Mixed field of agglutination on DVI+ and DVI-

[Amra23]

Hi all,I am new here so please excuse my lack of experience.
On a routine ABO/Rh typing for a pacient I got a mixed field of agglutination on both  DVI+ and DVI- (I work with DiaMed ABO/Rh cards),phenotype ccEeK- , having the same mixed field of agglutination for E.Male pacient,over 60 years old,no transfusions hystory,no transplant and no twin brothers.I repeated the test from a new sample,even washed the red cells,same result.On a slide test I could see also very clear that there was a mixed field of agglutination.DAT negative,control negative.We do not perform test for partial or week D's,so I sent the blood sample for further investigations at our regional blood bank.I get the result that is a week D.Could this be possible..?Have you ever encountered such D(I mean no week D,but that mixed field of agglutination which I have never seen before.I swear it looked like a D positive transfused with a D negative...,except the fact that pacient was never tranfused!)
Thank you!

[Malcolm Needs ☆]

Given that the patient has never been transfused and, being male, is unlikely to have been pregnant (!) there are several possible explanations that may explain this phenomenon.

The first is that the patient is a Weak D Type 2.  The D antigens on the red cells of a Weak D Type 2 (the red cells would, incidentally, express the c and E antigens) tend to be particularly weakly expressed and, depending upon the anti-D reagent in use, can appear like mixed-field.  However, this is a little unlikely, given that you are finding a mixed-field reaction with the anti-E reagent, as well as the anti-D, as the expression of the E antigen is not usually affected by the presence of a Weak D Type 2 phenotype.

The second is that he is a genuine Rh mosaic, as a result of his underlying pathology.  Certain pathologies result in weakening of Rh antigens, and this may explain why both the D and the E are appearing as a mixed-field.  It would be interesting to know his underlying pathology, if you could tell us.

The third is that he may have been a twin in utero, but may have fully adsorbed his twin, so that the pregnancy appeared as a "normal" single pregnancy, and neither he, nor his parents may ever have known that the pregnancy was originally a twin pregnancy, resulting in the birth of a single baby.  This means that he may be a genuine "natural" chimera.  In this case, it would be interesting to know if you get a mixed-field reaction with any other grouping reagents, such as anti-Fy^a and anti-Fy^b, and/or anti-Jk^a and anti-Jk^b.  I should say, however, that such individuals are extremely rare.

There may be other reasons (more plausible) than those I have put forward, but these are all I can think of "off the top of my head".

[Amra23]

The pacient will be programmed for a cardiac by-pass(miocardial ischemia);he has also diabetes type 2 and mixed dyslipedimia.Of course he is on medication for all theese.
We did not request the blood bank to perform tests for anti-Fy^a and anti-Fy^b, and/or anti-Jk^a and anti-Jk^b.

Edited November 8, 2017 by Amra23

[Malcolm Needs ☆]

Thanks Amra23.

As far as I know, the underlying pathology does not lead to a weakening of Rh antigens.

To be honest, I am not at all surprised that you did not request those antigen typings, as there would have been so reason so to do.

[Amra23]

We decided to prepare Rh(D) negative red cells for this pacient.
We have a very strict protocol in our hospital.We perform ABO and Rh typing,Kell and Rh phenotype when needed,DAT and salin/enzyme/IAT for compatibility test and we request blood bank help only when discrepancies are descovered.
Thank you so much for your answer,Malcom!

Edited November 8, 2017 by Amra23

[Malcolm Needs ☆]

Absolutely no problem Amra23.  I just wish I had been able to come up with a definitive answer.