I had a patient this weekend with a history of type A pos, negative antibody screen. We last transfused her on 05/13/10 with 2 units of A Pos RC with no adverse reactions. Ten days later, she is forward typing A but reverse typing O; all reactions are 4+ in strength. While everything is incubating/spinning I did an immediate spin XM and the unit was 1+ incompatible. Her antibody screen was 4+ positive with 2 of 3 screening cells. Panel turns out to be anti-c (4+) and anti-E (4+). The patient has been in the hospital continuously due to gangrenous transverse colon and subsequent surgery. Both units that were tx on 5/13 turned out to be c positive and one was E positive.

I think the reverse typing reactions are due to the fact that the reverse cells are c positive, but I have never seen an antibody response this dramatic. Has anyone else seen anything like this? Can an antibody really form that quickly and strongly that it would agglutinate at immediate spin? I know that intestinal bacteria can modify antigens on cells, but could they be playing a part in this as well?

Thanks in advance.

I think you are correct--the antibody response is quite dramatic which probably IS causing the back type problems. Is the patient's hemoglobin dropping; is this a delayed hemolytic transfusion reaction? This is classic presentation for one.

As Bill said this is not abnormal at all. Unless the patient has a severly weakened immune system the response is agressive and rapid in many cases.

I would agree with Bill and Deny, however, it is quite rare for an Rh antibody to cause interference with the ABO reverse grouping, unlike an anti-M. It suggests to me that you have just managed to "catch" the anti-c as it is converting from the initial IgM response to the secondary IgG response (which can be very quick indeed.

I once had something very similar (now seems eons ago) with, of all things a cracking anti-Jka that only reacted at room temperature by direct agglutination, but two days later could only be detected at 37oC by IAT and with enzyme-treated red cells. It was all very alarming for a, then, callow (or was it callous?) youth!

:D:D:D:D

I would agree with Bill and Deny, however, it is quite rare for an Rh antibody to cause interference with the ABO reverse grouping, unlike an anti-M. It suggests to me that you have just managed to "catch" the anti-c as it is converting from the initial IgM response to the secondary IgG response (which can be very quick indeed.

Well, the patient denies any transfusions other than what we have done in the past so I was thinking along the lines of Malcolm in that it was IgM and just formed, especially since it was reacting at Immediate Spin. I was very surprised, to say the least, at the change from negative, to 4+ so quickly!

As for the possibility of DHTR, her hemoglobin was dropping slightly, but due to this or the surgical intervention I cannot say. I would love to get another specimen to see what it shows now, but since they dismissed her, I doubt I will get to find out.

Have you done an antigen type on the reverse group cell for c?

Have you done an antigen type on the reverse group cell for c?

Yes, it was c positive. That is why I concluded that was the cause of the ABO discrepancy. It really surprised me that they would be c positive, but then I remembered that anti-c isn't supposed to react at IS.

Yes, it was c positive. That is why I concluded that was the cause of the ABO discrepancy. It really surprised me that they would be c positive, but then I remembered that anti-c isn't supposed to react at IS.

The trouble is, the blank, blank antibodies never read the books!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

:eek::eek:

In day to day work it gets really easy to space off that those reverse group cells have other antigens on them. It gets in your head - that's an A cell or B cell, etc - and the other antigens just get swept under the rug until they jump out and surprise you, like this patient did. It's something that is really stressed in the teaching materials I get for my Medical Technology students. They get several exam questions about just that sort of situation. Makes me wonder if the person who wrote the materials had an interesting experience with this kind of patient.

? A2 with anti-A1 due to initial transfusion of A Pos Red Cells.

? A2 with anti-A1 due to initial transfusion of A Pos Red Cells.

That was actually my first thought, but the patient was A1 so that blew that theory. I was lucky that I still had the patient specimen and the segs from the transfused units to perform my typing on.

Nice try John, b ut no way would an anti-A1 give you that type of reaction in the antibody screen as the antibody screen cells are all group O....

In my defefence, I was not looking at the antibody screen as the anti-c/E were already confirmed. I was looking only at the ABO grouping as O in reverse group. We recently had a haematology proficiency here where a CLL patient had p.falcip. Nobody spotted the malaria because they were too busy looking at the high WCC. Maybe the ABO dicrepency has nothing to do with the Anti-E/c. The only other reason I could think of other than the ones mentioned in other replys was an anti-A1 etc. As the patient is A1 then the suspician falls back on the anti-E and c as the most probable culprits.

I believe this anti-c was IgM so it reacted @ IS. We had similar case with anti-c...you need to rule out hemolytic reaction(acute or delayed) most likley it will be extreavascular hemolysis...but this case due to IgM you may see some intravascular hemolysis.

I think the reverse typing reactions are due to the fact that the reverse cells are c positive, but I have never seen an antibody response this dramatic. Has anyone else seen anything like this? Can an antibody really form that quickly and strongly that it would agglutinate at immediate spin? I know that intestinal bacteria can modify antigens on cells, but could they be playing a part in this as well?

QUOTE]

I agree with the many comments that, although it is not common, I have seen situations where Rh (or other) antibodies can show up on the immediate spin reverse grouping.

On the topic of intestinal bacteria modifying antigens on cells......I don't think that phenomenon has anything to do with the case you have described. (There's no indication that there's anything wrong with the patient's red cells.)

Another comment, commercially-prepared reverse grouping cells are usually Rh(D) negative, (so they are c positive.)

A late responce but maybe stil a good addition.

I see this quite often now a days, specialy in the gel technic. In tube be only will be botherd by IgM antibodies (M, new anti c) but in gel we see alos very strong anti c antibodies who are reactive at RT even long after formation. I think the gel is more sensitive for strong IgG Rh antibodies then we want.

Sorry I was forgetting to read the next page, and see now that L106 has given my commend.

Edited October 31, 201113 yr by Rh-fan
not reading all posts

How can a method be *too* sensitive. If they've got anti-c, surely you're best picking it up than ignoring it? I'd rather have a 3+ reaction than a 1+ reaction...

In this case we want our methode to detect IgM antibodies (anti A and anti , and therefore the methode can not be too sensitive. But if this methode detects antibodies you want to detect in an other methode (like anti c in your antibody screen/identification) it becomes too sensitive for things I do not want to see there. Every methode that is very sensitive is nice but also will have its disadvantages, also for the PEG IAT methode, it is very sensitive for all IgG antibodies but is to sensitive for IgG warm antibodies. So it is not the fact the methode is to sensitive but we see more than we want to see.

We recently had a haematology proficiency here where a CLL patient had p.falcip. Nobody spotted the malaria because they were too busy looking at the high WCC.

So it WAS Falcip. ? Everyone took the Mick out of me for calling a dual pathology! I never did get round to looking at the results...