ORIGINAL ARTICLE Nasal eosinophilia: an indicator of eosinophilic inflammation in asthma M. M. Amorim, A. Araruna, L. B. Caetano, A. C. Cruz, L. L. Santoro and A. L. G. Fernandes Asthma Research Group Respiratory Division – Federal University of Sa˜o Paulo-Brazil (UNIFESP), Sa˜o Paulo, Brazil Clinical & Experimental Allergy Correspondence: Prof A. L. G. Fernandes, Disciplina de Pneumologia, Rua Botucatu 740 31 andar, Sa ˜o Paulo-SP CEP 04023-004, Brazil. E-mail: analuisa@pneumo.epm.br Cite this as: M. M. Amorim, A. Araruna, L. B. Caetano, A. C. Cruz, L. L. Santoro and A. L. G. Fernandes, Clinical & Experimental Allergy , 2010 (40) 867–874. Summary Background It is noteworthy that there is a clear clinical, epidemiological and pathophysiolo- gical association between upper and lower airway inflammation in rhinitis and asthma. Objective The aim of this study was to compare the eosinophil counts in induced sputum and nasal lavage fluids in asthma, checking their association and the accuracy of nasal eosinophilia as a predictor of sputum eosinophilia by a cross-sectional study. Methods The clinical evaluation, asthma control questionnaire (ACQ), pre- and post- bronchodilator spirometry, nasal and sputum sample was performed. The nasal eosinophilia was analysed by a receiver operating curve and logistic regression model. Results In 140 adults, the post-bronchodilator forced expiratory volume in 1 s (FEV 1 ) did not differ between patients with or without sputum eosinophilia (0.18). After adjusted for upper airway symptoms, age, ACQ score and post-bronchodilator FEV 1 , sputum eosinophilia was associated with 52 times increase in odds of nasal eosinophilia, whereas each 1% increase in bronchodilator response was associated with 7% increase in odds of nasal eosinophilia. Conclusion This study brings further evidence that upper airway diseases are an important component of the asthma syndrome. Furthermore, monitoring of nasal eosinophilia by quantitative cytology may be useful as a surrogate of sputum cytology in as a component of composite measurement for determining airway inflammation. Keywords asthma, eosinophils, induced sputum, nasal lavage Submitted 30 June 2009; revised 16 November 2009; accepted 19 November 2009 Introduction Asthma is a variable chronic inflammatory disorder of the airways. Airway inflammation has been demonstrated to represent an important factor underlying asthma clinical expression [1]. In order to achieve optimal control of asthma, many steps should be taken as defined by the GINA and NIH guidelines [2, 3]. The airway inflammation in asthma is persistent even though symptoms are episodic, and the relationship between the severity of the asthma and the intensity of the inflammation is not clearly established [4]. The eosi- nophil is a cellular maker of a type of inflammation in asthma, and an indicator of response to treatment as well [5, 6]. Sputum eosinophilia has been associated with asthma exacerbations [6]. It has been taken as a marker of airway inflammation that might be adopted for the assessment of asthma control status [7]. It is noteworthy that there is a clear clinical, epidemio- logical and pathophysiological association between upper and lower airway inflammation in rhinitis and asthma, which suggests that inflammatory cells may play a key and similar role in both of these syndromes [8–11]. However, little information is available concerning the relevance of the cellular patterns of nasal secretions on the assessment of the type and intensity of the lower airways inflammation and asthma control status. The collection of sputum to obtain eosinophil counts in subjects with asthma requires a lengthy procedure, and not always allows for a proper sample [12]. If one believes that the airway mucosa behaves as a continuum from the nose down to the bronchi, findings from nasal secretions could be a proxy of those obtained in the less assessable lower airways. The proportion of eosinophils in a quanti- tative nasal cytology could become a quick test to identify eosinophilic airway inflammation. The aim of this study was to compare the eosinophil counts in induced sputum and nasal lavage fluids in patients with asthma, checking their association and the accuracy of nasal eosinophilia as a predictor of sputum eosinophilia. Asthma and Rhinitis  EC doi: 10.1111/j.1365-2222.2009.03439.x Clinical & Experimental Allergy, 40, 867–874  c 2010 Blackwell Publishing Ltd