C3d Positive DAT in cord blood.

[Malcolm Needs ☆]

This isn't a Case Study, per se, but I have posted before on this site that, every now and again, we perform a DAT on the cord blood of a baby from a mother who has anti-Jka in her plasma, and we find that the DAT is positive both with anti-IgG and anti-C3d.

We had one at the end of last week, re-tested today, that was barely 1+ DAT by anti-IgG, but is 4+ DAT by anti-C3d.

I've never seen one showing this phenomenon quite so strongly before.

Anti-Jka could be eluted from the cord blood.

:eyepoppin:eyepoppin:eyepoppin:eyepoppin:eyepoppin

I have asked for the card to be preserved so that I can take a photo of it tomorrow (my camera is at home) and I will try to post it here then.

The emphasis is, however, on the word "try"!!!!!!!!!!!

Edited November 14, 2011 by Malcolm Needs
Missed off a bit.

[Yanxia]

Thank you Malcolm for sharing such a interesting case with us.

The DAT result of anti-C3 is so strong, does it mean this case of anti-JKa is strong complement binding. I guess to do a test about complement binding of the mother's blood antibody and to test the antibody‘ s subgroup will find more interesting things. This is just my guess.

[Yanxia]

Because the baby's DAT is 1+, so the free antibody in the baby's blood is weak, so I say use the mother's blood to detect. But I think the baby's antibody is ideal.

[Malcolm Needs ☆]

There was free maternal anti-Jka in the baby's plasma (2 to 3+ by enzyme-IAT and weakly positive by IAT with untreated red cells), but the baby's red cells are Jk(a+b+), and we were able to elute anti-Jka from the baby's red cells.

[Dr. Pepper]

This case is an excellent reminder that we still should be concerned about complement activation. When I first started in BB in 1973 we did, ahem, room temp crossmatches along with AHG crossmatches using polyspecific AHG. Needless to say, we found an awful lot of insignificant IgM antibodies. Why did we do this? In part because the saintly Peter Issitt in the first edition of Applied Blood Group Serology said cold agglutinins were significant. (I also suspect he got a cut from sales of anti-P1, etc. typing serum.) I believe in the second edition he recanted, with some embarassement, stating the evidence had been out there that they weren't much of a problem unless active at body temperature.

So it wasn't long after that we dropped the room temp test and everyone started using just anti-IgG for routine testing. EDTA plasma is now commonly used instead of serum. Gel and solid phase are heavily slanted towards detecting just IgG. I think that complement has become a serologically forgotten blood bank villain, and we also forget that once in a while some IgG antibodies, notably anti-Jka, are more readily detectable by the complement they can bind than by coating of cells with IgG.

In recognition of this, in our compreghensive transfusion reaction investigation we perform repeat antibody screens and full crossmatches using poly.

[Malcolm Needs ☆]

I agree with you Phil, but this was a positive direct antiglobulin test on cord blood - and the received knowledge is that babies' complement is at such a low level that we only need to perform an anti-IgG DAT on cord blood.

As mentioned above (and elsewhere on this site), I have seen this phenomenon before, but only when the mother's antibody is within the Kidd BGS (and usually anti-Jka at that - although this may be because anti-Jkb is that much rarer), but I have never seen it as strongly as this before, together with such a weak reaction with anti-IgG.

[Dr. Pepper]

Thanks for piquing my curiosity on this subject (and excuse my age-addled musings on our neglected friends C3 and its siblings...). I found an article in Vox Sanguinis from a few years ago where they found newborns had about half the adult levels of complement. I would think that would be enough to cause some problems. We haven't had babies born in our hospital for years, but if this can happen what would be the harm in doing baby DATs with poly AHG? Don't most places limit their DATs anyway to symptomatic infants to avoid all the subclinical ABO-caused positive DATs? Are there other conditions that can cause a newborn's cells to be coated with complement that could muddle the clinical picture?

Hope the baby is doing OK. )I'm not sure our patients would always share our enthusiasm over the unusual things we find in their serum and on their cells....... )

[Auntie-D]

All of the gel cards we use are IgG/C3d, mainly because they are the same cost the same as soley IgG ones and we do that few that they would expire - so we use them for everything. We do seem to pick up a few antibodies that our reference lab who use IgG only Ortho cards don't seem to find. If the antibodies are C3d reacting that would explain it... It has been a bug-bear of mine for a while - they describe us as 'oversensitive'.

Does anyone know if anti-c is more reactive with C3d? We have a patient who has Anti-c but the titres are too low for our reference lab to pick up - we get 3+ though...

[Malcolm Needs ☆]

Does anyone know if anti-c is more reactive with C3d? We have a patient who has Anti-c but the titres are too low for our reference lab to pick up - we get 3+ though...

No Rh (no, that's wrong), an incredibly few examples of Rh antibodies are able to activate complement through to the membrane attack phase ( we all know about the anti-D "Crawford" that did do this from textbooks), so, unless you have an anti-c worthy of a paper, I very much doubt this.

What I think your reference Centre is doing is quantification on the anti-c (IU/mL), rather than a titration, and, if the quantification is exceedingly low, as I would suspect in this case, as your reactions are 3+, then the figure obtained would be unreliable, as there is a certain amount of "background noise" with quantification, and so, in terms of IU/mL, it would be unreportable.

