KIR genotype distribution among symptomatic patients with and without Helicobacter pylori infection: is there any role for the B haplotype?

UNLABELLED: Contact of peripheral blood lymphocytes with Helicobacter pylori was proved to induce non- major histocompatibility complex-restricted cytotoxicity and natural killer cells are thought to play an important role in the immunity against H. pylori. AIMS: In this research, we investigated any possible association between killer immunoglobulin-like receptors (KIR) genotypes and H. pylori infection. METHODS: KIR genotype was analysed in 101 Lebanese symptomatic patients (51 H. pylori positive and 50 H. pylori-negative) using the KIR Genotyping SSP kit. RESULTS: Among the H. pylori-positive patients, the AA, AB and BB genotypical frequencies were, respectively, 43.14%, 41.18% and 15.68% with an A:B ratio of 1.76:1. The AA, AB and BB genotypes frequencies for H. pylori-negative individuals were 18%, 62% and 20%, respectively, with an A:B ratio of 0.96:1. No significant difference between patients and controls was detected. CONCLUSIONS: We noticed a reduced distribution of A haplotype among the 'H. pylori-negative' patients as compared with the "H. pylori-positive" group. This is the first study in the international literature that targets the correlation between KIR genotypes and H. pylori.

KIR genotype distribution among patients with multiple myeloma: Higher prevalence of KIR 2DS4 and KIR 2DS5 genes.

INTRODUCTION: 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. AIM: 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. CONCLUSION: 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.