Transcript ABO BLOOD GROUP SYSTEM

Hello
ABO BLOOD GROUP
SYSTEM
Introduction
• All human blood may look
alike but when it is tested
using special agents,
differences become
apparent.
ABO Genes
1 = A/A
1 = Homozygous A
Phenotype A
Genotype A/A
Can Contribute Only an A
Gene to Offspring
2 = A/O
2 = Heterozygous A
Phenotype A
Genotype A/0
Can Contribute A or O
Gene to Offspring
White
O+
OA+
AB+
BAB +
AB -
37%
8%
33%
7%
9%
2%
3%
1%
African
American
47%
4%
24%
2%
18%
1%
4%
0.3%
Hispanic
53%
4%
29%
2%
9%
1%
2%
0.2%
Asian
39%
1%
27%
0.5%
25%
0.4%
7%
0.1%
ABO phenotypes and genotypes
1. Group A phenotype = A/A or A/O
genotype
2. Group B phenotype = B/B or B/O
genotype
3. Group O phenotype = O/O
genotype
4. Group AB phenotype = A/B
genotype
Blood Type Inheritance
Parent 1 AB AB AB AB B A A O O O
Parent 2 AB
Possible
blood
type
of
child
B
A
O
O
B B A B A O
+ + + + +
A
+
+
+
+
B
+
+
+
+
AB
+
+
+
+ +
+ +
+
+
+
+
BIOCHEMISTRY OF THE ABO
SYSTEM
Production H Antigens
Production A Antigens
Production B Antigens
Indications for ABO grouping
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•
•
•
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Blood Donors
Transfusion recipients
Transplant Candidates and Donors
Prenatal Patients
Newborns
Paternity testing
BLOOD GROUP
ANTIGEN
ANTIBODY
A
A
anti-B
B
B
anti-A
AB
A and B
neither
O
neither A
norB
anti-A,B
Landsteiner's rules for the
ABO Blood Group
•
•
•
A person does not have
antibody to his own antigens
Each person has antibody to
the antigen he lacks (only in
the ABO system)
Below are the four blood
groups and the antigens and
the expected, naturallyoccurring antibodies present.
ABO Typing
Routine ABO Typing
Reaction of Cells
Tested With
Red
Cell
ABO
Group
Anti-A Anti-B
Reaction of
Serum Tested
Against
Reverse
ABO
Group
A cells B Cells
0
0
O
+
+
O
+
0
A
0
+
A
0
+
B
+
0
B
+
+
AB
0
0
AB
Discrepancies in ABO typing
•
•
•
Results of forward and reverse typing
must agree before reporting out blood
type as seen in the about table.
If forward and reverse do not agree,
must identify cause of discrepancy.
If cannot resolve discrepancy, must
report out blood type as UNKNOWN
and give group O blood