Lecture 3: ABO Blood Groups Flashcards

1
Q

Name and Construct antigens on the Red Cell in the ABO system: A, B, H antigens

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Carbohydrates on the outside serve as _________ for macrophages to recognize and discard the cells as necessary.

A

receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Carbohydrates on the outside of the cell can be ________ or straight but if they are arranged in a specific format they are called Type ___ Substance.

A

branchy, 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Any _____ ___ substance are red cells, endothelial cells, platelets, lymphocytes and epithelial cells.

A

type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Given an ABO blood type, determine which antigens and antibodies would be expressed serologically in the patient.

What is the interpretation of:
anti-A: Pos
anti-B: Neg
anti-A, B: Pos

A

Interpretation: A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the interpretation of:
anti-A: Neg
anti-B: Pos
anti-A, B: Pos

A

B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the interpretation of:
anti-A: Pos
anti-B: Pos
anti-A, B: Pos

A

AB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the interpretation of:
anti-A: Neg
anti-B: Neg
anti-A, B: Neg

A

O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ABO gene codes for a _________ that adds a sugar to the end of ___ substance on the red cell.

A

transferase, H

-If a stop codon is in the gene, no transferase is created, no sugar added and the patient is type O.
-A transferase adds the sugar N-acetyle-galactosamine
-B transferase adds the sugar Galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

A transferase

A

N-acetyle-galactosamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

B transferase

A

Galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Does type O blood have transferase?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the % of US population frequencies between phenotypes O, A, B, AB?

A

O: 50%
A: 35%
B: 15%
AB: 5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

2 genes make a ________

A

Phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

H gene codes a _______ transferase that adds a fucose to the outer most sugar of a type 2 or type 1 precursor chain.

A

fucosyl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The more H substance that is transferred to an A or B antigen, the _____ detectible it is.

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Rank these in order of the highest H antigen express to the less antigen expressed

O, A2, B, A2B, A1, A1B

A

O> A2>B>A2B>A1>A1B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The immunodominant sugar responsible for group B specificity is

a) N-acetyl galactosamine
b) D-Galactose
c) Fucose
d) N-acetyl glucosamine

A

b) D-Galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

**What is the most common cause of the following results?

Anti-A: 3+mf, Anti-B: 4+, A1 cell: 0, B cell: 0

a) bacterial infection
b) transfusion
c) hemolytic disease of the newborn
d) immunocompromised

A

b) transfusion

When you have mixed field, this means that you have 2 cell populations in one tube or person. How would you get 2 cell populations in one person? By transfusion, is the most common.

A3 is another cause, but it is not common. Bacterial infection is a cause, but it is not common. Another answer that was correct is that you could have had less reactive in your reverse type which would be from the immunocompromised patient. HDN can also cause mixed field, b/c if there is a significant fetal bleed you will have another population of cells that shows up in the mother’s circulation. That’s usually a really bad sign, not common.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

**Acquired B antigens are found in which individuals?

a) Bombay individuals
b) Group O persons
c) All blood groups
d) Group A persons

A

Group A persons

The rest of the other people do not have that.

The science of acquired B:
-Bacteria (E.coli) have a deacetylating enzyme that effects the A sugar.
-Bacteral enzyme removes the acetyl group
-Thus Galactosamine now resembles D-galactose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which blood type should NOT result from the union of an AB make to an O female?

a) A
b) B
c) O
D. None of these

A

c) O

22
Q

A child is blood typed as A, their mother is blood type B, what blood type must the father be?

a) A
b) B
c) O
d) Bombay

A

a) A

23
Q

Which of the following statements is true?

A. An individual with AO genotype is homozygous for A.
B. An individual with BB genotype is homozygous for B
C. An individual with OO genotype is heterozygous for O
D. An individual with AB genotype is homozygous for A and B

A

B. An individual with BB genotype is homozygous for B.

24
Q

What blood type is the following patient?

Anti-A: 0, Anti-B: 4+ , A1 cell: 4+, B cell: 0

a) A
b) B
c) O
d) AB

A

b) B

25
Q

Which subgroup do you suspect from the following results?

Anti-A: 0, Anti-B: 1+ mf, Anti-A, B: 1+mf, A1 cell: 3+, B cell: 0

a) A2
b) A3
c) B3
D) Bel

A

C. B3

26
Q

An ABO type on a patient gives the following results, what is your next step?

Anti-A: 4+, Anti-B: 0, A1 cell: 0, B cell: 0

a) Reverse type with A2 cells
b) Forward type with Anti-A,B
c) Forward Type with A1 lectin
d) inculcate at 4C for 5-10 minutes

A

d) incubate at 4C for 5-10 minutes

Give the IgMs what they want.

27
Q

Bombay people still have __, __, __ genes that they may transfer to their offspring they just don’t exhibit the antigens themselves.

