Blood Types/Groups

HST II

2008

Background:

• Until 1901, many patients who received blood died.

• In 1901, Landsteiner discovered human blood groups (ABO) which helped blood transfusions become safer.

• For this discovery, he earned the 1930 Nobel Prize in Medicine

Why is it important?

• Blood transfusions – blood must be compatible or death occurs

• Pregnant females – may cause problems with the baby if mother is not given shots to prevent antibody production

• Organ transplants – ABO antigens are found on most organs; rejection of organ by the body if not compatible

• Paternity testing – determines if alleged father could be true father

• Crime scene investigations – helps identify victims and suspects

Terms:

• Antibody- A special protein made by the body as a defense against foreign material that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

• Antigen- Anything that causes the body to launch an immune response against that antigen through the production of antibodies.

Blood Group Systems:

• A person's ABO blood type--A, B, AB, or O--is based on the presence or absence of the A and B antigens on his red blood cells.

• Inherited from parents• ABO antigens are present at birth • Antibodies against the antigens not present

in the blood will develop within 6 months after birth and persist throughout life (i.e. Anti-A and Anti-B)

4 ABO Blood Types

• A

• B

• AB

• O

Type A

• 40% of population• Has A antigens on RBC surface• Has anti-B antibodies in plasma

Type B

• 11% of population• Has B antigens on RBC surface• Has anti-A antibodies in plasma

Type AB

• 4% of population• Has A and B antigens on RBC surface• Has NO antibodies in plasma• Universal Recipient (can receive Type A, B,

AB, and O blood) because it has NO antibodies in the plasma

Type O

• 45% of population• Has NO antigens on the RBC surface• Has anti-A and anti-B antibodies in plasma• Universal Donor (blood can be given to Type

A, B, AB, and O) because it has NO antigens on the RBC surface

• Can ONLY receive type O blood

Blood TypesBlood Type Antigen

(on RBC surface)

Antibodies (in plasma)

A A Anti-B

B B Anti-A

AB A and B None

O None Anti-A and Anti-B

Genotypes (inherited blood type) /Phenotypes (what blood type it is

called)• AA and AO are both Type A blood• BB and BO are both Type B blood• AB is Type AB blood• OO is Type O blood

ABO Blood System

Rh System• Discovered by Landsteiner and Wiener in 1937• Discovered in the Rhesus monkey

Rh + has the antigens (84% of the population)(also known as D antigen positive)

Rh – does NOT have the Rh antigens (16% of the population)(also known as D antigen negative)

Rh + can accept Rh + or Rh – bloodRh – can accept ONLY Rh - blood

• Rh – mother and Rh + father can also develop Rh problems with having children. If the mother has a baby that is Rh +, her body will develop antibodies to the Rh antigen so that a second pregnancy with a Rh + baby will result in the mother’s antibodies attacking the unborn child’s RBCs. To prevent this, a shot of Rhogam is given shortly after birth to block the development of antibodies.

General Blood Type Distribution • O Rh-positive, 38% • O Rh-negative, 7% • A Rh-positive, 34% • A Rh-negative, 6% • B Rh-positive, 9% • B Rh-negative, 2% • AB Rh-positive, 3% • AB Rh-negative, 1%Percentages of blood types vary by race; these

are avg. % for all races combined

So what happens if a person is given the wrong blood type?

• A transfusion reaction occurs!• Symptoms of transfusion reaction: chills,

fever, rash, itching, SOB (shortness of breath), nausea, nephralgia (kidney pain), hematuria (blood in urine), shock and death.

• All blood is tested for compatibility to determine that the donor blood will not react against the recipient's blood before transfusion

Rh Incompatibility

• When a Rh – person receives Rh + blood in a transfusion, the person develops antibodies against the Rh + factor (Anti-D antibodies).

• This becomes a clinical problem if they receive a second transfusion of Rh + blood.

Incompatible blood types can result in:

• Agglutination – a reaction in which red blood cells clump together

• Hemolysis- breakdown of red blood cells

• Blood is tested prior to transfusion; if agglutination or hemolysis are seen, this indicates the blood is not compatible and is not given to that patient