Posted August 31, 20177 yr comment_70684 Hi everyone! I hope everyone had a nice summer! I have a confusing scenario going on. I have a mom who received 2 doses of Rhogam (one for spotting and the other at 28 weeks) and upon delivery, I am picking up a strong Anti-D on the baby's cells and I did a titer on mom and it is 1:512. Anyone ever experience something like this before? I deal with a lot of Rhogam and this is a first for me . Thanks!
August 31, 20177 yr comment_70686 I think that, without doubt, this is an immune anti-D that has been produced by the mother. Anti-D immunoglobulin (Rhogam), even several doses, would never reach a titre of 512. I would keep a very close eye on that baby!
August 31, 20177 yr Author comment_70687 Thank you Malcolm! We have done an exchange on the baby but now I am completely confused - one of my seasoned techs just did a quick few D+ cells on mom and she is getting barely weak reactivity. Needless to say - a redraw is happening.
August 31, 20177 yr comment_70690 I wouldn't expect to see many D Positive red cells in the mother's circulation. Any such red cells can only have come from the baby, and these would have been sensitized by the maternal anti-D and immediately removed from the maternal circulation by her own reticuo-endothelium system. It is very likely that the mother was sensitized to produce an immune anti-D by a foeto-maternal haemmorhage quite early in her pregnancy for this baby to be so badly affected, possibly with a chronic FMH further into the pregnancy.
August 31, 20177 yr comment_70693 I think saralm88 is saying that the Mom's plasma vs D+ cells is barely reactive. Where is the high titer Anti-D?
September 1, 20177 yr comment_70697 12 hours ago, richj said: I think saralm88 is saying that the Mom's plasma vs D+ cells is barely reactive. Where is the high titer Anti-D? Oh, sorry, I misunderstood. An anti-D with a titre of 512 is pretty high (not the highest I have ever seen, by any means, but pretty high. An anti-D with a titre of 512 is quite capable of forming blocking, by swamping the D antigen sites on the red cells, even with the use of AHG. This could be the answer (it may not be, but it could be).
September 1, 20177 yr comment_70701 There is clearly a problem here. If you did a titre on a D+ cell and it was 512 then the antibody should be coming up quite strongly positive against ALL D+ cells unless...... 1. this is not an anti-D but another antibody and you were just lucky that you hit the spot when you did the titre (or maybe a weak anti-D + an anti-LFA) 2. Technical error during the titre 3. technical error during the 'quick few D+ cells on mum 4. Mum has been plasmapheresed inbetween you doing the titre and the 'quick few D+ cells 5. The titre is actually now higher than 512 and you are seeing a prozone effect I suggest you re-test the cell you used for the titre, plus do a panel - and look for anti-LFA
August 12, 20195 yr comment_77922 On 8/31/2017 at 8:03 AM, saralm88 said: Thank you Malcolm! We have done an exchange on the baby but now I am completely confused - one of my seasoned techs just did a quick few D+ cells on mom and she is getting barely weak reactivity. Needless to say - a redraw is happening. Could it also be that because the baby has been delivered that the Anti-D crossed the placenta and has coated the baby's RBCs? This might cause a decrease in reactions if there is not the same amount of antibody to detect?!?
August 12, 20195 yr comment_77927 I posted a stupid question and then deleted it. I answered my own question...... Edited August 12, 20195 yr by R1R2
Create an account or sign in to comment