If they are not finding it at all, by serological techniques, then I would worry about the Reference Laboratory!

[galvania]

I'm musing - Malcolm, do you think the complement on the baby's cells was its own complement, or complement that might have crossed the placenta from the mother?  Apologies if this is a silly question.

[galvania]

something wierd is happening here. Letters appeared on their own in my last post and I can't edit it

[Malcolm Needs ☆]

It is by no means a silly question Anna, but the thing that I have noticed is that I have only ever seen this phenomenon in cord bloods with a positive C3d DAT when the maternal antibody is within the Kidd Blood Group System, and, leaving aside antibodies known not to regularly cause complement activation, such as those within the Rh Blood group SYstem, I would have expected to have seen the same phenomenon from time to time with other maternal antibodies (such as anti-Vel) if this were the case.

[AMcCord]

So....here's my question, Malcolm. In light of this, do you think that using anti-IgG only for routine testing for cord blood DATs is good practice? And in cases where mother is known to have a clinically significant antibody, use anti-C3 as well? or only if she has anti-Jk a or b?

Question to everyone - what do you all use for cord blood DATs? Poly or anti-IgG?

Our DAT testing on cord bloods is not limited to only infants who seem to be having problems or infants of women with antibodies, so we have the potential to pick up lots of positive DATs due to ABO incompatibility.

Edited November 15, 2011 by AMcCord
Why do I get two Malcolms but can't edit one away??

[Malcolm Needs ☆]

So....here's my question, Malcolm. In light of this, do you think that using anti-IgG only for routine testing for cord blood DATs is good practice? And in cases where mother is known to have a clinically significant antibody, use anti-C3 as well? or only if she has anti-Jk a or b?QUOTE]

Well, to be honest with youI have only seen this phenomenon involving Kidd antibodies and, except for some incredibly isolated cases, Kidd antibodies are not clinically significant as far as HDFN is concerned (although, of course, it is exactly the opposite as far as transfusion is concerned), so no, I would not recommend in any way using anti-C3d routinely for any cord DAT's.

The reason that I detected this is because we use exclusively DAT cards that have anti-IgG, anti-IgA, anti-IgM, anti-C3c, anti-C3d and a control in my laboratory, and that is because we use them on many of our AIHA cases, and very rarely indeed do we perform DATs on cords, because we do not often get such samples sent to us.

I will now do my very best to upload the photograph, but I also have a question for you AMcCord. I see from the reason you edited your post, it was because you had two Malcolms and wanted to get rid of one. What's wrong with having two of me????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!

:rofl::rofl:

[ATTACH=CONFIG]577[/ATTACH]

You will notice from this that, when I said that the reaction with the anti-IgG was about 1+, I was being a bit liberal; it is probably closer to 0.25+!!!!!!!!

[L106]

Wow! Great picture! (Now, aren't you proud of yourself?)

To answer AMcCord's question....Because our entire staff rotates, I have to admit that we took the "Keep It Simple, Stupid" route. Since we do our Direct Antiglobulin Tests in duplicates on adults (ie: one tube using Anti-IgG and one tube using Polyspecific AHG) we do the same for Direct Antiglobulin Tests on newborns.

Donna

[AMcCord]

I will now do my very best to upload the photograph, but I also have a question for you AMcCord. I see from the reason you edited your post, it was because you had two Malcolms and wanted to get rid of one. What's wrong with having two of me????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!

:rofl::rofl:

My oh My, WHAT was I thinking! If two heads are better than one, then 2 Malcolms would have to be exponentially better than that! I grovel before thee, oh wise one.

Well actually, now I'm only seeing one Malcolm.........guess I won't have to grovel after all.

P.S. Nice photo.

[Liz]

What is the method that you use for quantification?

[Liz]

.....

Edited November 16, 2011 by Liz
Duplicate, pressed twice.

[Malcolm Needs ☆]

What is the method that you use for quantification?

Sorry to be thick Liz, but quantification for what?

[Liz]

..........What I think your reference Centre is doing is quantification on the anti-c (IU/mL), rather than a titration, and, if the quantification is exceedingly low, as I would suspect in this case, as your reactions are 3+, then the figure obtained would be unreliable, as there is a certain amount of "background noise" with quantification, and so, in terms of IU/mL, it would be unreportable.

If they are not finding it at all, by serological techniques, then I would worry about the Reference Laboratory!

Hello Malcolm, I was referring to this.

[Malcolm Needs ☆]

Oh, right Liz.

The best thing I can do is send you an email from home with a lecture and explanation included.

I can't post it here, as it is huge and needs to be zipped (unless, of course, you can open the lecture in the library bit, education, lecture on HDN. I tried to do this myself the otherday and failed miserably).

[Liz]

That would be great Malcolm, thanks, looking forward to it

[Liz]

I was inspecting your lab in the picture that you posted here!!

[Liz]

Lots of timers!

[Malcolm Needs ☆]

Lots of timers!

Well, two, and both about the same age as me!

Place needs a lick of paint though.

:haha::haha: