BB Overview of ABO Blood group

ABO Blood Group System

➢ Most important of all

blood groups

➢ Blood group system in

which individuals already have antibodies in their serum

to antigens that are absent from their red blood cells

(RBCs)

lysis

Presence of antibodies results to __________ of RBCs once ABO is

incompatible

hemolytic

transfusion reactions

ABO ➢ Remains as the predominant cause of death for________________

genes of three separate loci

ABO Principles

The formation of ABH antigens results from

interaction of____________

GLUCOTRANSFERASE

ABO Principles

Responsible for the production of____________________that add sugars to a basic precursor substance

α – 2 – L – fucosyltransferase

H GENE AND ANTIGENE GLYCOSYLTRANSFERASE

L – fucose

H GENE AND ANTIGENE IMMUNODOMINANT SUGAR

α – 3 – N –

acetylgalactosaminyransferase

A GENE AND ANTIGENE GLYCOSYLTRANSFERASE

N–acetyl–D–

galactosamine

A GENE AND ANTIGENE IMMONODOMINANT SUGAR

α – 3-D - galactosyltransferase

B GENE AND ANTIGENE GLYCOSYLTRANSFERASE

D –galactose

B GENE AND ANTIGEN IMMUNODOMINANT

SUGAR

Type-2-precursor chain

ABO Precursor

Bombay phenotype

hh Precursor structure unchanges

N-acetyl galactosaminyl and galactosyl transferases

A AND B GENES GLYCOSYLTRANSFERASE

N-Acetyl galactosamine and galactose

A AND B ANTIGEN IMMUNODOMINANT SUGAR

FORWARD TYPING

ABO TESTING

➢ Using known sources of commercial antisera (anti-A,

anti-B)

➢ Detects antigens on an individual’s RBCs

Blood Group O

Interpretation of Blood Group

Patient RBCs with Anti-A: 0

Patient RBC’s with Anti B: 0

Blood Group A

Interpretation of Blood Group

Patient RBCs with Anti-A: 4+

Patient RBC’s with Anti B: 0

Blood Group B

Interpretation of Blood Group

Patient RBCs with Anti-A: 0

Patient RBC’s with Anti B: 4+

Blood Group AB

Interpretation of Blood Group

Patient RBCs with Anti-A: 4+

Patient RBC’s with Anti B: 4+

agglutination

A positive antigen-antibody reaction is usually

demonstrated by______________

Anti-A Reagent

Type of Reagent

Anti-B Reagent

Type of Reagent

Monoclonal Antibody

• Contains antibody from a single type of B cell, clonally

expanded

• Preferred in testing

• Highly specific

4+

Agglutination Grading

3+

Agglutination Grading

2+

Agglutination Grading

W+ to 1+

Agglutination Grading

0

Agglutination Grading

REVERSE TYPING

ABO TESTING

➢ Using known reagent RBCs (A and B cells)

➢ Detects ABO antibodies in the patient’s serum