Weak backtypes on Echo- why?

[Karrieb61]

Hey all Echo users, we seem to be experiencing an increase in the number of patients who are backtyping very weakly, 99% of the time on the B which drives us to double check the type manually. These are not elderly (although our new young 23 ish tech though that the current patient at 52 was elderly..... ) or immunocompromised patients to the best of our knowledge. Daily QC is fine. Anyone else seeing this?

[OkayestSBB]

Yes, we get this all the time, mostly with our B Cells too.  Whats frustrating is when you repeat in tube and its 2+ or greater!  One thing I thought about was I believe Immucor recommends to refrigerate the A1 and B red cells occasionally to keep the expiration on the bottle, otherwise they are only good for like 5-7 days at continuous RT (not 100% about the 5-7 days, it may be 3).  Another explanation I got from Immucor is the analyzer shakes the strips a certain amount of times but it will stop when the monoclonal control is negative. When you read your tubes you generally do one at a time so you wouldn't notice the difference between the monoclonal and B cells.  Therefore if you were to shake the tubes together you'd be more likely to get results like the ECHO. 

I don't think I explained their reasoning very well.  Or maybe they didn't explain well to me. Or it maybe its just bologna, and they can add bad lots of B cells to their bad lots of ready screen strips/indicator cells.

[Karrieb61]

Thanks RaeRae, I heard from a couple of other Echo users that they see this often when the bottle is "old" but its still a pain in the neck.

[goodchild]

With all of these Echo posts over the last few months it makes me feel warm inside regarding my ProVue.

[marvy1]

Tightening or loosening the belt on the strip carrier can optimize the strength of the reverse cells. On the Echo I have found the strengths to normally be at least 1 grade less than tube strength. With regards to Gel vs Echo, I have found approx equal number of clinically signficant antibodies on either method that were not found on the other method (We use both Gel and solid phase methods)

[Karrieb61]

Funny that another Echo user just emailed me about this belt thing. Overall, it appears to be an issue with the cells getting older in their little bottles, as it only seems to happen when we've been using the bottles for many days.

We are too small for a ProVue but I have to say that where I was before, they had constant mechanical breakdowns. So nothing is perfect. Both are better than tube for sure for a variety of reasons so despite occasional problems, I would hate to give up the Echo.

[Dansket]

I've been using 2 ProVues the past 6 years. We don't experience constant mechanical breakdowns.

[AMcCord]

We do see weaker reactivity in backtypes with older bottles (down to the last drop) and lots nearing outdate. Once lots near outdate, even the QC results weaken by about 1 grade. It's possible that the belt can be adjusted a bit to improve performance. Ours needed that done after it had been in use for a number of years.