Intranasal administration of allergen increases specific IgE whereas intranasal omalizumab does not increase serum IgE levelsA pilot study

BackgroundAdministration of the therapeutic anti-IgE antibody omalizumab to patients induces strong increases in IgE antibody levels. ObjectiveTo investigate the effect of intranasal administration of major birch pollen allergen Bet v 1, omalizumab or placebo on the levels of total and allergen-specific IgE in patients with birch pollen allergy. MethodsBased on the fact that intranasal allergen application induces rises of systemic allergen-specific IgE, we performed a double-blind placebo-controlled pilot trial in which birch pollen allergic subjects were challenged intranasally with omalizumab, placebo or birch pollen allergen Bet v 1. Total and allergen-specific IgE, IgG and basophil sensitivity were measured before and 8weeks after challenge. For control purposes, total, allergen-specific IgE levels and omalizumab-IgE complexes as well as specific IgG levels were studied in subjects treated subcutaneously with either omalizumab or placebo. Effects of omalizumab on IgE production by IL-4/anti-CD40-treated PBMCs from allergic patients were studied invitro. ResultsIntranasal challenge with Bet v 1 induced increases in Bet v 1-specific IgE levels by a median of 59.2%, and this change differed significantly from the other treatment groups (P=.016). No relevant change in allergen-specific and total IgE levels was observed in subjects challenged with omalizumab. Addition of omalizumab did not enhance IL-4/anti-CD40-induced IgE production invitro. Significant rises in total IgE (mean IgE before: 131.83 kU/L to mean IgE after: 505.23 kU/L) and the presence of IgE-omalizumab complexes were observed after subcutaneous administration of omalizumab. ConclusionIntranasal administration of allergen induced rises of allergen-specific IgE levels, whereas intranasal administration of omalizumab did not enhance systemic total or allergen-specific IgE levels.