Influence of allergy on clinical, immunological and histological characteristics of nasal polyposis

Influence of allergy on clinical, immunological and histological characteristics of nasal polyposis. Objectives: Although polyps seem to be a manifestation of the chronic inflammation of nasal/paranasal sinuses mucosa in both allergic and non-allergic subjects, the pathogenesis of nasal polyposis remains unknown. The aim of this prospective study was to compare the clinical characteristics of nasal polyposis in non-allergic and allergic patients, to compare the cytokine levels in nasal secretions in atopic and non-atopic nasal polyp patients and to correlate these levels with eosinophil counts in nasal polyp tissue specimens. Methods: This study included thirty patients with nasal polyposis (13 atopic and 17 non-atopic) requiring surgical treatment. Nasal secretion samples were collected from the nasal cavities of all 30 subjects a few days before the surgical treatment. The levels of tumour necrosis factor-alpha (TNF-alpha), tumour necrosis factor-beta (TNF-beta), interleukin (IL)-1 beta, IL-2, IL-12, interferon-gamma (IFN-gamma), IL-4, IL-5, IL-6, IL-10, and IL-8 were measured using the flow cytometric method. Each of the 30 patients was staged clinically according to nasal symptom score, endoscopic score and Lund-Mackay computed tomography (CT) score. All these patients had undergone sinus surgery. Eosinophils were counted in hematoxylin- and eosin-stained sections of all nasal polyp samples. Results: Our results showed that allergy does not modify the symptoms, or the endoscopic and CT findings, of nasal polyposis. We found significantly higher concentrations of IL-4 (p < 0.01), IL-5 (p < 0.05), IL-6 (p < 0.05) and TNF-beta (p < 0.05) in nasal secretions of allergic nasal polyp patients than in non-allergic ones. Eosinophil counts were significantly higher in tissues of atopic patients' polyps than in non-atopic subjects (p < 0.01). No correlation was observed between cytokine levels and eosinophil counts. Conclusion: Non-atopic and atopic patients' polyps have different immunological patterns. Our results showed that the presence of Th2 cytokines was a more significant feature in allergic patients with nasal polyposis than in non-allergic patients.