From attending a recent TAG meeting, it appears that some of the newer analysers (Column Agglutination Techniques), are cross-contaminating patient samples observable when there is a high titre antibody present . It would be useful to know the extent of this problem.

Also, have users:
a) Reported to the supplier as a formal complaint?
b) Reported as incident due to potential to cause testing delays to subsequent patients as well as having to re-bleed them. Possible distress to the patients if it is thought they may have a clinically significant antibody ( but likely caused by contamination)?
c) Reported on-going issues to Medical Devices?

Really disappointing that suppliers may not be properly evaluating their equipment during their Alpha and Beta testing phases for this very basic function.

Possible causes:
1) Reduced probe wash time between samples. (perhaps to increase sample turn-around times?)
2) Reduced wash fluid used (either due to time or flow rate)
3) Change in the actual probe material.

Labs should test their equipment to know the limits of carry-over. This is easily done by running a high titre Anti-D (eg use vial of 1500 IU Anti-D Ig) as sample 1 for screening and 9 further blank samples of Saline or AB Plasma/ FFP- which should all be negative if there is good washing. I am sure our Transfusion Guru- on this forum will suggest other ways.

Be very useful to discuss further.

Many thanks, Rashmi