An update to HLA Nomenclature, 2010

Bone Marrow Transplantation (2010) 45, 846–848 & 2010 Macmillan Publishers Limited All rights reserved 0268-3369/10 $32.00 www.nature.com/bmt SPECIAL REPORT An update to HLA Nomenclature, 2010 SGE Marsh1, ED Albert2, WF Bodmer3, RE Bontrop4, B Dupont5, HA Erlich6, M Fernández-Viña7, DE Geraghty8, R Holdsworth9, CK Hurley10, M Lau11, KW Lee12, B Mach13, M Maiers14, WR Mayr15, CR Müller16, P Parham17, EW Petersdorf8, T Sasazuki18, JL Strominger19, A Svejgaard20, PI Terasaki11, JM Tiercy21 and J Trowsdale22 1 Anthony Nolan Research Institute, London, UK; 2Laboratory of Immunogenetics, Department of Pediatrics, University of Munich, Munich, Germany; 3Weatherall Institute of Molecular Medicine, Oxford University, Oxford, UK; 4Biomedical Primate Research Centre, Rijswijk, The Netherlands; 5Sloan-Kettering Institute for Cancer Research, New York, NY, USA; 6Roche Molecular Systems, Alameda, CA, USA; 7MD Anderson Cancer Center, Houston, TX, USA; 8Fred Hutchinson Cancer Center, Seattle, WA, USA; 9 Victorian Transplantation and Immunogenetics Service, Melbourne, Victoria, Australia; 10Department of Oncology, Georgetown University, Washington, DC, USA; 11Terasaki Foundation, Los Angeles, CA, USA; 12Hallym University, Anyang City, South Korea; 13 University of Geneva, Geneva, Switzerland; 14National Marrow Donor Program, Minneapolis, MN, USA; 15Medical University of Vienna, Vienna, Austria; 16Zentrales Knochenmarkspender-Register, Ulm, Germany; 17Stanford University School of Medicine, Stanford, CA, USA; 18International Medical Centre of Japan, Tokyo, Japan; 19Harvard University, Cambridge, MA, USA; 20State University Hospital, Copenhagen, Denmark; 21Hôpital Cantonal Universitaire, Geneva, Switzerland and 22Cambridge University, Cambridge, UK The WHO Nomenclature Committee for Factors of the HLA System met during the 15th International Histocompatibility and Immunogenetics Workshop in Buzios, Brazil in September 2008. This update is an extract of the main report that documents the additions and revisions to the nomenclature of human leukocyte antigen (HLA) specificities following the principles established in previous reports. Bone Marrow Transplantation (2010) 45, 846–848; doi:10.1038/bmt.2010.79; published online 29 March 2010 Keywords: HLA; Nomenclature; update Introduction of colon-delimited HLA allele names The convention of using a four-digit code to distinguish HLA alleles that differ in the proteins they encode was introduced in the 1987 Nomenclature Report.1,2 Since then additional digits have been added, and currently an allele name may be composed of four, six or eight digits depending on its sequence. The first two digits describe the allele family, which often corresponds to the serological antigen carried by the allotype. The third and fourth digits are assigned in the order in which the sequences have been determined. Correspondence: Professor SGE Marsh, HLA Informatics Group, Anthony Nolan Research Institute, Royal Free Hospital, London NW3 2QG, UK. E-mail: Received 25 February 2010; accepted 25 February 2010; published online 29 March 2010 Alleles whose numbers differ in the first four digits must differ in one or more nucleotide substitutions that change the amino-acid sequence of the encoded protein. Alleles that differ only by synonymous nucleotide substitutions within the coding sequence are distinguished by the use of the fifth and sixth digits. Alleles that differ only by sequence polymorphisms in introns or in the 50 and 30 untranslated regions that flank the exons and introns are distinguished by the use of the seventh and eight digits. In 2002 we faced the issue of the A*02 and B*15 allele families having more than 100 alleles.3 At that time the decision taken was to name further alleles in these families in the rollover allele families A*92 and B*95, respectively. For HLA-DPB1 alleles, it was decided to assign new alleles within the existing system; hence, once DPB1*9901 had been assigned the next allele would be assigned DPB1*0102, followed by DPB1*0203, DPB1*0302 etc. When these conventions were adopted, it was anticipated that the nomenclature system would accommodate all the HLA alleles likely to be sequenced. Unfortunately this is not the case, as the number of alleles for certain genes is now fast approaching the maximum possible with the current naming convention. With the ever-increasing number of HLA alleles described, it has been decided to introduce colons (:) into the allele names to act as delimiters of the separate fields. To facilitate the transition from the old to the new nomenclature, a single leading zero must be added to all fields containing the values 1–9, but beyond that no leading zeros are allowed. This will help to lessen any confusion in the conversion to the new style of nomenclature. An update to HLA Nomenclature SGE Marsh et al 847 Hence: A*01010101 A*02010102L A*260101 A*3301 B*0808N DRB1*01010101 becomes becomes becomes becomes becomes becomes A*01:01:01:01 A*02:01:01:02L A*26:01:01 A*33:01 B*08:08N DRB1*01:01:01:01 For allele families that have more than 100 alleles, such as the A*02 and B*15 groups, it will be possible to encode these in a single series. Thus, the A*92 and B*95 alleles will now be renamed into the A*02 and B*15 allele series. For example: A*9201 A*9202 A*9203 B*9501 B*9502 B*9503 becomes becomes becomes becomes becomes becomes A*02:101 A*02:102 A*02:103 etc B*15:101 B*15:102 B*15:103 etc The names A*02:100 and B*15:100 will not be assigned. In case of other allele families in which the number of alleles reaches 100, these will be numbered sequentially; for example, A*24:99 will be followed by A*24:100. The DPB1 allele names that have been previously assigned names within the existing system will also be renamed, for example: DPB1*0102 DPB1*0203 DPB1*0302 DPB1*0403 DPB1*0502 becomes becomes becomes becomes becomes DPB1*100:01 DPB1*101:01 DPB1*102:01 DPB1*103:01 DPB1*104:01 etc The ‘w’ will be removed from the HLA-C allele names, but will be retained in the HLA-C antigen names, to avoid confusion with the factors of the complement system and epitopes on the HLA-C molecule, often termed C1 and C2, that act as ligands for the killer-cell Ig-like receptors. Cw*0103 Cw*020201 Cw*07020101 becomes becomes becomes C*01:03 C*02:02:01 C*07:02:01:01 etc The changes to the HLA Nomenclature will be officially introduced in April 2010. A full list of old and new HLA allele names will be made available through the IMGT/ HLA Database (www.ebi.ac.uk/imgt/hla) and the HLA Nomenclature web site (hla.alleles.org).4 for a single HLA allele to be unambiguously assigned. Often it is only possible to resolve the presence of a number of closely related alleles. This is referred to as an ambiguous ‘string’ of alleles. In addition, typing strategies are frequently aimed at resolving alleles that encode differences within the peptide-binding domains, but fail to exclude those that differ elsewhere. For some pur (...truncated)