Would there be any benefit in performing/following with titers for a prenatal patient with a warm auto C and e? 

None whatsoever, as long as you are absolutely certain that the antibodies are auto-anti-C and auto anti-e, and not an allo-anti-Ce, or worse, an allo-anti-hr^B that is mimicking an auto-anti-C+e.

 

May I be impertinent enough to ask the lady's ethnic background?

  The report of auto C and e is coming from our reference lab.  The reference lab only added that their facility does not "follow" prenatal patients with autoantibodies. 

 

  In 2011 her antibody screen was negative, no DAT was performed. Her phenotype is R1r(C+E+c+e). She is caucasion and has not been transfused.  This is her second pregnancy. 

 

Could you give me a little more information regarding the two allos you mention.

 

Lastly, is there anything documented that you know of that I can reference regarding not needing to "follow/titer" prenatals with auto antibodies.

 

Malcolm, have I told you recently how awesome I think you are?  Your expertise is greatly appreciated!

Whilst there is general agreement that Malcolm is, indeed, awesome, those of us lucky enough to know him try not to tell him too often in case it goes to his head  

  The report of auto C and e is coming from our reference lab.  The reference lab only added that their facility does not "follow" prenatal patients with autoantibodies. 

 

  In 2011 her antibody screen was negative, no DAT was performed. Her phenotype is R1r(C+E+c+e). She is caucasion and has not been transfused.  This is her second pregnancy. 

 

Could you give me a little more information regarding the two allos you mention.

 

Lastly, is there anything documented that you know of that I can reference regarding not needing to "follow/titer" prenatals with auto antibodies.

 

Malcolm, have I told you recently how awesome I think you are?  Your expertise is greatly appreciated!

 

Hi lab217,

 

First of all, thank you so much for your very kind words.

 

I am now happy that the antibodies are truly auto-antibodies, given both the lady's Rh phenotype and her ethnic origin, and I would agree with your Reference Laboratory that serial titrations during the pregnancy are not required.  The rational for saying this is in Petz LD, Garratty G.  Immune Hemolytic Anemias.  2nd edition, 2004, Churchill Livingstone, Chapter 9, pages 346-347.  Here, you will find reference to the fact that foetuses can be fatally affected in a pregnancy involving autoimmune haemolytic anaemia, BUT (and this is the important bit) these fatalities are due to the maternal Haemoglobin levels dropping to <60gL^-1, and so there is a lack of oxygen transfer to the foetal red cells, rather than the auto-antibody causing a haemolytic crisis in the foetus.

 

When the maternal haemoglobin levels are controlled (by steroids, transfusions, etc, so that sufficient oxygen was getting to the foetal red cells) there was little, if any, evidence of a clinically significant episode of haemolytic disease of the foetus and newborn, beyond the fact that some babies had a positive direct antiglobulin test.

 

Turning to the two alloantibodies I mentioned.  Anti-Ce (also known as anti-Rh7 and anti-rh_i - just to confuse matters!!!!!!!!) is a compound antibody that will only react with red cells expressing both the C and e antigens that have been encoded in the same haplotype (rather like anti-ce/anti-f, that will react with rr red cells [RHc and RHe genes in the cis position], but not with R1R2 red cells [RHc and RHe genes in the trans position]).  So, basically what I am saying is that, if a foetus has the phenotype of D+ C+ c+ E+ e+, if the baby's genotype is DCe/DcE, there is a chance that an anti-Ce could affect the baby, whereas, if the baby's genotype is DCE/dce, the baby will not be affected by a maternal anti-Ce.

 

The good news is that anti-Ce is usually only associated with very mild HDFN.

 

Anti-hr^B (anti-Rh31) is an antibody that can be produced by individuals who have a variant of the e antigen (a variant that is, to all intents and purposes, only seen within the Black populations - hence the fact that I am comforted by the fact that your pregnant lady is Caucasian).  Anti-hr^B mimics a mixture of anti-C and anti-e, with the anti-C-like element often showing as a stronger antibody than the anti-e-like element.  Again, anti-hr^B is not usually associated with clinically significant HDFN.  However, there is another Rh antibody, again, normally only found in an individual from the Black populations, anti-Hr^B (anti-Rh34) that, when weak, or just developing, can mimic an anti-hr^B.  Again, anti-Hr^B is usually associated with mild HDFN, although somewhere in the back of my mind, I seem to recall one case where the baby was severely affected, and required several transfusions (with washed and irradiated maternal blood, which was of the "wrong" ABO type, but the baby survived).  If I am correct, and I can find the reference, I will post this for you.

 

Anyway, I hope this post has served to help you in some way, rather than to confuse the issue further!

 

       

No, I can't find the reference, so treat what I say about anti-Hr^B causing severe HDFN with a bit of caution (but I still seem to recall reading about the case in some journal)!!!!!!!!!!!

Malcolm, you are a wealth of knowledge and are greatly appreciated! Thank you, thank you.

 

Apologies in advance to your fellow employees, but I must say I would be glad to "put up" with your ego, any day!

Don't worry lab217.  Peter and I have been friends for years - which will not stop me giving him a severe slapping next time I see him!