Deletion polymorphism of GSTT1 gene as protective marker for allergic rhinitis Andrea Iorio 1,2 , Renato Polimanti 1 , Sara Piacentini 1 , Giancarlo Maria Liumbruno 3 , Dario Manfellotto 2 and Maria Fuciarelli 1 1 Department of Biology, University of Rome ‘Tor Vergata’, Rome, Italy 2 Clinical Pathophysiology Center, AFaR – ‘San Giovanni Calibita’ Fatebenefratelli Hospital, Rome, Italy 3 Clinical Pathology Department, AFaR – ‘San Giovanni Calibita’ Fatebenefratelli Hospital, Rome, Italy Abstract Background and Aims: Allergic rhinitis (AR) is one of the most common respira- tory diseases among human populations. Strong evidence suggests that genetic predisposition and environmental factors could contribute to the development of this complex disease. Glutathione S-transferases (GSTs) are biomarkers of inflam- mation and oxidative stress. These phase II enzymes play a significant role in detoxifying xenobiotic compounds. To analyze the role of GST gene polymorphisms in AR pathogenesis in a case- control population of 103 patients affected by AR and 200 healthy non-allergic subjects. Methods: We screened genomic DNA extracted from buccal cells for GSTM1 positive/null, GSTP1*I105V (rs1695) and GSTT1 positive/null polymorphisms. The X 2 -test, odds ratio (OR) and logistic regression were used as statistical analyses. Results: Significant differences in null genotype distribution between AR patients (13%) and healthy controls (30%) were found for the GSTT1 null genotype (OR = 0.30, 95% confidence interval = 0.14–0.65; P = 0.001). GSTM1 and GSTP1 polymorphisms did not show any significant results. Conclusion: Our data indicated that GSTT1 may be a susceptibility locus for AR. Specifically, the positive/null polymorphism of GSTT1 may be involved in an oxidative stress-related mechanism that may enhance pathogenic pathways related to AR. Moreover, beside GSTT1, this deletion polymorphism affects also another gene potentially related to AR phenotype, LOC391322. This gene belongs to MIF (macrophage migration inhibitory factor) gene family and several studies indicated the role of this gene in several immunology-related phe- notypes. Therefore, two different scenarios may explain the observed genetic association. Please cite this paper as: Iorio A, Polimanti R, Piacentini S, Liumbruno GM, Manfellotto D and Fuciarelli M. Deletion polymorphism of GSTT1 gene as protective marker for allergic rhinitis. Clin Respir J 2014; ••: ••–••. DOI:10.1111/ crj.12170. Key words allergy – association study – genetic predisposition – genetic variants – glutathione S-transferases – respiratory diseases Correspondence Maria Fuciarelli, PhD, Department of Biology, University of Rome ‘Tor Vergata’, Via della Ricerca Scientifica, 1 00133 Rome, Italy. Tel: +390672594346 Fax: +39062023500 email: fuciarelli@uniroma2.it Received: 26 December 2013 Revision requested: 04 May 2014 Accepted: 29 May 2014 DOI:10.1111/crj.12170 Authorship and contributorship AI, RP and MF designed the study and wrote the first draft of the paper. AI and SP performed the genetic analyses. AI, SP, GML and DM collected the samples. AI and RP analyzed the data. All authors interpreted the data, contributed to the subsequent versions of the article and approved the final report. Ethics The human study has been reviewed by the appropriate ethics committee and has been performed in accordance with the ethical standards laid down in an appropriate version of the 2000 Declaration of Helsinki. All persons gave their informed consent prior to their inclusion in the study. Conflict of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article. Introduction Allergic rhinitis (AR) is one of the most common res- piratory diseases found among human populations. AR is a complex disease whose prevalence is not per- fectly known because of the complexity of the identi- fication of its perennial symptomatology, which often overlaps with chronic sinusitis, infections of the upper respiratory tract and vasomotor rhinitis. AR is charac- terized by a succession of symptoms involving the The Clinical Respiratory Journal ORIGINAL ARTICLE 1 The Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd