Therapeutic effect of capsaicin nasal treatment in patients with mixed rhinitis unresponsive to intranasal steroids.

Literature is convincing regarding the efficacy of capsaicin nasal treatment in idiopathic rhinitis (IR). However, up to 50% of IR patients do not meet the strict inclusion criteria of the trials conducted so far. As a consequence, the efficacy of capsaicin is unknown in a significant number of IR patients that do not meet the strict inclusion/exclusion criteria (J Allergy Clin Immunol. 2014;133:1332, J Allergy Clin Immunol. 2017; [Epub ahead of print]). "Mixed rhinitis" (MR) patients have more than one major etiologic factor involved in the mucosal pathology. We have no idea about the efficacy of capsaicin nasal spray in these patients nor about the time interval to seek a second application. We report here that capsaicin nasal spray is effective in a broader group of IR than the purely selected ones described before, that subjective nasal hyper-reactivity is a good predictor of positive outcome, and that the time interval for seeking a second treatment is likely to be shorter in MR patients than in the strictly selected IR patients.

Regulation of melanocortin 1 receptor in allergic rhinitis in vitro and in vivo.

BACKGROUND: α-melanocyte-stimulating hormone (α-MSH) was shown to inhibit allergic airway inflammation and exert suppressive effects on human basophils. OBJECTIVE: This study aims to extend our current knowledge on the melanocortin 1 receptor (MC1R) expression in nasal tissue of patients with allergic rhinitis (AR) and functional effects of α-MSH in human basophils especially from patients with allergic rhinitis. METHODS: MC1R expression before and after nasal allergen provocation was studied in nasal mucosal tissue of AR patients and in a mouse model of allergic airway inflammation using immunofluorescence. In vitro regulation of the MC1R and CD203c surface expression on whole-blood basophils of patients with AR and controls was assessed with flow cytometry. Functional effects of α-MSH on isolated basophils were analysed regarding apoptosis with flow cytometry and chemotaxis using a Boyden chamber assay. RESULTS: We detected an accumulation of MC1R-positive basophils in nasal mucosa tissue of patients with AR 24 h after nasal allergen provocation. Such accumulation was not present in mucosa sections from healthy controls. In mice with allergic airway inflammation, we found a clear accumulation of MC1R-positive basophils in the nasal tissue compared to control mice. MC1R expression was inducible in AR patients and controls by stimulation with anti-IgE. α-MSH inhibited anti-IgE and grass pollen induced upregulation of CD203c, but had no effect on chemotaxis or apoptosis of basophils in vitro. CONCLUSIONS AND CLINICAL RELEVANCE: MC1R-positive basophils accumulate in the nasal mucosa of patients with AR after nasal allergen provocation. Since α-MSH suppresses proinflammatory effector functions in human basophils via the MC1R, it constitutes an interesting novel target for modulating the allergic inflammatory response.