Analysis of killer imminoglobulin-like receptor genotypes in the acute and chronic myeloid leukaemia

ABSTRACT Analysis of Killer Immınoglobulin-like Receptor Genotypes in the Acute and Chronic Myeloid Leukaemia Objective: It is well-known that natural killer (NK, natural killer) cells have anti- tumour activities. This particular type of activity of NK cells is regulated mainly by specific receptors namely Killer Cell Immunoglobulin-like Receptor (KIR) which possess both activatory and inhibitory features. The proportion between the activatory and inhibitory receptors, binding strength of receptors to the given ligands and the balance in between composite signals, regulate NK cell functions. KIR genes variations among the populations, individuals and diseases. Previous studies have shown that these differences affect treatment response. In this study, we have investigated the frequencies of KIR genotypes in patients with acute and chronic myeloid leukemias. Material and Method: This study group consisted of 34 acute myeloid leukaemia (AML) and 46 chronic myeloid leukaemia (CML) patients who were followed in our haematology and oncology clinics between May 2016 and September 2017. In addition, 100 age and sex matched individuals were included. With the informed consent of all participants, the study was permitted by the Ethics Review Board at Çukurova University Faculty of Medicine. DNA from the venous-EDTA blood sample of all patients was extracted. Genotyping of KIR genes were performed by the multiplex KIRSSO kit. Polymerase Chain Reaction (PCR) and KIR typing through SSO method were processed out of patients' blood. Individuals having the characteristic gene content of group A haplotype (KIR2DL1, 2DL3, 2DL4, 2DP1, 3DP1, 3DL1, 3DL2, 3DL3 and 2DS4) were considered as AA genotype. If any gene among KIR2DL2, 2DL5, 2DS1, 2DS2, 2DS3, 2DS5, and 3DS1 were present, the individual was considered to be B haplotype (genotype Bx). Results: In this study, the median age for the AML, CML patients and healthy controls was 52±2,8, 56.5±2,2 and 53±1,2 years, respectively (P>0.05). Among CML patients % 34,8 had AA genotype, which was % 38,2 and % 30 for AML patients and control group respectively. Bx genotype was detected % 65,2, % 61,8 and % 70 in CML, AML patients and controls, respectively. When all the patients were compared to the control group, KIR2DL3 was found to be significant (P<0.05). For CMLpatients, KIR2DL3 was found to be significant at the higher frequencies whilst KIR2DS2 and KIR2DL2 got significant at lower frequencies (P ≤0.05). Conclusion: Our results suggest that alterations in KIR expression on the NK cells can be related to the development of acute and chronic myeloid leukaemias. However further studies with larger number of patients are required. Keywords:Leukaemia, KIR, Myeloid