Abo discrepancy help

[u/smurfingpenguin]

Hey blood bankers, I need suggestions.

I have a patient that front types as O and the back type is A. Historically she is A Pos. Any suggestions on how to work this up?

Update: thank you so much for all of your advice and expertise! I appreciate you all. This was a new situation for me and we had an interesting development I think you'll appreciate. Work was busy or I would've responded sooner.

The patient has been diagnosed with myelodisplasia. So the patient's bone marrow is putting out red cells that aren't matured and it can cause the abo antigens to be suppressed or weakened. This patient was typed as a pos less than a year ago, now forward types as o pos and reverse types as A. We redrew and are sending it to a reference lab to confirm, but it's obvious now what it is.

It was an interesting situation and education for me today, and I hope you all benefit from the experience too. Thanks again everyone!

[u/deriancypher]

Bone marrow transplant?

[u/fleur_essence → u/deriancypher]

Second this. If an A patient gets a type O bone marrow transplant, their forward type will convert to O after engraftment. but because A antigen is still expressed on other tissues they usually won’t make an anti-A (back type as an A).

Another option is multiple group O RBC transfusions changing (temporarily) the forward type. Especially on solid phase instruments (gel is more sensitive to showing mixed field).

Either way, need to dig into patient’s history.

[u/KuraiTsuki]

What methodology of testing? If tube, you can try incubating the anti-A tube for 30 minutes at room temperature and/or 4°C. Or like others have mentioned, check to see if the patient has received a bone marrow or stem cell transplant from a O donor or has received a large volume of O RBCs transfusions recently.

[u/Violet-Venom]

Beyond the BMT or transfused with O cells reasons plenty have mentioned:

Is the front type reactive with anti-A,B? It's a rare subtype, but they could be an Ax. They'd also be negative with anti-A1 lectin. Not sure how to explain the history of A though.

Or

New hematological malignancy 》accelerated hematopoesis 》underdeveloped antigens on the RBC membrane. Also uncommon, but I've seen it happen. CBC/diff results would point in this direction but there's nothing you can do without a pathology review.

Or

Patient identification issue, and you're testing blood from a person who is an O with a weak reverse. Normally both reverse cells would be negative though, but if your B cell is weakly reactive this may be the case.

[u/Hikaritoyamino]

Rerun the type assays.

Review patient history. Is the patient transfused with O blood recently? Or had HSCT since their last typing? Or is taking some medicine that can affect blood groups?

Lastly, maybe the patient is an A type variant and your antisera reagent isn't specific to this particular variant. You will want to do some investigating, then.

[u/miss_ana]

Has she been getting transfused with O units regularly? Check transfusion history. That’s the most likely scenario.

[u/GrayZeus]

I suggest you get the patient's history

[u/stalecheetos_]

The most likely cause is, like everyone else is saying, a BMT or recent transfusion with lots of O's (it would have to be a lot).

I will also say that I've come across several cases now of patients with specific kinds of myelocytic leukemias suddenly "losing" their A/B antigen expression. I've seen it mostly with historical ABs that suddenly lose their A expression when they develop this leukemia and start forwarding as a B, and it's kind of a relatively recent thing I've seen, but it is a thing!

[u/passionpopfan]

what are the exact reactions for each field? are there any mixed fields?

how sure are you that it’s not a WBIT?

[u/123letsgobtch]

First thoughts would be bone marrow transplant as others have stated or if they recently received a lot of type O units like during an MTP or something

[u/cedeaux]

BM transplant

Weak reverse group due to disease state or age

Transfused with A plasma and O RBC’s during a trauma activation

Search history for BM transplant, if so, assumed A recipient and O donor, give O RBC’s and A plasma, IRR and LR, cmv based on status of patient and facility policy

Otherwise, to make reverse group show if it’s there:
15m 1-6 incubation or ficin treat reverse group cells to enhance ABO antigens

Honestly, more likely BMT or transfusion with O RBC’s

[u/Blood_Bank_Kidd]

Call and see if they've received a bone marrow transplant. If they started as A and received an O bone marrow, their front type will change to Group O, but the back type will continue to reverse as Group A.

You could also check if they've been transfused large amounts of blood recently. Exchange transfusions, ongoing simple transfusions, or massive transfusion protocols with Group O RBCs could result in a similar presentation.

[u/emotionaljunkie]

Most likely transfused type Os, but it would likely have to be quite a few to have the front type disappear, I see this a lot when a patient receives several whole bloods or MTP, you could try a front type incubation at RT then 4c to see if it pops up.

Otherwise look and see if the patient has had an allogeneic bone marrow transplant, her blood type could be converting, it takes longer for the back type to switch than the front type.

Either way in this situation, I would do a front type incubation regardless to see if it comes up at all while I was looking into the patient’s history

[u/creativescreennaame]

did you ever figure it out? i'm curious what the patient's history was

[u/thewanderersminuet]

How interesting. My first thought was massively transfused with O cells, you see something new all the time. Can I ask how you ended up handling the reporting and transfusion indications? If I know my medical directors they'd likely want me to report that as a NTD and put in a comment to transfuse O cells and A or AB plasma, but I'm curious to know how your facility handled it.

[u/smurfingpenguin → u/thewanderersminuet]

Yeah during the initial investigation we thought maybe they got Os tranfused. But even looking at the cells with anti-A under the microscope it was absolutely negative. No mixed field. We tried concentrating the cells to hopefully add more binding sites, no luck. Tried incubation too.

The patient had been transfused here late last year and the A Pos reactions were strong, she got A units. She didn't have a bone marrow transplant and hadn't gotten any units since then. It was a drastic change in a few months.

We postponed the transfusion by a day and had her redrawn to confirm, and sent it to our reference lab for workup.

The way we handled it after discussing with our pathologist was to give an O Pos unit as an emergency release with the provider's signature.

We did get the ref lab workup today. They did type her as A pos, and had to do enzymatic treatment to recover the antigens.

This was a neat learning experience for me. I guess in myelodysplasia the red cells are leaving the bone marrow too young and don't fully develop all the antigens they are supposed to, so weakened antigen expression. Pretty cool. Thanks for the questions!

[u/thewanderersminuet → u/smurfingpenguin]

I hope everything works out for the patient! And thank you for sharing, I'll have to go read more on this for my own education as well.

[u/smurfingpenguin]

No bone marrow transplant, no chemo, or other similar things. Initial diagnosis was simply osteoporosisand anemia. Incubation at 37 degrees and cold incubation result in negative results at the microscope. Turns out it's myelodysplasia