The patient’s blood type may change after receiving an ABO-incompatible stem cell (HPC-A stem cell or HPC-M marrow) transplant. We must verify that the change detected is due to the transplant and NOT due to a mistake in identifying the correct patient at the time of the specimen collection. Thus, the first time there is a specimen after transplant, we should treat the patient as if there is an ABO/Rh discrepancy, i.e. positively identify the patient again and redraw a new specimen and verify the type.
After transplant, both the original and new clones of RBCs may survive. It is important to check for ABO discrepancies between the forward and reverse type.
Also note that the other RBC antigen phenotypes may have changed. Particularly, note if the D type has changed. The previous extended phenotype may no longer apply.
- On the first encounter with a patient post-stem cell transplant, if the ABO/D type has changed, request a second (NEW) specimen:
- Repeat the ABO/D type, verify that both specimens from this admission agree.
- Perform the ABO/D type using a gel or glass bead methodology, check for mixed field reactions.
- Verify that that forward and reverse types agree (i.e. are there any discrepant reactions?)
- Contact the Division Head, Transfusion Medicine, and give the history (i.e. date of the transplant) and describe all the reactions (historical type, new type, ABO discrepancies). He will tell you what blood groups of RBCs and plasma to use for transfusion.
Note: In an emergency situation, use group O RBCs and AB plasma. If the patient was previously D-positive and now post-transplant is D-negative, use D-negative RBCs if it is a female < 55 years old.