Abstract Background: Although not fully understood, oxidative stress has been implicated in the pathogenesis of different autoimmune diseases such as systemic sclerosis. Accumulating evidence indicates that oxidative stress can induce mitochondrial DNA (mtDNA) damage and variations in mtDNA copy number (mtDNAcn). Objective: The aim of this study was to explore mtDNAcn and oxidative DNA damage byproducts in peripheral blood of patients with systemic sclerosis and healthy controls. Methods: Forty six patients with systemic sclerosis and forty nine healthy subjects were studied. Quantitative real-time PCR used to measure the relative mtDNAcn and the oxidative damage (oxidized purines) of each sample. Results: The mean mtDNAcn was lower in patients with systemic sclerosis than in healthy controls whereas the degree of mtDNA damage was significantly higher in cases as compared to controls. Moreover, there was a negative correlation between mtDNAcn and oxidative DNA damage. Study limitations: The lack of simultaneous analysis and quantification of DNA oxidative damage markers in serum or urine of patients with systemic sclerosis and healthy controls. Conclusion: These data suggest that alteration in mtDNAcn and increased oxidative DNA damage may be involved in the pathogenesis of systemic sclerosis.

Abstract: Background: Behçet disease is a prototypical systemic autoimmune disease, caused by a complex interplay between environmental and genetic factors. The transmembrane immunoglobulin and mucin domain-3 (TIM-3) is a distinct member of the TIM family that is preferentially expressed on Th1 cells and plays a role in Th1-mediated autoimmune or inflammatory diseases, such as Behçet disease. Objective: The aim of this study was to test the potential association between TIM-3 gene polymorphisms and Behçet disease. Methods: Two single-nucleotide polymorphisms of TIM-3 (rs9313439 and rs10515746) were genotyped in 212 patients with Behçet disease and 200 healthy controls. Typing of the polymorphisms was performed using multiplex PCR amplification. Results: There were no significant differences in allele and genotype frequencies between the Behçet disease patients and controls who were successfully genotyped. Similar results were also found after stratification by gender, age, or clinical features. Study limitations: Lack of studies on various racial or ethnic groups and small sample size. Conclusion: This study failed to demonstrate any association between the tested TIM-3 polymorphisms and Behçet disease.

Abstract: IL-22 has been implicated in the pathogenesis of vitiligo. However, the role of aryl hydrocarbon receptor transcription factor that acts as a master regulator of IL-22-producing Th22 cells is not fully understood. The goal of this study was to investigate the expression pattern of aryl hydrocarbon receptor in peripheral blood mononuclear cells of patients with vitiligo and in normal controls. Transcript levels were determined by a reverse transcription quantitative real-time polymerase chain reaction. Aryl hydrocarbon receptor mRNA expression was drastically increased in patients with vitiligo compared to healthy controls (P = 0.000). Th22 cells may contribute to abnormal immune responses underlying vitiligo.

Abstract: Background: Psoriasis is a chronic inflammatory disorder, characterized by increased keratinocyte proliferation due to abnormal differentiation of basal keratinocytes. The etiology of the disease is unclear, and according to the survey results, it is hypothesized that a combination of genetic and environmental factors prompts an abnormal immune response in patients with psoriasis. CD4+ Th cells play a multifaceted role in both immune defense and pathogenesis of certain diseases such as psoriasis. Nonetheless, the exact contribution of different subpopulations of Th cells in psoriasis is still not clear. Objective: The aim of present study was to determine the mRNA expression level of RORC as potential inducer of Th17 cell differentiation and expression pattern of Th17-signature cytokines (IL-17A and IL-22). Methods: Twenty patients with psoriasis and twenty-one healthy subjects were included in the study. Peripheral blood mononuclear cells (PBMCs) were separated and expression of three genes were determined by quantitative real-time reverse transcriptase PCR (qRT-PCR). Plasma levels of IL-17 and IL-22 were also evaluated by ELISA. Results: RORC, IL-17A and IL-22 gene expression was significantly higher in patients with psoriasis compared with healthy controls (P<0.05). In addition, a marked increase in plasma IL-17A and IL-22 levels was observed in patient group compared to controls (P<0.001). Study limitations: small number of patients. Conclusion: These data suggest that Th17 response may contribute to the pathogenesis of psoriasis.