LAUSR

Background Behçet Disease (BD) is a relapsing inflammatory autoimmune disease. Although the etiology of BD is not yet known, genetic predisposition and immune dysregulation are thought to be critical factors in the pathogenesis of the disease. MicroRNAs (miRNAs) are small RNA fragments that can regulate the gene expression. miRNAs play a critical role in the pathogenesis of autoimmune or auto inflammatory diseases. Sinngle nucleotide polymorphisms (SNPs) may change the property of miRNAs through altering miRNA expression and/or maturation. Objectives The aim of this work was to detect miRNA-499 (rs3746444) genotyping and relative expression in BD patients in order to find out the possible association between them and disease activity and severity. Methods Relative expression of miRNA-499 was measured by Real-Time PCR and miRNA-499 gene (rs 3746444) genotyping was performed by TaqMan SNP Genotyping Assay in blood samples obtained from 47 patients BD diagnosed according to 1990 international criteria for behcet disease and 50 matched healthy controls. Disease activity was done using BD current activity form (BDCAF). Results Study of miRNA-499 polymorphism, showed that the genotype frequencies of TT, CT, and CC were 21.3%, 63.8%, and 14.9% in BD patients and 18.0%, 52.0%, and 30.0% in the control group respectively. A significant increase in the relative expression of miRNA-499 was found in BD patients compared to control (P<0.05). There was no significant relation between relative expression of miRNA-499 and activity of BD patients assessed by BDCAF (P>0.05). In addition there was association between genotypes of miRNA-499 and posterior uveitis (P<0.05). There was association of the relative expression of miRNA-499 with miRNA-499 (rs3746444) polymorphism and vascular manifestations (P<0.05). Conclusions Genotyping of miRNA-499 showed higher percentage of TT genotype in BD patients than control and also miRNA relative expession, they may be implicated in pathogenesis of the disease. Genotype TT for miRNA-499 is associated with posterior uveitis. miRNA relative expression is associated with vascular manifestations and aneurysm. Disclosure of Interest None declared