ABO Blood Group System - Exam 1

Name the compatible plasma types for the blood groups (not type specific)

Type A: AB plasma Type B: AB plasma Type AB: AB plasma Type O: A, B, AB plasma

What is the A sugar called?

n-acetylgalactosamine

Name the compatible cell types for the blood groups (not type specific)

Type A: O cells Type B: O cells Type AB: A, B, O cells Type O: O cells

What blood groups do not show dosage?

A, B, AB, O ABO does not show dosage

What are the five blood types?

A, B, AB, O, ?

What percentage of people secrete antigen?

80%

What is the auto control composed of?

1 drop 3% cell suspension and 2 drops serum, both from the patient

At what age are adult levels of ABO present?

2-4 years.

What reaction grade should forward typing have? Reverse typing?

4+ for forward 3+/4+ for reverse.

What age are ABO antigens able to be detected?

5-6 weeks of gestation, but low quantity of antigen.

What antibodies and antigens do type AB people have?

A and B antigen No anti-A or anti-B

Explain how A and B are expressed (H gene)

A and B replace a part of the H sugar with the A and B sugar. When the H gene is not modified the person is type O.

What are the genotypes for the four major ABO blood groups?

A: AA, AO B: BB, AO AB: AB O: OO

What does the Se gene do?

Allows people to secrete soluble forms of the ABO antigens on the cells. Controlled by Se/Se.

What antibodies and antigens do type B people have?

Anti-A B antigen

What antibodies and antigens do type O people have?

Anti-A and anti-B No A or B antigen

What antibodies and antigens do type A people have?

Anti-B A antigen

A patient has type hh, which means they have no H antigen. What blood type are they?

Bombay.

Why are red cells enzyme treated prior to gel agglutination based testing?

Enzymes cleave proteins on the surface of the RBC which allow underlying antigens to become available. Antigens that are not being testing for can be destroyed and others enhanced.

T or F: B is better at converting H than A

False. A is better at converting H.

Where do the antibodies in known serum come from?

Human or monoclonal (murine) <-- rat

What is the H antigen?

It is a string of sugars on the cell that are the base for the ABO blood groups. It controls the expression of the A and B gene.

Where do the antigens come from?

The cells

How is ABO inherited?

Mendelian genetics: Alleles of the same gene at a given locus. Co-dominant

Are anti-A and anti-B present at birth?

No.

Can you tell the difference between HH and Hh?

No.

What blood group has the most H? The least?

O has the most AB has the least

What is the frequency of the four major blood groups?

O: 45% A: 40% B: 11% AB: 4%

Describe forward typing.

Patient blood of an unknown type is mixed with known sera. A positive result is agglutination. An example: If anti-A serum causes a positive reaction, and the anti-B serum has a negative reaction, then the cells only have the A antigen and the blood type is type A.

Describe reverse typing.

Patient serum of unknown type is mixed with known cells. Example: if A cells do not cause a reaction, and B cells do cause a reaction, then the patient serum contains anti-B, which means they do not have the B antigen and (going off of the forward being A type), are confirmed to be type A.

What blood group does Bombay blood resemble? What is the difference?

They look like type O because they have anti-A and anti-B, but they can make anti-H if given O blood.

What happens if you give type O blood to a Bombay?

They will make anti-H because they lack the H antigen and O blood has the most H antigen.

How do we test for secretor status?

We look for the inhibition of agglutination. Soluble antigens will bind to the antibody and neutralize it before it can bind to the RBC

What is the B sugar called?

d-galactose