Study of Th1/Th2 balance in peripheral blood mononuclear cells of patients with alopecia areata

Alopecia areata represents an autoimmune pathological process driven primarily by cellular aberrations contained within the immune system, which activates various humoral and cellular elements of the immune response. The aim of this study was to determine the mRNA expression levels of T-bet and GATA-3 as potential inducers of T helper (Th)1 and Th2 differentiation, respectively, as well as Th1(IFN-γ) and Th2(IL-4) cytokine mRNA expression in patients with alopecia areata. Using real-time reverse transcriptase PCR (RT-PCR), the relative amounts of T-bet, GATA-3, IFN-γ, and IL-4 mRNA transcripts were determined in PBMCs from 20 Iranian patients with alopecia areata and compared with those of 20 healthy control subjects. In comparison with the normal group, T-bet and IFN-γ mRNA expression levels were significantly up-regulated in the alopecia areata patients, while GATA-3 and IL-4 mRNA expression levels were down-regulated. Notably, positive correlation (P < 0.05) was found between IFN-γ and T-bet levels in patients and controls. In addition, significant positive correlations existed between GATA-3 and IL-4 (P < 0.05). These results indicate that a Th1/Th2 imbalance exists in alopecia areata, and it may be implicated in the pathogenesis of disease

Expression patterns of Th1/Th2 transcription factors in patients with guttate psoriasis

Many lines of evidence propose that psoriasis is a T cell-mediated disease where T cell activation is followed by secretion of inflammatory cytokines. To elucidate the functional state of T cells in guttate psoriasis, we analysed mRNA expression levels of T-bet and GATA-3 for Th1 and Th2 differentiation, respectively together with Th1 (IFN-γ) and Th2 (IL-4) cytokine mRNA expression. Relative quantification of T-bet, GATA-3, IFN-γ and Th2, and IL-4 transcripts in peripheral blood leukocytes (PBL) was conducted by real-time reverse transcriptase PCR (RT-PCR). Serum levels of IFN-γ and Th2 and IL-4 were also determined by ELISA. GATA-3 and IL-4 mRNA expression levels were lower in psoriatic patients as compared to normal healthy controls. The expression levels of T-bet and IFN-γ and Th2 genes were relatively similar in the patients and controls. In addition, a marked decrease in plasma IL-4 levels was observed in the psoriasis group, while no differences were observed with regard to levels of IFN-γ and Th2 between patients and normal subjects. Furthermore, a clear correlation between decreased IL-4 mRNA expression and IL-4 (P < 0.05) was revealed. These results suggested that altered balance between Th1 and Th2 cells transcription factor genes and they products may be implicated in the pathogenesis of psoriasis