A

A, B, O

28
Q

Autosomal Recessive hh genotype produces no ___ antigen meaning no ABO antigens can be formed on red cells

A

H

-Most likely mutation of FUT1 gene that silences the gene from expressing fucosyltransferase

29
Q

Parabombay phonotypes have red cells completely devoid of ___ antigen and still exhibit small amounts of __ or ___ antigen.

A

H, A, B

-Most likely a mutated FUT1 gene that makes a fucosyltransferase with very low activity
-All H antigen available is converted to A or B by the normal acting A or B transferase
-Or FUT2 is functional

30
Q

define Bombay

A

Absence of H antigen

31
Q

If fewer branch H substances are transferred to A or B, the patient may appear as a weaker version of the blood type. (__________)

A

Sub group.

-Subgroup is more common in type AB blood group.

32
Q

If only one type of H substance is transferred in the patient then if a patient sees a transferred other form (through transfusion ) it may appear as foreign. Thus an _____ can form

A

antibody

33
Q

What are the most common A phenotypes?

A

A1 and A2

34
Q

Subgroup people have ______ less antigen converted from H substance.

A

quantitatively

-Described by serological activity.
-May make an antibody against the most common expression of the antigen
-A sub groups are more common than B.

35
Q

Red Cell Reactions with anti-A and/or anti-A, B what are the possible A phenotypes that have
- no agglutination
-adsorbs and elutes anti-A

A

Am, Ay, Ael

Am - (1. anti-A easily absorbed and eluted, 2. secretors demonstrate quantities of A substance in saliva)
Ay - (1. anti-A adsorbed and eluted, 2. secretors contain small amount of A substance in saliva)
Ael (1. anti-A absorbed and eluted 2. secretors contain only H substance and no A substance in saliva

36
Q

Red cell reactions with anti-A and/or anti-A, B, what are the possible A phenotypes that have
-weakly agglutinated

A

A3, Ax, Aend

A3- mixed field (mf) agglutination
Aend - <10% red cells show very weak mf agglutination
Ax - weak agglutination with anti-A, B only

37
Q

You would use Ulex euorpaeus reagent to investigate what?

a) A subgroup
b) B subgroup
c) Potential Bombay
d) Cold agglutinin

A

c) Potential Bombay

Serologically appear as type O, but also fail to react with Ulex Eruopaeus (H lectin)

38
Q

Which blood type has the most amount of H substance?

a) A1
b) B
c) AB
d) O

A

d) O

When a sugar is added at the end, it no longer has an H.
-O has the most.
-AB has the least.
-A1 has the second least, but it does a better job than B

O>A1>B

39
Q

B Subgroup: B-

A

-very efficient transferase activity
-Strong serological activity
-Detected by bandeirasea simplicifolia lectin
-600,000 - 800,000 antigens on the cell

40
Q

B Subgroup: B3

A

-characterized by mixed filed with anti-B and anti-A, B.
-Weak glycosyltransferase
-does not make anti-B

41
Q

B Subgroup: Bx

A

-reacts weakly with anti-B and anti-A,B
-Does not have detectible amounts of glycosyltransferase.
-Usually makes a weakly reactive anti-B

42
Q

B Subgroup: Bm

A

-transferase is detectable but does not actively work well
-normal amounts of B substance is on secretions and no anti-B is detected.
-(More frequent in Japan)

43
Q

B Subgroup: Bel

A

-must be detected by adsorption and elution studies.
-weak anti-B may be present but B is not in secretions

44
Q

What does these lectins detect?

a) Dolichos biflorus
b) Bandeiraea simplicifolia
c) Ulex europeaus

A

a) detects A1
b) detects B
c) detects H

45
Q

CIS-AB:
-have A and B transferases that are inherited on the _______ chromosome

A

same.

-Can pass AB blood type with an O mate.
-rare splicing anomaly.

46
Q

Alternative antiges:

The B(A) patient: the transferase is able to do _____, but prefers to transfer ________.

A

both, galactose

-genetic variant of the B gene
-Mostly found by polyclonal anti-sera

47
Q

Alternative antiges:

The Acquired B patient is part of the ________ ____

A

Group A1.

-Cancer of colon/rectum or
-intestinal obstruction
-gram negative septicemia
-mostly apparent with acidified anti-sera.

48
Q

This is an example of acquired __?

Anti-A: 4+
Anti-B: 1+
Anti-A,B: 4+

A

acquired B

49
Q

Why is the ABO system so important?

A

Antibodies.

ABO is the ONLY system that the reciprocal antibodies (antitheitcal) are consistent and predictable and these are present in the plasma of humans that never had been exposed to other human antigens (naturally occurring antibodies)

50
Q

The ABO group shall be determined by testing the red cells with anti-__ and anti-____ reagents and by testing the serum or _______ for expected ________ with A1 and B reagents red cells.

A

anti-A, anti-B, plasma, antibodies

51
Q

Anti-A1 lectin is QC’s everyday of use. It is used today, what two reagent

A