Immunoglobulin heavy variable (IGHV) genes and alleles: new entities, new names and implications for research and prognostication in chronic lymphocytic leukaemia

Aliki Xochelli, Andreas Agathangelidis, Ioannis Kavakiotis, Evangelia Minga, Lesley Ann Sutton, Panagiotis Baliakas, Ioanna Chouvarda, Véronique Giudicelli, Ioannis Vlahavas, Nikos Maglaveras, Lisa Bonello, Livio Trentin, Alessandra Tedeschi, Panagiotis Panagiotidis, Christian Geisler, Anton W. Langerak, Sarka Pospisilova, Diane F. Jelinek, David Oscier, Nicholas ChiorazziNikos Darzentas, Fred Davi, Paolo Ghia, Richard Rosenquist, Anastasia Hadzidimitriou, Chrysoula Belessi, Marie Paule Lefranc, Kostas Stamatopoulos

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Νext generation sequencing studies in Homo sapiens have identified novel immunoglobulin heavy variable (IGHV) genes and alleles necessitating changes in the international ImMunoGeneTics information system (IMGT) GENE-DB and reference directories of IMGT/V-QUEST. In chronic lymphocytic leukaemia (CLL), the somatic hypermutation (SHM) status of the clonotypic rearranged IGHV gene is strongly associated with patient outcome. Correct determination of this parameter strictly depends on the comparison of the nucleotide sequence of the clonotypic rearranged IGHV gene with that of the closest germline counterpart. Consequently, changes in the reference directories could, in principle, affect the correct interpretation of the IGHV mutational status in CLL. To this end, we analyzed 8066 productive IG heavy chain (IGH) rearrangement sequences from our consortium both before and after the latest update of the IMGT/V-QUEST reference directory. Differences were identified in 405 cases (5 % of the cohort). In 291/405 sequences (71.9 %), changes concerned only the IGHV gene or allele name, whereas a change in the percent germline identity (%GI) was noted in 114/405 (28.1 %) sequences; in 50/114 (43.8 %) sequences, changes in the %GI led to a change in the mutational set. In conclusion, recent changes in the IMGT reference directories affected the interpretation of SHM in a sizeable number of IGH rearrangement sequences from CLL patients. This indicates that both physicians and researchers should consider a re-evaluation of IG sequence data, especially for those IGH rearrangement sequences that, up to date, have a GI close to 98 %, where caution is warranted.

Original languageEnglish (US)
Pages (from-to)61-66
Number of pages6
JournalImmunogenetics
Volume67
Issue number1
DOIs
StatePublished - Jan 1 2015

Keywords

  • CLL
  • New IGHV gene alleles
  • New IGHV genes
  • Prognostication
  • SHM

ASJC Scopus subject areas

  • Immunology
  • Genetics

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    Xochelli, A., Agathangelidis, A., Kavakiotis, I., Minga, E., Sutton, L. A., Baliakas, P., Chouvarda, I., Giudicelli, V., Vlahavas, I., Maglaveras, N., Bonello, L., Trentin, L., Tedeschi, A., Panagiotidis, P., Geisler, C., Langerak, A. W., Pospisilova, S., Jelinek, D. F., Oscier, D., ... Stamatopoulos, K. (2015). Immunoglobulin heavy variable (IGHV) genes and alleles: new entities, new names and implications for research and prognostication in chronic lymphocytic leukaemia. Immunogenetics, 67(1), 61-66. https://doi.org/10.1007/s00251-014-0812-3