The purpose of this study is to determine if treatment with the anti-IgE antibody, Xolair (omalizumab), will improve objective and subjective evidence of chronic sinusitis.

At its most basic level, sinusitis is defined as an inflammation of the lining membrane of the paranasal sinuses. Sinusitis affects all age groups, including 17% of people above the age of 65 years. On the basis of national population surveys and insurance-reimbursement claims, sinusitis is one of the most common health problems in the U.S. Thus, each year, billions of dollars are spent on direct medical costs for the treatment of this enigmatic illness.

Despite the enormous cost of the problem, there are no definite studies of treatment and management. There are some data indicating that intranasal steroids are effective, and recently Nasonex was approved for the treatment of nasal polyps. All other treatments are empirically based.

There is evidence that IgE antibodies play a role in chronic sinusitis. The investigators have shown that total IgE levels correlate with the severity of sinusitis, as assessed by CT scan. Staphylococcus enterotoxins cause local increases in total IgE in over 50% of nasal polyp patients. Allergies occur more frequently in patients with chronic sinusitis than in the general population. Elevations in total IgE have been shown to occur in patients with allergic fungal sinusitis and the levels of total IgE decrease with successful treatment. Thus, the investigators speculate that IgE contributes significantly to the pathogenesis of chronic sinusitis.

The purpose of this study is to determine if treatment with the anti-IgE antibody, Xolair, will improve objective and subjective evidence of chronic sinusitis.

Inclusion Criteria:

• Chronic sinusitis, as defined by symptoms for greater than 12 weeks, despite treatment
• Paranasal sinus CT scan showing evidence of chronic sinusitis
• Positive skin or RAST test to an inhalant allergen
• Serum total IgE between 30 and 700 International Units/ml
• Body weight less than 150 kg
• Impaired quality of life, as measured by the Rhinosinusitis Disability Index (RSDI)

Exclusion Criteria:

• Women of childbearing potential not using a contraception method(s) (birth control pills, Depo Provera, double barrier) as well as women who are breastfeeding
• Known sensitivity to Xolair
• Patients with severe medical condition(s) that, in the opinion of the investigator, prohibits participation in the study (heart, lung, kidney, neurological, oncologic or liver disease)
• Use of any other investigational agent in the last 30 days
• No measurable disability on the RSDI
• Immunocompromised patients or patients with ciliary disorders