A team of American researchers has discovered a significant cause of asthma that could result in effective prevention and management of the condition.
According to their recent report in the journal Nature Medicine, they of immunologists and pediatricians found that a viral infection in newborns leads to the impairment of regulatory facets of the immune system, increasing the chance of asthma later in life.
In their experiment, researchers repeatedly exposed infant mice to respiratory syncytial virus (RSV) through their mother´s milk. The disease eventually stripped the immune cells of the regulatory ability to stop inflammation in its lung’s passages after being exposed to a pathogen or irritant.
When an irritant enters the airways of the person with asthma, the defense mechanisms reacts to it as if it were a pathogen, resulting in the airways being inflamed and produce mucus which makes breathing difficult. This research illustrates that early exposure to RSV causes it to be hard for your body to tolerate the response of its own immune system, which makes it prone to asthma.
Previous research has revealed an association between repeated lung exposures to RSV and developing asthma later in life. A 2010 study by Swedish scientists demonstrated that 39 percent of infants come to hospital with RSV had asthma when they were 18. Additionally they noted that 9 % of their control group developed asthma without contracting RSV.
The latest study, which was led by researchers at the University of Pittsburgh´s Med school, expands on that research by giving evidence for any mechanism that drives the stop by immune tolerance.
Their experiments demonstrated that herpes suppressed regulatory T cells. According to the report, repeated exposure to RSV resulted in a “complete loss of suppressive function” from the regulatory T cells. This ultimately resulted in the mice developing asthma-like symptoms.
Researchers said the outcomes of the study pointed to a period at the begining of development when the immune system´s regulatory cells were susceptible to being “crippled”. They added this knowledge can lead to new treatments and prevention measures.
“These studies provides vital information about how viruses communicate with our immune cells and why this might result in a heightened risk of asthma,” said Malayka Rahman, from Asthma UK. “What’s really exciting may be the potential of these findings to translate into new treatments for asthma later on.”
The University of Pittsburgh study comes on the heels of a British study published earlier this year that showed boosting asthmatics’ immune systems might help lessen the quantity of asthma attacks due to viral infection.
According towards the outcomes of that relate, the therapy could prevent up to 80 % of infections that trigger asthma attacks.
“We have demonstrated the potential of cure, simply breathed in by the patient, which significantly reduces worsening of asthma symptoms and also the patient’s need to use their asthma inhaler in reaction to common cold infection,” said lead author Ratko Djukanovic, a respiratory specialist in the University of Southampton. “By presenting an defense mechanisms protein molecule, interferon beta, towards the patient’s lungs we are able to prime themselves to challenge infections more effectively.”