Analysis of Ambiguities of HLA-DR Typing using the Dynal RELI(TM) SSO HLA-DRB Kit and Development of an 'Interpretation Program for Koreans'

Song, Eun Young; Park, Sung Keun; Kim, Sun Mee; Kim, Byoung Cheol; Han, Bok Yeon; Lim, Young Mi; Park, Myoung Hee

Abstract

BACKGROUND: HLA-DR typing kits using reverse-SSO (sequence specific oligonucleotide) method show considerable ambiguities in HLA-DRB1 generic typing. We analyzed the ambiguities of the Dynal RELI(TM) SSO HLA-DRB test (Dynal DRB test) and developed an 'Interpretation Program for Koreans'.
METHODS
A total of 3,000 Koreans were typed for HLA-DRB1/B3/B4/B5 using the 36 probe Dynal DRB test and all of the cases showing ambiguities in HLA-DRB1 generic typing were subjected to confirmatory typing using the PCR-single strand conformation polymorphism (SSCP) method. On the basis of these results, an 'Interpretation Program for Koreans'was developed for the 45 probe Dynal DRB test.
RESULTS
Among 3,000 Koreans tested by the 36 probe Dynal DRB test, 456 cases (15.2%) showed ambiguities. In 95% of the ambiguity cases (433/456) and 99.2% of the total cases tested (433/3,000), the'most probable type'could be expected from the DRB1 gene frequencies and DRB1-B3/B4/B5 associations in Koreans and these results were in accordance with the confirmatory typing results as well as the results given by the 'Interpretation Program for Koreans'. Similarly, the 'Most Probable'could be assigned by the program in 99.4% (348/350) of the cases tested with the 45 probe Dynal DRB test.
CONCLUSIONS
Ambiguity in the Dynal DRB test was observed in >15% of the Korean samples tested. The majority (95%) of the ambiguities could be resolved on the basis of HLA-DRB1 gene frequencies and DRB1-B3/B4/B5 associations in Koreans. Furthermore, using the program developed in this study, the correct assignment of DRB1 generic types was possible without additional typing in the majority (>99%) of the cases tested.