Blood Type Overview

Blood Types Overview

• Topic: Total blood types

  • Total number of blood types: 8

  • These include: A, B, AB, O

  • Each blood type can be classified as either positive (+) or negative (-)

  • Four basic blood types:

  • A

  • B

  • AB

  • O

  • Resulting combinations give:

  • A+, A-

  • B+, B-

  • AB+, AB-

  • O+, O-

Understanding Blood Types

• To really understand blood transfusions, one must grasp basic concepts:

  • Antigens

  • Definition: Type of protein that helps recognize cells

  • Functions:

    • Distinguishes cells (e.g., skin cells vs. heart cells)

  • Antibodies

  • Definition: Another type of protein linked to the immune system

  • Key property: Highly specific; can only attach to certain antigens

  • Function: Acts as a marker for immune cells to destroy target cells

Blood Type Antigens and Antibodies

• Blood types can be simplified to A, B, AB, and O differentiating by antigens present:

  • Blood type A

  • Antigens present: A

  • Antibodies present: Anti-B

  • Blood type B

  • Antigens present: B

  • Antibodies present: Anti-A

  • Blood type AB

  • Antigens present: A and B

  • Antibodies present: None

  • Blood type O

  • Antigens present: None

  • Antibodies present: Anti-A and Anti-B

Positive and Negative Blood Types

• Understanding Rh factor:

  • D antigen determines whether blood is Rh positive or negative

  • If a person is positive, they have the D antigen; if negative, they do not

• Combinations based on Rh factor:

  • A+

  • Antigens: A, D

  • A-

  • Antigens: A

  • B+

  • Antigens: B, D

  • B-

  • Antigens: B

  • AB+

  • Antigens: AB, D

  • AB-

  • Antigens: AB

  • O+

  • Antigens: D

  • O-

  • Antigens: None

Antibody Characteristics

• Anti-D antibodies:

  • Not produced if a person is Rh positive

  • Only developed if Rh negative individuals are exposed to the D antigen (sensitization) which can occur through blood transfusion or pregnancy

• Process of sensitization:

  • Implies prior exposure leading to future antibody production

Blood Transfusions

• Overview of blood transfusion process:

  • Donor side (blood giver)

  • Recipient side (blood receiver)

• Example: A person with blood type A donating to another person with type A. This is a successful transfusion because:

  • No A antibodies are present in the recipient to attack the donated blood.

• Complications arise when mismatched blood types are involved:

  • Example: A blood type recipient receiving B type blood will have a negative reaction due to the presence of Anti-A antibodies which attack the A antigens in the received blood

Universal Donors and Recipients

• Universal Donor: O negative

  • Reason: No antigens present to be attacked by antibodies in any recipient

• Universal Recipient: AB positive

  • Reason: Can accept any blood type without an immune reaction

Pregnancy and Blood Types

• Complications can occur when a sensitized mother (especially Rh-) has a baby with Rh+:

  • If the first baby is Rh+ and the mother becomes sensitized, subsequent Rh+ pregnancies could be dangerous due to mother's Anti-D antibodies attacking the fetus's cells leading to potential miscarriage

  • Preventive measure: Administration of Rho(D) immune globulin to Rh- mothers to prevent sensitization

Blood Typing Lab Test

• Method to categorize blood types:

  • Use of serums that mimic antibodies (anti-A, anti-B, anti-D)

  • Procedure involves placing blood sample in sections and adding serum to check for reactions

  • Positive reaction: coagulation indicating the presence of corresponding antigen

  • No reaction: indicates absence of antigen

  • Results help determine blood type based on what coagulates or does not coagulate with added serums