Montelukast effects on inflammation in allergic rhinitis: a double blind placebo controlled pilot study.

It has been demonstrated that Leukotriene modifiers reduce rhinitis symptoms, but montelukast preventive effect on inflammatory cells pattern in intranasal challenge studies has not been already assessed. This pilot study has been designed to explore the montelukast effects in preventing early/late inflammatory cells response to specific allergen challenge in persistent rhinitis. After a 4 week wash-out period, patients were randomised to receive montelukast/placebo for 4 weeks. Pre-post treatment nasal washing and scraping before and after specific nasal challenge were performed. No difference in baseline inflammatory cells count before and after treatment was shown between groups. Despite at a basal level a decrease of inflammatory cells in active group after treatment was observed, the statistical significance was not reached. The generalised mixed model showed that, after therapeutic interventions, the inflammatory cells increased 30' and 6 hour after challenge but, only in the active group the cells amounting was less for eosinophils (-34%), macrophages (-56%), lymphocytes (-45%) and neutrophils (-46%; p = 0.001). The longitudinal generalised linear model with just one time variable showed a decrease of all inflammatory cellular types although a significant relevance was reached only for macrophages (p = 0.038) and neutrophils (p = 0.001). The modulatory effect on neutrophils and macrophages could lead to montelukast still unexplored effects. Specific trials, sized according to the results of this pilot exploratory study, could add relevant evidences concerning the leukotrienes receptors antagonist treatment of specific rhinitis and asthma phenotypes.

Antihistamines: do they work? Further well-controlled trials involving larger samples are needed.

Histamine is one of the most important steps in the phlogistic allergic reaction. Its activity is due to the link to specific receptors on the cellular surface. H1-receptors of second generation are the most currently prescribed drugs in allergic diseases for their high selectivity, little or no central sedative effect, rapid onset of action and long half lives. Antihistamines can modulate part of immunological mechanisms involved in the pathogenesis of allergic inflammation reducing mediator release and expression of adhesion molecules, regulating the release of cytokines, chemokines and consequently inflammatory cells recruitment. The anti-inflammatory effects of cetirizine, desloratadine and levocetirizine are reviewed. Quality of life is considered too, as a main parameter in a global evaluation of the antihistamine's effects.