Navigation Links
Air pollution alters immune function, worsens asthma symptoms
Date:10/5/2010

Berkeley Exposure to dirty air is linked to decreased function of a gene that appears to increase the severity of asthma in children, according to a joint study by researchers at Stanford University and the University of California, Berkeley.

While air pollution is known to be a source of immediate inflammation, this new study provides one of the first pieces of direct evidence that explains how some ambient air pollutants could have long-term effects.

The findings, published in the October 2010 issue of the Journal of Allergy and Clinical Immunology, come from a study of 181 children with and without asthma in the California cities of Fresno and Palo Alto.

The researchers found that air pollution exposure suppressed the immune system's regulatory T cells (Treg), and that the decreased level of Treg function was linked to greater severity of asthma symptoms and lower lung capacity. Treg cells are responsible for putting the brakes on the immune system so that it doesn't react to non-pathogenic substances in the body that are associated with allergy and asthma. When Treg function is low, the cells fail to block the inflammatory responses that are the hallmark of asthma symptoms.

The findings have potential implications for altered birth outcomes associated with polluted air, much the same as those noted for the effects of cigarette smoke.

"When it came out that cigarettes can cause molecular changes, it meant the possibility that mothers who smoked could affect the DNA of their children during fetal development," said study lead author Dr. Kari Nadeau, pediatrician at Stanford's Lucile Packard Children's Hospital and an assistant professor of allergy and immunology at Stanford's School of Medicine. "Similarly, these new findings suggest the possibility of an inheritable effect from environmental pollution."

Forty-one participants came from the Fresno Asthmatic Children's Environment Study (FACES), a longitudinal study led by principal investigator Dr. Ira Tager, professor of epidemiology at UC Berkeley's School of Public Health, and co-principal investigator S. Katharine Hammond, UC Berkeley professor and chair of environmental health sciences. The researchers also recruited 30 children from Fresno who did not have asthma.

"I'm not aware of any other studies that have looked at how chemicals can alter cells so early in the regulatory process, and then connected that effect to clinical symptoms," said Tager. "There are people who still question the direct link between air pollution and human health, but these findings make the health impact of pollutants harder to deny."

Fresno was chosen because it is located in California's Central Valley, where trapped hot air mixes with high traffic and heavy agriculture to create some of the highest levels of air pollution in the country. It is also a region known for its high incidence of asthma: Nearly one in three children there have the condition, earning Fresno the nickname, "The Asthma Capitol of California."

The researchers compared the participants from Fresno with 80 children, half with asthma and half without, in the relatively low-pollution city of Palo Alto, Calif. The children were matched by age, gender and asthma status, among other variables. The children were tested for breathing function, allergic sensitivity and Treg cells in the blood.

Daily air quality data came from California Air Resources Board monitoring stations. The researchers calculated each child's annual average exposure to polycyclic aromatic hydrocarbons (PAH), a byproduct of fossil fuel and a major pollutant in vehicle exhaust.

The study found that the annual average exposure to PAH was 7 times greater for the children in Fresno compared with the kids in Palo Alto. Levels of ozone and particulate matter were also significantly higher in Fresno.

Not surprisingly, the study found that the children in Fresno had lower overall levels of Treg function and more severe symptoms of asthma than the children in Palo Alto. For example, the non-asthmatic children in Fresno had Treg function results that were similar to the children with asthma in Palo Alto.

The study authors correlated increased exposure to PAH with methylation of the gene, Forkhead box transcription factor (Foxp3), which triggers Treg cell development. Methylation effectively disables the gene's function, leading to reduced levels of Treg cells. The connection between Treg function and the severity of asthma symptoms held for children in both groups.

While previous studies have found associations between pollution especially motor vehicle exhaust and an increased risk of developing asthma, few have traced its molecular pathway so completely, the study authors said.

"The link between diesel exhaust and asthma could simply have been that the particulates were irritating the lungs," said Nadeau. "What we found is that the problems are more systemic. This is one of the few papers to have linked from A to Z the increased exposure to ambient air pollution with suppressed Treg cell levels, changes in a key gene and increased severity of asthma symptoms."

The researchers noted that Treg cells are important for other autoimmune disorders, so the implications of this study could go beyond asthma.


'/>"/>

Contact: Sarah Yang
scyang@berkeley.edu
510-643-7741
University of California -- Berkeley
Source:Eurekalert

Related medicine news :

1. Years of Exposure to Traffic Pollution Raises Blood Pressure
2. Air Pollution Slows Womens Marathon Times
3. Whats Cookin? It Could Be Air Pollution
4. Hear the World Survey Reveals Growing Noise Pollution Affecting both Physical and Mental Health
5. Air Pollution Raises Risk of Heart Disease, Death
6. Revised Oil Pollution Act Case Digest and Source Book to be Published June 2, 2010
7. Revised Edition of the Oil Pollution Act Case Digest and Source Book Released
8. Air Pollution Tied to Breathing Problems in Sleep
9. Studies confirm presence, severity of pollution in national parks
10. New map offers a global view of health-sapping air pollution
11. Using new approach, Mayo Clinic researchers find level of gene alters risk of Alzheimers disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/24/2017)... ... 24, 2017 , ... Medic CE , a Career Step company, is ... Shock” hosted by the Journal of Emergency Medical Services (JEMS). The free webinar, to ... presented by Captain Rommie Duckworth, LP, a career fire captain as well as founder ...
(Date:5/24/2017)... ... May 24, 2017 , ... Rob Lowe is a sought after actor, and ... “Informed” brings the public important topics from all aspects of life, and a new ... issues surrounding feet and ankles. , Podiatry is essential to people’s overall well-being, and ...
(Date:5/24/2017)... ... May 24, 2017 , ... ... based sleep diagnostics sensors, announced today it had completed the first phase of ... mix of domestic and rest of world (ROW) authorized dealers specializing in polysomnography ...
(Date:5/23/2017)... (PRWEB) , ... May 23, 2017 , ... ... the pharmaceutical and medical device sectors, today announced the winners of its 3rd ... Entrepreneurs) represent the most influential people in the healthcare industry today. , Out ...
(Date:5/23/2017)... ... ... The National Council on Strength and Fitness (NCSF), a ... Strength Coach credential has earned accreditation from the National Commission for Certifying Agencies ... qualified candidates for jobs in the Strength and Conditioning profession. The CSC distinction ...
Breaking Medicine News(10 mins):
(Date:5/23/2017)... PLEASANTON, Calif. , May 23, 2017 /PRNewswire/ ... world,s most innovative medical devices for pressure ulcer ... at the American Association of Critical Care Nurses, ... Houston May 22-25. The Leaf Patient ... designed specifically for the hospital environment.  The system ...
(Date:5/22/2017)... MAITLAND, Fla. , May 22, 2017 /PRNewswire/ ... industry as a whole continue to make the ... evidence becomes increasingly important for ensuring positive patient ... Key industry stakeholders are shifting focus away from ... results and effects of long-term specialty drug therapy ...
(Date:5/18/2017)... May 17, 2017  Bayer announced today that the ... be presented at the 53 rd Annual Meeting ... place June 2-6 in Chicago . ... span prostate, colorectal, liver and thyroid cancers, as well ... Phase II CHRONOS-1 trial of copanlisib in patients with ...
Breaking Medicine Technology: