Does anyone report the strength of reactivity of the DAT to the Hospital Information System?  There are some doctors questioning this here but I was always taught that any positive reactivity would clear the cells no matter what strength.  Thoughts?
 

I agree with ENTIRELY JoyG. The strength of the DAT means ABSOLUTELY nothing.

Sometimes, you get quite a weak, or even negative DAT, because the red cells are swamped by antibody.

A little knowledge is a dangerous thing in the hands of SOME doctors!

We just result Pos or Neg. 

^{Managing many transfusion services over the years, I have never reported anything other than Pos or Neg as a DAT result to MD/RN.  99% of these DAT results were on newborns where the bilirubin level was the strongest predictor for phototherapy, not the DAT result.}

Edited March 9, 201411 yr by Dansket

We do report the strength when positive for each component (IgG, C3 and Poly). Not sure if anyone is doing anything with the results but we have reported it for over 20 years...

The DAT strength does not correlate with the severity of the hemolysis. In Rh D hemolytic disease,            the DAT may be strongly positive without clinical signs of disease; whereas in ABO hemolytic disease,clinical features may exist with only a weak or negative DAT.                                                           In the transfusion reaction as Malcolm, mentioned; you may have a negative DAT if all the transfused donor cells (that are carring the corresponding antigen) are removed from the system.

Edited March 19, 201411 yr by Abdulhameed Al-Attas

We report only positive or negative. If positive we specify what's on the cells - IgG, C3 or both.

We usually report only pos or neg but we have one oncologist who wants the strength because he wants to follow its changes as he treats the patient for the autoantibody.  Is it of no value in this context even?  It seems to me that it gets weaker when they take steroids and gets stronger again when they quit although one can't tell much from a difference between 2+ and 3+.  When it goes from microscopic to 4+ it seems like it might be meaningful.  I am talking only of warm autoantibodies, not HDFN or TRX.

I don't think that it does.

My experience with my tame haematology consultants (all too many, over the years) bears out Mabel and her singular oncologist - they found the strength of the DAT very helpful in monitoring treatment although whether our numerical report provided a 'comfort blanket' or actually aided them in following a rigorously tested, peer-reviewed, scientifically validated process is not for me to say.

 

Other than that I tend to agree that reporting the strength of the reaction adds nothing of clinical value - EXCEPT - (bee in bonnet alert) - except for a mixed field reaction.

Mixed pictures always tell a story.

In my humble opinion the story is invariably worth careful unravelling and the interpretation carefully reporting.

I refer my learned friends to a paper I often quote:

Sachs UJH, Roder L, Santoso S, Bein G. Does a negative direct antiglobulin test exclude warm autoimmune anaemia? A prospective study of 504 cases. British Journal of Haematology 2006; 132: 651-661.

The answer is, it doesn't. Therefore, the strength of the DAT tells you precisely nothing.