SELECTED ARTICLES FROM THE RECENT LITERATURE 2007 December 10, 2007 H4 Receptor Expression in Nasal Polyps Summary The authors studied the expression of all four types of histamine receptors in nasal polyp tissue. They found that all four receptors were present and that there were elevated levels of H1 and H4 receptors. The level of eosinophil cationic protein correlated with increased H4 receptor expression. The authors concluded that H4 receptor stimulation might be important in recruitment of eosinophils to polyp tissue. Editor's Comments H4 receptors are for the most part restricted to cells of hematopoietic lineage. The H4 receptor is prominently expressed on eosinophils, mast cells, basophils, dendritic cells, and T cells. The H4 histamine receptor can be blocked by thioperamide and the H4 receptor antagonist JNJ 7777120. H4 receptor stimulation of eosinophils enhances their chemotactic response to eotaxin and also up-regulates the expression of cell surface adhesion molecules on the eosinophil. The authors therefore postulate that H4 receptor stimulation may play a prominent role in the recruitment of eosinophils to polyp tissue. Reference Jokuti A, et al. Histamine H4 receptor expression is elevated in human nasal polyp tissue. Cell Biology International 2007; 31:1367-1370.   © Copyright 1997-2007 American Academy of Allergy, Asthma and Immunology All rights reserved