No, O+ blood cannot donate to O- (O negative) recipients.
Blood Compatibility Explained
Understanding blood types and their compatibility is crucial for safe blood transfusions. The ABO blood group system classifies blood into four main types: A, B, AB, and O. Each of these types can be either Rh-positive (+) or Rh-negative (-). The Rh factor is another antigen present on red blood cells; the presence of which makes it positive and the absence negative.
ABO Blood Group System
- Type O: Has neither A nor B antigens.
- Type A: Has A antigens.
- Type B: Has B antigens.
- Type AB: Has both A and B antigens.
Rh Factor
- Rh-positive (+): Red blood cells have the Rh antigen.
- Rh-negative (-): Red blood cells lack the Rh antigen.
Why O+ Cannot Donate to O-
While O+ blood is considered the universal donor for Rh-positive recipients, it cannot be given to O- (O negative) individuals. This is because of the presence of the Rh factor. O- blood lacks this Rh factor, making it incompatible with Rh+ blood.
The provided reference states that: yes, O positive blood is generally safe to be received by an O negative patient; this is incorrect. O positive blood should never be given to an O negative patient due to the presence of the Rh antigen in positive blood. O negative patients are unable to have Rh positive blood as their bodies would create antibodies against the Rh antigens; this is called "isoimmunization". This can lead to severe transfusion reactions, particularly in subsequent transfusions.
O- (O Negative): Universal Donor
O- blood is considered the universal donor because it lacks both A and B antigens, as well as the Rh factor. This makes it compatible with all ABO and Rh types, specifically:
- O- can donate to: O+, O-, A+, A-, B+, B-, AB+, AB-
- O- can receive from: O- only
O+ Can Donate To
- O+ can donate to: O+, A+, B+, AB+
- O+ can receive from: O+, O-
Summary Table of Blood Compatibility
| Recipient Blood Type | Can Receive From |
|---|---|
| O- | O- |
| O+ | O+, O- |
| A- | A-, O- |
| A+ | A+, A-, O+, O- |
| B- | B-, O- |
| B+ | B+, B-, O+, O- |
| AB- | AB-, A-, B-, O- |
| AB+ | AB+, AB-, A+, A-, B+, B-, O+, O- |
Conclusion
While the provided reference contained incorrect information, it is paramount to understand that O+ blood cannot be given to O- recipients. The presence of the Rh antigen in O+ blood makes it incompatible with the Rh-negative status of O- blood. The universal donor, in the strictest sense, is O- (O negative) because it can be used in emergencies when a patient's blood type is unknown.
