Molecular immunology and immunotherapy for chronic sinusitis.

The development of chronic sinusitis is a complex multifactorial process characterized by inflammation of nasal and sinus mucosa. Many studies have shown that the composition of the inflammatory substrate in chronic sinusitis is similar to that seen in allergic rhinitis and in the late-phase response to antigen challenge. Mononuclear cells, consisting of T and B lymphocytes and activated eosinophils, are prominent in the sinus mucosa of patients with chronic sinusitis, especially in atopic patients. Cellular recruitment and activation of the inflammatory infiltrate have been largely attributed to the effects of T(H)2 cytokines (namely interleukin -4, IL-5, IL-13, and granulocyte-macrophage colony-stimulating factor). Current treatment of allergic chronic sinusitis consists of nasal corticosteroids and immunotherapy. A subgroup of steroid-insensitive patients demonstrates an overexpression of a variant of the glucocorticoid receptor (GR). Despite these advances, the management and treatment of chronic sinusitis is often fraught with failures and remains a frustrating task for both physician and patient.