Interleukin-17 mRNA expression and serum levels in Behçet's disease.

Behçet's disease (BD) was considered a T-helper 1 (Th1)-mediated autoimmune disease, but with the introduction of Th17 cells, their role in the pathogenesis of BD was also addressed. Despite studies on IL-17 in BD, the prognostic value of this cytokine in BD is unclear. The aim of this study is to determine the IL-17 mRNA expression rate and serum levels in patients with BD and its correlation with clinical manifestations and activity of BD. Forty-six BD patients in the active phase of the disease and 70 healthy controls were recruited in this study. BD activity was measured by Behçet's disease current activity form (BDCAF), Iranian Behçet's disease dynamic activity measure (IBDDAM) and total inflammatory activity index (TIAI). The IL-17 mRNA expression and serum levels were significantly higher in the BD patients compared with the healthy controls. These parameters in the BD patients aged <25 at disease onset, positive pathergy test, and positive HLA-B5 and HA-B51 were significantly higher than the healthy controls (P < 0.05). The IL-17 serum level in the patients with active uveitis was lower than the patients with in-active uveitis. There was no association between other clinical manifestations of BD and these parameters. No significant correlation was found between BDCAF and IBDDAM with IL-17 mRNA expression and serum levels. However, TIAI had a significant and negative correlation with the serum levels of IL-17.

Analysis of Methylation and Expression Profile of Foxp3 Gene in Patients with Behçet's Syndrome.

Forkhead box P3 (Foxp3) gene is an important means in the Treg cells function, in both maintenances of immune tolerance and regulation of response. Epigenetic modifications of the foxp3 gene at its regulatory regions control the chromatin accessibility for the transcription factors and other transcriptional regulators in order to control Foxp3 expression. In addition, the methylation status of CpG islands within the Foxp3 promoter and regulatory elements regulate the expression of Foxp3. This study was performed to assess the role of the foxp3 gene in patients with Behçet's syndrome (BS). Venous blood samples were collected from all participants and peripheral blood mononuclear cells (PBMC) were extracted through Ficoll-Hypaque method. Genomic DNA was randomly sheared by sonication and immunoprecipitated with a monoclonal antibody. The status methylation of the foxp3 gene was estimated in 108 blood samples of active BS patients and healthy individuals (controls); using methylation DNA immunoprecipitation (MeDIP) technique. Expression analysis was carried out; using Real-time PCR. The expression of foxp3 gene in the patients' group (mean±SD: 1.79±1.12) was significantly lower than the healthy group (mean±SD: 2.73±1.33) (p<001). Also, the methylation levels of Foxp3 promoter showed that its level in patients (mean±SD: 2.3±1.16) was higher than the healthy group (mean±SD: 1.85±0.59). However, this increase was not statistically significant (p>0.05). Also, these results indicated that increasing the amount of methylation of the foxp3 gene by reducing its expression leads to an increase and intensifying of the disease. The decrease in Foxp3 expression is possibly associated with hypermethylation of the gene, and it can be considered as a risk factor for BS. Future studies may be needed to identify the capability of specific DNA methylation alterations in this syndrome.