1.2000
#36-OR
DETERMINATION OF PERMISSIBLE HLA CLASS I MISMATCHES IN HIGHLY SENSITIZED KIDNEY RECIPIENTS (OR THE CONTINUE OF STORY OF HLA MATCHMAKER ALGORITHM).
Andrew L. Lobashevsky, MD,Ph.D.,, Rhonda W. Senkbeil, BS,MT, Cindy A. Mink, James L. Shoaf, BS, Mark H. Deierhoi, MD and Judith M. Thomas, Ph.D.. Birmingham AL, USA, UAB hospital, 35294, Surgery.

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HLA compatibility and permissible mismatches (PMM) predict the results of cross match (XM). Flow Cytometry non-reactive antigens (NRA) contribute to the set of PMM. The goal of this study was to define more accurately the NRA with sera from sensitized patients using HLAMatchmaker algorithm. Sera from fifteen recipients were analyzed. Three to four samples were tested from each patient. PRA was detected using One Lambda FlowPRA Class I Screening Test and Luminex method (LM) and varied between 89% and 97%. The NRA were defined using Flow specificity beads (FSB), LM, high resolution class I beads and single antigen Luminex beads. The overlapping NRA in each serum comprised consensus of negative reactions that were used subsequently to define PMM. This was done by entering of patient and donor HLA and consensus of NRA into HLAMatchmaker program. The number of NRA varied from one to five and the number of PMM ranged from two to ten antigens. Strong correlation (r = 0.965) has been demonstrated between PRA values determined by FSB and LM as well as between patterns of NRA in consensuses and those defined by FSB (r = 0.912). However, correlation between patterns of NRA in consensuses and those defined by LM was lower (r = 0.752). Negative results were observed when patient serum (PRA=97%) was FCXM with cells from individual whose HLA phenotype consisted of PMM. Thus, our results showed that FSB methodology seemed to be a reliable method in determining NRA. The pattern of PMM producing negative FCXM results depends considerably on how accurately NRA were determined.