BLOOD GROUPS
6. BLOOD GROUPS
Discovered by Landsteiner
Awarded Nobel Prize
Blood group systems:
ABO system
Rh System
Lewis System
MN system
Luthern System
ABO
system
Grouping depends on presence/absence of Antigens/Agglutinogens
Antigens –A & B
Blood groups are A(A1&A2), B, AB(A1B & A2B) & O
Antibodies/Agglutinins Are in plasma
Landsteiner’s
Law:
- If an agglutinogen is present on the RBC, corresponding agglutinin will be
absent in the plasma
- If an agglutinogen is absent corresponding agglutinin will be present
[Exception to the 2nd part is Rh System - Rh-ve people will not have Rh
Antibodies]
Rh Blood Group:
Discovered by Landsteiner & Weiner
The Rh Antigens are C, D, E. The common antigen is D antigen
People having ‘D’ antigen are called Rh +ve (85%)
People not having ‘D’ antigen are called Rh-ve (15%)
There are no naturally occurring antibodies
Uses of Blood Grouping:
In Blood Transfusion
In Pregnancy
In Disputed Paternity
Infertility and Early Fetal loss
Disease Relation e.g O group have twice incidence of Duodenal ulcer than A or B
In forensic science
In Anthropological studies
Blood Transfusion:
Transferring blood from one person to another person
Cross matching :
Major cross matching
Recipient’s Serum + Donor’s RBC
Minor Cross matching
Recipient’s RBC + Donor’s Serum
Universal Donor - O group persons have no agglutinogen and so can give blood to
anyone.
Universal Recipient - AB group persons have no agglutinins and so can receive any
type of blood
The above are no longer valid as complications can be produced by Rh and other
sub groups. But in case of extreme emergency O-ve blood can be used
ABO incompatibility:
- ABO incompatibility rarely produces hemolytic disease of newborn
- Anti A & Anti B antibodies are of IgM
- Cannot cross the placenta
Rh
Incompatibility:
When 2nd time Rh +ve blood is transfused into negative blood–severe reactions occur
In women – during pregnancy incompatibility leads to ERYTHROBLASTOSIS
FOETALIS – a hemolytic disease of new born
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