Abstract:

Li Yujuan*, Jiang Yong, Li Huiqing, Wang Xiumin. *Department of Dermatology, Second Hospital of Tianjin Medical University, Tianjin 300211, China Corresponding author: Wang Xiumin, Email: wangxiumin@medmail.com.cn 【Abstract】 Objective To explore the effects of narrow-band ultraviolet B （NB-UVB） on the serum levels of thymic stromal lymphopoietin （TSLP） and interleukin-25 （IL-25）, as well as on the expressions of TSLP receptor （TSLPR） and IL-25 receptor （IL-25R） mRNAs in peripheral blood mononuclear cells （PBMCs） from patients with atopic dermatitis （AD）. Methods A total of 40 patients with AD and 30 healthy volunteers were enrolled in this study. All the patients were treated with NB-UVB at 0.3 － 2.5 J/cm2 thrice a week for 12 consecutive weeks. Venous blood samples were obtained from these patients before and after the treatment as well as from these healthy controls. Double-antibody sandwich enzyme-linked immunosorbent assay （ELISA） was performed to detect serum levels of TSLP and IL-25, and reverse transcription PCR （RT-PCR） to determine the mRNA expression levels of TSLPR and IL-25R in PBMCs from these subjects. The scoring atopic dermatitis （SCORAD） system developed by the European Task Force on Atopic Dermatitis was used to estimate the severity of AD, and visual analogue scale （VAS） to evaluate the degree of itch. Statistical analysis was carried out by the two-independent-sample t-test for intergroup comparisons and paired t-test for comparisons between pre- and post-treatment samples from these patients. Results After the treatment with NB-UVB, the total response rate reached 75% （30/40） in these patients, with a significant decrease in SCORAD score from 55.26 ± 10.88 before the treatment to 20.36 ± 5.12 after the treatment （t = 10.29, P < 0.05） and in VAS score from 8.20 ± 1.37 to 3.05 ± 1.02 （t = 8.16, P < 0.05）. Before the treatment, the patients showed a significant increase in the serum levels of TSLP （198.24 ± 29.47 ng/L vs. 120.13 ± 19.65 ng/L, t = 29.70, P < 0.05） and IL-25 （160.54 ± 34.89 ng/L vs. 120.41 ± 43.07 ng/L, t = 14.65, P < 0.05）, as well as in the mRNA expression levels of TSLPR （8.57 ± 1.34 vs. 1.94 ± 0.39, t = 7.07, P < 0.05） and IL-25R （6.81 ± 0.50 vs. 1.48 ± 0.47, t = 18.89, P < 0.05 ） compared with the healthy controls. With the improvement of conditions after the treatment, a significant decrease was observed in the serum levels of TSLP （151.87 ± 14.78 ng/L, t = 18.56, P < 0.05） and IL-25 （130.52 ± 29.65 ng/L, t = 9.07, P < 0.05）, as well as in the mRNA expression levels of TSLPR （2.89 ± 0.53, t = 5.21, P < 0.05） and IL-25R （3.90 ± 0.37, t = 7.35, P < 0.05 ） in PBMCs from these patients compared with those before the treatment, and differences disappeared in all of these parameters between the patients and controls （all P > 0.05）. Conclusions TSLP and IL-25 may play important roles in the development of AD, and NB-UVB may treat AD by downregulating the expressions of them and their receptors.