HEALTH SCIENCE TECHNOLOGY

Ms. Sally Duke, R.N.

TYPE AND

CROSS MATCHING

Important vocabulary terms:

Agglutination: The clumping together of blood cells in response to a specific antibody

Antigen: Any substance that will trigger an immune response by a host organism

Antibodies: Compounds produced by plasma cells that react with specific antigens invading the body

Plasma: The fluid portion of blood that contains proteins and salts, in which the blood cells and platelets are suspended

Proteins: Essential makeup of all living things that are either made by the body or assimilated from foods

Hemolysis: Destruction of the membrane of red blood cells

Transfusion: The process of giving blood from one individual to another

THE BASIC FUNCTION OF BLOOD MUST BE UNDERSTOOD BEFORE

TYPE AND CROSS MATCHING CAN BE ADDRESSED :

WHAT IS IT MADE OF?

WHY DO WE NEED IT?

WHAT IS IT’S FUNCTION?

HISTORY:

•In 1661 Marcello Malpighi discovered that blood is composed of large red cells that had no nucleus

•200 years later Joseph Davaire discovered that blood also had large white cells that out -numbered red cells by 650:1

HISTORY In 1901, Karl

Landsteiner reported that blood had TYPES.

By matching these types one could achieve success in blood transfusions.

The first successful human trans -fusion was accomplished in 1818 by

James Blundell

1.Type B: Has a B antigen on the red cells

2.Type AB: Has both A and B antigens on the red cells

3.Type O: No antigens on the red cells

LANDSTEINER IDENTIFIED FOUR BASIC BLOOD TYPES:

4.Type A: Has an A antigen on the red blood cells

Note: Many more types can be identified today but these four groups are still the

dominate categories.

Blood Groups:

Population breakdown:•46% is type O•40% is type A •10% is type B•4% is type AB

These percentages may vary within different ethnic groups.

There is another type of antigen that needs to be considered-

The Rh Antigen:

•This antigen was first discovered on the surface of red blood cells of the Rhesus monkey

•When the Rh antigen is present, a individual’s blood type is designated as Rh + (positive).

•When the Rh antigen is absent, an individual’s blood type is designated as Rh –(negative).

•In humans it was found to be present to on the surface of erythrocytes (red blood cells)

•The four different blood types are caused by the presence of this “chemical marker”- an antigen-on the surface of the Type A and Type B red blood cells

•When mixed with the wrong blood type, antigens are picked up by antibodies in a patient’s system which causes the cells to clump (agglutination)

•This data is why someone with type AB blood can receive any type blood and someone with Type O blood is the universal donor

Another important fact about blood transfusions:

•Many minor antigens are not routinely detected during “blood typing”

•If allowed to go unrecognized, these minor antigens can initiate a blood transfusion reaction

•These minor antigens can be detected through a process called “cross-matching.”

•Cross matching consists of incubating the recipient’s serum with the donor’s red blood cells in a saline solution. A reagent , called “Coombs”, is then added to test for incompatibility.

BLOOD:

•Although blood appears to be a red liquid it is actually composed of a yellowish liquid called plasma and billions of cells.

•The vast majority of these cells are red cells and these give blood its red color.

BLOOD:

•Contains several types of infection-fighting cells called “WHITE” cells which help heal wounds.

•Contains tiny cell fragments called platelets which are essential for clotting.

• Carries oxygen and nutrients to all parts of the body

• Carries carbon dioxide and other waste products back to the lungs, kidneys and liver for disposal.

BLOOD:

BLOOD:

•Is the only tissue that flows throughout the body

• Is an essential part of the immune system, crucial to fluid and temperature balance

BLOOD:

•Acts as a “hydraulic fluid” for certain functions and is a “highway” for essential hormonal messages

•The blood cell membrane controls the flow of substances into and out of the cell

BLOOD:

• It contains molecules called antigens that are specific to the cell and the person.

•The major cellular structures are shown in this very simplified drawing.

3D Image: Copyright Bristol Productions

Do You Know Your Blood Type?

• When attempting to determine blood types both the ABO system and the Rh types must be considered.

• For example, if you have both the A antigen and the Rh antigen on your red cells, you are A+.

Example:

A (protein) B (protein) Rh (protein)

A + B + AB + O +

Has none of these

A - B - AB - O -

Why is it important that we know about the different blood

types and Rh factor?

•If an individual with Rh – (negative) blood receives a transfusion of Rh + (positive) blood, it cause the formation of anti-Rh agglutination.

•Subsequent transfusions may cause serious transfusion reactions that include agglutination and hemolysis of cells.

A similar reaction takes place when---

A pregnant women, who is Rh – (negative), becomes sensitized by the blood of a fetus she carries that has Rh + (positive) blood.

In subsequent pregnancies, if the fetus is Rh +, Rh antibodies produced in maternal blood may cross the placenta and destroy fetal cells, causing erythroblastosis fetalis.

This is why these types (and other less striking types)

must be properly matched for a blood transfusion to work.

NOW---- TURN TO YOUR WORK -SHEET AND SEE IF YOU CAN APPLY WHAT YOU HAVE JUST LEARNED USING THE FOLLOWING FORMULA:

•IF YOU HAVE IT, YOU CAN GET IT!!!!

•IF YOU DON’T HAVE IT, YOU CAN’T GET IT!!!

DONOR O+ O- AB+ AB- B+ B- A+ A-

A+

A-

B+

B-

AB+

AB-

O+

O-

BLOOD TYPE AND CROSSMATCH WORKSHEET

REMEMBER:

There is no substitute for blood. If people lose blood from surgery, disease or injury or if their bodies cannot produce enough, there is only one place to turn –

VOLUNTEER BLOOD DONARS!

REMEMBER---

DONATE BLOOD---

THE LIFE YOU SAVE MAY BE SOMEONE YOU

KNOW AND LOVE!