**Histamine-Releasing Factor, a New Therapeutic Target in Allergic Diseases**

**Yu Kawakami 1, Kazumi Kasakura 1 and Toshiaki Kawakami 1,2,\***


Received: 30 October 2019; Accepted: 21 November 2019; Published: 26 November 2019

**Abstract:** Histamine-releasing activities on human basophils have been studied as potential allergy-causing agents for four decades. An IgE-dependent histamine-releasing factor (HRF) was recently shown to interact with a subset of immunoglobulins. Peptides or recombinant proteins that block the interactions between HRF and IgE have emerged as promising anti-allergic therapeutics, as administration of them prevented or ameliorated type 2 inflammation in animal models of allergic diseases such as asthma and food allergy. Basic and clinical studies support the notion that HRF amplifies IgE-mediated activation of mast cells and basophils. We discuss how secreted HRF promotes allergic inflammation in vitro and in vivo complex disease settings.

**Keywords:** allergy; mast cells; basophils; IgE; FcεRI; HRF; translationally controlled tumor protein (TCTP)
