Strange ABO Discrepancy

[donellda]

I got a call from one of my staff members. They have a patient who forwards as a group B and reverses as an O with a weak rx on the B cell. They prewarmed the reverse group and the B cell got stronger. The antibody screen was negative, autocontrol positive, DAT negative. The patients serum is incompatible with all group O cells and group B cells. I'm thinking possible anti-H. So I'm having them do a room temp screen (although the B cell was stronger at 37??). I also asked them to test the patient cells with the serum of a group A patient to check for acquired B. The patient is supposed to be transfused Monday in dialysis but if we don't resolve it by then we will send it to ARC reference lab.

She got these reactions: 3+ reaction with group A serum and 4+ with Anti-AB so it's probably not aquired B or a subgroup of B. Screen cell I 3+ and II 2+ at room temp,so my guess is anti-H or HI. Maybe someone else can think of something. The patient's Hb is 8.0 so it's okay for now.

[bmarotto]

You said the screen is negative and auto control positive. At what phase(s) and/or method? You mentioned screening cells I and II are positive at RT. I assume you are using a 2 cell screen? Has the patient been transfused recently and if so does the auto appear mixed field? What about mixed field reactions on the positive B cell? It is strange that the B cell reacted stronger at 37 degrees. How do O cells react at 37?

[donellda]

The screen cells I and II were negative at 37 and AHG so O cells at 37 give a negative reaction. Immediate spin crossmatches with O cells and B cells were incompatible. The patient has no record of being transfused. The reaction with the O cells at RT and the positive autocontrol (I'm not there until Tuesday but I think the auto was done at RT) leads me to believe it is most likely an anti-H although the fact that the B cell in the reverse group got a stronger reaction when she tried to prewarm it confuses me a little. As far as mixed field reactions, she didn't mention a mixed field with the B cell.

Since it is the weekend and we only work with 2 people on the weekend, I told them to put it aside for now. Dialysis is aware of the situation and since his hemoglobin is 8.0, there really isn't a dire need for blood at this point. ARC reference will not go in on a weekend for a patient with a hemoglobin of 8.0 so we can probably wait it out until Monday until my senior tech goes in. I'm sort of curious and wish that I had not scheduled a vacation day for tomorrow but I'm pretty confident in my staff especially my 2 senior techs.

[bmarotto]

It doesn't sound clinically significant. You are probably correct that it is an anti-H or IH. Be sure to post back when you have an answer.

Enjoy your day off!

[donellda]

Thanks! I need the day off;)! I don't think it is anything clinically significant either. If I was there, I could probably play with it myself. It's something that I find fun (if you can call it fun:confused:). I'll post the final outcome when I find out what it is.

[javvcr]

Hi!

I´ll like to tell u, what would i do if i were u!

fist, title the antibody at 4º, and if it´s higher than 1/64, it´s clinically important so u most eliminate this interfirence by 37º. if it continue reactiing at 37, it´s probably an antibody of whide range of temperature, some times IgM can do that kind of things.

if u could use a Coombs reactive monospecific for IgG and other for C3d, it could help u to understand whats going on!

probably warm transfusion will resolve this situation but u most recomend that this pacient most be under attention and medicated.

Search for information such as CMV, Heptein Barr, Mycoplasma or othet infections that can start an policlonal inmune reaction and IgM of whide termic range!

Jimmy

[OPUS104]

You could REST adsorb the patient's serum to remove the suspected I or IH. However, the adsorbed serum can not be used for ABO testing as the rabbit stroma removes anti-B as well. The stronger reactions at 37 are strange for an I or IH. We have a lot of success with the REST system. Good luck and looking for your update

[donellda]

Well, they obtained a new specimen yesterday and there was absolutely no discrepancy in the reverse type. So they got out the 2 specimens from the weekend and whatever was there probably adsorbed out in the cold. They just did an AHG crossmatch to be on the safe side and called it a non specific cold antibody for now and everyone is happy.

[bmarotto]

Thanks for the update. At least you saved a reference lab charge.

[Yanxia]

It looks like protein agglutination or agglutination caused by fluid the patient have infused. Those kind of agglutinations can be differed through saline replacement or microscope.

Would you tell me the stronger reaction of the B cell at 37 degree C is how strong compare to O cell?

[donellda]

This happened back in June. I don't think that I could find it again since I don't remember which patient this happened to. We did get a new specimen and there was no problem with the new specimen so your guess is probably correct. Who knows though until it happens again:confused: