Evaluation of In-house Lymphocyte Panel of 72 Wells for the Identification of HLA Antibody Specificity

Lee, Seong Gyu; Yang, Yoon Sun

Abstract

BACKGROUND: To detect anti-human leukocyte antigen(HLA) class I alloantibodies in patients awaiting solid organ transplantation, panel reactive antibody(PRA) test using complement-dependent lymphocytotoxicity(CDC) has been used. The enough size of lymphocyte panel in PRA test enables the identification of HLA antibody specificities. So we made lymphocyte panel of 72 wells to evaluate the usefulness comparing with 36 wells screening panel.
METHODS
A total of 55 sera(positive 20, negative 25, quality control materials provided by "International Cell Exchange" program of UCLA Tissue Typing Laboratory 10), which had been tested for PRA using 36 wells screening panel, were re-tested using newly produced 72 wells lymphocyte panel.
RESULTS
The results of the 25 negative sera were same except one serum, which might be due to non-specific reaction. The %PRA values of the 20 positive sera using 36 wells screening panel were distributed into 1-10%(n=4), 10-50%(n=9), 50-80%(n=5), and 80-100%(n=2). Using lymphocyte panel of 72 wells, %PRA values of 20 positive sera showed no difference(p=0.61) from that of 36 wells and we could not identify the specificity of HLA antibodies for the 10 sera, which previously had not been identified with 36 wells screening panel. But we additionally or newly identified the specificity of HLA antibodies in 4 positive sera and 2 quality control materials.
CONCLUSION
Identification of HLA antibodies was not much improved using a PRA test with 72 lymphocyte panel and therefore 36 lymphocyte panel is considered to be enough to screen the HLA antibodies. However the increase of the size of lymphocyte panel is expected to resolve the difficulty, caused by linkage disequilibrium, for the identification of HLA antibody specificity.