Th17 cells Causes Asthma
Scientists have found Th17 cells play a major role in development of asthma. Credit: King’s College London

The major culprit that causes asthma has been identified by scientists from King's College London.

Th17 cells, as they are called, produce lung damaging molecules leading to lung inflammation and asthma.

Previously, researchers had believed that Th17 causes an inflammatory condition such as multiple sclerosis but now they have found that TH17 cells cause asthma.

A study found that Th17 cells play an important role in people with persistent asthma symptoms, particularly in those whose symptoms do not respond to treatment with steroids.

Asthma is often triggered by an immune response mounted against an inhaled allergen, which leads to inflammation or swelling in the airways. The study has found a significant link between Th17 and airway remodelling in asthma, which involves structural changes and thickening of the airways. These changes make the lungs susceptible to severe asthma attacks by disrupting the control mechanisms that prevent asthma in healthy individuals, according to a press release.

Until now, researchers believed that the Th2 response was recognised as the predominant immune response behind asthma symptoms due to its association with allergic inflammation. However, researchers have for the first time uncovered the role of Th17, which contributes to lung inflammation and asthma, according to the study published in Mucosal Immunology Journal.

"We're extremely excited about the results of this research, as they point to immune signals that could be targeted to reduce airway remodelling. This could guide the use of new medicines that block the Th17 response in certain groups of people with severe asthma," said Dr Alistair Noble, researcher at the division of asthma, allergy and lung biology at King's College London.

Leanne Metcalf, Assistant Director of Research & Practice at Asthma UK, said apart from generating new information on the causes of severe asthma, the study results suggest significant treatment possibilities, particularly for those individuals for whom conventional steroid therapies do not work.

Metcalf said pursuing these lines of enquiry could have a dramatic impact on the lives of tens of thousands of people living with asthma in the UK.