IgE recognition of bullous pemphigoid (BP)180 and BP230 in BP patients and elderly individuals with pruritic dermatoses Luca Fania a , b , Giacomo Caldarola b , c , Ralf Müller a , Oliver Brandt a , Riccardo Pellicano c , Claudio Feliciani b , ⁎ , Michael Hertl a a Department of Dermatology and Allergology, Philipps University of Marburg, Marburg, Germany b Dermatology, Università Cattolica del “Sacro Cuore”, Rome, Italy c Dermatology, Ospedale “Casa Sollievo della Sofferenza”, San Giovanni Rotondo, Foggia, Italy Received 23 February 2011; accepted with revision 21 February 2012 Available online 13 March 2012 KEYWORDS IgE; Bullous pemphigoid; Hemidesmosome; BP230; BP180; Pruritus Abstract Bullous pemphigoid (BP) is the most common autoimmune bullous disease of the elderly and is associated with IgG and IgE autoantibodies against the hemidesmosomal proteins, BP180 and BP230. The purpose of this study was to characterize the epitope specificity of IgE against de- fined regions of BP180 and BP230 in 32 BP patients and 21 elderly patients with pruritic disorders who did not yet fulfill all the criteria of BP by immunoblot (IB), ELISA and indirect immunofluo- rescence microscopy. Our findings show that IgE from BP sera preferentially targets the COOH- terminus of BP230 (IB: 16/32, ELISA: 12/32) and, to a lesser extent, the BP180-NC16A domain (IB: 11/32, ELISA: 9/32). Noteworthy, a subgroup of elderly patients with pruritic dermatoses also showed IgE recognition of BP180-NC16A (IB: 1/21, ELISA: 4/21) and less frequently of BP230 (IB: 2/21, ELISA: 2/21). Thus, IgE recognition of the BP autoantigens is presumably an early pathogenetic event in BP. © 2012 Elsevier Inc. All rights reserved. 1. Introduction Bullous pemphigoid (BP) is the most common autoimmune bullous skin disease and has become of major clinical and so- cioeconomic importance because of its increasing preva- lence in the aging population. Classical BP is characterized clinically by tense blisters on the limbs and trunk; in contrast, the prodromal phase or early clinical phases of BP are charac- terized by the presence of severe itch accompanied by a ⁎ Corresponding author at: Dipartimento di Dermatologia, Univer- sità Cattolica del Sacro Cuore, L.go Gemelli 8, 00168 Rome, Italy. Fax: + 39 063016293. E-mail address: feliciani@rm.unicatt.it (C. Feliciani). 1521-6616/$ - see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.clim.2012.02.003 available at www.sciencedirect.com Clinical Immunology www.elsevier.com/locate/yclim Clinical Immunology (2012) 143, 236–245