Chronic Sinusitis: Characterization of Cellular Influx and Inflammatory Mediators in Sinus Lavage Fluid

Abstract

Chronic sinusitis is a recurrent disorder commonly found in atopic individuals, yet few studies have explored the role of inflammatory mediators in sinusitis. Sinus lavage fluid from ten patients with chronic sinusitis obtained during endoscopic surgery was analyzed for total cell counts and then assayed for histamine, immunoreactive leukotriene C<sub>4</sub>/D<sub>4</sub>/E<sub>4</sub> (LTC<sub>4</sub>/D<sub>4</sub>/E<sub>4</sub>), and prostaglandin D<sub>2</sub> (PGD<sub>2</sub>). All ten patients had been unresponsive to medical treatment, including oral corticosteroids in most cases. High concentrations of histamine, LTC<sub>4</sub>/D<sub>4</sub>/E<sub>4</sub> and PGD<sub>2</sub> were found in sinus fluid and were comparable to levels seen in nasal secretions of allergic rhinitis patients following allergen challenge. In the sinus fluid, inflammatory cells were predominantly neutrophils with only low percentages of mast cells, basophils or eosinophils. On the basis of the histamine and PGD<sub>2</sub> concentrations in sinus fluid, we conclude that mast cell/basophil activation does occur in chronic sinusitis and may contribute to the persistent inflammation present in sinusitis.