Meeting Report 16 th IHIW: Population Global Distribution of Killer Immunoglobulin-like Receptor (KIR) and Ligands J. A. Hollenbach*, D. G. Augusto†, C. Alaez‡, L. Bubnova§, I. Fae¶, G. Fischer¶, F. F. Gonzalez-Galarza∥, C. Gorodezky‡, L. Karabon**, P. Kusnierczyk**, J. Noble*, O. Rickards††, C. Roberts‡‡, M. Schaffer§§, L. Shi¶¶, S. Tavoularis∥∥, E. Trachtenberg*, Y. Yao¶¶ & D. Middleton***,††† Summary In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide. However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels. Here, we present a summary of the collec- tion of KIR gene-content data for 105 worldwide populations collected as part of the 15th and 16th Inter- national Histocompatibility and Immunogenetics Work- shops, and preliminary results for data analysis. Introduction The killer cell immunoglobulin-like receptors (KIR) are receptors expressed on natural killer (NK) cells that function to inhibit or activate NK cells. Several of the inhibitory KIR use the human leucocyte antigen (HLA) class I molecules as their ligand, while the ligands for most of the stimulatory KIR have not been identified definitively (Biron, 1997; Vales-Gomez et al., 1998; Vilches & Parham, 2002; Young & Uhrberg, 2002; Hsu, 2004; Smyth et al., 2005; Bashirova et al., 2006). The KIR gene complex is located on human chromosome 19q13.4 and is both polygenic and extre- mely polymorphic. While extensive allelic variability has been identified, particularly in the inhibitory genes (http://www.ebi.ac.uk/cgi-bin/ipd/kir; Robinson et al., 2010), variability in gene-content haplotypes is respon- sible for significant diversity both within and between populations. In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide and are available on the public database www.allelefrequen- cies.net (Gonzalez-Galarza et al., 2011). However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels (Single et al., 2007; Middle- ton et al., 2008; Hollenbach et al., 2010, 2012). The KIR anthropology component (Population Global Dis- tribution of KIR and Ligand) of the 15th and 16th International Histocompatibility and Immunogenetics Workshop (IHIW) have been intended to collect and collate KIR and HLA frequency data in a diverse set of human populations to more closely examine worldwide variation in the KIR loci and the relation- ship between KIR genes and their HLA ligands. Evi- dence that KIR and HLA are co-evolving was first demonstrated by Single et al. (2007); in the 15th IHIW KIR Anthropology component, we presented further support for this notion, finding a significant correlation between KIR2DL2/L3 and its ligand, HLA-C group 1(Hollenbach et al., 2010). A primary aim of the 16th workshop project was to confirm and extend this finding in additional worldwide popula- tions. During the course of the 15th IHIW project, fifteen laboratories submitted KIR genotype and HLA ligand * Children’s Hospital Oakland Research Institute, Oakland, CA, USA, † Federal University of Parana, Curitiba, Brazil, ‡ Department of Immunology & Immunogenetics, Instituto de Diagnostico y Refer- encia Epidemiologicos (InDRE), Secretary of Health, Mexico City, Mexico, § Russian Tissue Typing Center, Russian Research Institute of Hematology and Transfusiology, St. Petersburg, Russia, ¶ Depart- ment for Blood Group Serology & Transfusionsmedicine, University of Vienna, Vienna, Austria, ∥ Institute of Integrative Biology, Univer- sity of Liverpool, Liverpool, UK, ** Polish Academy of Sciences, Wroclaw, Poland, †† Universit a di Roma ‘Tor Vergata’, Rome, Italy, ‡‡ London School of Hygiene & Tropical Medicine, London, UK, §§ Karolinska Institutet, Huddinge, Sweden, ¶¶ Institute of Medical Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Kunming, China, ∥∥ Head Office, HLA Laboratory, Canadian Blood Services, Ottawa, ON, Canada, *** Royal Liverpool and Broadgreen University Hospital, Liverpool, UK and ††† Institute of Infection and Global Health, University of Liverpool, Liverpool, UK Received 23 October 2012; revised 6 November 2012; accepted 12 November 2012 Correspondence: Jill A. Hollenbach, Children’s Hospital Oakland Research Institute, Oakland, CA, USA. Tel: 1 510 428 3885 X 5934; Fax: 1 510 450 7920; E-mail: jhollenbach@chori.org The data were contributed by 34 laboratories during the 4-year course of this project, including data for the HGDP-CEPH popula- tions. Additionally, data from the 15th IHIW and data contributed to the allelefrequencies.net (AFND) database were combined with the current workshop data set © 2012 Blackwell Publishing Ltd International Journal of Immunogenetics, 2013, 40, 39–45 39 doi: 10.1111/iji.12028