Fattouh Mona, El-Din Asmaa N, El-Hamd Mohammed A
Department of Medical Microbiology & Immunology, Faculty of Medicine, Sohag University, Sohag, Egypt.
Department of Dermatology & Venereology & Andrology, Faculty of Medicine, Sohag University, Sohag, Egypt.
Egypt J Immunol. 2017 Jan;24(1):105-117.
Psoriasis is one of the most common chronic, inflammatory, T-cell-mediated autoimmune diseases. Narrow-band UVB (NB-UVB) therapy is widely used in the treatment of psoriasis; however, its mechanism of action is still not well understood. The objective of this study was to investigate the circulating T-lymphocyte subpopulations in psoriasis patients before and after NB-UVB, to get insights into the mechanism of NB-UVB in the treatment of psoriasis. The severity of psoriasis was assessed by means of the Psoriasis Area and Severity Index (PASI-score). The percentage of CD4+ T helper, CD8+ T cells, CD4+ CD25+T reg cells and CD4+ CD161+ T h17 cells were determined in the peripheral blood mononuclear cells in 40 untreated psoriasis patients with moderate-to-severe disease (PASI-score ?12) and in 30 age and sex matched healthy controls using flow cytometry. Psoriasis patients were treated with NB-UVB therapy three times / week for 8 weeks. Disease severity (PASI-score) and T cells frequencies in the blood were evaluated on enrolment (W0) and at 8 (W8) weeks. Compared with healthy controls, psoriasis patients with active disease had significantly higher proportion of peripheral CD4+Th, CD8+ T cells, and CD4+CD161+Th17 with lower proportion of CD4+CD25+Treg cells. Patients demonstrating marked improvement after NB-UVB phototherapy with significantly reduced circulating Th1and Th17 and CD8+ cytotoxic T cell levels while increasing Treg cell levels with a highly statistically significant difference after therapy (P < 0.001). In conclusion, our data indicated that the overexpression of CD4+Th, CD8+ T cells and CD4+CD161+Th17 cells together with the decreased frequency of Treg cells may play an important role in the pathogenesis of psoriasis. NB-UVB phototherapy is an effective and safe treatment for psoriasis acts through the inhibition of CD4+Th and CD4+CD161+Th17 cell immune response as well as the promotion of Treg cell immune response.
银屑病是最常见的慢性、炎症性、T细胞介导的自身免疫性疾病之一。窄谱中波紫外线（NB-UVB）疗法广泛用于银屑病的治疗；然而，其作用机制仍未完全明确。本研究的目的是调查银屑病患者在接受NB-UVB治疗前后循环T淋巴细胞亚群的情况，以深入了解NB-UVB治疗银屑病的机制。采用银屑病面积和严重程度指数（PASI评分）评估银屑病的严重程度。运用流式细胞术测定40例未经治疗的中度至重度银屑病患者（PASI评分≥12）和30例年龄及性别匹配的健康对照者外周血单个核细胞中CD4+辅助性T细胞、CD8+T细胞、CD4+CD25+调节性T细胞和CD4+CD161+辅助性T细胞17亚群的百分比。银屑病患者接受NB-UVB治疗，每周3次，共8周。在入组时（W0）和第8周（W8）评估疾病严重程度（PASI评分）和血液中T细胞频率。与健康对照者相比，处于疾病活动期的银屑病患者外周血CD4+辅助性T细胞、CD8+T细胞和CD4+CD161+辅助性T细胞17亚群的比例显著更高，而CD4+CD25+调节性T细胞的比例更低。接受NB-UVB光疗后病情显著改善的患者，循环中的辅助性T细胞1和辅助性T细胞17以及CD8+细胞毒性T细胞水平显著降低，而调节性T细胞水平升高，治疗后差异具有高度统计学意义（P<0.001）。总之，我们的数据表明，CD4+辅助性T细胞、CD8+T细胞和CD4+CD161+辅助性T细胞17亚群的过度表达以及调节性T细胞频率的降低可能在银屑病的发病机制中起重要作用。NB-UVB光疗是一种有效且安全的银屑病治疗方法，其作用机制是抑制CD4+辅助性T细胞和CD4+CD161+辅助性T细胞17亚群的免疫反应以及促进调节性T细胞的免疫反应。
