Contents lists available at ScienceDirect Immunobiology journal homepage: www.elsevier.com/locate/imbio Assessment of circulating FCεRIa in Chronic Spontaneous Urticaria patients and its correlation with clinical and immunological variables Shereen A. Baioumy a , Marwa M. Esawy b, ⁎ , Marwa A. Shabana b a Department of Microbiology and Immunology, Faculty of Human Medicine, Zagazig University, Egypt b Department of Clinical Pathology, Faculty of Human Medicine, Zagazig University, Egypt ARTICLE INFO Keywords: ASST APST Autoantibody Fc receptor Urticaria ABSTRACT Chronic spontaneous urticaria (CSU) is a chronic type characterized by episodes of wheals with or without angioedema. Autoantibody against the alpha subunit of Fc epsilon receptor (FcεRIa) was detected in CSU pa- tients' sera. The study aims to evaluate the clinical utility of skin tests in CSU patients. In addition, it assesses the presence of circulating FcεRIa in CSU patients and their correlation with other clinical and immunological variables. The study includes 40 healthy controls and 40 CSU patients who had urticaria symptoms for at least 8 weeks. All subjects underwent the following tests: autologous serum skin test (ASST), autologous plasma skin test (APST), immunoglobulin E (IgE), antinuclear antibodies (ANA), antithyroid antibodies (ATA). An in-house enzyme-linked immunosorbent assay was used for FcεRIa detection. The prevalence of ANA and ATA in CSU was 7.5% and 20% respectively. Total IgE was significantly higher in CSU than in controls (p < 0.0001). The study detected circulating antibody to FcεRIα in 2.5% of controls and 52.5% of CSU patients (p < 0.0001). The prevalence of antibody to FcεRIa was 27.3% and 83.3% of ASST negative and positive patients respectively (p = 0.0004). But the prevalence was 17.6% and 78.3% of APST negative and positive patients respectively (p = 0.0002). In conclusion, Circulating antibody to FcεRIa has a role in the pathogenic mechanisms of CSU. 1. Introduction Chronic spontaneous urticaria (CSU) is a chronic type characterized by episodes of wheals with or without angioedema. CSU has a recurrent course which lasts more than 6 weeks (Lima et al., 2017). CSU may have an autoimmune pathogenesis (Sabroe et al., 1999). Immunoglobulin E (IgE) binds to the Fc epsilon receptor (FceR) to mediate its action. The high-affinity FcεRI is expressed on the cell surface (eosinophils, mast cells, basophils, and Langerhans cells) (Kraft and Kinet, 2007). Allergic reactions to allergens are mediated by his- tamine release when allergen binds to surface-bound IgE on mast cells (Hayes et al., 2014). Immunoglobulin G (IgG) binds the alpha subunit of Fc receptor (FcεRIa) was firstly detected in CSU patients' sera by Hide et al. (1993). Circulating antibodies against either IgE or its receptor can release basophil and mast cell mediators. The role of such anti- bodies in CSU was previously assessed by several studies (Fiebiger et al., 1995; Kikuchi and Kaplan, 2001; Ulambayar et al., 2017). The autologous serum skin test (ASST) is used to detect urticaria patients. This test was first performed by Grattan et al., (1986). It is an autoreactivity detection test in which intradermal injection of auto- logous serum acts directly on the skin vessels or acts indirectly by the release of skin mast cell mediators. Autoreactivity does not denote autoimmune mechanism, but it may be an indicator of mast cell acti- vating autoantibodies (Sajedi et al., 2011). ASST specificity was doubtful as false-positive results appeared due to bradykinin and pro- tease cleaved C5, which released during blood clotting to separate the serum. So, autologous plasma skin test (APST) was used instead of ASST in order to increase the specificity (Asero et al., 2006). Heparin inhibits the cells degranulation process (Asero et al., 2001), so sodium citrate is used for plasma separation (Asero et al., 2006). This study is designed to evaluate the clinical utility of ASST and APST as reflections of the autoreactivity in CSU patients. In addition, the study assesses assessed the presence of circulating FcεRIa in CSU patients and their correlation with other clinical and immunological variables. https://doi.org/10.1016/j.imbio.2018.08.009 Received 16 May 2018; Received in revised form 14 August 2018; Accepted 19 August 2018 Abbreviations: ANA, antinuclear antibodies; APST, autologous plasma skin test; ASST, autologous serum skin test; ATA, antithyroid antibodies; CSU, chronic spontaneous urticaria; FcεRIa, alpha subunit of Fc receptor Epsilon; IgE, Immunoglobulin E; IgG, Immunoglobulin G; USA, urticaria activity score ⁎ Corresponding author. E-mail address: MMAtya@medicine.zu.edu.eg (M.M. Esawy). Immunobiology xxx (xxxx) xxx–xxx 0171-2985/ © 2018 Elsevier GmbH. All rights reserved. Please cite this article as: Baioumy, S.A., Immunobiology (2018), https://doi.org/10.1016/j.imbio.2018.08.009