Asthmatics less able to fight off flu

Lynchpin in $220M fight against breathlessness

New research by NIHR Southampton Respiratory Biomedical Research Unit has discovered that asthmatics have a weaker immune system, explaining why they are more likely to get flu.  

A study led by Dr Ben Nicholas and Professor Ratko Djukanović, working closely with the University of Southampton spin-out company Synairgen, has discovered that an asthmatic’s immune system can’t fight the flu virus as well as a person who doesn’t have asthma.

These results help researchers better understand why asthmatics are more affected by influenza. They could also help find new treatments for common lung infections, which often make asthma symptoms worse.

The study formed part of U-BIOPRED, a large-scale European project using information and samples from adults and children to learn more about different types of asthma.

A decade of research

Over the course of ten years, Dr Nicholas has developed and improved a method of growing lung samples taken from asthmatics and healthy volunteers in the laboratory.

Unlike other techniques, which separate and grow a single layer of cells in a dish, Dr Nicholas keeps the whole sample intact. This lets him study a pin-head sized piece of lung, as it would be found in the body, in the lab. He then infects these lung samples with the flu virus to see how they react.  

By using this method, he can study the effects of viruses on lung cells in conditions similar to those in the body, without affecting participants’ health.        

Weaker immune system

This study looked into whether immune system differences explain why asthmatics are more likely to get flu than the general population. This is important, as flu can cause a person’s asthma symptoms to get worse.

Samples from healthy people showed a strong immune system-triggering reaction to the flu virus. But in lung samples from asthma patients, this reaction was much weaker.

While the team can’t say this difference is due to the asthma itself, or the steroids used by participating asthmatics, it does provide an explanation why asthmatics are affected more. These findings could inform the search for new treatments to prevent and better manage lung infections in asthma.

Posted on Wednesday 15 March 2017