A suspected HDN case

[Yanxia]

There is a mother is B neg, have a 4 years old son. The newborn is AB pos.

The anti-D in mother's blood titer is IgM 1 and IgG 2.

The cord blood is weak positive and elution anti-D is weak, too .

I wonder this is first-immune or memory reaction.

If the prenatal antibody titer is weak can it indicate the HDN is mild?

Is ABO HDN plus Rh HDN serious or weaker than Rh HDN lonely?

Can we use the same type of blood as the mother to do the exchange transfusion( compatible with the mother serum antibodies)?

If we can do like this, what is the meaning of eluate the baby's blood cells?

If prenatal antibodies titer is too high, Caesarean birth or not Caesarean birth( sorry, I don't know how to say the birth without surgical interfereance) will be better to the baby?

So many questions just because a case, I look forward to any help.

[GilTphoto]

ABO HDN is unlikely in type A or B mothers, since the anti-A and anti-B are primarily IgM and do not cross the placenta. The anti-A,B from type O mothers is IgG and can cross the placenta. Even if the baby's DAT is positive due to anti-A,B, it rarely caused hemolysis or the need for exchange transfusion.

Anti-D - A titer of less than 4 usually indicates passively acquired due to ante-partum RhIG. You didn't mention whether this mother received RhIG, and if so, how soon before delivery.

Even if anti-D is eluted from the baby's cells, it does not indicate a need for exchange transfusion. The biggest indicator for exchange transfusion is the total bilirubin. In a normal birth weight baby with no complications, the bilirubin would need to be around 20 mg/dL before transfusion is necessary.

[galvania]

If the baby is ill enough to require an exchange transfusion, maybe you should also try testing the eluate against the father's red cells. If this is reacting much more strongly that the reaction you are getting with D+ cells, it's possible that there's another antibody, maybe an antibody against a low frequency antigen, present

[bbbirder]

Did the baby actually require exchange transfusion? or are you just trying to plan ahead?

ABO incompatibility can be somewhat protective against sensitization against other antigens, at least in a group O mother. I guess it is possible that this woman has IgG anti-A, the result of previous pregnancy.

I knew a tech who worked in Saudia Arabia for a while and commented that ABO HDN could be quite severe (requiring exchange at times) in the Arab population. I have no idea why this would be the case, have not read about it, and maybe she was just telling me tales. But maybe there are real differences in this in different populations.

Based on the anti-D titer, I would not think you'd have too much trouble due to the anti-D.

Maybe there is another 'private' antigen involved (as galvania, suggested, test the father's blood.)

I have question for you, Yanxia, where are your red cells for antigen typing and antibody ID (panels) made? Since you are in China, I would assume that you need a somewhat different mix of cells for screening and ID than we do in the US or Canada, but as our population becomes more diverse, we may need to be on the lookout for other antibodies as well.

[galvania]

Did the baby actually require exchange transfusion? or are you just trying to plan ahead?

I have question for you, Yanxia, where are your red cells for antigen typing and antibody ID (panels) made? Since you are in China, I would assume that you need a somewhat different mix of cells for screening and ID than we do in the US or Canada, but as our population becomes more diverse, we may need to be on the lookout for other antibodies as well.

....Especially Mia

[Mabel Adams]

Did you test the eluate against A cells? If there happened to be any anti-A in it, this would react with the father's cells and could mislead you.

If a baby needs to be delivered early due to risks of HDN, then a Caesarean might be necessary, but unless there are other reasons to do a Caesarean, a vaginal delivery should be fine.

If you needed to do an exchange transfusion, donor blood should be ABO and Rh compatible with both the mother and the baby and compatible with any other antibodies the mother has--at least if you are going to do the crossmatch using the mother's serum. You could use B neg or O neg units in the case you described.

[Yanxia]

Thanks. I learnt lots of things in this post, I feel very happy to read all the replies.

The baby had not done exchange transfusion, he is fine, and he is delivered through vaginal. We have not test anti-A in the baby's elution.

In China we use the screening cells made in Shanghai Blood Center China which include Mia antigen.

In China Han ethnic people part of ABO HDN need do exchange transfusion and some just need blue-light cure, lot of just have jaundice which is a little severe than normal need no medical cure.

[Yanxia]

Oh, there is a question I forget. In China the D neg peole's frequency is 4 in 1000 peole, and in those D neg peole 1 in 3 is Del which may not produce anti-D, and because the price we don't use RhIG routinely.

I suspect the reaction in the mother is first immune, because her IgM and IgG titer is so low.