All of a sudden clinically significant anti-A1

[Jyoung]

Your right, I read about that in "The Discovery & Significance of the Blood Groups." A, B, H, I, Rh, YTa, and Colton antigens are all affected by leukemia. I wonder if the front type would show signs of this "alter state?"

[Malcolm Needs ☆]

Oh yes, without a doubt. The genes encoding the transferase enzymes that eventually confer the A and B antigens on red cells are on chromosome 9, as is a gene involved in myeloid proliferative disorders, and these genes are quite close to one another.

It would appear that the gene that is involved in the myeloid proliferative disorders can affect the gene that encodes the ABO transferase enzymes, so that these do not "work" as "efficiently" as they would be expected so to do.

I remember, way back, someone telling me of a doctor who had AML at one of the London Hospitals (if I remember correctly, it was The Royal London Hospital, but that is neither here nor there really) who was group A, but "changed" to become group O. I was told that one could almost tell whether this doctor was in remission or relapse just from the strength of the A antigen expressed on his or her red cells.

[Malcolm Needs ☆]

PAPER ALERT!!!!!!!!

There is a paper that is very interesting on this particular subject, whcih has just been published.

Jaben EA, Jacob EK, Tauscher C, D'Souza A, Hogan WJ, Stubbs JR. Clinically significant anti-A1 in a presumed ABO-identical hemopoietic srem cell transplant recipient: a case report. Transfusion 2013; 53: 202-205.

[sshel55]

I hesitate to respond but here goes. You might want to look at the anti-A titer in the platelets the patient received. There are numerous papers (including ours) that address hemolysis from group O apheresis platelets transfused to group A recipients. The fact that he is negative with A1 lectin is suspect, especially if he has been receiving A RBC as `80% would be expected to be A1. That would mean he has cleared most of the transfused cells. Does he show clinical evidence of hemolysis? Regardless of the reason, group O RBC should be given until or if, group A RBC are crossmatch compatible again.

[Malcolm Needs ☆]

Agreed, and never hesitate to respond! I've learned tons from this site from people who regard themselves as "not worthy" of responding!

[Jyoung]

At the time when I discovered the anti-A1 I did not think about, what platelets the patient recieved. We actually started crossmatching this patient's platelets, but I think that was after finding the anti-A1 and I'm sure we transfused platelets before finding the anti-A1. So definitely possiblity! Thanks!

[apajares]

It could be a case of minor incompatibility caused by the O platelets transfused with a powerful anti A

In the previous answer I had mentioned this, but apparently no one was interested

[Malcolm Needs ☆]

Sorry, I missed that Alex.

[apajares]

Don´t worry Malcolm, I tought it was because of my problems with the language, because I do not speak or write the english well.

[Jyoung]

I missed it too! Sorry!

[Jyoung]

All this input about anti-A1 is great. And I will definitely benefit from all of it if I ever see a patient with anti-A1 again. Since I'm one of those people that can't help but to ask why about everything. Im sorry, but I have another question.....

When a patient that is A1 and is transfused with an O platelet that has a high anti-A1 titer wouldn't that prompt an acute intra and extra vascular transfusion reaction?

[profbaud]

OK - so I ran the eluate vs A1 and A2 cells: A1: 4+; A2: 2+. Screening cells are negative. Last wash was negative. Anti-A? Seems like that to me . . . Could this guy have an auto-anti-A? or is the sensitivity in gel such that the A2 cells are reacting with an anti-A1 (I don't think so)? If I ran it in tubes, the A2 cells might be negative . . . Opinions . . .

Thanks

David, test your eluate against B cells to make sure it isn't Anti-A,B which is an IgG antibody present in the plasma of group O patients. If it is, then giving group O cells will be ok, but I wouldn't transfuse group O platelets.

[David Saikin]

To me it is a moot point whether it is anti-A1 or anti-A,B . . . I am treating the pt the same way. I don't always have a choice of types for plts . . . either A or O, whatever the blood center has at the time. It is even more of a moot point as my pt has gone for his BMT.

[janet]

We had a group A MDS patient have a hemolytic reaction to a group O platelet - so we starting titering our platelets before issuing incompatible. He came in a year later and all we had were O's again. Titre was okay so they were issue = hemolytic reaction AGAIN

Dr. tested for PNH and he was positive..... a high percentage of MDS patients transform to PNH and since their cells are primed with complement from the disease there is a risk of hemolysis if incompatible products are given. The Canadian Blood Services area Medical Director prepared a poster for AABB - I will try to post it when I'm back at work tomorrow, recommendation was to watch for these MDS patients!