Enzyme tied to WTC ills
May explain cough, study sez

http://www.nydailynews.com/front/sto...p-391263c.html

BY PAUL H.B. SHIN
DAILY NEWS STAFF WRITER
10/25/2006

Doctors unveiled a tantalizing glimpse yesterday into why some firefighters may suffer from the "World Trade Center cough" while others who endured the toxic dust and fumes at Ground Zero are relatively healthy.

Firefighters whose lung capacity deteriorated faster in the wake of 9/11 were more likely to be deficient in a key natural enzyme that protects against lung damage, according to a study of 90 of the 12,000 Bravest who responded to the attacks at Ground Zero.

But Dr. David Prezant, the study's lead researcher and the FDNY's co-chief medical officer, cautioned against drawing too broad a conclusion from the report.

"This is very, very preliminary information that cannot in any shape or form be translated into a diagnosis or treatment initiative," Prezant told the Daily News from Salt Lake City, where he presented his findings at a gathering of the American College of Chest Physicians.

"It is only one small piece of a puzzle," he said. "We are trying to understand the science behind why some patients come down with World Trade Center respiratory diseases and others do not."

However, the research could eventually help solve the puzzle years down the road, said Prezant, a lung specialist at Montefiore Medical Center.

Using a blood test normally used to screen people at risk of early-onset emphysema, Prezant found that 11 of the 90 firefighters had low levels of an enzyme called alpha-1 antitrypsin, or A1AT.

Of the 11, four had a significant deficiency of A1AT while seven had a moderate deficiency, the blood tests showed.

But none had the most severe kind of genetic deficiency. All have the WTC cough.

"What this enzyme does is it protects the lungs from damage," said Dr. Mark Rosen, a pulmonologist at North Shore-Long Island Jewish Medical Center and president of American College of Chest Physicians.

"It prevents the destruction of lung tissue by a variety of mechanisms," he said.

About 150,000 Americans have a severe shortage of A1AT, but many are undiagnosed.

"Many more have a partial deficiency, and most of those people are not diagnosed for their whole lives because most of those people don't get sick" unless they are exposed to toxins such as cigarette smoke, Rosen said.

Prezant stressed that trying to determine whether a particular disease - whether it's WTC cough or breast cancer - is due to genetic or environmental factors is a science that's still in its infancy.

"It's not going to be one genetic trait" that is responsible for WTC cough, Prezant said.

That's why simply testing responders for the enzyme won't be useful, he said.

But the ongoing research at the FDNY is "on the cutting edge for trying to find future cures."

A study published in August by one of Prezant's colleagues at Montefiore painted a grim picture of the lung ailments among the 12,000 firefighters who inhaled dust and smoke on 9/11 and in the following months.

Those firefighters suffered a dramatic loss of lung capacity - 12 times the normal rate that occurs each year as people age, the study found.