The Effect of Desloratadine on Eosinophil/Basophil Progenitors and Other Inflammatory Markers in Seasonal Allergic Rhinitis: A Placebo-Controlled Randomized Study Journal Articles uri icon

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abstract

  • <i>Background:</i> Eosinophil/basophil (Eo/B) progenitors fluctuate in the peripheral circulation during seasonal allergen exposure in atopic subjects. Several drugs have been shown to modulate Eo/B progenitor levels in the peripheral blood but, to date, the possible effect of antihistamines on Eo/B progenitors has not been explored. Our objective was to evaluate whether the antihistamine desloratadine (DL) can modulate peripheral blood Eo/B progenitors or other markers of allergic inflammation. <i>Methods:</i> We performed a randomized double-blind placebo-controlled study on the effects of DL on peripheral blood Eo/B progenitors in subjects with symptomatic, seasonal allergic rhinitis during a ragweed pollen season. Forty-five subjects were randomized to treatment for 4 weeks with DL 20 mg daily or placebo. <i>Results:</i> The expected fall in the number of Eo/B progenitors from baseline to 2 weeks of treatment was seen in the placebo group [median drop of 1.0 colony-forming unit (CFU)/10<sup>6</sup> cells], and was greater than in the DL group (median drop of 0.0 CFU/10<sup>6</sup> cells) (p = 0.013). The change in histamine concentration per colony from baseline to 2 weeks of treatment was lower in the DL group (median decrease of 6.1 pg/colony) compared to placebo (median increase of 1.8 pg/colony) (p = 0.01). An increase in the nasal lavage eotaxin concentration from baseline to 4 weeks of treatment was statistically significant in the placebo group but not in the DL group. Eo/B CFU were not affected by varyingin vitro concentrations of DL. <i>Conclusion:</i> These results suggest that DL can modulate aspects of allergic inflammation in vivo through mechanisms other than simple blockade of H<sub>1</sub> histamine receptors.

publication date

  • 2005