Possible connection between air pollution and tuberculosis susceptibility
A team of researchers, led by Dr. Stephan Schwander, of the University of Medicine and Dentistry of New Jersey - School of Public Health (UMDNJ-SPH), has determined a possible link between exposure to a common component of urban air pollution and a change in the function of important immune cells that protect against the bacteria that cause tuberculosis (Mycobacterium tuberculosis). Writing in the Journal of Immunology, the scientists describe their findings that exposure to diesel exhaust particles (DEP) suppresses the function of phagocytic immune cells (a type of white blood cells that ingest foreign particles, such as bacteria) on a cellular level. They conclude that this exposure probably causes exposed individuals to be less able to fight off new Mycobacterium tuberculosis infections or to suppress a reactivation of a latent infection by these bacteria.
“In laboratory experiments using DEP generated from an
automobile diesel engine as model air pollutant particles, and
blood samples gathered from 20 healthy individuals, we
demonstrated that exposure to DEP makes cells less
responsive,” said Schwander. “The cells, in
effect, became desensitized to stimulation with the bacteria
that cause TB,” he explained. “This effect was
even greater in cells that had prior exposure to DEP than in
those that had concurrent DEP and
Mycobacterium tuberculosis
exposure.”
Tuberculosis is estimated to
afflict approximately 8-10 million people and to cause 1.5
million deaths each year worldwide. The incidence of the
disease is particularly high in low- and middle-income
countries that are experiencing rapid industrial growth and
increases in motor vehicle traffic in densely populated urban
areas. By the year 2030, scientists estimate that 50 percent
of the world’s population will live in urban
environments.
“Because there is already
epidemiological evidence that connects tuberculosis to
cigarette smoking and some forms of indoor air pollution, it
seemed logical to look at outdoor air pollution for a similar
correlation,” Schwander added. “The models we used
indicated that this may, in fact, be the case. The next step
is to see if these results can be confirmed by larger
epidemiological studies, conducted in a real world
environment.”
The University of Medicine and
Dentistry of New Jersey (UMDNJ) is New Jersey’s only
health sciences university with more than 6,000 students on
five campuses attending the state's three medical schools, its
only dental school, a graduate school of biomedical sciences,
a school of health related professions, a school of nursing
and New Jersey’s only school of public health. UMDNJ
operates University Hospital, a Level I Trauma Center in
Newark, and University Behavioral HealthCare, which provides a
continuum of healthcare services with multiple locations
throughout the state.
University of Medicine and Dentistry of New Jersey
