Inflammatory Cells and Mediators in Nasal Secretions during Early Response to Ragweed Challenge: Correlation between Type of Cellular Influx and Mediator Release

Abstract

The early and late phase responses in nasal tissues exhibit release of lipid-derived mediators, granule-associated mediators, and a mixed cellular influx in separate nasal challenges. To explore this phenomenon further, concentrations of inflammatory mediators were measured along with characterization of cell influx during dose-dependent ragweed challenges. Ten allergic rhinitis subjects underwent two unilateral nasal lavages using incremental 3-fold concentrations of short ragweed antigen. Low doses of ragweed (0.016–0.114 units Amb a I) rarely induced cell influx (1/18 challenges), whereas moderate doses (0.432–1.3 units Amb a I) caused cell influxes in 7/18, and high doses (3.39–11.7 units Amb a I) resulted in cell influxes in 8/17. The eluent contained >50% neutrophils in 7 challenges; >50% eosinophils in 3; and a mixed pattern in 6. There was a significant association between the dose of antigen and the level of histamine, prostaglandin D2 (PGD2), and leukotriene C4/D4/E4 (LTC4/D4/E4). Challenges with an eosinophilic influx tended to be associated with higher concentrations of mediators than neutrophilic influxes. Similar to the immediate skin response, the early allergic response in the nose demonstrated a cell influx with release of histamine, PGD2, and LTC4/D4/E4. Nasal cellular inflammation, therefore, can occur within minutes of allergen exposure.