e and C titer

[tkakin]

What can I do?  I have an OB patient that we reported out as having an Anti-e unable to rule out Anti-C (no e neg C positive cells), Patient antigen types as C negative.  We will give e neg C neg units,.  The OB Dr. just put an order in to do a titer on both Anti-e and Anti-C, but I don't have any cells to titer the C.  Any ideas?   

[tkakin]

just realized only cells available to titer e homo are also C pos.  So if the patient does have Anti-C at least it will be included in the titer result.  Just won't know how they titer individually.

[Yanxia]

Maybe you can adsorb the anti-e with ccee cells, then to see if there are still reaction with Ce cells, then you can figure out if there are anti-C here.

[Malcolm Needs ☆]

The thing is tkakin, that most examples of anti-C (anti-Rh2) are not; they are actually anti-Ce (anti-Rh7)!  This is largely because almost every red cell that causes immunisation against the C antigen expresses both the C and e antigens as a result of having the RHCe gene, rather than both the C and e antigens as a result of having both the RHCE gene and the RHce gene (which is why both the DCE and dCE haplotypes are so rare).  On the other hand, monospecific anti-e is comparatively common.

So, your lady's plasma is more likely to contain anti-Ce and anti-e, rather than anti-C and anti-e.  As a result, if, as yan xia suggests, you would undoubtedly adsorb out the anti-e, but you still would not know if the remaining antibody specificity is anti-C or anti-Ce (or, of course, a combination of the two).

Anyway, the specificity really doesn't matter.  The point is that, as you suggest, the individual titres of what ever antibodies are present are totally irrelevant.  Normally, an antibody, such as anti-C (or anti-Ce) or anti-e, are not going to cause clinically significant haemolytic disease of the foetus and newborn, until the titre reaches 32, and it really doesn't matter whether the specificity of the antibody is anti-C, anti-Ce or anti-e.  Your Pathologist should explain this to your OB doctor to get him or her off your back (actually, to be honest, your OB doctor should already know this, but hey, life ain't always like that!).

[tkakin]

wow! Great explanation thank you