Hi All,

I am reviewing procedures and trying to pin down when to do an elution outside of cord blood elutions, i.e. Lui Freeze. I think an acid elution should be done in the presence of a positive DAT when the patient has been transfused in the previous three months; alot of places are using the 21 day rule as it should take 21 days for a delayed reaction to occur but keeping it at three months is more safe in covering those who make take longer to form an antibody or weak responders. A positive DAT when the patient has not been transfused may be attributed to drugs.

Somers Point, NJ

You may want to take a look at the following articles when developing your policy:

Judd WJ, Barnes BA, Steiner EA, et al., The evaluation of a positive direct antiglobulin test (autocontrol) in pretransfusion testing revisited, Transfusion 1986;26:220-4 and also

Judd et al. The evaluation of a positive direct antiglobulin test in pretransfusion testing, Transfusion 1980;20:17-23.

...which basically, 14 days should do it...

We use a month as the cut-off point in the NBS, but I think that this time frame is quite emperical.

In facilties that I have worked in, we always performed an elution in the patient had been transfused in the previous 3 months. We also perform elutions on any patient suspected of having a warm auto antibody, just to help confirm.

In facilties that I have worked in, we always performed an elution in the patient had been transfused in the previous 3 months. We also perform elutions on any patient suspected of having a warm auto antibody, just to help confirm.

We would also do the latter on the first occasion we seem them, but not after that unless they suddenly require more frequent transfusions. If we cannot detect a "new" atypical alloantibody in the plasma after differential alloadsorption, we will go on to perform differential alloadsorption on the eluate ( and a complete pain it is to do so too)!!

I have worked in Blood bank for 30 years and recently transfused has always been 3 months. If there is a doubt that the patient has been recently transfused (i.e. patient incoherent) do an eluate.