RHINITIS, SINUSITIS AND UPPER AIRWAY DISEASE: Edited by Ruby Pawankar and David P. SkonerDifferential expression and role of S100 proteins in chronic rhinosinusitisSumsion, Jorgen S.∗; Pulsipher, Abigail∗; Alt, Jeremiah A.Author Information Department of Surgery, Division of Otolaryngology – Head and Neck Surgery, University of Utah School of Medicine, Salt Lake City, Utah, USA Correspondence to Jeremiah A. Alt, MD, PhD, FACS, University of Utah School of Medicine, Division of Otolaryngology – Head and Neck Surgery, 50 North Medical Drive, Room 3C120, Salt Lake City, UT 84132, USA. Tel.: +1 801 585 7143;. fax: +1 801 585 5744; e-mail: [email protected] Current Opinion in Allergy and Clinical Immunology: February 2020 - Volume 20 - Issue 1 - p 14-22 doi: 10.1097/ACI.0000000000000595 Buy Metrics Abstract Purpose of review Immune system modulators have been under investigation to help elucidate the underlying pathophysiologies of chronic rhinosinusitis (CRS). Psoriasin (S100A7) and calgranulins (S100A8, S100A9, and S100A12) are S100 proteins that have been studied for their immune-mediating responses to pathogens within the context of CRS. This review highlights the expression patterns and proposed roles of S100 proteins in CRS with (CRSwNP) and without (CRSsNP) nasal polyps. Recent findings Elevated levels of S100A7 and S100A12 were measured in the sinonasal tissues of patients with CRSsNP compared with CRSwNP and controls. S100A12 expression in CRSsNP was significantly correlated to disease severity. Contrastingly, increased S100A8, S100A9, and S100A8/A9 levels were demonstrated in the nasal polyp tissues of patients with CRSwNP compared with those in inferior turbinate and uncinate tissues of patients with CRSsNP and controls. Summary The reported differential expression patterns and activities of psoriasin and calgranulins suggest that S100 proteins exert unique and concerted roles in mediating immunity in different subtypes of CRS. These studies will enable further investigations focused on understanding the immune-modulating mechanisms of S100 proteins in different inflammatory signaling pathways and disease phenotypes of CRS toward the pursuit of identifying new biomarkers and targets for improved outcomes. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.