Investigation of promoter methylation status of intertleukin-16 (Il-16) and aire gene mutation in behçet's disease

Introduction: Behçet's disease is a common disease in our country, especially in young adults, with serious morbidity, and we have not yet been able to reach a clear consensus on its etiopathogenesis. This study, it was aimed to determine the epigenetic changes in Interleukin-16 (IL-16) and Autoimmune Regulator Genes (AIRE) in Behçet's Disease and to investigate the relationship of these epigenetic changes with the disease mechanism. Methods: Patients over the age of 18 who applied to Ondokuz Mayıs University Faculty of Medicine, Department of Internal Medicine, and Department of Rheumatology Outpatient Clinics were included in our study. The study was conducted by taking peripheral blood samples from 40 patients diagnosed with Behcet's disease according to the 2014 International Behcet's Disease Criteria and 40 healthy volunteers. DNA concentrations and purity of genomic DNAs obtained from blood samples taken from volunteers using DNA isolation kit were measured with nanodrop. Afterwards, the DNA samples were modified using the bisulfite modification kit. Then, promoter methylation profiles of IL-16 and AIRE genes were determined by methylation-specific PCR method using primers designed specifically for methylation. The results of the study were evaluated with the statistical analysis program. Results: The promoter region of IL-16 was found to be methylated in both Behçet's Diseases and healthy controls included in the study, and it was shown that the expression of the IL-16 was not strong. On the other hand, while the promoter region of the AIRE genes was methylated in all healthy individuals, it was found to be unmethylated in all Behçet's patients. Discussion: Our study is the first to evaluate the role of both AIRE genes and IL-16 in Behçet's disease. Considering the results of our study, the unmethylation of the promoter region of the AIRE genes, which has been shown to have an important role in the development and maintenance of self-tolerance, shows that the AIRE genes gene is activated in Behçet's Disease and produces an autoimmune regulatory protein that eliminates autoreactive T cells. We think that this result indicates the autoimmune nature of Behçet's disease. Another result of our study shows that IL-16, which has a xiii role in the pathogenesis of many rheumatic diseases, does not have an important role in the pathogenesis of Behçet's disease.