Salivary ECP levels in patients with active rhinitis

<bold>Background:</bold> A classical feature of airway inflammation is the infiltration of leukocytes. Eosinophils are critical mediators of disease activity. They are rather involved in the late-phase reaction, their toxic granule proteins leading to epithelial cell damage and tissue remodeling. Eosinophil cationic protein (ECP) is released into biological fluids under inflammatory conditions such as allergy and infections. Тhe aim of our study was to compare salivary ECP levels in patients with allergic and non-allergic rhinitis. <bold>Methods:</bold> We followed-up 67 patients (47 female and 20 males, median age 29, range 18 - 50 years) with persistent rhinitis, with special emphasis on the episodes of seasonal symptoms in the previous two years. Serum IgE specific for inhalation allergens was determined by еnzyme allegro-sorbent test (Euroline Allergy, Euroimmun). Symptom severity was assessed by visual analog scale. Тotal symptom score (TSS) was calculated for each participant. All patients were instructed to collect unstimulated saliva. ECP levels were measured with Human eosinophil cationic protein ELISA kit (MyBioSource). <bold>Results:</bold> In 49 patients serum IgE specific to at least one inhalation allergen was detected, the other 18 participants were defined as non-atopics. Mean saliva ECP concentration was 28.99 (0.90÷50.0) ng/mL in atopics and 28.98 (5.6 ÷44.3) ng/mL in non-atopics. No significant difference was found in saliva ECP concentration between atopic and non-atopic participants (p=0.84). Similar result was obtained for TSS(p=0.69). <bold>Conclusions:</bold> Salivary ECP cannot serve as a predictive marker for allergic inflammation. A single quantitative measurement of ECP has no significant diagnostic value.