Late Phase Inflammation during Nasal Grass and Ragweed Challenge in a Double-Blind Placebo Controlled Trial with Astemizole

Abstract

Allergic rhinitis is an IgE-mediated inflammatory reaction characterized by an early “classic” immediate hypersensitivity response and/or a subsequent late phase response. Nasal provocation to antigen challenge is a useful method of evaluating this dual response. Several H₁ antagonists may exhibit antiinflammatory properties by diminishing histamine release or inhibiting eosinophil chemotaxis. To determine whether astemizole has any anti-inflammatory characteristics, we studied 20 patients with allergic rhinitis in a double-blind placebo-controlled fashion after a 4-week course of treatment with this H₁ antagonist. Nasal provocation over 30 minutes was performed out of season using increasing concentrations of grass or ragweed extract from 10–1000 PNU. Patients were evaluated for their clinical response, and nasal lavage secretions were analyzed over 6 hours by ELISA for alpha interleukin-1, interleukin-8, albumin, and histamine levels. Total sneezing and other symptom scores for rhinorrhea, nasal congestion, and pruritus were decreased in astemizole-treated compared to placebo-treated patients both at 30 minutes (early phase), and at 3 and 6 hours (late phase) after nasal provocation. However, these results did not reach statistical significance. Nasal α IL-1 levels diminished from diluent control lavage to a significantly greater degree in astemizole than in placebo-treated patients (P < 0.05). This diminution in late phase α IL-1 suggests that astemizole may possess anti-inflammatory properties.