The Nasal Smear for Eosinophils, Its Value, and Its Relation to Nasal Mucosal Eosinophilia in Allergic Rhinitis

Iranian Journal of Otorhinolaryngology Vol. 22, No.60, Summer-2010, (73-78) Original Article The Nasal Smear for Eosinophils, Its Value, and Its Relation to Nasal Mucosal Eosinophilia in Allergic Rhinitis *Mehdi Bakhshaee1, Mohammad Fereidouni2, Mehdi Farzadnia3, Abdol-Reza Varasteh4 Abstract Introduction: There is no single test as a gold standard for the diagnosis of allergic rhinitis (AR). The aim of this study was to assess the usefulness and validity of nasal smear as a quick, easy and inexpensive diagnostic method for diagnosis of allergic rhinitis. Materials and Methods: This study was conducted in a university hospital setting. Nasal smears were taken from 39 patients with a clinical history of nasal allergy and a positive skin prick test to at least one aeroallergen as well as 26 controls without any history and negative test. Biopsy specimens from the inferior turbinate as well as nasal smears of 19 cases including 9 patients and 10 controls with the same criteria were taken. Nasal smears and biopsy slides were stained with Giemsa and Hematoxilin-Eosin and were examined blindly by two separate pathologists. Results: Fifty one percents of the patients and 11.5% of the controls showed eosinophilia in their nasal smear (≥10% eosinophils, P=0.001). The sensitivity of nasal eosinophil count as a diagnostic test for AR was 51.3% with a specificity of 88.5%, a positive predictive value of 87% and a negative predictive value of 54%. Eosinophilia in nasal biopsies was found in 44% and 30% of allergic patients and controls respectively. There was no significant correlation between symptoms or positive skin tests with either smear eosinophilia or tissue eosinophilia. Conclusion: Evaluation of eosinophils in nasal smear is an insensitive but fairly specific test for the diagnosis of allergic rhinitis. It seems that the nasal secretions and nasal tissue represent two distinct cellular compartments. Keywords: Eosinophilia, Nasal mucosa, Rhinitis Received date: 6 Jan 2010 Accepted date:18 May 2010 1 Ear, Nose, Throat Research Center, Department of otorhinolaryngolgy , Mashhad University of Medical Sciences, Mashhad, Iran 2 Birjand University of Medical Sciences, Birjand, Iran 3 Department of pathology, Mashhad University of Medical Sciences, Mashhad, Iran 4 Immunology Research Center, Department of immunobiochemistery, Mashhad University of Medical Sciences, Mashhad, Iran *Corresponding author: Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. E-mail: , Tel: +985118413492 , Fax: +985118413492 73 The Nasal Smear for Eosinophils Bakhshaee M, et al aeroallergen as well as 26 controls without history of any allergic diseases and negative skin prick test to the same panel of aeroallergens as patients’ group. Biopsy specimens were taken from the inferior turbinate of all patients as well as 10 controls. Complete allergic work up including history of special stress on allergic disorders, total serum IgE, allergic symptoms and physical examination was carried out for all cases. Participants taking local or systemic corticosteroids or those with chronic rhinosinusitis were excluded. Nasal smears and biopsy slides were stained with both Giemsa and Hematoxilin-Eosin method and were examined blindly by two separate pathologists. A smear was considered positive for eosinophilia when there was more than 10% eosinophils of total leukocytes and for mucosal eosinophilia (tissue biopsy) with at least more than three eosinophils in each high power field (X 40) of microscopic slide. The data were analyzed using SPSS (PC version 11.5) software. Proportion equality test was used for two independent populations and chi–square test was done to compare those populations. P<0.05 were considered significant. Introduction Allergic rhinitis is an IgE-mediated hypersensitivity reaction in nasal mucosa which is characterized by sneezing, itching, watery nasal discharge and a sensation of nasal obstruction. Depending on the part of the world, the rate of symptoms attributed to allergic rhinoconjunctivitis ranges from 1.4 to 39.7% of the population (1). A characteristic feature of allergic inflammation is local accumulation of inflammatory cells including T lymphocytes, mast cells, eosinophils, basophils and neutrophils (2). Release of various mediators from these cells is responsible for the symptoms of allergic rhinitis which can be divided into early or delayed (late) phase response (3). Accumulation of additional inflammatory cells such as eosinophils and T cells occurs in response to various chemokines. These inflammatory cells can be easily identified in nasal mucosa or secretions by performing nasal biopsies and then, preparing nasal smears to confirm the diagnosis of allergic rhinitis. Moreover, these methods are simple, reproducible, easy to perform and costeffective as compared to other tests e.g. skin prick test or radioallergosobent test (RAST), etc (3). The present study was planned to evaluate the diagnostic value of nasal smear as a simple, noninvasive and inexpensive method for diagnosing allergic rhinitis and comparing it’s validity to nasal tissue biopsy. Results In the control group, 10 were males and 16 were females, while in the study group, 20 and 19 were males and females respectively. The mean age was 22 and 24 years for patients and controls, respectively (range: 656 years). Table 1 shows the demographic characteristics of patients and controls. 51% and 11.5% of the patients and the controls demonstrated nasal smear eosinophilia respectively, and the difference was statistically significant (P=0.001) (Fig 1,2). The sensitivity for nasal smear eosinophilia in the diagnosis of allergic rhinitis was 51.3% with a specificity of 88.5% and a positive and negative predictive value of 87% and 54%, respectively. The specificity of test was increased to 100% when the rate of eosinophilia was considered more than Materials and Methods In a prospective, cross-sectional controlled and single-blinded study, we analyzed the value of nasal secretion and tissue eosinophilia in diagnosis of allergic rhinitis. The study was approved by Research Ethics Committee of Mashhad Medical School, Mashhad, Iran and was conducted in Imam Reza Hospital and Immunology Research Center, Mashhad, Iran. Participants were recruited through regional advertising from September 2006 to August 2007. Nasal smears were taken from 39 patients with a clinical history of perennial allergic rhinitis and a positive skin prick test to at least one 74 Iranian Journal of Otorhinolaryngology Vol. 22, No.60, Summer-2010, (73-78) 50% but at the same time the sensitivity of the test declined (Fig 4). 60 51 50 Group Smear Patients (39) Controls (26) Age (mean) / Range (year) Sex (F/M) Family history (Allergy) 19/20 9/17 60% 46% E osinophilia(% ) Table 1: Demographic characteristic of patients and controls. 44 40 30 30 20 11.5 10 0 21.67 / (6-56) 22.54 / (6-38) Smear Tissue Patients (...truncated)