Antigen (RBC) and antibody complex removed slowly in spleen

Question 25

What is the first thing you do if you find an ABO/Rh typing discrepancy?

Answer 25

Repeat testing

Question 26

Order of decreased in H substances

Answer 26

O > A2 > B > A2B > A1 >A1B > >Oh

Question 27

Which blood type would be most likely to make anti-H?

Answer 27

A1B because it has the least H on surface. Seen as foreign

Question 28

Antigen: patient RBCs Antibody: purchased reagent

Answer 28

Front testing

Question 29

Antigen: purchased RBCs Antibody: patient serum

Answer 29

Reverse testing

Question 30

Antigen: patient RBCs Antibody: purchased reagent + potentiator

Answer 30

D tube testing

Question 31

Antigen: patient RBCs Antibody: none + same potentiator as D tube

Answer 31

Rh control tube

Question 32

What antibody class is naturally occuring ABO antibodies?

Answer 32

IgM

Question 33

What temp does IgM antibodies react at?

Answer 33

Broad thermal range. Reacts at 4 degrees, room temp (24 degrees), and body temp (37 degrees)

Question 34

What blood group has H antigen missing?

Answer 34

Bombay

Question 35

H specificity sugar

Answer 35

Fucose

Question 36

A specificity sugar

Answer 36

N-acetylgalactosamine

Question 37

B specificity sugar

Answer 37

D-galactose

Question 38

When can ABO antibodies first be detected?

Answer 38

3-6 months

Question 39

Lectins

Answer 39

Plant proteins that act like particular antibodies

Question 40

Lectin for anti-A1

Answer 40

Dolichos biflorus

Question 41

Lectin for anti-H

Answer 41

Ulex europaeus

Question 42

What determines the specificity of A and B antigens?

Answer 42

Terminal sugars attached by the inheritance of transferases

Question 43

What genes are involved to determine if a person has H antigen?

Answer 43

Hh

Question 44

What genes are involved to determine if a person is a secretor or not?

Answer 44

Sese and Hh

Question 45

What is the difference in the precursor molecule between an A, B, H, antigen and A, B, H substance?

Answer 45

Substances are glycoprotein | Antigens are glycolipids

Question 46

Purpose of using lectin for anti-A1 and anti-H

Answer 46

Typing A1 and A2 individual donors

Question 47

How to determine if a patient is A1 or A2

Answer 47

Use anti-A1 lectin (Dolichos biflorus)

Question 48

Substances found in saliva of type A secretors

Answer 48

A, H

Question 49

Substances found in saliva of type B secretors

Answer 49

B, H

Question 50

Substances found in saliva of type AB secretors

Answer 50

A, B, H

Question 51

Substances found in saliva of type O secretors

Answer 51

H

Question 52

What ABH substances would be found in the saliva of nonsecretors?

Answer 52

None

Question 53

Why isn't the crossmatch tube showing agglutination if an Rh pos donor is crossmatched with an Rh neg recipient?

Answer 53

No antibody (anti-d) in recipient's blood to react with donor D antigen.

Question 54

Rh antigen that is always significant for transfusion purposes

Answer 54

D

Question 55

3 reasons for Rh typing to appear as weak D pos

Answer 55

Genetic Trans Mosaic

Question 56

Rh null

Answer 56

Patient does not have D, Cc, Ee antigens

Question 57

Rh deletion

Answer 57

Patient is missing Cc or Ee

Question 58

Rh mosaic

Answer 58

One or more the antigenic determines of the D antigen are missing.

Question 59

LW antigens

Answer 59

LWa, LWb, LW (silent)

Question 60

LW antibodies

Answer 60

Anti-LW may react with D pos cells & very weakly with d neg cells. Anti-LW reacts with cord cells whether the baby was Rh pos or neg

Question 61

Cw

Answer 61

Antigen present in 2% whites | Anti-Cw may be NRBC stimulated

Question 62

G

Answer 62

Antigen is an epitope present on most C & D pos RBCs. | Anti-G reacts like anti-C plus anti-D, truly only an antibody to a specific epitope that is present on both AGs.

Question 63

f

Answer 63

Antigen is on RBC surface if c, e is in the cis position on the chromosome

Question 64

rhi

Answer 64

Ce are in the cis position on the RBC.

Question 65

V

Answer 65

ce. | Found in 30% of African Americans

Question 66

VS

Answer 66

e | Another compound antigen seen in African Americans

Question 67

Rh control reagent

Answer 67

Suspension or potentiator used in anti-D reagent. Used to confirm that the agglutination with anti-D was because of an antigen-antibody combination

Question 68

How many antigens are in the Rh system?

Answer 68

About 50

Question 69

Which Rh antigens are the most likely to make non-red blood cell stimulated antibodies?

Answer 69

E, Cw

Question 70

Control for weak D testing

Answer 70

Indirect AHG

Question 71

When is it essential to do weak D testing?

Answer 71

For donors who initially typed as Rh negative

Question 72

Purpose of albumin

Answer 72

Enhances Rh reactions

Question 73

Purpose of LISS

Answer 73

Not as strong as albumin, but stays less sticky

Question 74

Two reasons why a patient may type as Rh positive and also have anti-D

Answer 74

Anti-LW | D mosaic

Question 75

Rh gene combinations in Native Americans

Answer 75

DCe

Question 76

Rh gene combinations in black populations

Answer 76

Dce

Question 77

Rh gene combinations in Caucasian populations

Answer 77

DCe

Question 78

Order of immunogenic strength of Rh antigens

Answer 78

D > c > E > C > e

Question 79

Which Rh antigens show dosage?

Answer 79

All but D

Question 80

how do the Rh antigens (DCcEe) react with enzymes?

Answer 80

All enhanced

Question 81

If a donor was DCe/dce and the recipient was dce/Dce, what are the possible antibodies that may be produced?

Answer 81

Anti-C

Question 82

If a patient has both anti-D and anti-C, what antibody combination is this called?

Answer 82

anti-G