en ايمونولوژي Immunology پژوهشي Research <p><b>Background:</b> The airway surfaces are one of the most common ways of entry of infectious agents. Oral cavity associated lymphoid tissues are inductive site of humoral immune responses in inflammatory and infectious disorders of the upper respiratory tract. These lymphoid tissues play important roles in the induction of salivary IgA. The impact of upper respiratory tract diseases on salivary IgA production has not been fully understood. Therefore, in this study, we investigated the salivary IgA levels in patients suffered from upper respiratory tract diseases to indicate the effect of these diseases on salivary IgA production.<br> <b>Materials and Methods:</b> In this study, salivary IgA level of 156 patients with inflammatory diseases of the upper respiratory tract including chronic rhinosinusitis, ear and pharynx diseases have been evaluated by direct immunoenzymatic determination.<br> <b>Results:</b> In pharynx disorders 11.8 % of patients were IgA deficient , 76.2 % were normal and11.8 % had elevated level of IgA .In patients with chronic rhinosinusitis IgA deficiency was observed in 9.2 % , 75.9 % were normal and there was an elevation in 14.8 % of patients .In ear disorders 11.6% were IgA deficient ,76.7 % normal and 11.6 % had elevated IgA level.<br> <b>Conclusion:</b> This study provided evidence for the first time that changes in salivary IgA level are almost the same in different sites of infectious and inflammatory diseases of upper respiratory tract. Our investigation revealed that local up regulation of salivary IgA is not particular interest in majority of patients with upper respiratory tract infections.</p> Salivary IgA, Upper respiratory tract diseases, Mucosal defense. 40 42 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-186-1&slc_lang=en&sid=1 Abbas Hashemi abbas.hashemi30@gmail.com 10031947532846005819 10031947532846005819 No Faculty of Medicine, Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Saeid Abediankenari abedianlab@yahoo.co.uk 10031947532846005820 10031947532846005820 Yes Molecular and Cell Biology Research Center, Department of immunology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran Abdollah Madani 10031947532846005821 10031947532846005821 No Department of Ear,Nose,Throat, Head and Neck Surgery, Faculty of Medicine , Mazandaran University of Medical Sciences, Sari, Iran