Here's one for those of you using the Echo..

[lauried01]

Hi everyone-

We are finished validating our Echo, and are scheduled to go Live next week. We've seen it miss a few antibodies, ones that are a 1+ in gel. This obviously concerns us a little- have you guys seen this same thing? We used to have the ABS2000, and it missed an Anti-E that was also about 1+ in gel. Immucor said it was just below detectability of the ABS. I know they are both solid phase, but I sure was hoping somehow the Echo would be a little more sensitive than the ABS. Anyone have any thoughts?

Oh, and I have also read the posts about those of you that picked up stuff with the Echo that was not detectable in gel- we actually had 2 of those in the almost 200 screens we ran. I guess that's an acceptable rate of false positive (I'd personally rather see false pos than false neg )

I am anxious to hear input from those of you already live and running- overall we think everyone will like it, but I don't like missing antibodies!

[John C. Staley]

Interesting that you consider something missed by Gel and picked up by the Echo as false positive yet something missed by the Echo and found by Gel as worrisome.

No system is 100% sensitive or 100% specific. Over the years I have seen every system pick up something missed by another system and heard similar reports yet all of those systems are still being used. We do the best we can with the tools available.

Having said that, we have been testing with the ABS2000 since 1999 and the Echo since 2007. I have not seen anything that made me want to abandon the technology for something else. Until some one comes up with the perfect, never miss system we will have to learn to live with the occasional misses no matter what we are using.

I'll be concerned we we start seeing problems with the ABO testing.

[lauried01]

Point taken, John:). I guess we would all like to see that 100% perfect system- I guess I have just really come to trust Gel results- it's hard to get used to something new, I suppose.

Thanks for the response (and for the reality check)!!!

[AMcCord]

We are finishing up validation on Echo and we just found and ID'd an anti-E on Echo that gel missed. On the ID panel, it was weak with Capture - one question mark result, with other wells that were fuzzy when the camera shots of the ID panel were visually examined. When the specimen was repeated with tube/PeG, the anti-E was also ID'd. My lesson from this one (and a couple of other samples we've run) is that we need to actually look at the camera shots even if Echo calls it negative.

[sgoertzen]

We are in the process of purchasing an Echo, but have been using the Capture method for almost 2 years. Our blood bank techs love it. We also perform antibody ID testing for several very small local hospitals who prefer to send out any screens that come up positive using their ProVue. What we have seen is consistent weak positives being detected by the ProVue. When they send us their specimens, we repeat the antibody screens using first the Capture method, and if negative, we repeat with tube LISS/PEG methods. So often we find that there is nothing there. I can't imagine that all of these patients actually have weak "real" clinically significant antibodies that neither Capture or tube methods can pick up.

[lauried01]

I totally agree- in the process of our validation, we have seen some that have been called negative, but when you look at the camera shot, it looks to be weakly positive. Unfortunately, it won't let you edit those results! How do you guys handle those? Do you record the results on the panel sheet as your visual read (in those instances where you don't agree w/ what the Echo called)?

[Oldtimer]

We are currently training staff to go live on Echo after using the ABS 2000. We too, are seeing some wells called negative that if the camera shot is viewed or if the strip is viewed on a light box are 1 + to 2+ positive. The ones I have seen are reactions with heterozygous E cells. My feeling for reporting purposes is to indicate the Echo results on paper and then put in a manual reading in another column. I think I would be comfortable reporting a result from the manual reading. The Echo results would not give you a firm interpretation in this instance so further testing would be necessary.

No testing system is perfect, we have to weigh the risks. In my career, most often the antibody that has been in question has been Anti-E.

[marilynm]

From an "old time blood banker", There is no perfect test, as you all are saying.

I have found that everyone has their preference of commercial companies and automation technologies and all work, or they would not have been licensed by FDA!!

Maybe we need to look at "clinical history" with some of these antibodies, which we are doing in our laboratory. Stay tuned.

Marilynm

PS I would encourage each of you to look at patient/donor history and do followup studies to see if the antibodies are clinically significant. I am always curious as to why these "unusual" antibodies do what they do. Plus, you can have a nice paper out of it for aabb in New Orleans next year.

[hmust1]

I, too, am just about to go live with an ECHO. And with regard to the antibody discussion...I'm curious to see when we'll stop referring back to the tube method as the "gold standard." Isn't it really a matter of "ignorance was bliss?"

If there's one thing I've discovered during validation of Capture (and I'm sure Gel users would say the same...) it's that tube is by far the LEAST sensitive method (specificity discussion aside). If I'm getting a weak (1+ or 2+) reaction in Capture via the ECHO...I can't see it in tube at all (not even with different enhancement or longer incubation times).

