A D - lady presently pregnant with history of one previous delivery of a D- baby, developed anti- C post delivery. Now 4 years later we see she has anti-D. The titer of her antibodies was 8, 4 months ago, is now 2.

She has not yet recieved RhIg for this pregnancy.

So what happened ? why the +1 for anti-D (she has +2 for the C)??

thanks

Liz

A D - lady presently pregnant with history of one previous delivery of a D- baby, developed anti- C post delivery. Now 4 years later we see she has anti-D. The titer of her antibodies was 8, 4 months ago, is now 2.

She has not yet recieved RhIg for this pregnancy.

So what happened ? why the +1 for anti-D (she has +2 for the C)??

thanks

Liz

Hi Liz,

As the lady has an anti-C with a titre and avidity that is greater than her anti-D (as I read your post), I would suggest that actually what she has is an anti-G, or possibly an anti-G+C, rather than an anti-D+C.

It might be well worth your while finding out the Rh phenotype of her partner, to see if he is an r'r (or could possibly have an r' haplotype), and, if she has been transfused, whether any of the units given were r'r, which would point in this direction.

The other thing you could do (unless you are lucky enough to have some r"Gr red cells available), is to split an aliquot of her plasma into two. Adsorb one of these with r'r red cells and the other with Ro red cells. Then, once the adsorption is completed, test the aliquot adsorbed with the r'r red cells against Ro red cells, and test the aliquot adsorbed with Ro red cells against r'r red cells.

If both tests are then negative, you have an anti-G on its own.

If the r'r red cells react, but the Ro red cells do not, then you have an anti-G+C.

If only the Ro red cells react, but the r'r red cells do not, then you have an anti-G+D.

If both the r'r and Ro red cells react, then you have an anti-C+D (+ or - an anti-G).

Obviously, if the lady turns out to have an anti-G (+ or - an anti-C), she should be offered anti-D immunoglobulin prophylaxis, if appropriate (i.e. if her partner carries the RHD gene).

I may well be wrong; this is only a suggestion.

:confused::confused:

I will follow what you said and hopefully post my results.

Thank you very much,

Liz

Is r"Gr a typing error? should it be r"G red cells?

I just drew blood from the husband; I am so excited about this case.

Thank you,

Liz

[ATTACH]396[/ATTACH]

Is r"Gr a typing error? should it be r"G red cells?

I just drew blood from the husband; I am so excited about this case.

Thank you,

Liz

Well, it is and it isn't!

Very rare r"r red cells are G+ (it was this that caused anti-G to be discovered in the first place). It should be written r"Gr (with the G being a superscript - but we can't do superscript on here.

I (think) I've attached a short lecture I wrote on the subject about a year ago that may (or may not) help.

:D:D:D:D

I didn't! I'll email it to you.

The G Antigen and Anti-G.ppt

Edited September 2, 201014 yr by Malcolm Needs
Trying to add the lecture.

Actually you did, I read it and it is very clear!! Excellent.

Seems to be exactly our case. Today the lady received her 28th week dose of RhIG.

I still need to perform the procedure that you wrote.

Thank you so much!

Liz

Thanks a lot for this post. I only vaguely remembered the circumstances surrounding anti-G and was happy to have a reminder.

can RH postive patient who is C+ can make anti-G?

can RH postive patient who is C+ can make anti-G?

That sounds like an auto-antibody, but Malcolm would know better.

Unless the individual is of the exceedingly rare r'r G- type, then the antibody would be an auto-antibody.

Interestingly, some of the Partial D Types are G-, and so it is possible for an Ro with one of these Partial D Types to make a true alloanti-G, but these are, once again, very rare.

Thank you Malcolm

Any news on your case yet Liz???????????????

I am waiting for the lady to come back next week to draw another sample to perform the adsorbances.

I also asked our supplier if he has any anti-G, or RBCs with G...

I have been catching up on my reading. Pretty incredible how many people luckily Do Not get allo-immunized.

Hmmm you promised us something after your inspection, now if only I can remember what ??

Oh dear; I can't remember either!

If it comes to you, let me know and I will address it.

Today I recieved the patients serum.

Should I put equal volumes of cells and serum to adsorb the Abs?

Today I recieved the patients serum.

Should I put equal volumes of cells and serum to adsorb the Abs?

