The ABO and H Blood Group System

False positives in forward reverse grouping?

1. Contaminated reagents adn dirty glassware 2. Over centrifugation 3. Incorrect interpretation or recording of results

Hh and Sese are linked closely to which chromosome?

19

Percent of people who are SeSe or Sese?

78%

Percent of A² or A²B individuals that will make an A¹ antibody naturally?

8%

Percent of Group A people that are A1?

80%

The ABO locus is on what chromosome?

9

Frequency Distributions of ABO phenotypes?

A = 40% whites, 27% blacks, 28% asians B = 11% whites, 20% blacks, 27% Asians AB = 4% whites, 4% blacks, 5% asians O = 45% whites, 49% blacks, 40% asians

A person with the Bombay phenotype are devioded of what antigens?

A, B, & H

Lectin Anti-A1 reagents agglutinate?

A1

Anti-A1 will only agglutinate what cells?

A1 cells

4 allelic genes of the ABO system?

A1, A2, B, and O

Possible genotypes of A1B?

A1/B

What do A1 and A2 red blood cells agglutinate?

Anti-A reagent

The serum of a Bombay person contains?

Anti-A, Anti-B, and Anti-H

Serum from O people contain what antibody?

Anti-A,B in addition to Anti-A and Anti-B

The most common cold autoantibody encountered in back typing?

Anti-I

When are full levels reached?

Approximately 2-4 years of age

When can A and B antigens be detected?

As early as 5 weeks

Possible genotypes of B?

B/B, B/O

Why can't a Bombay person recieve group A, AB, B or O blood?

Because the anti-H that Bombay posses would agglutinate the H antigen found in A, A, AB, and O.

Why do Bombay people not agglutinate anti-H?

Because they have hh

Best way to differentiate between A1 and A2?

By testing with Lectin Anti-A1 made from Dolichos biflorus seeds

A very rare cause of weak or missing ABO isoaggultination. The individual has 2 cell populations that their bodies recognizes as self throughout their life span. They have type A and type B cells that are separate frmo one another adn since they are seen as self, they not produce anti-A or anti-B?

Chimerism

Sugar for B?

D-galactose

The bombay phenotype is due to the absence of what?

H

Low gamma antibody production?

Hypogammaglobulinemia

How to enhance ABO reactions?

Incubate at room temperature longer, if th reaction does not strengthen, incubate at 4°C.

Sugar for H?

L-fucose

Sugar for A?

N-acetylglucosamine

Sugar for O?

None

People who don't have the Se gene adn are homozygous sese?

Nonsecretors

The amount of H antigen on RBCs in blood types going from most to least?

O, A2, B, A2B, A1, A1B

Possible genotypes of O?

O/O

Common structure for A,B,& H?

Type 1 or Type 2 oligosaccharide chain

What do they secrete?

Water-solube H, H and A, or H and B antigens into their saliva and other body fluids

When are type 1 chains formed?

When carbon of D-galactose is linked with the number 3 carbon of N-acetylglucosamine.

When aer type 2 chains formed?

When number 1 carbon of D-galactose is linked with the number 4 carbon of N-acetylglucosamine

Antibody titer of A and B are able to be deteceted when?

about 3-6 months of age

Flase negative results

1. Didn't add specimen 2. Used an incorrect serum:cell ratio 3. Undercentrifugation or incorrect temperature incubation 4. Using old, outdated or inactive reagents 5. Incorrect inerpretation or recording results and not recognizing hemolysis as a positive reaction

Two Types of Anti-H

1. The cold reacting type antibody in the serum of people with only small amounts of H on their RBCs (usually A1 or AB). 2. Found in the rare Oh (bombay) phenotype whose RBCs have no H antigen on them, but their anti-H reacts strongly at 37 degrees resulting in tranfusion ractions if they recieve any type blood but Bombay.

What genes are codominant?

A and B

Possible genotypes of A1?

A1/A1, A1/A2, or A/0

Possible genotypes of A2?

A2/A2, A2/O

Possbile genotypes of A2B?

A2/B

May be seen in type O adn B with severe aseptic infection with Proteus mirabilus?

Acquired A antigen

This occurs mostly with the A1 blood type, much less frequently in teh A2 type adn not at all with type O?

Acquried B antigen

No gamma antibody production?

Agammaglobulinemia

AABB

American Association of Blood Banks

What we are able to see from common tests?

Phenotype

Weak or missing antigen reactions?

Subgroups of A or B antigen Disease states such as leukemia can weaken antigen reactions