Introduction:

A protein that may have originally evolved to help protect the airways
now appears to be a biomarker that indicates severe asthma. And it may
also play a role in the development of asthma, according to new research.

Reporting in the Nov. 15 issue of theNew England Journal of Medicine,
Yale University researchers said that people with severe asthma were
more likely to have elevated levels of the protein known as YKL-40 in
their blood compared to people without asthma.

"We believe that it's a marker of the inflammatory response associated
with asthma," said the study's lead author, Dr. Geoffrey Chupp, an
associate professor of medicine at Yale University School of Medicine.
And, he added, "These new novel family of molecules could be very
important in asthma pathogenesis. Down the road, there could be new
treatments and new ways to characterize asthma."

YKL-40 is what's known as a chitinase-like protein. It attaches itself
to chitin, an abundant substance found in fungi, crustaceans and in
insects like dust mites and cockroaches. It's also present in the
pharynx and eggs of parasitic worms called helminths. Infection with
helminths used to be common but is now rare in developed countries,
according to the author of an accompanying editorial in the same issue
of the journal, Dr. Burton Dickey, chairman of pulmonary medicine at
M.D. Anderson Cancer Center in Houston. These worms migrate through
the skin into the bloodstream and travel through the lungs to get into
the gastrointestinal tract, he said....

Link to full article:
http://www.washingtonpost.com/wp-dyn/content/article/2007/11/14/AR2007111401926.\
html