Well, the first thing I would say is that you would be wasting time and reagents to cross-match at the hospital, for the precise reason you quote; of course the units will be incompatible, so just perform an "immediate spin" cross-match (if you must) or perform an electronic issue, as you say that you trust RCI results.  As far as antibodies directed against low prevalence antigens are concerned (the antibodies are usually quite common, it is the antigen that is usually quite rare), I would advise you to read Garratty G.  How concerned should we be about missing antibodies to low incidence antigens?  Transfusion 2003; 43 (7): 844-847, which, basically says what I said above - i.e.  that NO TRANSFUSION IS 100% SAFE, but such antibodies are low down on the list of risks.

Just before I retired, there was a move that all RCI Departments would go over to electronic issue, when there was a positive DAT and no detectable underlying atypical alloantibodies, but whether or not this ever went through, I don't know; you would have to contact your local RCI Department.

We turn out a negative DTT-treated screen and do electronic crossmatch.  If the screen has gone out as positive our computer won't allow EXM so we would do IS as Malcolm suggests.  More complicated if there are alloantibodies but we haven't seen that yet.

On 6/3/2017 at 1:21 AM, Malcolm Needs said:

I haven't heard of that method Mabel.  What is the "weird" Lutheran antibody.

Anti-CD38 did not react with In(Lu) cells and showed very low signals when anti-CD38 was tested with In(Lu) cells in a flow cytometry. Before we knew the patient was on anti-CD38 and In(Lu) cells has depressed CD38 marker, we have mistaken it being an antibody to high incidence antigen in Lutheran blood group system, based on the reactivity with In(Lu) cells. 

Edited June 9, 20187 yr by dothandar

I've been told that the concentration of DTT in RESt is different that what is used for treatment of reagent cells.  But that sure would have been convenient.

20 hours ago, SBBSue said:

I've been told that the concentration of DTT in RESt is different that what is used for treatment of reagent cells.  But that sure would have been convenient.

RESt = Rabbit Erythrocyte Stroma - basically stabilized red cell membranes from rabbits. There is absolute no DTT in RESt.

Edited June 13, 20187 yr by exlimey
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