Voorter CEM, Mulkers E, Liebelt P, Sleyster E, van den Berg-Loonen EM. Reanalysis of sequence-based HLA-A, -B and -Cw typings: how ambiguous is today?s SBT typing tomorrow.
ACTA ACUST UNITED AC 2007;
70:383-9. [PMID:
17868258 DOI:
10.1111/j.1399-0039.2007.00921.x]
[Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The permanently increasing number of human leukocyte antigen (HLA)-alleles and the growing list of ambiguities require continuous updating of high-resolution HLA typing results. Two different kinds of ambiguities exist: the first, when two or more allele combinations have identical heterozygous sequences, and the second, when differences are located outside the analyzed region. The number of HLA-A, B and C alleles recognized in 1999 was almost tripled in 2006. Two hundred individuals, sequence-based typing (SBT) typed in the period from 1999 to 2002, were reanalyzed using the 2006 database. A final allele typing result of at least four digits was obtained for HLA-A, -B and -C by heterozygous sequencing of exons 2 and 3 and, if necessary, additional exons and/or allele-specific sequencing. Storage of the individual sequences in a specially developed database enabled reanalysis with all present and future HLA releases. In the 5-year period HLA-A, -B and -C typing results became ambiguous in 37%, 46% and 41% of the cases. Most were because of differences outside the analyzed region; ambiguities because of different allele combinations with identical heterozygous sequences were present in 7%, 8% and 13% of the HLA-A, -B and -C typings. These results indicate that within 5 years, approximately half of the HLA SBT typings become ambiguous.
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