1.1000
#16
USE OF ABSORPTION BEADS IN FLOW-PRA.
M. Sims, K.D. Cox, C.L. Murphey and J.L. Morrisey. San Antonio TX, SW Immunodiagnostics, Inc.

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Some candidates for solid organ transplantation develop non-HLA antibodies that interfere with Flow-PRA beads, causing a false shift in the fluorescence. The use of absorption beads (abs-beads) allows these antibodies to be removed from patient sera so that accurate results can be obtained.
The non-HLA antibodies can be removed from the patient sera using a new absorption bead from One-Lambda. These beads are made of the same material as the Flow-beads; however they are not coated with any HLA antigen. The absorption beads remove antibody that is binding non-specifically with the latex beads. Six patient sera were treated with abs beads and retested against Flow-PRA, Flow Specific, or Flow Single Antigen (SA) beads with varying results.
Treatment with abs-beads allowed 2 patient Flow-PRA results to be accurately reported. Of the 3 patients tested with Flow Specific Beads only one was totally neutralized allowing an accurate antibody analysis. The other 2 patients showed partial or no neutralization. The sixth absorbed patient was run against Class II SA beads with only partial neutralization.
This false shift phenomenon is most prevalent in cardiac patients possibly due to the increasing use of the LVAD or one of the myriad of drugs which these patients are given. A combination of these factors may explain the varying success of neutralization. For some patients, multiple serial absorptions may be effective in neutralizing the non-HLA antibodies. Further study is needed to further assess the true effectiveness of the abs beads.