Echo Users- seeing huge tube vs Echo discrepencies?

[Karrieb61]

Hi to all Echo users- I have an email into Immucor but am not assuming that I'll get the answer I need: had an adult female patient on Friday, history of one rbc transfused back in November at our hospital, patient says she has not been transfused elsewhere. Patient is on no meds except aspirin.  ABS at that time was neg. This past Friday her Echo results were 4+ for all 3 screening cells, 3-4+ on all Capture ID cells and the DAT on Echo was 1+. Tech repeated using the tube and got NEGATIVES for everything except a weak micro DAT reading. Repeat sample from patient had exact same results. I had the techs release only units that were Echo negative and we got about 20% of the tested units compatible that way. Local reference lab admits that they would have stopped with the first tube screening if it was negative and couldn't offer me any suggestions.

Have any of you seen this much of a discrepancy between tube and Echo? I've seen lots of tube=neg, Echo= 1+, sometimes 2+ but never this. Comments?

[Malcolm Needs ☆]

My bet is that your patient has a "cold-reacting" auto-antibody.  Tube is less sensitive to these than are other "modern" techniques, but, because the antibody senitises the patient's own red cells in vivo, the DAT tends to still be positive.

[Karrieb61]

Thanks Malcolm but wouldn't a cold show up in the immediate tube spin? I may have someone play with it today and see what happens if we run a cold screen from the frig but I would think it would have come up during the IS phase.

[Malcolm Needs ☆]

Not necessarily Karrieb61.

 

Of course, I am not saying that it actually is a "cold-reacting" auto-antibody; just that that is my bet.

[CMCDCHI]

Gel is currently our back-up and we see this occasionally.  If we get a negative gel screen and panel, we call it negative.  

[galvania]

The other possibility is that the patient is reacting to one of the components in the reagent buffers used on the Echo.  The reagent buffers of all manufacturers are a bit different; the same manufacturer might also use different buffers for different types of cells/reagents.  these antibodies can sometimes be very strong, but have  no clinical significance.  Can you try by a different method?

[Malcolm Needs ☆]

Very good point Anna.

[marvy1]

We get a lot of patients reacting like this. Attribute reactivity on the Echo to an autoantibody. Do need notice cold autos coming up that much, so assume it is a warm (Echo supposedly on reacts with IgG). I'm guessing if you do tube DAT it might be microscopically positive for IgG? If saline IAT  tube reactivity is negative we issue blood that is compatible by that method, especially if the patient was not recently transfused. I find autoantibodies love solid phase method.

[jayinsat]

We call this an "Anti-ECHO" antibody.  We see this often and believe it is somehow related to the stroma process.  We have no problem defaulting to the back-up negative results.  We have wasted too much time, money and resources investigating these false positives.  We have sent them out to our reference lab only to get back a report of " NO ANTIBODY DETECTED". 

 

Since about March of 2014 ECHO has had a huge problem with false positives.  Normally they are weak 1+ or ?'s but we have seen 3-4+ reactions across the board that will be completely negative in GEL (our primary backup) and tube with LISS.  We have noticed that if the DAT is positive, expect all sorts of sporatic positives in the READY ID!

 

Just my 2 cents.

Edited February 3, 2015 by jayinsat

[Karrieb61]

2 cents well taken Jayinsat and my fear is that what we are seeing sometimes at least are truly false positives.  I dont' recall reading the term false pos before this related to Echo use but now I am paying attention to it. I called Immucor on this and they did mention reactions to reagents so maybe Anna's comment is the "truth". Our only backup is tube LISS. A couple of times we have used outdated Echo panels with varied results.

I guess I am just frustrated since the techs, particularly the part-time 2nd and third shift techs are confused and call me looking for the definitive answers I don't have. If Immucor is insisting that the antibodies that we see on Echo are indeed developing antibodies that I want all Echo compatible crossmatch RBCs to go out at least and not use tube as the xmatch method. Otherwise, well I don't know. Unfortunately, we have had several of these events over the last 3 weeks. I may call Tech Services for a genuine service  call on this.

[mrdth5]

This is very common with solid phase and from what I've read, gel as well.   In our experience, it's almost always a "solid-phase antibody" or a strong cold.  Seen many a cold antibody identified by the reference lab that was 3-4+ on Echo.  Immucor does not agree but I have to go with the reference lab on these.  

 

I suggest that you and your medical director develop a workflow on how you want techs to handle these scenarios, either very conservative or liberal, institution variable.   I did and it stopped all the off-shift confusion.

 

[Karrieb61]

Thanks mrdth5, I am actively working on the workflow diagram now as it turns out. In this particular case that still worries me, it was not a cold antibody at all. Still have no idea what is going on but the patient did get two Echo xmatched units that were compatible with no repercussions.

[Malcolm Needs ☆]

In that case Karrieb61, I think that Anna's suggestion is correct, because the screening and panel cells will be in the preservative about which she spoke, but the units from your stock would not be in this preservative.

 

Sorry to have lead you down the garden path with my suggestion of a "cold-reacting" auto-antibody - but that was, nevertheless, a "live option" at one point.

[EDibble]

This is very common with solid phase and from what I've read, gel as well.   In our experience, it's almost always a "solid-phase antibody" or a strong cold.  Seen many a cold antibody identified by the reference lab that was 3-4+ on Echo.  Immucor does not agree but I have to go with the reference lab on these.  

 

I suggest that you and your medical director develop a workflow on how you want techs to handle these scenarios, either very conservative or liberal, institution variable.   I did and it stopped all the off-shift confusion.

I totally agree. We see this here all the time. It is not a problem with the ECHO, it is usually a non specific ab reacting to either the stroma or the "glue" used to bind the stroma to the wells.