Yes, but depending upon the strength of the antibody(ies), you may need to adsorb the same aliquot of plasma several times with fresh aliquots of the red cells.

I am glad you are here, thank you Malcolm.

The titer is 16, as I have not performed Adsorptions previously, I am following the AABB Technical Manual on allo adsorption of autoAbs. I need to reach the 37 C step and not add AHG. Is that right?

I am glad you are here, thank you Malcolm.

The titer is 16, as I have not performed Adsorptions previously, I am following the AABB Technical Manual on allo adsorption of autoAbs. I need to reach the 37 C step and not add AHG. Is that right?

Personally, I would enzyme-treat your Ro and r'r red cells (we always use papain, but you can use other proteolytic enzymes), wash them well and pack them as much as possible. Then use an equal volume of the washed red cells to an equal volume of the patient's plasma. Mix these well (each individual tube I mean, not the tubes containing the Ro cells and the r'r cells - obviously, these need to be kept separate!) and incubate at 37oC for about 20 minutes. Then centrifuge as hard as you can, and take the plasma off the r'r red cells and add it to another tube of enzyme treated r'r red cells, and the plasma from the Ro red cells and add it to another tube of enzyme treated Ro red cells, mix again and incubate again.

Do this about 4 times, and then test the plasma adsorbed with the r'r red cells against untreated Ro red cells by IAT, and the plasma adsorbed with the Ro red cells against untreated r'r red cells by IAT and see what you get as reactions!

Edited September 14, 201014 yr by Malcolm Needs
Spelling - as ever!

By the way, what was the probable Rh genotype of the lady's partner?

Her partner typed: D+, C+, , I have to check the rest.

She typed D-. C-. I again have to check the rest.

Thank you very much for the method. I was at a loss.

Liz

A D - lady presently pregnant with history of one previous delivery of a D- baby, developed anti- C post delivery. Now 4 years later we see she has anti-D. The titer of her antibodies was 8, 4 months ago, is now 2.

She has not yet recieved RhIg for this pregnancy.

So what happened ? why the +1 for anti-D (she has +2 for the C)??

thanks

Liz

Have you considered the presence of anti-G? We had a similar case a few months ago and we sent it to our reference lab where they confirmed anti-G which looks like CD combination. It was very interesting.

Yes, CABMT that is what Malcolm proposed and I am working on it.

Thank you

Malcolm, the final tubes were neg for both: the one adsorbed with r'r (and AHG with Ro) and the one with Ro, (and AHG with r'r).

So I am repeating the 4 adsorptions and running the final on gel for more clarity.

What do you think?

Malcolm, the final tubes were neg for both: the one adsorbed with r'r (and AHG with Ro) and the one with Ro, (and AHG with r'r).

So I am repeating the 4 adsorptions and running the final on gel for more clarity.

What do you think?

That proves the original antibody to be a monospecific anti-G!

As both the Ro and the r'r red cells used for the adsorption will be G+, they will both remove anti-G.

If the original was an anti-G+C mixture, the Ro cells used for the adsorption would remove the anti-G, but not the anti-C, and so the r'r red cells in the final test would still react, but the Ro red cells in the final test would not react (as they are C Negative).

If the original was an anti-G+D mixture, the r'r cells used for the adsorption would remove the anti-G, but not the anti-D, and so the Ro red cells in the final test would still react, but the r'r red cells in the final test would not react (as they are D Negative).

If the original was an anti-C+D (or anti-C+D+G), the r'r cells used for the adsorption would remove the anti-C (and anti-G were it present), but leave the anti-D, and the Ro cells used for the adsorption would remove the anti-D (and anti-G were it present), but leave the anti-C. Therefore, the r'r red cells used in the final test would react with the anti-C, and the Ro red cells used in the final test would react with the anti-D - in other words, you would get positive results with both cells.

To cut a VERY long story short, however, as you got negative results with both final test cells, the lady has a monospecific anti-G!!!!!!!!!!!!!!!!

Congratulations!

:D:D:D:D

Of course, the important thing to remeber now, is that this lady should be offered prophylactic anti-D immunoglobulin during and after pregnancy, as she has yet to make alloanti-D and her partner is D-Positive.

A true alloanti-D is much more likely to cause severe haemolytic disease of the newborn/foetus, than is an anti-G.

:):)