No method is perfect...but when deciding whether or not to worry about the few antibodies being missed by Gel or Capture...think of all those we've already missed in tube!

Heather

[AMcCord]

I, too, am just about to go live with an ECHO. And with regard to the antibody discussion...I'm curious to see when we'll stop referring back to the tube method as the "gold standard." Isn't it really a matter of "ignorance was bliss?"

If there's one thing I've discovered during validation of Capture (and I'm sure Gel users would say the same...) it's that tube is by far the LEAST sensitive method (specificity discussion aside). If I'm getting a weak (1+ or 2+) reaction in Capture via the ECHO...I can't see it in tube at all (not even with different enhancement or longer incubation times).

No method is perfect...but when deciding whether or not to worry about the few antibodies being missed by Gel or Capture...think of all those we've already missed in tube!

Heather

Agree! Agree! Agree!

[Likewine99]

PEG, gel, LISS, solid phase, tubes, cards, Echo, Gallileo, ProVue, whatever! They are all tools that we have in our tool belt that we use to try to find the most compatible units for our patients.

Things have changed a lot in the 30 years that I've been Blood Banking but nothing can replace the critical thinking skills that we all have and are hopefully passing on to the new techs entering the field.

John is right once we see problem with ABO testing then we (and our patients) REALLY have problems.

[lauried01]

Thanks so much for all your input. Irregardless, we are so looking forward to Go Live- and to unloading a lot of routine screens (Prenatals, etc). We have seen the Echo miss a few, but after reviewing things, they may have been newly forming. You guys are all absolutely right- just THINK of what we've missed when all we had was our beloved tube system!!

Again, thanks for your thoughts- hope everyone is doing well (I am sure if anything, you are warmer than we are here!!)

[John C. Staley]

lauried01,

please don't limit your Echo to just routines. If you do that you might as well tie one hand behind your back. It's fast, very fast. We use it for everything, STATS, routines, prenatals, dosen't matter. It's hard for even your best tech to beat 22 minutes test time for 4 group and screens.

[bbbirder]

We are still in the process of validating our Echo and we had one anti-E that was strongly positive in gel, detectable in tube (PEG and N-Hance), but called negative by the Echo (hazy/fuzzy when viewed on screen or with light box). We submitted that specimen to Immucor.

We also had a frozen specimen on a patient with an anti-c and we had ruled out the anti-E in gel, but guess, what? it was positive on the Echo. (In that case it really didn't matter too much because of the anti-c).

So which is right?

As I recall, in the olden days before gel or capture, there were anti-E's that were only detectable with enzyme treated cells. We did not change to enzyme treated screens for every patient. It seems to be the nature of anti-E's to have some variation in them, and they may not be clinically significant.

I agree with John, not every technique will detect everything.

Linda Frederick

[RR1]

I, too, am just about to go live with an ECHO. And with regard to the antibody discussion...I'm curious to see when we'll stop referring back to the tube method as the "gold standard." Isn't it really a matter of "ignorance was bliss?"

If there's one thing I've discovered during validation of Capture (and I'm sure Gel users would say the same...) it's that tube is by far the LEAST sensitive method (specificity discussion aside). If I'm getting a weak (1+ or 2+) reaction in Capture via the ECHO...I can't see it in tube at all (not even with different enhancement or longer incubation times).

No method is perfect...but when deciding whether or not to worry about the few antibodies being missed by Gel or Capture...think of all those we've already missed in tube!

Heather

What would be really worrying however....is to have a negative or weak reaction by Capture- that works quite strongly by tube IAT.

[Eoin]

Clinically significant! How the heck do we measure that? From historical cases I suppose, but as we all know every persons immune response is different. We are not going to transfuse units with the same reaction as we find in screening cells if there are clearer bags. I have seen a few delayed Tx reactions in my 40 years in bloodbanking due to labile Abs. Haven't seen a patient die from that, nevermind weak reacting antibodies. I feel I might do a literature search on the topic and see what I come up with.

We have got so sensitive nowadays. Maybe ignorance was bliss (no pun intended) in those days, but were the patients any worse off if we did miss weak Abs in those days? Don't know the answer to that. In the sixties in Oz, in a small outback hospital I heard of a crossmatch of a donor on the hoof (Known O) - with a patient whowas critical due to blood loss - conducted in a saucer - Patient survived.

If anyone knows of a good paper on the subject of "clinically significant antibodies" or even a good definition of it, would be glad to see the reference.

I know this doesn't help with system validation, but we all hope that assessors have enough experience not to get spooked by it.

