BLOOD GROUPS

What is a blood transfusion?

• the process of receiving blood or blood products

into one's circulation intravenously.

Transfusions are used for various medical

conditions to replace lost components of

the blood.

Who needs blood transfusions?

Blood Groups

• In the early 1900s, Dr. Karl Landsteiner discovered that

there are 4 major blood types

• A, B, AB, O

• There are two major blood type systems: ABO and

Rhesus (Rh)

ABO Blood Group

• A person’s blood type depends on the presence

or absence of antigens A or B on the surface of

red blood cells.

• Antigen: A protein on the surface of a red blood

cell that is capable of causing an immune

response.

Antigen vs Antibody

Antibody

• Proteins in blood that

bind to antigens to

destroy them

Antigen

• A protein on the

surface of a red blood

cell that is capable of

causing an immune

response.

• People with

type A blood

have A

antigens

• People with

type B blood

have B

antigens

• People with

type AB blood

have A and B

antigens

• People with

type O blood

have no

antigens

Blood Antibodies

• Antibody: Proteins in blood that bind to antigens to

destroy them

• A person is born with antibodies against antigens not

contained in the person’s blood

• Plasma contains antibodies that will bind to foreign red

blood cells

Blood Type Antigens Antibodies

A

B

AB

O

• https://www.redcrossblood.org/donate-blood/blood-

types.html

• https://www.youtube.com/watch?v=xfZhb6lmxjk

Rh Factors

• Whether your blood is “positive” or “negative” depends

on the Rh antigen on the red blood cells

• If your blood is Rh positive,

you have the Rh antigen.

If it's Rh negative, you

do not have the Rh antigen.

• First found in rhesus monkeys

(hence “Rh”)

Rh Factors and Pregnancy

Blood Types

• There are 8 different blood types

Why Does Blood Type Matter?

• Blood transfusions=procedure in which a person

receives blood or its components through an

intravenous (IV) line in one of their blood vessels.

• Most often given to alleviate anemia, to increase blood

volume, or to improve immunity.

Blood Donation Process

• 1. Complete a donor questionnaire

• 2. Screening• Go over questionnaire

• “Finger prick” test to check your hemoglobin level

• Check blood pressure and temperature

• 3. Donation• Choose left or right arm

• Area is disinfected

• Staff member finds vein and inserts needle

• After needle is removed, apply pressure for 5 minutes

• 4. Enjoy some cookies and snacks

• The blood is tested for blood type and transmissible diseases before being used.

Transfusions

• For a blood transfusion to be safe, the recipient must not

have antibodies that will react with any A, B, or Rh

antigens in the donor’s blood

• Agglutination: If you receive the wrong blood type, the

RBC will (clump together) which may clog the blood

vessels.

• This aggressive, whole-body response can give someone a fever,

chills, and low blood pressure. It can even lead vital body systems

— like lungs or kidneys — to fail.

Donor’s antigens must be

compatible with

Recipient’s antibodies !!!

Rh Factor

• An Rh+ individual can receive both Rh+ and Rh-

blood

• An Rh- individual can receive only Rh- blood

Plasma

• Used in emergency situations to restore blood volume

and maintain blood pressure

Universal Donor

• People with type O- blood

• They do not have A or B antigens to be attacked by

antibodies in the recipient’s blood plasma

• They can donate to all 4 ABO blood types

• Can only receive from O-

Universal Recipients

• People with type AB+ blood

• Do not have anti-A or anti-B antibodies in their blood

plasma to attach to antigens on donated RBC

• They can receive blood from donors of all 4 blood types

• Can only donate to AB+

• https://www.youtube.com/watch?v=fRB98GpELD4

• https://www.youtube.com/watch?v=oZwtv9IJH6A

Matching ABO Blood Types

Blood Type Antigen Antibody Can donate to Can receive

from

A A anti-B A, AB A, O

B B anti-A B, AB B, O

AB A and B none AB A, B, AB, O

O none anti-A

anti-B

A, B, AB, O O

Rh Factors and Pregnancy

• During pregnancy, if a mother is Rh- and the baby

has inherited Rh+ from the father there maybe be

a problem.

• During birth, there may be some leak between

the circulatory system of the baby and the mother

and the baby’s Rh+ blood can enter the mother’s

Rh- blood

• Her immune system detects the Rh+ blood as

foreign and begins to form anti-Rh antibodies

• The first pregnancy is rarely affected

First Rh incompatible pregnancy

Rh Factors and Pregnancy

• In later pregnancies, anti-Rh antibodies from the mother

can enter the new baby’s blood

• If the baby is Rh+, the anti-Rh antibodies destroy the new

baby’s red blood cells

Rh Factors and Pregnancy

• The Rh problem can be eliminated if the Rh-

mother is injected with anti-Rh antibodies shortly

after the birth of each Rh+ child.

• These antibodies destroy any Rh antigens on the

baby’s blood cells that have entered the mother’s

circulatory system.

• The mother’s immune system does not produce

anti-Rh antibodies and there is no problem with

the next Rh+ baby.