we have a mom who by adsorption and elution studies i believe has both anti-D and anti-G......what would be the best cells to use to do the titers the doc wants throughout the pregnancy?

thanks, jane

I haven't done this before AND am a newbie. But if I had to pick one, I'd choose an R1R1 - that way both the D and C ags are strongly expressed. According to my handy text, the RBCs used for each titration should be of the same genotype and from the same donor, of the same concentration, and the same storage time.

Has anti-G been implicated in HDN? How do you differentiate between an anti-G and a true anti-D plus anti-C? (Or is anti-G just presummed in cases where the patient hasn't been exposed to the C ag but appears to have anti-D,C anyway?)

we have a mom who by adsorption and elution studies i believe has both anti-D and anti-G......what would be the best cells to use to do the titers the doc wants throughout the pregnancy?

thanks, jane

Or it might be better to use an r'r with C but no D since anti-G reacts with all C positive cells and G expression is greater on D negative cells?

I haven't done this before AND am a newbie. But if I had to pick one, I'd choose an R1R1 - that way both the D and C ags are strongly expressed. According to my handy text, the RBCs used for each titration should be of the same genotype and from the same donor, of the same concentration, and the same storage time.

Has anti-G been implicated in HDN? How do you differentiate between an anti-G and a true anti-D plus anti-C? (Or is anti-G just presummed in cases where the patient hasn't been exposed to the C ag but appears to have anti-D,C anyway?)

What is the typing of the father, use a cell that is most close to his typing or even better to the expected typing of the child.

Peter

I agree (and disagree!) with Peter.

I agree with typing the father (he may actually be an r'r - suggesting that the antibody is anti-G or anti-C+G), but, once you think (or better still, prove) an anti-D is present, then titration is fairly useless (as is the quantification we use for anti-D in the UK). You will never know (unless you are blessed with r"rG+ red cell samples), whether the higher titre is the anti-D or the anti-G.

Anti-G can cause HDN (although, as far as I know, it has never been implicated in HDF), but, of course, anti-D has been implicated in both; many, many times.

It would be much, much better, therefore, for the doctor to monitor the foetus by MCA Doppler or ultrasound, so that he/she has a direct test of the health of the foetus, rather than relying on an indirect test, which cannot be relied upon in such circumstances. SUch an indirect test can either lead to intervention that is not required (very dangerous) or non-intervention when it really is required (critically dangerous).

Malcolm - please can I come and work with you?

I didn't say the doctor would listen!!!!!!!!!!

But let's say the titer against R1R1 cells is 2. Would it not be okay to monitor with titers until the titer of the combination rises nearer to 16? I guess since doppler ultrasound is not invasive it wouldn't be like the old days where they had to risk amniocentesis, but the ulstrasound is probably a lot more expensive--especially if they have to repeat it every month.

Oh yes, I agree entirely Mabel.

What I meant was, once/if the titre rises above a certain level, under such circumstances, the titre is not reliable.