blood groups

BLOOD GROUPS

FACTS ABOUT BLOOD GROUPS

• THE MOST IMPORTANT BLOOD GROUP IN THE U.S. IS THE ABO GROUP

• 3 ALLELES FOR THIS GROUP: A,B & O

• A PERSON CAN ONLY INHERIT 2 ALLELES (GENES) FOR THIS

POSSIBLE GENE COMBINATIONS

GENOTYPE PHENOTYPE (alleles) (actual blood

type) AA

AO

BB

BO

AB

OO

A

A

B

B

AB

O

Antigen

• In immunology, an antigen is a substance that evokes the production of one or more antibodies. Each antibody binds to a specific antigen by way of an interaction similar to the fit between a lock and a key

Antibody• An antibody (Ab), also known as an

immunoglobulin (Ig), is a large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses

• So the foreign antigen is the “bad guy” and the antibody is the molecule your body uses to fight the foreign antigen

• Serology – the study of antigen – antibody reactions

Laboratory Examination - Individualization

• The surface of a RBC contains antigens

• Antigen (Ag) – a glycoprotein that stimulates the body to produce antibodies (Ab) against it

• Antigens impart blood-type characteristics to the RBC

Laboratory Examination –ABO and Rh system

Recipient Donor A B AB O

A (antigen A and antibody B)

B (antigen B and antibody A

AB (antigen A and B and no antibodies)

O (not antigens but both antibody A and B*)

Meaning they have the following blood type

Recipient Donor A B AB O

A (antigen A and antibody B)

B (antigen B and antibody A

AB (antigen A and B and no antibodies)

O (not antigens but both antibody A and B*)

Rh FactorRh Factor

Recipient Donor Positive Negative

Positive Negative

Laboratory Examination –ABO and Rh system

• The population distribution of blood types varies with location and race throughout the world

• In the US, a typical distribution:

0

20

40

60

O type A type B type AB type

Percent

FREQUENCY OF BLOOD TYPES

A

B

AB

O

45% MOST COMMON

41 %

10 %

4 % LEAST COMMON

UNIVERSAL DONOR: THE BLOOD TYPE THAT CAN BE GIVEN TO ALL OTHER BLOOD TYPES.

TYPE O- IS THE UNIVERSAL DONOR.

UNIVERSAL ACCEPTOR: THE BLOOD TYPE THAT CAN RECEIVE ALL OTHER BLOOD TYPES.

TYPE AB+ IS THE UNIVERSAL ACCEPTOR.

Rh FACTOR

• THE Rh FACTOR IS ANOTHER ANTIGEN (PROTEIN) THAT CAN BE FOUND ON THE SURFACE OF SOME RBC’S

• PEOPLE WITH THIS PROTEIN ON THEIR RBC’S ARE Rh+

• .• PEOPLE WHO LACK THIS PROTEIN ARE Rh-.

ERYTHROBLASTOSIS FETALIS

• A HEMOLYTIC DISEASE OF NEWBORNS.

• THE RESULT OF Rh INCOMPATIBILITY

• THE MOTHER IS Rh- & THE FATHER IS Rh+

• BOTH HEMOLYSIS & AGGLUTINATION WILL RESULT

NORMAL RBC

IMMATURE RBC

(NUCLEATED)

BROKEN RBC

WHAT DISEASE CONDITIONS WOULD YOU EXPECT THIS BABY

TO HAVE AT BIRTH?

•ANEMIA

•JAUNDICE

WHAT IS THE Tx FOR THESE BABIES?

A COMPLETE BLOOD TRANSFUSION

• RHOGAM: CONTAINS ANTI-Rh ANTIBODIES• HOW IS IT ADMINISTERED?

• INJECTION• WHEN IS IT ADMINISTERED?

• DURING THE PREGNANCY & WITHIN 72 HOURS AFTER DELIVERY

.

PREVENTION?