We have received one pregnant patient who had history of parabombay A (Ah-secretor). Four years ago, she was admitted for elective LSCS for her pregnancy.The blood group test done at that time showed forward reaction negative and reverse reaction positive to B cells (4+). The patient has received one parabombay A unit from her sister at that time. Recently, she was admitted for another LSCS and I was curious about the blood group testing. Her forward grouping was same, but reverse grouping showed 4+ reaction to A1 and B cells, 2+ to O cells. We used Bio-vue system for grouping. Antibody screening was negative. My question is the patient can actually develop anti-A1 antibody if her blood group is parabombay A. Thanks in advance!

Dear Kyaw

What you are seeing here is surely NOT an anti-A1.  You also have a reaction with the O cells.

You should put up a complete panel at room temperature .  The antibody screen was negative at room temperature, but that does not exclude the presence of cold antibodies (for example P1, M) active at room temperature.  It may also be a mixture of a cold anti-H and another cold antibody (It can't be just an anti-H as the reaction with the A cells is stronger than that in the O cells)

Dear Galvania,

 

Thanks for reply.

Yes, I really don't know whether she can develop anti-A1, and made me confuse.

To update information, we received her new sample after the one in question. Forward and Reverse reaction were the same, but antibody screening was 1+ reaction in cell III (We use Abtectcell III 0.8%), and DAT was negative. Then we put the panel (We use Diamed panel), but the panel was negative.

To make it more complicated was when we knew that she was admitted for LSCS, before we can get either bombay or parabombay blood, we try to get some compatible units if possible, for emergency. Our plan is we will crossmatch with A pos units, again cross match was incompatible. However, we got one unit O pos compatible. That's weird.

Fortunately, we got two bombay units for her and more fortunately, her pregnancy was delivered safely.

Edited January 12, 201510 yr by Kyaw

It is a little strange that your panel was completely negative when all the crossmatches were positive - UNLESS we are talking about a cold antibody and the blood bags were taken straight out of the fridge and tested cold, where the panel was allowed to warm up.  In addition, if you performed a crossmatch with LISS, this would enhance any cold antibodies.

How did you do the panel?  If you did not carry out a panel at 4°C or at room temperature, rather than on Coombs, then I would recommend this.  Exceptionally you could also do a Coombs panel with 15mins incubation at room temperature (but never do this in routine!!)

Yes, Galvania, we did crossmatch with LISS and panel at 37°C.

One thing I am not clear is if it is cold antibody; why it didn't react with bombay units?

And it cannot be anti-A1?

This is only for my learning process, as for patient's management, we will give, for sure, bombay units.

Well, I am guessing from the information in your mails  that there are two antibodies - one is an anti-H and the other is something like anti-P1 or anti-Lewis.  But most importantly, I think, is the temperature your blood bags were at when you sampled them.

If you can carry out the cold panel that should resolve the problem.

Actually, we didn't do cold panel.

As the patient has only soluble A antigen, my consultant concluded that may be different epitopes can stimulate to produce anti-A1 or like antibody.

However, next time, when the patient come back, I have to keep in mind about certain cold antibodies. Thanks.

Dear Kway

Well, the important thing is that the baby was OK.  But, perhaps your consultant would like to explain how an anti-A1 can give a 2+ reaction with O cells?

If she comes in again let us know what the results are

For reaction to O cells, we concluded due to presence of anti-H or anti-HI. For A1 cell, because of 4+, the possibility of another antibody was raised. 

I will update when the patient comes back in future.

Thanks for your reply, Galvania.