keisterkid

I don't disagree with the comments about using GEL, we try to duplicate our clients results with GEL if that is what they used. But for the sake of discussion, what are the reference labs to do when a large group of their clients begin using ECHOs? Will clients expect us to purchase ECHOs so we can duplicate their work? At what point do we stop being lead around by blood bank companies/suppliers coming out with new and better "must have" technologies every 5 to 10 years? In my area we now have approx. 7 hospitals that are using or validating their ECHOs.

Just a sidebar as to why we use PEG: We did testing for a tube manufacturer, wanting to bring plastic BB tubes to market, for all common clinically significant alloantibodies and found that, in our hands, PEG gave consitently stronger reactions and for a longer time. The testing was done at 3, 7,10,14 and 21 days.

Our current SOP requires that each workup is done in two media, either LISS panel with all negative reactions tested using PEG 22% albumin panel with all negative reactions tested using PEG or the method used by client (ex. GEL) and negative reactions tested using PEG Do other reference labs always use two media? We are thinking of using PEG as the primary potentiator and if we aren't able to solve the problem then resort to the other methods. This is a cost cutting/time saving idea but we want to hear what other reference labs are doing....

Recently we have experienced multiple antibody workups with negative reactions using the LISS tube technique, PEG tube technique and 22% albumin technique but the GEL was positive. We prepare all of our 0.8% panels using Immucor, Ortho and Medion panel cells. Recently we had a workup where 26 to 39 GEL cells tested were 1+ to 2+ but all tube testing was negative. A titer performed in GEL was 2 and 0.2 MDTT treated cells tested in GEL were no different than the "neat" testing. Our client had the same findings. Ortho was contacted and they will "try" to get back to us within a week; that would be by today, no response yet. Any ideas?

Besides...who said anything about cost...I said the price we charge is the same. I didn't confuse the two, so don't assume that I did!!

Malcolm, why the hostility and pontification about cost? We charge the client the same as a packed cell, that is all, they don't complain. We are a nonprofit facility and care more about using the "gift" given to us and the community good will. As we are an expanding facility, I don't think we need lectures on cost. Everyone is happy...

I work for a large blood center that washes all of our antibody positive units. There is no difference in pricing. We don't want to waste a usable product, our clients don't haven't complained (knock on wood).

This reply is from an Ortho technical specialist: I got an email with your concerns for testing the gel card with multiple incubation times. This question came up in my very early years (1995!) and the answer was yes there many studies done incubating actually hotter than 37C(up to 40C). One microtube was opened and incubated followed by the second one etc. until all 6 were used. The main reason heating does not cause a problem to the gel is the gel does not come in contact with heat…….only the upper reaction chamber. Important to keep the foil intact and not open and try to incubate using that well later. Drying could occur which would not be good. Also the package insert states that storage should be between 2 – 25C (not testing environment). So the bottom line is ……..multiple incubation times does not affect the gel card. I hope this helps. Would be glad to talk to you or anyone else who is concerned about this.

We repeat panels every 14 days as long as the antibody screen results don't change and the antigen negative units are compatible. In the above scenario, the new sample crossmatched with E-, M-, Fy(a-), Jk(a-) some of the units should be incompatible; this would trigger our doing a complete workup on the patient.

We did a study a few years ago that showed antigen integrity was maintained in our panels for 3 months post expiration (Immucor, Ortho and Medion panels). After 3 months the Duffy antigens and S antigen got remarkably weaker. A potential problem, we think, was that we were using commercially prepared antisera and not a human source that was "manipulated" to give a 2+ reaction with known antigen positive cells. We felt the data could be skewed because the commercially prepared would be the strongest reacting, not typical of a patient's antibody.

1. We are talking about a donor and calling it an ABO discrepancy means, to us, that the unit is not distributed. 2. We do transfuse A units to patients with anti-A1 after proving that the antibody is clinically insignificant.

It is probably missed more than we BBers would like to admit. In our reference lab when ABO discrepancies are referred to us we use A1, A2 and B cells for the reverse typing. If we can't bring up an anti-A with the A2 cells we call the donor an ABO discrepancy. When requested we will perform adsorption/elution studies to prove the ABO type, but the product isn't labelled since the client that receives the product won't want to take the time and expense to duplicate our work to confirm the ABO.

Does anyone use the BioArray system for HLA typing? I was wondering if it was a viable method that gave accurate results. Thanks.

At our blood center all antibody positive units are washed before they are shipped to our clients. We don't charge for that and only ship to clients that have agreed to accept them or are looking for antigen negative units. We don't feel that we can discard such a valuable product given to us in good faith. Besides, you would be surprised how many Rh negative donors have an anti-D; we would need to import Rh negs if we didn't wash the units.

For giggles we typed our panels with commercially prepared antisera when we received them and for the next 6 months after outdate. The S and Fy antigens became weak to undetectable after 3 months on the Immucor panels while the Ortho and Medion panels maintained their S and Fy antigens for 4+ months. The Rh antigens got stronger in many instances. We are in the process of getting human plasma with the antibodies, diluting to a 2+ reactivity, and repeating the work.