Sounds EXACTLY like a weak anti-D to me.

The number of D antigen sites is, on average, much higher on R₂R₂ red cells than on R₁R₁ red cells, and so your results reflect this to a tee.

Yes - however, I would have expected an increase in the reaction with the R2R2 cell in the enzyme-IAT and it did not move.  Or did it go from a weak 1+ to a strong 1+.  Even so - for a 1+ in IAT, I would expect a +++ in an enz-IAT for a  'normal' anti-D.

Which country is this in?

Sorry - just seen this is UK.  Do you have access to DC screening cards with anti-IgG, -IGM, and IgA??

(Sorry colleagues from the US - this will mean nothing to you)

History History History pregnancies, transfusions, daddies, medications, High BP?   Early autoantibody,  early autoantibody mimicking anti-D?  One pathologist I have worked with considered pregnancy a disease, you may have some non-red cell stimulated mimicking antibody specificities due to a hyped up immune system.  We have seen an Anti-K titer rise during the pregnancy only to find the subsequent child and daddy to be Kell negative.

Would be nice to be able to follow patient, antibody detections, titers, Rh-hr typing of infant, etc...................  make a good abstract case presentation at a meeting.....

We have received a further sample from this patient but it is now further complicated by the fact she has now been given anti-D prophylaxis. It is a very interesting case and I would have liked to follow it through however I no longer work in the lab. Thank you for all your input.