Investigation of the relationship between KIR genes polymorphism and disease and disease clinical characteristics in rheumatoid arthritis

Investigation of the relationship between KIR genes polymorphism and disease and disease clinical characteristics in rheumatoid arthritis Background and aims: Relation of KIR genes to transplantation rejection and diseases in particular with the increasing number of studies showing, KIR genes in all societies,Population screening for identification of genotypes and alleles started to be done. The genes encoding the KIR genes exhibit a very high polymorphism, indicating that there is a significant diversity among populations. This suggests that it is very difficult to find the same KIR genotype in two unrelated individuals1. Because of these characteristics, KIR genes can be evaluated as a good population genetic determinant. In our country, studies showing the relation between some autoimmune diseases and KIR genes are being made. Our study is the first study to evaluate the KIR gene frequencies, haplotype and genotype ratios in patients with rheumatoid arthritis in Turkey. We aimed to determine the genotype structure of our region by comparing the ratios we found in our study with the other populations, to identify 16 different KIR genes from immunogenetic markers that could play a role in the pathogenesis of the disease in rheumatoid arthritis patients and to evaluate the relationship between KIR genes and clinical characteristics of RA patients Material and methods:120 randomized patients with rheumatoid arthritis who met the criteria for studying rheumatoid arthritis disease classification were included. We formed 120 volunteer control groups in terms of age and gender that were compatible with the patient group and had no health problems or any findings related to RA. KIR typing of these subjects were evaluated by SSOP (Luminex100, Tepnel Lifecodes). This method is based on hybridization of tagged and single stranded PCR to SSO probes. The ratio of KIR genes in the patient and control groups were compared using the Minitab 17 statistical program and the two ratio comparison test and Fisher's exact Chi-square tests Results: When the healthy and the patient group were compared, it was found that the KIR2DS5 gene was significantly more frequent in the patient group than the activator gene in the healthy group, while the 3DL1 gene was found to be significantly larger in the healthy group than the inhibitor genes. When we examined the genotypes of the whole group, it was observed that the number of individuals bearing the AA genotype was 33 (% 27,4) and the number of individuals carrying the BX genotype was 87 (% 72,6). The study resulted in 6 new genotypes. There were no significant differences in DAS28, CRP and RF values in the patient group. A significant excess in the KIR2DS4 gene was detected in the anti-CCP negative group compared to the anti-CCP positive group. The excess of the KIR2DS4 gene in the Anti-CCP negative group suggests that it may have a protective role in severe disease. Conclusion: As a result of the studies performed, it has been observed that some of the activator genes are more meaningful in the RA patients than in the healthy group. Different results were obtained in comparison with different populations. The differences between the workshops may be due to ethnic disparities and the number of patients not being high enough. Keywords: aRA, aKIR, aclinical, apolymorphism