Analysis of Ambiguities of HLA-DR Typing using the Dynal RELITM SSO HLA-DRB Kit and Development of an ‘Interpretation Program for Koreans’
2002; 22(4): 267-277
Korean J Lab Med 2003; 23(5): 345-351
Published online October 1, 2003
Copyright © Korean Society for Laboratory Medicine.
Background :For HLA-DR typing, PCR-SSO (sequence specific oligonucleotide) kits are most commonly used in Korea. However, the PCR-SSO method generally shows more ambiguities than PCR-SSP (sequence specific primer) method in generic-level typing of HLA-DRB1 alleles. We evaluated the newly developed NeoDin SSPTM HLA-DR Typing kit based on the PCR-SSP method. Method :A total of 118 selected samples with known DRB1 alleles were tested with the NeoDin SSPTM HLA-DR Typing kit and the band patterns were interpreted by two investigators in a blind manner. Result :Correct assignment of HLA-DRB1 alleles at a generic level was possible in 117 (99.2%) out of 118 samples tested. Only one sample carrying DRB1*1403 as a homozygote showed ambiguity: DR14 homozygote versus DR14, DR13. Some HLA-DR specificities (DR8, DR11-14) were dividied into 2-11 allelic groups and the typing results (allelic groups) were fully concordant with the known DRB1 allelic specificities. When a proper concentration of DNA with good purity was used, band patterns were clear and easy to read and no false positive or false negative band was observed in the DRB1 assignments. The occasional presence of 1-2 faint nonspecific bands did not much influence the correct assignments of specific bands. In a small proportion (5 samples, 4%) of samples tested, a random occurrence of PCR failure of 1-2 internal control bands was observed; however it did not affect the correct assignments of DRB1 alleles. Conclusion :When a proper concentration of DNA with good purity is used, the correct assignments of HLA-DRB1 alleles at a generic level are possible in >99% of the samples without ambiguity, using the NeoDin SSP kit.
Keywords: HLA-DR, DRB1, Ambiguity, SSP (sequence specific primer)