yan xia

I am sorry about the mistake I have made. I remember it wrong.

I post this question today, it is because I just met an ABpos baby,he is 3 months old, and still has anti-A in his blood, his mom is Bpos. Someone had transfused him with AB pos packed red cells yesterday, and I can still detect the anti-A in his plasma. I think it was stronger before transfution. So, the questions confused me are 1. B mom produce IgG anti-A , I used to think only O type produce IgG anti-A/B 2. 3 months the maternal antibodies are still here, so the half life of IgG is longer than 20 more days

I remember (not clearly) that AABB states for neonate less then 4 months, we should give type O washed red cells. If I remember rightly, but the IgG antibody' s half life is more than 20 days, then why we need 4 months to avoid the maternal sourced antibodies?

It seems like an acquired-B to me. Maybe you can try to lower the pH to 4.5 to see the lady's cells react with anti-B reagents.

The transfused cells are denser, so most of them at the bottom, and patients' own cells at the top.

I guess there are a mixture of alloantibodies anti-C and anti-hrs. What puzzled me is the autocontrol is neg, but the eluation result is pos. As for the eluation result, it maybe anti-LW.

Because the 37 degree C pos result was in tube, I thought maybe the room temperature saline reaction using tube will be better to interprete the result.Because card and tube are two different methods. Just personal opinion

Because of the normal B antigens on the cells, so we can see strong reaction on MF with anti-AB.

Brilliant post StevenB. I just out of curiosity, you said the after-adsorption plasma reactived with IAT, and had a titer of 16,384 , which is very high, but non reactive with PEG IAT. So interesting. If my understading of English is right

In my opinion, if we cannot select an antigen neg reverse cells, there are things we can do, it is adsorbing the plasma/serum using pooled O cells, then do the reverse typing, to get a neat anti-A or anti-B result.

Would you please explain why we can different the maternal blood and fetus's blood by using NaOH? Thanks!

Thanks for your advice. We often see neg DAT results with ABO HDFN in our work.( Because the A B antigens on the newborn red cells are weak ) You are right that I need an eluation result to support the HDFN . As to anti-A1, we got 3 pos with A cells and 3 neg results with O cells. And yes, maybe due to infection the baby's cells can be polyagglutinatable, just cannot interfere with the plasma reaction with donors and screen cells.

The baby's and his mom's plasma screen test is neg , and baby's plasma reacted with three different A donors' cells, so I suspect it is anti-A( anti-A1).

I have met two cases of babies. Their plasma had anti-A or anti-B, as their correspond type. And the doctors had not seen HDFN signs clinically. We found it through crossmatch.( we issue same type blood to infant have no ABO HDFN).

The baby's DAT is negative. Yes, the baby has anaemic and very bad sicked on the machine to help him breath. He has very servere infection, maybe this cover the symptoms which shows HDFN. And ABO HDFN is always mild. The jaundice is normal.