1.2000
#26
TRIPLET MATCHING FOR HIGHLY SENSITIZED PATIENTS.
S. Pang, D. Phelan, B. Duffy and T. Mohanakumar. Barnes-Jewish Hospital HLA Lab and St. Louis MO, Washington University, Dept.Surgery.

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Highly sensitized (HS) potential renal transplant recipients pose many challenges for finding compatible donors for transplantation (TX).Recent studies have shown that HLA class I matching at the triplet level may identify potential compatible donors for HS patients. The goal of our study is to determine whether HLA specificity analysis in combination with HLA matchmaker program can result in negative crossmatches(XM) in a HS patient waiting for renal TX for 16 years. This patient (BD) demonstrated antibody specificity to HLA by ELISA. Single antigen ELISA as well as antiglobulin augmented (AHG)cytotoxicity techniques identified 71% PRA with specificities to HLA-A2,3,11,24,25,26,HLAB8,18,27,35,38,45,51,53,62,64,65,71,75 and 78. These results along with BD's phenotype A23,- B48,57 CW4,CW7 were entered in the HLA matchmaker program for analysis,which resulted in the definition of HLA -B63,70,72 as ZERO triplet mismatches and HLA-B58,62,75,77 as one triplet mismatches. Acceptable and unacceptable antigens were entered into the program and HLA-A1,19,36,80,HLA-B7,13,21,40,41,42,47,59,72,76,77,and 81 were identified as ZERO and one triplet mismatches additionally. Based on these results obtained from HLA matchmaker, 5 local cell donors were identified. XM analysis was performed using four wash amos and AHG against both T and B cells. All of the XM were negative,thus validating that potential donors identified using HLA matchmaker program for HS recipient can identify compatible donors for TX. From this preliminary study we conclude that extensive HLA antibody specificity analysis in combination with definition of acceptable triplet mismatches can be successfully employed to predict negative XM leading to identification of compatible donors for HS patients waiting for TX.