Abstract: Li Lingling, Zhang Yujie*, Yin Lisha, Dong Daqun, An Rongzhen, Zhang Junhua. *Department of Dermatology, Affiliated Hospital of Binzhou Medical College, Binzhou 256603, Shandong, China Corresponding author: Zhang Yujie, Email: byfyzyj@126.com 【Abstract】 Objective To detect the expression levels of interleukin （IL）-25 and IL-33 in peripheral blood of patients with chronic urticaria. Methods Ninety-three patients with chronic urticaria were included in this study along with 30 healthy individuals． All the patients were treated with loratadine for four weeks. Blood samples were collected from the healthy controls and patients before and after the four-week treatment. Enzyme-linked immunosorbent assay （ELISA） was performed to detect the serum levels of IL-25 and IL-33. The relationship between the expression levels of the two cytokines and urticaria severity was analyzed. Results The serum levels of IL-25 and IL-33 in the patients before treatment were significantly higher than those in the healthy controls （IL-25, 139.86 ± 28.48 vs. 114.41 ± 34.00 ng/L, P < 0.01; IL-33, 91.95 ± 21.88 vs. 79.80 ± 30.72 ng/L, P < 0.05）, and positively correlated with the severity of urticaria （r = 0.38, 0.42, respectively, both P < 0.01）. After four weeks of treatment, clinical improvement was observed in 81.72% of these patients with a significant decrease in the serum IL-25 level （116.48 ± 21.94 vs. 139.86 ± 28.48 ng/L, P < 0.01）, but no obvious changes in the serum IL-33 level （90.88 ± 20.62 vs. 91.95 ± 21.88 ng/L, P ＞ 0.05） compared with those before treatment. Conclusions The expressions of IL-25 and IL-33 are elevated in peripheral blood of patients with chronic urticaria, and positively correlated with the severity of urticaria.

Key words: Urticaria, Interleukin-33, Interleukin-25, Loratadine