Current views on the molecular biology of chronic sinusitis

The development of chronic sinusitis is a multifactorial process primarily related to allergen exposure, genetic predisposition, and persistent infections. Like allergic rhinitis, the inflammatory substrate in chronic sinusitis is highlighted by the abundance of mononuclear inflammatory cells, eosinophils, and T helper type 2 (Th2) cytokines. Corticosteroids are the most potent agents available for relieving the symptoms of chronic sinusitis, and they act by inhibiting the synthesis of Th2 cytokines and other inflammatory mediators. The mechanisms of corticosteroid insensitivity in chronic sinusitis and other inflammatory conditions are poorly understood. Microbial products and abnormalities in cytokine expression and corticosteroid receptors have been suggested as potential mechanisms of corticosteroid resistance. The purpose of this article is to review our current knowledge of the pathogenesis of chronic sinusitis and highlight recent advances in the molecular biology of the inflammatory process underlying this condition. The issue of corticosteroid insensitivity in chronic sinusitis will also be addressed.