Possible roles of basophils in chronic itch

Takashi Hashimoto, Jordan D. Rosen, Kristen M. Sanders, Gil Yosipovitch

Basophils are blood granulocytes and normally constitute less than 1% of blood peripheral leukocytes. Basophils share some morphological and functional similarities with mast cells, and basophils were once regarded as redundant and negligible circulating mast cells. However, recent studies reveal the indispensable roles of basophils in various diseases, including allergic and pruritic diseases. Basophils may be involved in itch through the mediation of a Th2 immune response, interaction with other cells in the skin, and secretion of a wide variety of itch-related mediators, e.g., histamine, cytokines and chemokines (IL-4, IL-13, IL-31, and TSLP), proteases (cathepsin S), prostaglandins (PGE2 and PGD2), substance P, and platelet-activating factor. Not only pruritic skin diseases (e.g., atopic dermatitis, irritant contact dermatitis, chronic urticaria, prurigo, papulo-erythroderma of Ofuji, eosinophilic pustular folliculitis, scabies, tick bites, and bullous pemphigoid) but also pruritic systemic diseases (e.g., primary sclerosing cholangitis and polycythemia vera) may be affected by basophils. This article is protected by copyright. All rights reserved.