|
 Dr. Dana Meaney-Delman, who has been leading the inquiry at the U.S.
Centers for Disease Control and Prevention (CDC) in Atlanta, wants
to know where that oil came from. The answer will help explain
whether these cells play a key role in the vaping-related outbreak
that has killed seven people and sickened 530 so far.
It may also reveal whether some of these cases have been occurring
all along, undetected.
"We're looking to partner with any lab that can assist in the
identification of what those lipids (fats) are," Meaney-Delman said
in a telephone interview.
A group of researchers who have been studying the long-term effects
of vaping told Reuters they have taken up the challenge. They have
begun to re-examine lung cell samples they have collected in recent
years for evidence of these oil-filled immune cells in people who
vaped but didn't get sick.
One possibility: The deposits are residue from inhaling vaping oils,
such as those containing the marijuana ingredient
tetrahydrocannabinol (THC) or vitamin E acetate. Both are considered
possible contributors to the current illnesses.
Some researchers suspect the oils are formed inside the lungs as
part of the body’s natural response to chemicals found in many
commercial vaping devices. One theory is that vaping these chemicals
may impair the immune system, and make people who vape more
vulnerable to respiratory distress, they say.
A study published in the Journal of Clinical Investigation earlier
this month has fueled the latter theory.
It found that mice exposed to aerosols of propylene glycol and
vegetable glycerin - common solvents used in conventional nicotine
vaping devices - developed these same fat-clogged immune cells even
though they were never exposed to vaping oils. These mice also had
impaired immune systems compared to mice exposed to room air.
ALARM BELLS
The study set off alarm bells for Thomas Eissenberg, co-director of
the Center for Tobacco Products at Virginia Commonwealth University.
For years, doctors have reported isolated cases of pneumonia-like
illnesses in people who vaped. In many cases, patients also had
these fat-filled immune cells - called lipid-laden macrophages.
Now, these same abnormalities have been found in mice, and in at
least some of the people who have fallen ill recently.
"For me, the implication is there may be some underlying level of
disease, like what we're seeing in this cluster, that's been going
on all along," Eissenberg said in a phone interview.
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Early last week, Eissenberg joined some 25 vaping experts on a
hastily arranged conference call. At least three researchers who
have already collected lung cell samples from otherwise healthy
vapers told Reuters they would see whether these people also had
fat-laden pockets within their immune cells. Other researchers, like
Eissenberg, are seeking funding to collect new samples of their own.
They want to help determine whether these abnormalities have been
present for years, and whether they have made vapers generally more
vulnerable to severe disease, possibly triggered by some new vaping
substance.
The group’s members say they have been in regular contact with
officials at the CDC and the National Institutes of Health on how
they can best help with the multistate investigation.
They include Robert Tarran, a physiologist and vaping expert at the
University of North Carolina School of Medicine, and Dr. Peter
Shields, a lung cancer specialist at The Ohio State University
Wexner Medical Center, who has one of the country’s largest sets of
lung samples from vapers, smokers and never-smokers.
"It could be that we'll see something in the general, normal
population of people who are using e-cigarettes," Shields said.
Investigators at the CDC and the U.S. Food and Drug Administration
(FDA) have pointed to THC vaping oils or vitamin E, a substance used
in some THC products, as a possible cause of these illnesses. But
they have not ruled out anything yet, including conventional
nicotine liquids.
CDC pathologists are examining hundreds of lung cell samples
gathered from patients in the outbreak. Meanwhile, forensic chemists
at the FDA are testing more than 150 products to determine whether
there is a common ingredient that may help explain the illnesses.
"We need to parlay what we're seeing in product samples with what
we're seeing in lung tissue,” Meaney-Delman said.
Dr. Laura Crotty Alexander, a lung specialist at the University of
California at San Diego, has been studying vaping’s effect on health
since 2013. Two years ago, she treated a patient with the same set
of symptoms that are now being described across the country, and is
now checking her lung cell samples to look for clues.
"It's possible that everybody who is vaping is at risk," she said.
(Reporting by Julie Steenhuysen; editing by Michele Gershberg and
Jonathan Oatis)
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