Department of Geriatric and Environmental Dermatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
J Dermatol. 2018 Mar;45(3):287-292. doi: 10.1111/1346-8138.14213. Epub 2018 Jan 25.
Phototherapy utilizes the beneficial effects of ultraviolet (UV) wavelengths to affect immunoregulatory functions. UV light phototherapy using narrowband UV-B (NB-UVB) and bath-psoralen UV-A (bath-PUVA) therapy are well-established treatments for psoriasis. Dual-action mechanisms of UV phototherapy have been identified: apoptosis and immune suppression. NB-UVB depletes pathogenic T cells by inducing apoptosis and regulatory T cells. Other wavelengths are also utilized for phototherapy, namely 308-nm excimer light and 312-nm flat-typed NB-UVB. Excimer light (308-nm) therapy effectively targets the affected skin without unduly exposing other areas and increases the levels of regulatory T cells. Phototherapy improves impaired resting regulatory T cells and increases activated regulatory T cells in patients with psoriasis. Intensive studies of phototherapy effects have led to several improvements in the design, protocols, and light sources, such as UV light-emitting diodes, thereby providing several options for patients with refractory skin disease, such as psoriasis.
光疗利用紫外线（UV）波长的有益影响来影响免疫调节功能。窄带 UV-B（NB-UVB）和沐浴补骨脂素 UV-A（bath-PUVA）光疗的 UV 光疗是治疗银屑病的成熟方法。已经确定了 UV 光疗的双重作用机制：细胞凋亡和免疫抑制。NB-UVB 通过诱导细胞凋亡和调节性 T 细胞来耗尽致病性 T 细胞。还利用其他波长进行光疗，即 308nm 准分子光和 312nm 平板 NB-UVB。准分子光（308nm）疗法可有效靶向受影响的皮肤，而不会过度暴露其他区域，并增加调节性 T 细胞的水平。光疗可改善银屑病患者受损的静止调节性 T 细胞，并增加激活的调节性 T 细胞。对光疗效果的深入研究导致设计、方案和光源（如紫外线发光二极管）的改进，为患有难治性皮肤病（如银屑病）的患者提供了多种选择。
