Asthma could be more dangerous than previously thought, according to a new study which found the disease could affect the whole body, not just the lungs.
Researchers at the University of California, Los Angeles found that genetic damage that asthma caused is not limited to the lungs.
They found the damage is present in circulating, or peripheral, blood.
Researchers looked for the over-expression of a cytokine called interleukin 13 (IL-13), which is known to mediate inflammation, a critical problem for people with asthma.
The study, which was conducted in an animal model that mimicked human asthma, was the first to assess the role of IL-13 in genetic damage to cells, or genotoxicity, said Robert Schiestl, a professor of pathology and radiation oncology at the David Geffen School of Medicine at UCLA.
“Asthma is a very widespread disease, and we show for the first time an association between asthma and genotoxicity in peripheral blood,” said Schiestl, senior author of the study.
“This is important because it shows a whole-body effect from asthma, not just damage in the lungs,” Schiestl added.
Schiestl said it appears that IL-13 increases important elements of the inflammatory response, including reactive oxygen species molecules – ions or very small molecules that include free radicals.
The team found that ROS-derived oxidative stress induced genetic damage with four types of systemic effects in the peripheral blood: Oxidative DNA damage, single and double DNA strand breaks, m Micronucleus formation and protein damage.
Schiestl said all four effects causes the chromosomes to become unstable, which could result in a variety of other diseases.
“We found four different markers of DNA damage and one marker of protein damage in blood cells in the body periphery, which was very surprising,” Schiestl said.
“This could indicate that other organs in asthmatics have a higher risk of developing disease,” said Schiestl.
Asthma, a chronic disease that inflames and narrows the airways of the lungs, affects more than 150 million individuals worldwide, researchers said.
It causes recurring periods of wheezing, chest tightness, shortness of breath and coughing, and the symptoms can worsen at any time, making breathing difficult.