We have a patient who is now typing as A positive (2+ with gel and tube in the forward A type, no mixed field, 4+ with anti-D, no mixed field).  This patient was originally A negative and had a bone marrow transplant in 2010 from a type O Positive donor. The patient fully converted to a type O Pos forward type as of 2015, but never made anti-A (this happens, I understand, so I'm not concerned about it).  I would maybe think the patient was relapsing to his prior A blood type, but that does not explain the D+ typing. I would expect to see mixed field reactions if the patient was relapsing as well.  I did run his cells against the plasma of three type B patients, and the result was negative. I typed his cells with 5 different anti-A antisera from 4 different manufacturers, three of which gave positive results and two were negative. I did not test with A1 lectin.  Any idea what is going on here?

It COULD be that the patient is a secretor, and is secreting sufficient A substance, which is then adsorbed onto the group O red cells, for some very strong anti-A reagents to detect this adsorbed A substance (remember that the patient will still secrete A substance throughout his life, as the secretion is not affected by the bone marrow transplant).  This is a bit of a long shot, but I have seen it happen on very rare occasions.

Are you sure someone didn't transfuse this patient elsewhere with A positive red cells?  Sometimes patients relapse and another hospital transfuses them according to their current type (which may have been mixed field with no anti-A).  The vast majority of transplant patients in similar situations do not make anti-A.  The graft is presumably tolerized by all the A antigen present on non-lymphohematopoietic cells and in soluble form (even in non-secretors).  Worth getting a history in these instances. 

Edited March 26, 20187 yr by Neil Blumberg

Thanks for the input. Very good information. The patient's physician is investigating a possible relapse.  The suggestion that the patient may have been transfused elsewhere is a good one, but it wouldn't explain the strongly positive D typing, which is that of the patient's donor.  A relapse would involve both the ABO and the Rh types, would it not? 

1 hour ago, Kathy said:

Thanks for the input. Very good information. The patient's physician is investigating a possible relapse.  The suggestion that the patient may have been transfused elsewhere is a good one, but it wouldn't explain the strongly positive D typing, which is that of the patient's donor.  A relapse would involve both the ABO and the Rh types, would it not? 

Yes!

keep us posted

Is there anything I can do to resolve this?  Would adsorption and elution be helpful?

Not as far as the ABO group is concerned, as you are already getting reactions with anti-A.

What about neutralizations?

I don't think that would work either.

What I would suggest is looking for chimerism (HLA).

Edited March 29, 20187 yr by Malcolm Needs

 "A relapse would involve both the ABO and the Rh types, would it not?" 

 

One can have a relapse with recipient cells,  and still have donor cells present, which in this case would be Rh positive, yes?  If both donor and recipient types are present (as Malcolm suggests testing) you could have both O+ and A- cells, something we've seen on rare occasions.  Sometimes one cannot rely on mixed field typing to explain what's going on clinically. 

Usually with relapse, the graft is lost, but not always completely. Relapse is usually obvious on peripheral smear and cytogenetics. 

If the patient had been typed as A+ elsewhere due to the presence of both donor and recipient red cells, the patient might be transfused with A+ cells if that facility did not have a correct history and did not observe mixed field typing.  In this situation, we would probably transfuse washed O+ red cells. 

Edited April 2, 20187 yr by Neil Blumberg

Thank you.  Our transfusion director has spoken with the patient's physician and requested a peripheral smear, but I don't see any mention in the chart about suspicion of relapse. The patient is an outpatient with cGVHD who comes in for photopheresis.

If there is suspicion the patient was unknowingly transfused (has the patient been asked?), you could compare the genotype panel of peripheral blood and the phenotype (and look for mixed field in other typings)

The patient stated that he has NOT been transfused anywhere in the past 3 months. 

On ‎4‎/‎6‎/‎2018 at 10:26 AM, Kathy said:

The patient stated that he has NOT been transfused anywhere in the past 3 months. 

HI  Kathy, any follow up for this patient?