Eluates - 30 days or 3 months?

[jhaig]

Our reference lab has recently changed its guidelines regarding eluate testing. Instead of doing them on patients who have been transfused within the previous 3 months, they will now only do them on patient transfused within the previous 30 days, citing that eluate testing on patients who haven't received a transfusion within the last 30 days is neither cost-effective or time efficient.

My policy has always been performing an eluate on a patient with a positive DAT when the patient has been transfused within the previous 3 months. Last I checked the AABB standards say the same thing (15th ed., pg 455). It may not be cost-efficient, but there's the possibility of missing clinically significant antibodies that may slowly develop after transfusion. AABB says that antibody can appear as early as 7-10 days post-transfusion, but may take 2 weeks to several months).

Does this sound OK or am I right in thinking this leaves a patient open to a potential antibody reaction?

[GilTphoto]

we use 3 months, but maybe the logic is that after 30 days post transfusion, the antibody should be detectable in the serum.

[OPUS104]

Hey J! We also have the 90 day rule. Several have mentioned at area hospitals that the Ab should be detectable in the plasma after 30 days.......but we have ran into quite a few antibodies that are completely clean in neat and 2+ in eluate after the 30 day mark. The titer (we think) is still so low that all produced Ab is still bound onto transfused cells. I have seen this alot with Ca. patients. We will not change our policy unless there is some very good data present.

[bbbirder]

I recall reading a study (I'm thinking it was JJudd) that showed very tiny number of specimens with antibody detectable only in eluate, and the authors concluded it wasn't worth it do perform elutions....

Sorry I can't find it now. Perhaps someone else can put their finger on it. Maybe your reference lab used that data to support their decision?

Linda F

[tar1heel]

My interpretation of the statement on page 455 referred to by the original poster is that the author was stating what some "workers" do - they were not presenting 3 months as a "standard".

Here is another quote from the Technical Manual 15th Ed. page 456, "In the case of transfusion reactions, newly developed antibodies initially detectable only in the eluate are usually detectable in the serum after about 14 to 21 days." Based on this statement, we perform an eluate if the patient has received blood components in the previous 4 weeks.

Sandy