HAD A PATIENT THAT GAVE A 2+ REACTION IN ALL SCREEN CELLS AND WITH ALL UNITS CROSSMATCHED. DAT NEG, NO ALLOANTIBODIES. SENT TO ARC FOR WORKUP. PT ONLY REACTED LIKE THIS IN THE GEL SYSTEM. EVERY OTHER METHOD WAS NEGATIVE. IT WAS DETERMINED THAT THE PT WAS ACTUALLY REACTING TO SOMETHING IN THE GEL SYSTEM. IN FACT PATIENT WAS REACTING TO MTS DILUENT. HAS ANYONE ELSE EXPERIENCED THIS PROBLEM?

DBritt,

We have experienced this at our facility enough so that we have a protcol of washing the sceening cells in saline and reconstituting in saline as well, and repeating the screen. The repeat is usually negative. I have some reservations about this procedure because there would be a difference in buffering range between MTS and saline. And I am not sure I accept the idea that a patient is reacting specifically with the MTS diluent either. I think that the correct way to describe this anomally is to say that a reaction is taking place in the presence of MTS but not in the presence of Saline. We have had no trnsfusion problems, however. So the MTS, with respect to certain patients, does cause what appears to be clinically insignificant reactivity.

HAD A PATIENT THAT GAVE A 2+ REACTION IN ALL SCREEN CELLS AND WITH ALL UNITS CROSSMATCHED. DAT NEG, NO ALLOANTIBODIES. SENT TO ARC FOR WORKUP. PT ONLY REACTED LIKE THIS IN THE GEL SYSTEM. EVERY OTHER METHOD WAS NEGATIVE. IT WAS DETERMINED THAT THE PT WAS ACTUALLY REACTING TO SOMETHING IN THE GEL SYSTEM. IN FACT PATIENT WAS REACTING TO MTS DILUENT. HAS ANYONE ELSE EXPERIENCED THIS PROBLEM?

Yes, we've seen this a few times with patients whose plasma has reacted to red cells kept in DiaMed Preservacell, but not in DiaMed Diluent 2. Apparently, it is an antibody directed against one of the antibiotics in the former, that coats the red cells.

DiaMed told me this, or, rather, Imelda Bromilow of DiaMed told me this, and I have huge respect for Imedla, and so I am quite content that this is the true reason.

:D:D:D:D

We have found this several times. We believe the reaction is to antibiotic in the Gel media itself. If we have a patient's plasma that reacts with all cells on Gel antibody panel, we perform a PEG screen in tube. If the results are negative, we feel the reactivity is related to Gel system, and we flag the patient's demographics so we know to perform antibody screening in PEG in future.

We have seen this too quite a few times. We jokingly call them "gelibodies".

We have found that as Malcolm says it was an antibody to the antibiotic in the diluent which by the way is in the liquid in the gel card itself.

We have had enough "gelbodies, I really like this term", that I take Immucor screening cells, wash them with MTS diluent and them dilute them to 0.8%. Most of our "weird" ones are negative with these screening cells. Our only other option is to go to tubes and I'm afraid that any negative reactions are due to using a weaker screening technology.

We run daily QC on these Immucor gel diluted cells. Does anyone see a problem with this?

Antrita

We have seen this problem a few times. We even have one patient that will react with only Ortho reagents. The specimen is fine if you use Immucor or other reagents. We like the term, "Anti-Ortho antibody".

Would you all agree that if the patient is reacting to the antibiotic in the red cell diluent that it should react with the entire panel. We are seeing this quite often but sometimes it doesn't react with all ten donor cells on the Ortho panel but the reactivity really looks like an ARD. I would appreciate any feedback.

22 hours ago, mimi03 said:

We are seeing this quite often but sometimes it doesn't react with all ten donor cells on the Ortho panel but the reactivity really looks like an ARD.

It's remotely possible that Ortho use different diluents for different cells. I remember a rumor that "fresh" cells are suspended in one kind of diluent, but frozen-thawed cells are in a similar diluent with a couple of extra chemicals to compensate for the freeze-thaw process. I think that frozen-thawed (deglycerolized) cells are sometimes used in emergencies when the scheduled donor(s) don't appear.

Thank you for that information.  That makes sense and explains a lot

Most of our antibodies to gel diluent react only with the pre-diluted reagent cells, but not in cells suspended in MTS diluent 2 (auto control, XMs).  There are no antibiotics in the diluent 2 because those suspensions are discarded promptly whereas the reagent cells must remain stable for weeks.   If there are antibiotics in the gel itself, we have not seen reactions to that, but it makes sense.

Me, too. I had two patients within a week that had reactions to MTS. We sent it out to ARC and it was all negative. 

On 5/6/2023 at 11:18 AM, Mabel Adams said:

Most of our antibodies to gel diluent react only with the pre-diluted reagent cells, but not in cells suspended in MTS diluent 2 (auto control, XMs).  There are no antibiotics in the diluent 2 because those suspensions are discarded promptly whereas the reagent cells must remain stable for weeks.   If there are antibiotics in the gel itself, we have not seen reactions to that, but it makes sense.

I'm correcting this because I learned that Diluent 2 does have antibiotics, but it lacks some other chemicals used in prediluted cells.  This information is from the instructions for use so you can verify what is in each.