Can Plastics Trigger Lupus?
Ubiquitous Compounds Trigger Lupus in Mice
July 15, 2005 - A family of chemicals used to make toys, polyesters, and
cosmetics triggers in mice bred to develop the
autoimmune disease, research shows.
The chemicals, called phthalates, don't cause lupus in normal mice. And it's
not at all clear that the mouse findings are relevant to humans.
Even so, the study raises questions about the link between the ubiquitous
compounds and says researcher
Swapan K. Ghosh, PhD, professor and interim chair of life sciences at Indiana
In some autoimmune diseases, the immune system makes antibodies that attack
the body's own cells. These are called anti-self antibodies. Mouse antibodies
against phthalates, Ghosh found, are nearly identical to certain anti-self
"We found out the antibody to phthalate is 98% the same as the anti-self
antibody found in mouse lupus," Ghosh tells WebMD. "Then we started a
more vigorous investigation to find out why not every strain of mouse gets
disease. And we found it is genetic susceptibility."
Mouse Exposure Not Same as Human Exposure
To raise antiphthalate antibodies in mice, Ghosh injected the animals with
several potent doses of phthalates to boost antibody reactions.
In their report, published in the current issue of the Journal of
Autoimmunity, Gosh and colleague So-Yon Lim, PhD, report that all commonly
used types of phthalates are harmful to susceptible strains of mice. Normal
mice, however, soon block the antiphthalate antibodies and suffer no ill
Ghosh is quick to point out that the doses of phthalates given to mice in
this study have no relation to human exposure to the phthalate compounds that
leach into the environment from plastics, cosmetics, dyes, flexible PVC
products, artificial leather, adhesives, and many other products.
While noting that the study has no direct relevance to humans, the findings
are quite interesting, says lupus expert Jennifer Anolik, MD, PhD, assistant
professor of medicine and an investigator at the autoimmunity center of
excellence at the University of Rochester in New York.
"In autoimmune diseases and in lupus, we know there are strong genetic
and environmental influences -- but we do not know what the environmental
factors are," Anolik tells WebMD. "Because that is such an unknown, it
makes this paper interesting. There might be chemical exposures in the
susceptible individual that might contribute to autoimmunity."
WebMD asked the phthalate esters panel of the American Chemical Council --
an industry group that includes many major phthalate manufacturers -- to
comment. The panel was unable to comment before publication.