Evaluation of the role of interleukin-31 in inflammatory acne vulgaris: A case-control study

Background Acne vulgaris (AV) is a chronic inflammatory disease with multifactorial etiology and a significant psychological disability. Inflammation is a fundamental process in the early and late stage of acne. Physical symptoms of AV include soreness, itching, and pain. Interleukin-31 (IL-31) is a novel T-helper-lymphocyte-derived cytokine with an established role in inducing inflammation and pruritus. Objective Evaluation of the role of IL-31in inflammatory AV and its correlation to itching. Patients and methods Forty patients with AV as well as 40 healthy controls were included. History taking and clinical examination of patients to assess the severity of AV were done and the grade of itching of the lesions was recorded. Biopsy from an acne lesion and a serum sample were taken. For controls, a biopsy from normal skin as well as a serum sample was taken for comparison. Tissue and serum levels of IL-31 were measured by the sandwich ELISA technique. Results The mean tissue and serum levels of IL-31 were significantly higher in patients than in controls (P<0.001). The tissue level of IL-31 was significantly higher in patients with severe AV in comparison with its levels in moderate AV (P=0.001). A statistically significant correlation was found between the Cardiff Acne Disability Index and levels of IL-31 in both tissue (P=0.001) and serum (P=0.049). Conclusion IL-31 potentially plays a role in the pathogenesis of inflammatory AV. Larger scale studies are required to verify this finding.