2. List the type of antigen(s) and type of antibodies present in each of the 8 ABO/Rh blood types.

Question

Explain why blood type O- is the universal donor.

Answer 1

The ABO blood group system categorizes human blood into four main types: A, B, AB, and O. These types are determined by the presence or absence of specific antigens on the surface of red blood cells. Additionally, the Rh factor is another important antigen that can be either positive (+) or negative (-).

ABO Blood Types and Their Antigens and Antibodies

1. Type A

   • Antigen: A antigen
   • Antibodies: Anti-B antibodies

2. Type B

   • Antigen: B antigen
   • Antibodies: Anti-A antibodies

3. Type AB

   • Antigen: A and B antigens
   • Antibodies: No antibodies (neither anti-A nor anti-B)

4. Type O

   • Antigen: No A or B antigens
   • Antibodies: Anti-A and Anti-B antibodies

For the Rh factor:

1. Rh+ (Positive)

   • Antigen: Rh antigen (D antigen present)
   • Antibodies: No anti-Rh antibodies

2. Rh- (Negative)

   • Antigen: No Rh antigen (D antigen absent)
   • Antibodies: May develop anti-Rh antibodies if exposed to Rh+ blood

Combined ABO and Rh Blood Types

1. A+

   • Antigens: A, Rh+
   • Antibodies: Anti-B

2. A-

   • Antigens: A
   • Antibodies: Anti-B, potentially anti-Rh

3. B+

   • Antigens: B, Rh+
   • Antibodies: Anti-A

4. B-

   • Antigens: B
   • Antibodies: Anti-A, potentially anti-Rh

5. AB+

   • Antigens: A, B, Rh+
   • Antibodies: None

6. AB-

   • Antigens: A, B
   • Antibodies: None, potentially anti-Rh

7. O+

   • Antigens: Rh+
   • Antibodies: Anti-A, Anti-B

8. O-

   • Antigens: None
   • Antibodies: Anti-A, Anti-B, potentially anti-Rh

Why Blood Type O- is the Universal Donor

Blood type O- is considered the universal donor because:

• No A or B Antigens: Individuals with type O blood have no A or B antigens on their red blood cells. This means that when O- blood is transfused into a person with any other blood type (A, B, AB, or O), there will be no reaction due to the presence of A or B antigens, thus minimizing the risk of an immune response.

• Rh- Factor: People with O- blood lack the Rh factor. Rh- blood can safely be given to Rh+ recipients without causing an immune reaction, as Rh+ individuals do not have an immune response against the absence of Rh antigens.

Because of these factors, type O- blood can be transfused safely to any patient, making it crucial in emergency situations when blood type is unknown, thereby establishing it as the universal donor.