Despite the fact that extensive degranulation is a likely prerequisite for a pathogenic role of eosinophils, little is known about the degranulation status of these cells in eosinophilic conditions. The present study of the ultrastructure of tissue eosinophils explores eosinophil degranulation in allergic rhinitis before and during seasonal allergen exposure.A total of 23 patients scored symptoms q.d., prior to and during the pollen season. The numbers of mucosal eosinophils and their degranulation status were determined in nasal biopsies. Furthermore, nasal lavage fluid levels of eosinophil cationic protein (ECP) and a 2 -macroglobulin were assessed as indices of eosinophil activity and plasma exudation, respectively.Seasonal allergen exposure was associated with increased nasal symptoms, increased lavage fluid levels of ECP and a 2 -macroglobulin, and increased numbers of tissue eosinophils. In the tissue, transmission electron microscopy revealed a moderate piecemeal degranulation already prior to the season (mean¡SD 37¡2.7% altered granules). Seasonal allergen exposure increased this degranulation (87¡1.8%), and produced local areas with extensive deposition of granule proteins. The degree of eosinophil degranulation correlated with levels of ECP in lavage fluids obtained at histamine challenge.In conclusion, this study demonstrated that the nasal mucosa in allergic rhinitis features moderately degranulated eosinophils already at nonsymptomatic baseline conditions. In association with the development of symptomatic seasonal allergic rhinitis, the tissue deposition of eosinophil granule proteins is dramatically elevated through increased eosinophil numbers, together with markedly augmented degranulation of individual cells.

BackgroundInteractions between Th1 and Th2 immune responses are of importance to the onset and development of allergic disorders. A Toll-like receptor 7 agonist such as AZD8848 may have potential as a treatment for allergic airway disease by skewing the immune system away from a Th2 profile.ObjectiveTo evaluate the efficacy and safety of intranasal AZD8848.MethodsIn a placebo-controlled single ascending dose study, AZD8848 (0.3-600 μg) was given intranasally to 48 healthy subjects and 12 patients with allergic rhinitis (NCT00688779). In a placebo-controlled repeat challenge/treatment study, AZD8848 (30 and 60 μg) was given once weekly for five weeks to 74 patients with allergic rhinitis out of season: starting 24 hours after the final dose, daily allergen challenges were given for seven days (NCT00770003). Safety, tolerability, pharmacokinetics, and biomarkers were monitored. During the allergen challenge series, nasal symptoms and lavage fluid levels of tryptase and α2-macroglobulin, reflecting mast cell activity and plasma exudation, were monitored.ResultsAZD8848 produced reversible blood lymphocyte reductions and dose-dependent flu-like symptoms: 30–100 μg produced consistent yet tolerable effects. Plasma interleukin-1 receptor antagonist was elevated after administration of AZD8848, reflecting interferon production secondary to TLR7 stimulation. At repeat challenge/treatment, AZD8848 reduced nasal symptoms recorded ten minutes after allergen challenge up to eight days after the final dose. Tryptase and α2-macroglobulin were also reduced by AZD8848.ConclusionsRepeated intranasal stimulation of Toll-like receptor 7 by AZD8848 was safe and produced a sustained reduction in the responsiveness to allergen in allergic rhinitis.Trial registrationNCT00688779 and NCT00770003 as indicated above.

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Repeated administration of AZD8848 activated TLR7 and produced IFN-induced effects. This was associated with a sustained reduction in allergen responsiveness.

KOS treatment with high amplitude pressure did not have significant beneficial effects as compared to low amplitude pressure on TVRSS. Numerical improvements in TVRSS and SNOT 22 were found when comparing high and low amplitude pressure treatments with uninflated balloon treatment. However, this part of the study was initially single-blinded, and these results were secondary objectives.