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DEVELOPMENT OF A WEB-BASED PROGRAM FOR THE IDENTIFICATION OF HLA ANTIBODY SPECIFICITIES.
Choong-Hwan Cha MD 1, Heung-Bum Oh MD, PhD 1, Sanghyun Hwang MD 1 and Jeong-min Chae MA 1. 1 Department of Laboratory Medicine, College of Medicine, University of Ulsan and ASAN Medical Center, Seoul, Korea .
Panel reactive antibody (PRA) test is used to determine whether a patient awaiting transplantation is previously sensitized. The information of patient
s antibody specificities is extremely valuable in performing crossmatches with cadaveric donors.
We developed a computer program based on tail analysis algorithm and implemented on the internet (www.koreanhla.net). It was designed to be able to make each lot on the web-page if researchers own panels are enrolled. We adopted two CREG classifications of Rodey (R)s and Takemoto (T)s and designed to perform 3 methods simultaneously (ABC, R-ABC, T-ABC). The ABC method did not consider CREG. If the two methods (R-ABC, T-ABC) output the same CREG, the specificity was assigned. However, in case the specificities are discrepant, the CREG specificity which was consistent with the private specificities by ABC method was finally assigned.
We analyzed 159 sera with 
6 PRA% by lymphocytotoxicity assay. Antibody specificities were identified in 151 cases. The remaining 8 cases were all over 96%. CREG specificities were identified in 41 (27.2%) cases (both in R-ABC and T-ABC (32 cases), only in R-ABC (2), only in T-ABC (7)). Among 40 cases showing more than 50% PRA, however, CREG was identified in 28 cases (70%). HLA-C specificity was identified in 17 cases (11.3%).
As the application of different CREG classification can give different output in some cases, it would be reasonable to compare those results before reporting an appropriate result. As our program is available on the internet, sharing and communication of PRA results between laboratories in Korea would be facilitated.