Immunohistochemical study of interleukin-31 in patients with atopic dermatitis

Abstract

Background Atopic dermatitis (AD) is a common chronic inflammatory skin disease of unknown etiology. Reduction of pruritus as one of the hallmarks of AD is the most effective therapeutic strategy for improving quality of life and for preventing aggravation of skin lesion. Interleukin-31 (IL-31) has been suggested to play a role in pathogenesis of AD through itch stimulation and correlation with development of pruritus. Aim The aim of this work was to study the immunohistochemical expression of IL-31 in skin lesions of patients with AD. Patients and methods The current study comprised 20 patients with AD. The severity of AD was assessed according to Six Area, Six Sign Atopic Dermatitis score. From the patients, 3-mm punch biopsy specimens were taken from lesional skin and nearby apparently normal skin to serve as control. Histopathological examination and immunohistochemical staining for IL-31 were done. Results IL-31 expression was significantly increased in lesional skin of patients with AD in comparison with nearby apparently normal skin of the same patients. IL-31 expression in the lesional skin of patients with AD showed a significant positive correlation with severity of the disease evaluated by Six Area, Six Sign Atopic Dermatitis score. Conclusion IL-31 expression was increased in the lesional skin of patients with AD compared with control specimens, and it was positively correlated with severity of AD. IL-31 may be a therapeutic target for AD and associated pruritus.