Discordant Panel Results (Manual Gel vs. ProVue Gel)

[ABQ bloodbanker]

Help Blood Bankers!

Last week, I reviewed a panel that a tech performed, and I wanted to run a few more cells to prove an Anti-Fyb. (A non specific antibody was also identified). I decided on running a ficin panel, so the Duffy would be destroyed, so I could maybe identify the non specific. The entire panel was negative. I ran the same panel with untreated cells, and that too was totally negative. I then repeated the panel that the tech ran on the ProVue (she had run it manually first), and got totally different results. :eek:Yikes! The Fya was ruled out so we only had the non-specific antibody.

Before I could pull the tech in to retrain, I had another tech get basically the same senario of results, so it made me think I didn't have a tech problem, but a ProVue problem.

Ortho came in and did a complete analysis on both of our ProVues, they were fine and reading/grading with no discrepancies.

I now have all techs running panels both manually and on the ProVue. I am terrified :eek:because I am seeing lots of discordant results! However, they are only on the non-specific antibodies. Any "real" antibody (Anti-D, E, K, etc) we are getting results that match perfectly.

According to Ortho, I am the only one seeing this. It is happening on both of our ProVues, with all 3 panels that Ortho has, so it isn't a reagent problem.

This is a new problem, because everytime we run parity studies, all results have been great.

Any ideas?????

Denise - lost in Albuquerque:confused:

[Malcolm Needs ☆]

Two things immediately spring to mind. However, it might be both, one or the other, or neither that is causing the problem!

Firstly, we have come across several cases of patients that have produced antibodies to the preservative/antibiotic in which the panel cells have been suspended. When the cells are washed and resuspended in a different medium, they no longer agglutinate. Obviously, in our cases, the red cells themselves are coated with the preservative/antibiotic against which the antibody has been raised, and once this coating is removed, we no longer see the agglutination.

I surmise that this is probably not the problem in your case, as you do not mention having to wash the panels,

Secondly, there may well be a temperature difference at which the red cells and plasma are initially mixed in the reaction chamber of the cassettes. This temperature difference may only be subtle, but it may just be enough.for the auto-antibody/non-specific antibody to sensitise the red cells quickly enough to result in agglutination. "Cold reacting" antibodies have a tendency to sensitise red cells very quickly indeed under optimal or just "suboptimal" conditions, but are not as quick to dissociate. It could be that the temperature difference between the manual and automatic technique is just enough to make the difference.

Lastly, it always amazes me the number of times that I have heard a commercial company say "you are the only one reporting this problem", only to find out later that other people have also reported the same problem.

I am not saying that Ortho are not telling the absolute truth in this case (they probably are, as they are a very reputable company), but I just make the comment.

[younglau]

We have all kinds of dicrepant results with our Ortho products, they always say it is just us...........

[huntilla]

Secondly, there may well be a temperature difference at which the red cells and plasma are initially mixed in the reaction chamber of the cassettes. This temperature difference may only be subtle, but it may just be enough.for the auto-antibody/non-specific antibody to sensitise the red cells quickly enough to result in agglutination. "Cold reacting" antibodies have a tendency to sensitise red cells very quickly indeed under optimal or just "suboptimal" conditions, but are not as quick to dissociate. It could be that the temperature difference between the manual and automatic technique is just enough to make the difference.