Question

Having located 6 E-negative donor units, you perform crossmatches on the units. One of the units is incompatible in the antiglobulin phase (2+ reactivity).

The physician is becoming insistent on beginning the transfusion because the patient is having some shortness of breath.

How do you respond to the physician’s request? List several reasons to explain the one incompatible donor unit. What additional testing do you perform?

Answer 1

How do you respond to the physician's request?

1. I would inform the physician that one of the donor unit has come positive.
2. The antiglobulin testing has come positive ( 2 + = red blood cell agglutinates are scattered throughout the tube).
3. Further tests need to be run on the patient's blood

List several reasons to explain the one incompatible donor unit?

1. ABO Incompatibility
2. A2 / A2B recipient who is Anti A1 antibodies
3. cold antibodies
4. Presence of Alloantibodies
5. Cold and ward autoantibodies

What additional testing do you perform?

• Antibody screening needs to be done.
• Antibodies other than anti A and anti B are called unexpected antibodies
• Alloantibodies ( antibodies against antigens not present in the body) to non ABO system -duffy, MNS, Kell, Kidd
• IgG antibodies can be missed by the initial immediate spin test. They are reactive at room temperature.