[hmust1]

I just ran a prenatal antibody screen on my Echo. The screen was positive (one cell called "?" by the Echo, and visually interpreted as positive too). A scan of the antigram revealed a homozygous E on the positive cell. I ran the Ready ID panel (which also had a homozygous E cell) and the Echo called all wells negative. When looking at the **** E cell on the panel visually...it has a similar weakly positive haze around the cell button. I truly believe this patient has a brand new/weak anti-E. (One of my old-timers, who I'm training on the Echo today...couldn't believe that PEG wouldn't bring up this anti-E in tube...so I let her try. :-) Anyway, here's my question (now that we know it won't demonstrate in tube :-)...

I have a preganant patient with an anti-E...and I can't titer it. Is it clinically significant? What would you do?? Of course I'm headed into my pathologist's office when I'm done typing this...but couldn't resist picking your brains too!

I would appreciate any input!

Heather

[AMcCord]

I'd report it as too weak to titer and recommend a repeat in a month. Is it clinically significant? Maybe yes, maybe no. I would treat it as if it were, especially until you see what it does over the next couple of months, and let the doc decide how he wants to play it.

I think a visual exam of all apparently negative wells is a good idea, because I've seen several antibodies that showed up just the same way, below Echo's cutoff but definitely there. We've even ID'd one in a recently transfused patient that way. All the fuzzy wells were a perfect match for anti-Jk(a) double dose cells. It will be interesting to see what's there the next time we see her.

[Eoin]

Hi Heather,

In the antenatal setting it could be significant. Follow-up to see if it increases. Rh phenotype the Dad (if known) - could be helpful. I have seen HDNB requiring exchange due to an Anti-E

Regards

Eoin

[jlemmons]

We had a patient whose physician's office sent us paperwork from a different lab showing the patient was B negative. We would then issue Rhogam based on this blood type as the doctor's offices have to pay so much more for the Rhogam than we do. We already had a history from a previous hospital admission showing this same patient was B positive. I looked at our Provue results and realized that the Anti-D testing showed only a 2+ so I immediately suspected that the patient would have typed out using tube typing as a B negative, weak D positive. I called the other lab and was told that they use the Galileo for their testing. What is the technolgoy used by the Galileo? I know that they use Capture solid phase for antibody testing and ID but what about their ABO/Rh testing? This particular lab has a disclaimer on their results that they do not do Weak D testing as it is not required but we now have patients getting Rhogam based on these results who do not need it (not that it will hurt them). Any ideas for me to explain to the docs who want to know why the difference.

[John C. Staley]

The Galileo uses hemagglutination, just like tube testing for ABO/Rh. I believe the cutoff for Rh Pos is 2+. I would try to explain to the doctors that the other lab does not do weak D testing so they consider the patient as Rh negative. I would then, if allowed by my medical director, stop weak D testing as well.

At my previous employement I tried for years to get the corporate transfusion medical director to allow us to drop weak D testing but they feared change so it never happened. I keep hoping that someday they will come around but I just could not wait any longer.

[marvy1]

I am doing Echo Validation. So far the Echo picked up 1 Anti- C, 1 Anti-E and 1Anti- Jk( missed by Gel. On the other hand, Echo missed 7 Anti-K found by Gel. Did not DTT treat to see if the Kell were IgM as some people on this forum are suspecting. Also of note: found multiple examples of Anti-D or Anti-D +E found in Gel that only appear as Anti-E (+ or - the occassionaly D pos E neg cell reacting weakly) on Echo. Has any one else noticed the difference in reactivity of specimens with Anti-D between Gel and Echo/Immucor Solid phase?

[RR1]

Thats excellent work- have you tried repeatability testing- to see if the results are the same on the ECHO, when sample put through again?

Also it would be useful for you to know if these reactions: detection/ non-detection are the same with the next batch of Capture plates you get.

Keep us informed !

Best Wishes

Rashmi

rashmirook@hotmail.com

[MM@WIH]

Hello everyone,

I just recently purchased two Echos and was wondering if anyone had any advise on how many samples to use to perform the parallel testing? I have not seen any guidelines from AABB, CAP or Immucor.

[clmergen]

We did 100 Groups against tube, 40 confirms against tube, 40 confirms against microtiter plate testing, 100 Screens against tube, 50 Screens against manual solid phase, 100 Groups/Screens against tube, 30 Ready IDs against tube, and 20 REady IDs against manual Solid phase.

No wonder it tooks us so long to validate the instrument. That was for the first instrument in our system. The other hospitals in our system are performing less testing.