Interleukin-31 pathway and its role in atopic dermatitis: a systematic review

Background: Atopic dermatitis, a chronic inflammatory disease, has a lifetime prevalence of 10–20%. Atopic dermatitis reduces quality of life, primarily due to pruritus. Interleukin-31 and its target receptor are newly discovered entities that are involved in pruritus.Purpose: To summarize the current understanding of interleukin-31 and its role in atopic dermatitis, potential therapeutic interventions and future prospects.Methods: A systematic review was designed to identify articles related to interleukin-31 and its role in pruritus. Predefined queries containing interleukin-31 and related key terms were searched with no past date restriction, through 31 August 2016, using MEDLINE, Cochrane Controlled Trials Register, ClinicalTrials.gov and the International Clinical Trials Registry Platform Search Portal database.Results: Of 151 identified articles, 61 met eligibility criteria. Interleukin-31 receptors are expressed constitutively on the surface of keratinocytes, eosinophils and small diameter neurons. Overexpression of interleukin-31, independent of mast cells and lymphocytes, induces clinical and histological features consistent with atopic dermatitis. In addition, overexpression of interleukin-31 causes reversible alopecia. Human monoclonal interleukin-31 antagonist, CIM331, decreased pruritus in phase-I and phase-II clinical trials.Conclusions: Interleukin-31 plays an important role in atopic dermatitis and alopecia. Inhibiting this pathway may provide an alternative to antihistamines for the pruritus of atopic dermatitis.