Antibody identification on the Echo

[MemphisLilli]

We have been live on our Echo for about 6 weeks. Currently we are only performing Type and Screens on the Echo but are in the process of validating Antibody Identifications. I would like to know what other institutions using the Echo are doing about the autocontrol when performing ABID on the Echo.

Thanks

Linda Liles MT(ASCP)SBB

[krichards]

We run a DAT on the Echo in lieu of an autocontrol.

[John C. Staley]

At my old facility we performed a manual DAT when ABID was performed on the Echo.

[rebel1]

We test the auto control using the tube method

[AMcCord]

We run a DAT on Echo.

[kmh76]

We do a DAt in tube. We used to do it on Echo but found it easier to go back and do it in tube.

[BrianD]

at our facility, we ran the ECHO DAT with an ID panel but the cost in time and materials was a bit too high so now, a manual (tube) ab screen is performed through the AHG phase with an auto-control to confirm positive ab screens from the ECHO. we went to this protocol after having an unusual number of positive screens due to "non-specific adhering factors" that couldn't be reproduced via tube testing with PEG.....this problem has not been an issue with later lots of Capture-R and we will soon stop confirming the positive Capture-R by tube testing and simply perform a manual DAT while we wait for the panel(s) to complete on the ECHO.

Edited June 29, 2010 by BrianD
grammar

[hmust1]

For those of you who perform DAT's on the Echo with the Antibody ID panels, what is your protocol when the DAT is positive?

[L106]

at our facility, we ran the ECHO DAT with an ID panel but the cost in time and materials was a bit too high so now, a manual (tube) ab screen is performed through the AHG phase with an auto-control to confirm positive ab screens from the ECHO. we went to this protocol after having an unusual number of positive screens due to "non-specific adhering factors" that couldn't be reproduced via tube testing with PEG.....this problem has not been an issue with later lots of Capture-R and we will soon stop confirming the positive Capture-R by tube testing and simply perform a manual DAT while we wait for the panel(s) to complete on the ECHO.

Brian -

We, too, see a fair number of Positive Antibody Screens on the Echo that turn out to be nothing or "non-specific-trash", but by immediately going to a PeG/Tube Antibody Screen and reporting the Antibody Screen as Negative (when the PeG Ab Screen is Negative), you are missing one of the advantages of the Echo instrument.

We have seen several antibodies that are detected by the Echo but not by PeG/Tube technique, particularly Kidd and a few Rh antibodies. So by following your protocol (and not performing an Echo Antibody Identification Panel), you are never going to find these antibodies.

Donna

[KDONATES]

When the Echo screen is positive and the Echo panel is negative or non specific reactions, we do a tube screen with Peg. It the Peg tube screen is negative, we report the antibody as SOLID PHASE ANTIBODY OF UNDETERMINED SPECIFICITY. We add a comment in the computer that the tube screen was negative.

[BrianD]

hi Donna, you've repeated the argument i made but i don't make the policy. fortunately, the issue resolved with later lots and now we are immediately going to the ID panel after a positive ab screen using the ECHO. whatever it was that Immucor "fixed" has us back to a high degree of confidence with the Ab Screen. if it is positive, we almost certain to find something on the ID panels (we do Ready-ID and Extend I and Extend II as needed).

[BrianD]

Brian -

We, too, see a fair number of Positive Antibody Screens on the Echo that turn out to be nothing or "non-specific-trash", but by immediately going to a PeG/Tube Antibody Screen and reporting the Antibody Screen as Negative (when the PeG Ab Screen is Negative), you are missing one of the advantages of the Echo instrument.

We have seen several antibodies that are detected by the Echo but not by PeG/Tube technique, particularly Kidd and a few Rh antibodies. So by following your protocol (and not performing an Echo Antibody Identification Panel), you are never going to find these antibodies.

Donna

hi Donna,

before Immucor did the "fix" [don't know what they did but the problem is uncommon now with later lots] it seemed to me that the false positive specimens tended to have elevated WBCs. is this similar to your experience?

i think i just arrived at yet ANOTHER project. oy.

b.

Edited July 1, 2010 by BrianD
grammar

[L106]

Hey, Brian......The elevated ABC count of the patient is one factor I had not looked at (or even thought about.) Thanks for the idea.....I'm going to pay attention and make note of that possibility. We are still occasionally seeing the Echo "unexplained positive", so I'd love to figure out what is going on. Thanks again, and I'll let you know if we see any correlation with the patients' high WBC count.

Donna

[dtpath]

what procedure do ECHO users employ when "?" appears in antibody screen?

[kmh76]

"?" is an equivocal result so we re rerun the screen. If it still comes up "?'" then we will visually look at the plate. Normally it is a weak reaction and will do a panel but most times repeating it it comes up negative. Can't figure that one out!