title: KIR genotype distribution among patients with multiple myeloma: Higher prevalence of KIR 2DS4 and KIR 2DS5 genes.
abstract: BACKGROUND
  Natural killer (NK) cells possess an antitumor activity against multiple myeloma cells proven by the susceptibility of plasmocytes to NK lysis. In the early stage of MM, the killing of MM cells is mediated by natural cytotoxicity receptors (NRC) and NKG2D-dependent pathway, while in the late stage, NK cells lose their killing potential against MM cells due to the high expression of HLA class I molecules on MM cells.
  
  
  OBJECTIVE
  The aim of this paper is to study KIR expression of NK cells in MM patients and in healthy controls, to check for any association between KIR genotypes and MM.
  
  
  METHODS
  KIR genotype was analyzed in 120 healthy Lebanese individuals and 34 MM patients using the KIR Genotyping SSP kit.
  
  
  RESULTS
  KIR 2DS4*001/002 and KIR 2DS5 were found to be significantly more prevalent among MM patients as compared to controls. For MM patients, the AA, AB, and BB genotype frequencies were, respectively, 38.23%, 47.06% and 14.71% with an A:B ratio of 1.62:1. As for the healthy controls, the AA, AB, and BB genotype frequencies were, respectively, 39.17%, 50%, and 10.83% with an A:B ratio of 1.80:1.
  
  
  CONCLUSIONS
  The interesting observation of the significant presence of KIR2DS4 and KIR2DS5 genes more among multiple myeloma patients than controls is worth further clinical, translational as well as survival research studies in these cases.
authors.affiliation: Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: R
authors.initials: R
authors.lastname: Hoteit
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: A
authors.initials: A
authors.lastname: Bazarbachi
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: A
authors.initials: A
authors.lastname: Antar
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: Z
authors.initials: Z
authors.lastname: Salem
authors.affiliation: Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: D
authors.initials: D
authors.lastname: Shammaa
authors.affiliation: Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut 1107-2020, Lebanon.
authors.forename: R
authors.initials: R
authors.lastname: Mahfouz
keywords: Genotype; KIR; Lebanon; Myeloma