Equivocal Reaction on the ECHO

[Jody]

We seem to experiencing a high rate of equivocal (?) reactions on the ECHO. We have made calls to the hotline. The outcome is usually bad strips/indicator cells.  Immucor has suggest that we visually interpret them. My blood bank staff is comprised of mostly generalist and I don't think they will feel comfortable about doing this. Our only experience with solid phase is the ECHO.

 I would like to know what other facilities do with the equivocal results.

Thank you in advance

[jalomahe]

At our lab, equivocal (?) reactions on the Echo are visually interpreted by the tech.

As I tell the techs when training them .... just as a one tech would ask another tech to look at a reaction they are unsure of in tube or gel testing, the Echo will ask for a tech to look at result it is unsure of (equivocal '?' reaction).

If they have not done so already, Immucor can provide you with pictures of equivocal reactions and what other 'experienced' facilities interpreted them as along with the rationale. This is in addition to the regular grading examples that they supply. The techs at our lab found these pictures very helpful when they first started on the Echos.

 

[Maureen]

You can use the Echo Report for Statistics to readily obtain the NTD rate for a date range.

I track this to help pinpoint when a lot of either RS3 or Indicator cells is involved in an issue.

Sometimes the issue is resolved by cleaning the washer manifold.

[Rapundaa]

We are a NEO user (and prior to that Galileos) since 2006. The Echo photos are much clearer that the ones on the NEO screens so I am aware that Immucor states that your techs may interpret equivocal reactions. We treat all equivocal reactions as positives because the clarity of the reaction is not as visible on the NEO screen and because we have found at least a dozen significant allo-antibodies over the last 3-5 years that reacted weakly on the screen and we much more apparent on the panel. I would use a great deal of caution in interpreting an equivocal reaction as negative.

I realize there a some populations which produce more equivocal reactions than others (in our experience prenatal and obstetric patients are frequent issues). You may wish to consider an antiglobulin crossmatch in cases where transfusion is necessary.

[AMcCord]

I train my techs - all generalists - to visually interpret the equivocal results. I agree with everything jalomahe said. Your techs will get comfortable with the review process after they've been doing it for a little while, especially with the photo job aid. They just need a little practice and some handholding until they reach their comfort zone.

A major advantage with having a screen visual is that they can ask another tech for a second opinion - a whole lot easier and more reliable with automation screen shots than taking a second look at a tube reaction. I also tell my techs to run a Ready ID panel if they are not feeling comfortable with what they are seeing. Even with equivocal results on the panel they can look for a pattern and do rule outs with the negative wells to rule out the clinically significant antibodies. Once in rare while we find a weak antibody this way. Over time they are running fewer panels as they've gotten more comfortable with the process. I visually review the results on these patients as well and so far they haven't missed anything important.

We also use AHG crossmatches for some of those cases that are still iffy after visual review. Another option we use for some of these types of patients is a repeat antibody screen using tube/PeG.

[CMCDCHI]

We visually interpret the equivocal results here too.  It took some coaching for our staff to get comfortable.  Last year our equivocal rate kept increasing.  Our instrument was 7 or 8 years old and it eventually died.  When we replaced the instrument, the Immucor technical specialists spent a lot of time with our techs explaining the technology and what causes the instrument to throw up a "?"  Take advantage of having those resources- it is what finally got our techs comfortable.

[dbarding13]

We have been using the Echo for just under 1 year.  Some of the most important information I have learned in dealing with equivocals is to be sure the washer manifold is clean, keep an eye on the indicator cells' expiration date (If it is close to the expiration of the lot, the cells tend to be more fragile, and they are not stable for the 24 hours on-board with the stir-ball beating them up.), and last but most important-we use the Technical communications from Immucor for interpretation questions and examples.  It is very helpful in deciphering all the strange little quirks solid phase exhibits. (halos, etc.)  I attempted to attach those Technical Communications, but keep getting errors when uploading.  They are PDF files.  If you e-mail me, I will send them to you that way!  Print them on a color printer, and they will become your new go-to.  They have helped our techs (all generalists) IMMENSELY!  : )

dawn.barding@hshs.org