MONDAY, Nov. 23 (HealthDay News) -- U.S. researchers say they've identified a protein that causes nasal and sinus polyps in 15 percent to 30 percent of people with chronic sinusitis.

The condition is one of the most serious forms of sinusitis, a constant irritation and swelling of the nasal passages. Polyps - unhealthy overgrowths of sinus tissue -- can block the sinus passages and make it difficult or impossible to breathe through the nose. This often leads to pain, swelling and infections.

"This type of sinusitis isn't subtle -- you can spot the patients with polyps across the room. They're breathing through their mouths, they talk with nasal voices, they're constantly sniffling, and their faces are swollen," Dr. Jean Kim, an assistant professor in the departments of otolaryngology and allergy and clinical immunology at the Johns Hopkins University School of Medicine, said in a news release.

Kim and colleagues analyzed sinus tissue from patients and concluded that a protein called vascular endothelial growth factor (VEGF) -- which is known to stimulate blood vessel growth -- causes the cell overgrowth that causes the polyps.

The protein may offer a target for new treatments for the condition, which typically resists all current therapies. Surgery is a common treatment but the polyps nearly always regrow. Oral steroids only temporarily treat the problem and have a number of harmful side effects.

"In the future, we might have a nasal spray with an anti-VEGF agent in it," Kim said.

The study appears in the Dec. 1 issue of the American Journal of Respiratory and Critical Care Medicine.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about sinusitis.

-- Robert Preidt

SOURCE: Johns Hopkins Medicine, news release, Nov. 23, 2009

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