Yonsei Med J.  2014 Jul;55(4):1005-1013. 10.3349/ymj.2014.55.4.1005.

Resolution of Ambiguous HLA Genotyping in Korean by Multi-Group-Specific Sequence-Based Typing

• Park Y
• Yoon CE
• Kwon OJ
• Kim YS
• Kim HS

• KMID: 2130827
• DOI: http://doi.org/10.3349/ymj.2014.55.4.1005

Abstract

PURPOSE
To evaluate a multi-group-specific sequence-based typing (SBT) method for resolving ambiguous results from human leukocyte antigen (HLA) genotyping.
MATERIALS AND METHODS
A total of 50 samples that showed ambiguous genotypes for at least two HLA loci from HLA-A, -B, -C and -DRB1 by the conventional SBT assay were evaluated using a new SBT test, the AVITA plus assay. The most likely HLA genotypes for the respective samples considering allele frequencies in Korean were concordant between the AVITA and conventional SBT assays.
RESULTS
An average of 3.3 loci among the HLA-A, -B, -C and -DRB1 loci per sample gave results with two or more possible allele combinations with the conventional SBT, and 48 (96.0%) out of 50 showed reduced numbers of possible genotypes for at least one HLA locus with the AVITA. A total of 41, 43, 42, and 38 cases among the 50 samples showed ambiguous results for HLA-A, -B, -C, and -DRB1 typing by the conventional SBT, respectively. The average numbers of possible allele combinations for the respective four HLA loci were 8.2, 6.7, 5.9, and 3.2, and they were reduced to 1.5, 2.2, 4.4, and 1.8, respectively, by the AVITA. Ambiguity was resolved by the AVITA in 33 (80.5%), 31 (72.1%), 17 (40.5%) and 28 (73.7%) samples among the ambiguous cases from the conventional SBT for HLA-A, -B, -C, and -DRB1 typing, respectively.
CONCLUSION
The multi-group-specific SBT method considerably reduced the number of ambiguous results, and thus may be useful for accurate HLA typing in clinical laboratories.

Keyword

Human leukocyte antigen; sequence-based typing; ambiguity; high resolution; multi-group-specific PCR

MeSH Terms

Asian Continental Ancestry Group/genetics
Base Sequence
Gene Frequency/genetics
Genotype
HLA Antigens/*genetics
Histocompatibility Testing
Humans
Polymerase Chain Reaction
HLA Antigens

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