"This study is the first to show a possible immunologic basis for chronic sinusitis, an important starting point to better understand the etiology of the illness," says Marshall Plaut, M.D., chief of NIAID's allergic mechanisms section. Despite the enormous health impact of chronic sinusitis--nearly 30 million people were diagnosed with sinusitis in 2002, according to U.S. Centers for Disease Control and Prevention, and direct costs of the illness exceed $5.6 billion per year--the condition is very poorly understood, he says.
The researchers, led by Hirohito Kita, M.D., of the Mayo Clinic in Rochester, MN, compared blood samples taken from 18 people diagnosed with chronic sinusitis with blood samples from 15 healthy volunteers. Nasal secretions from the two groups were also examined for the presence of fungal proteins and inflammation-causing immune system molecules.
Airborne microscopic fungi spores abound indoors and out. People may inhale a million or more fungal spores each day, notes Dr. Kita. The mere presence of such fungi in the airways, however, is not enough to cause sinusitis because these spores can be found in the upper respiratory tracts of both sinusitis sufferers and non-sufferers. Indeed, in this study, levels of fungal proteins in nasal secretions were similar in both groups.
The Mayo Clinic scientists looked for evidence that people with sinusitis respond abnormally to these harmless fungi. The investigators exposed immune cells derived from the blood samples to extracts of four common airborne fungi: Alternaria, Aspergillus, Penicillium and Cladosporium. T
Contact: Anne A. Oplinger
NIH/National Institute of Allergy and Infectious Diseases