I was wondering what everyone does with a pregnant lady with a Big E and little c, when you titer.

the panels we use you can either use a heterozygous E cell (RzR1 i believe) to titer the E or a Homozygous Big E cell with little c also on the cell?

Do you report the titer from both the homozygous and hetero E cell?

i was thinking neither result is accurate. the heterozygous E cell seems to give weak reactions and the homozygous E with the little c gives a false stronger reaction.

I think the heterozygous E and heterozygous c(R1R2) will be ideal. Because the fetus will not express homozygous E and c commonly,except some gene crossover or other gene change.

Edited March 2, 200916 yr by shily
change the word to use

we titer each antibody separatly. the baby was positive for both the big E and little c.

Edited March 2, 200916 yr by LISA140

Just as a side note, and I can't stop myself from commenting. The worst case of HDN I ever had to deal with was due to an Anti-c. From personal experience I would want to be able to follow that little c much more closely than I would the big E. Just my thoughts.

:blahblah:

I've seen a couple of stillbirths caused by anti-E.

Just goes to show how limited my personal experience can be. Every anti-E I have seen in pregnancy has been a non-factor and of no importance. The babies' bili did not even rise.

I would be interested in hearing more about anti-Es resulting in such serious complications as fetal demise and how it was determined that the cause was the anti-E.

The cases were so long ago that I don't actually remember all of the details about the anti-E's contributing to fetal demise. I think macerated fetus was the term used in the chart. This physician saw patients who had no prenatal workups, was completely unaware of the antibody, and probably at a loss as to what was important.

Titration should be performed by saline antiglobulin procedures that uses 60 mins incubation at 37C and anti-IgG. Selection of red cells for use in prenatal antibody titration is controversial. Some would say red cells with heterozygous expression of the offending antigen cuz these reflect the antigen expression on fetal red cells. Others would argue that it is best to err on the side of safety and use red cells with homozygous antigen expression.

Use R2R2 red cells for prenatal titration purposes in cases involving anti-c, -E, -cE, or combination of these. There is no value in determining separate titers for each Rh antibody in a mixture cuz the combined effect of the antibodies will likely determine the degree of HDFN.

For more information, please read AABB Guidelines for Prenatal and Perinatal Immunohematology. Hope that helps.

CK Cheng, MSc, SBB(ASCP), CQA(ASQ)

Hong Kong

March 4, 2009

As CK Cheng says, there may also be anti-Ec there that would figure into the case. I vote for R2R2 also. Consistency between titers is important. It would be interesting to know what Ags dad could contribute to the baby. I guess if sensitization was a previous pregnancy with same dad, we already know.

I had an anti-c once that there was a chance the baby could be Rh neg--and it was! But the HDN was mild so we didn't have to transfuse that rare c neg Rh neg unit we tracked down. I think mom was R1r' and Dad was something with r. I'll confess the details are fuzzy after all these years.