[Experience on identification of cross-reactive group specificity performed by anti-human globulin panel reactive antibody tests].
BACKGROUND
Panel reactive antibody (PRA) is to screen and identify HLA antibody. Majority of antibody specificities in high-PRA are directed against cross reactive group (CREG). Thus, this study was to know the advantage of identifying CREG specificity and whether antibody specificities are changed according to CREG classification.


METHODS
HLA class I antibodies were identified from 159 sera from 108 patients in Asan Medical Center, who had shown more than 5% PRA by anti-human globulin (AHG)-complement-dependent cytotoxicity (CDC). Tail analysis-based computer program was developed to identify specificities, applying both Rodey (R-ABC) and Takemoto (T-ABC) classification. The results were also compared with those obtained when without CREG application (ABC).


RESULTS
Among 151 cases in which HLA specificities was identified, the frequency of CREG specificity was 22.5% in R-ABC and 27.2% in T-ABC. Eleven cases showed CREG specificities only in one classification. However, the individual antigen specificities in one hand were all included in the CREG identified in the other hand. CREG specificities in samples with PRA >50% (60%) were more frequently identified than those in samples with PRA < or =50% (9%) (in R-ABC, P<0.0001). Without applying CREG to interpretation, specificity was not identified in 9 cases.


CONCLUSIONS
Application of CREG enhanced the rate of antibody identification. Antibody specificities of those cases where CREG specificities were different between Rodey and Takemoto classifications were almost the same when compared at the individual antigen level. Therefore, it was thought that it makes no difference to use any one of these two classifications in interpreting PRA.
Sohn
Yong-Hak
YH
Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea.
Cha
Choong-Hwan
CH
Kim
Myeong Hee
MH
Ko
Sun-Young
SY
Oh
Heung-Bum
HB
D000483:Alleles; D000906:Antibodies / Q000097:blood; D000918:Antibody Specificity; D003429:Cross Reactions; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D016030:Kidney Transplantation; D015203:Reproducibility of Results; D012189:Retrospective Studies
D000906:Antibodies; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I