Blood Group (ABO and Rh)
Definition
Two separate determinations are made:
- ABO typing: the blood sample is mixed with antibodies against type A and type B, and clumping is observed. Then reverse grouping is performed, in which the patient's serum is mixed with known type A and type B blood (double check)
- Rh typing: determines whether the Rh protein is present on the surface of the red blood cells → Rh+ (positive) or Rh− (negative)
Purpose
Safe blood transfusion and organ transplantation. The group of the blood you receive must closely match your own blood group. In the event of incompatibility, an immune response is triggered: antibodies develop against the transfused red blood cells and attack them.
Results, who you can receive blood from:
| Your blood group | Groups you can receive |
|---|---|
| A | A and O |
| B | B and O |
| AB | A, B, AB and O, universal recipient |
| O | O only, universal donor |
| Rh+ | Rh+ or Rh− |
| Rh− | Rh− only |
Importance in pregnancy: blood group determination is very important in pregnancy. Careful testing can prevent severe anemia and jaundice in the newborn. (Risk of Rh incompatibility)
Risks and Limitations
Besides A, B and Rh there are also minor antigens, which are not routinely detected. A reaction can develop even when the major antigens match; cross-matching and the Coombs test are used to detect these.