LShirley

I reported lots of nonspecific reactivity with several recent lots of Ortho Surgiscreen cells using gel method. Most were negative when the screen was repeated using PeG method.

When I first heard of this reg, I did some testing on random patient samples of all blood types. All good except for the Group B patients. Two Group B patients had detectable anti A1 in reverse type, but both were "compatible" with AB donors when tested in gel. I was very surprised at this. I'm hoping to get away with stating that our LIS will not allow incompatible donor units to be allocated instead of having to perform IS crossmatches. The LIS is less likely to make an error than a human. We do AHG crossmatches on the ProVue for patients with alloantibodies. Otherwise, we use electronic crossmatch. Performing IS crossmatches leaves you open to a host of other problems like rouleaux, cold autoantibodies, etc that I would just as soon not know about.

I have the following statement in my Rh Typing Procedure: If patient results are less than 2+, or mixed field, obtain patient transfusion/pregnancy history in order to prevent mistyping a D-negative patient as D-positive due to recent exposure to D-positive red cells.

Are you CAP Accredited? If so, refer to the latest CAP Checklist requiring (among other things) the transfusion service medical director to accept responsibility for apheresus procedures.

We use the ProVue and manual gel. If we ever need to perform a test by the tube method, we do QC along with the first patient sample. This has worked well for us. I order 1 set of 3% screening cells per month for tube testing.

Ortho does not "officially" recommend spinning cards before using. However, in my experience, it usually will make a previously unuseable card work on the ProVue. I don't think the new packaging has helped.

We do the "long" procedure each quarter. Our only daily QC is fill volume. Haven't had any problems with CAP or AABB on this.

Yes!!! Once we get to within a few days of the screening cells expiration date, we frequently encounter these questionable results. Sometimes there will even be positive cells on Ortho 0.8% Panel A...usually cells #5 and #10. We never "assume" that it is an anti-E or that it is nothing. We run more cells from a different manufacturer in gel and with PeG. Sometimes we still find reactivity that we cannot identify and sometimes everything else is negative. We will usually classify as "unable to identify" and perform AHG crossmatch for the patient. I don't think there is an easy answer.

Have you checked to see if the patient received any plasma expanders? Was the sample collected from an IV site? Try having the sample recollected.

Gel is great at detecting mixed field reactions both manually and on the ProVue. You can get mixed field results after transfusion of only a couple of group O red cells in a non-group O patient.