 

We have a great flow chart now and it has cleared up 99 percent of the confusion.

 

Beth

[Karrieb61]

Eddible, any chance of getting a copy of your flow chart? it might save me some time since I am working on building one now. Thanks

[macarton]

Right after we started using the Echo, we were seeing a lot of postives on the Echo, Echo panel had positive reactions, no pattern. Most of the reactions were all screening cells 3 or 4+.  We spent a lot of time doing back up manual Ortho and Immucor panels (untreated and ficin), only to get a negative reaction.  We finally decided to repeat the screen by gel and if negative report that.  If postive then do a workup.  We recently went back full time to the gel system.

[RWOOD57]

^{We have several patients that react with the solid phase but are negative by gel. We will do a panel by solid phase and if it is inconclusive we will resort to gel for reporting of results. We document the solid phase reactivity in the patient history to alert techs .}

[carolyn swickard]

^{We have several patients that react with the solid phase but are negative by gel. We will do a panel by solid phase and if it is inconclusive we will resort to gel for reporting of results. We document the solid phase reactivity in the patient history to alert techs .}

 

This is essentially what we do too, except our backup is PEG in tubes.  We have always treated these as Solid-Phase Warm Autos.  Sometimes they are very strong and react in tubes also, sometimes not.

 

I also would appreciate any flowcharts anyone might be able to share.

[MAGNUM]

Eddible, any chance of getting a copy of your flow chart? it might save me some time since I am working on building one now. Thanks

If at all possible could get a copy of your flow chart also.

[AMcCord]

I'm with Beth and mrdth5. Don't waste a lot of time and energy trying to make these samples 'be' something, especially for patients with no history of transfusion. They are method dependent non-specific reactions or warm autos (a few possibly cold autos). If they are non-reactive in tube or gel, it's very unlikely that they are going to be clinically significant.  - yes, they are annoying. I'm willing to put up with them because the increased sensitivity to antibodies that matter more than makes up for it.

 

We've been running a ReadyID on samples with this kind of reactivity. If all cells are reactive (plenty of these samples have 4+ reactions - solid phase and warm autos are BFFs), we run tube/PeG antibody screens with an auto. If the tube screen is negative, we do an AHG/PeG crossmatch and the compatible units are good to go. The antibody screen is reported out as negative. The funky results are noted on the patient record for future reference. We've been doing this for 5 years and have seen no reactions with transfusion for these patients.

 

I have seen some issues recently with refrigerated samples. We do Prenatal panels for the OB practice here. The samples are drawn at the clinic, arrive here in late afternoon and are put in the refrigerator overnight. If the techs the next day get in a big hurry to get these samples run through, we see some non-specific reactivity that isn't seen in tube testing. It isn't seen if the sample is retested the following day (after 2nd night in the fridge). I'm chalking these up to cold agglutinins. If the samples are allowed to fully warm to room temp prior to testing, we don't have any problems. Every method has a down side.

[emergency room]

What about reactivity that looks possibility of an alloantibody in the ECHO screen and yet ECHO ID panel non conclusive? Recently, we have a problem where the reaction in  screening cells "looked" like a  anti-Jka, two out of 4 homozygous Jka cells (ECHO panel) was positive and yet peg tube panel was negative and ficin negative..... How far should one go trying to prove its a significant alloantibody? Should I be worried since ECHO is known to pick up Kidd antibodies.The patient was typed and found to be Jka negative and we decided to give Jka negative as precaution.  

 

Does any of your flowchart address issue of where ECHO screen matches an antibody but ECHO ID panel is unclear?

 

 

Emergency room

 

 

 

[AMcCord]

What about reactivity that looks possibility of an alloantibody in the ECHO screen and yet ECHO ID panel non conclusive? Recently, we have a problem where the reaction in  screening cells "looked" like a  anti-Jka, two out of 4 homozygous Jka cells (ECHO panel) was positive and yet peg tube panel was negative and ficin negative..... How far should one go trying to prove its a significant alloantibody? Should I be worried since ECHO is known to pick up Kidd antibodies.The patient was typed and found to be Jka negative and we decided to give Jka negative as precaution.  

 

Does any of your flowchart address issue of where ECHO screen matches an antibody but ECHO ID panel is unclear?

 

 

Emergency room

 

In the case of anti-Jka-ish looking reactions, if it sort of looks like a duck, sort of quacks like a duck and the patient is negative for Jka (or Jkb)...call it a duck or in this case anti-Jka. This is what I've done with tube, PeG and now solid phase because Jka antibodies can be such sneaky little buggers and the chance of a reaction (at least delayed) is there if it truly is anti-Jka.

 

When I validated our Echo 7+ years ago, I found a lovely anti-Jka with solid phase that was totally non-reactive with PeG and gel. The Jk antibodies really do like solid phase best. Over the years we've seen other antibodies that react in solid phase, but not PeG and actually saw 3 in total that didn't react with gel during validation (anti-Cob, -Jka and -c). The reference lab will say they saw nothing, because they most likely didn't use solid phase. When I've done method comparisons for CAP requirements, I've  see antibodies that were clear cut and that reacted 2+ or greater on the Echo, then saw them react microscopically only with PeG and not at all with LISS. It's the nature of different methods and something to be aware of when working on these types of problems. Doing method comparison gives you a pretty good picture of what those varied reactivities could be.

 

BUT - before solid phase we did IDs for years with only LISS or PeG or gel and we didn't see all kinds of transfusion reactions delayed or otherwise. The only 2 reactions I saw, that we missed with a non-reactive antibody screen, were anti-Jkas that did not react with the method we were using at the time. Moral of the Story: Do the best you can and use your best judgement when deciding where to draw the line ( and it makes me more comfortable to call the Jka-ish antibodies - Quack Quack).