A breakthrough study has uncovered a potential root cause of asthma and a drug that reversed symptoms in lab tests. The finding brings hope to the 300 million asthma sufferers worldwide who are plagued by debilitating bouts of coughing, wheezing, shortness of breath and tightness in the chest.

In the journal Science Translational Medicine, they describe how manipulating CaSR (calcium sensing receptor) with an existing class of drugs known as calcilytics reversed all symptoms. While the breakthrough will be welcomed by all asthma sufferers, it will particularly excite the 1 in 12 patients who do not respond to current treatments.

The study – led by Cardiff University in the UK – reveals for the first time that the calcium-sensing receptor (CaSR) plays a key role in causing the airway disease. The team used human airway tissue from asthmatic and nonasthmatic people and lab mice with asthma to reach their findings. Calcilytics block the calcium-sensing receptor and were originally developed for the treatment of osteoporosis.

One of the crucial study results is that the symptoms the drug reversed include airway narrowing, airway twitchiness and inflammation – all of which make breathing more difficult. Daniela Riccardi, principal investigator and a professor in Cardiff’s School of Biosciences, describes their findings as “incredibly exciting,” because for the first time they have linked airway inflammation – which can be triggered for example by cigarette smoke and car fumes – with airway twitchiness. She adds: “Our paper shows how these triggers release chemicals that activate CaSR in airway tissue and drive asthma symptoms like airway twitchiness, inflammation, and narrowing. Using calcilytics, nebulized directly into the lungs, we show that it is possible to deactivate CaSR and prevent all of these symptoms.”

The researchers believe their findings about the role of CaSR in airway tissue could have important implications for other respiratory conditions such as chronic obstructive pulmonary disease (COPD), chronic bronchitis. There are currently no cure for these diseases, which predictions suggest will be the third biggest killers worldwide by 2020.

Asthma UK, the Cardiff Partnership Fund and the Biotechnology and Biological Sciences Research Council (BBSRC) helped finance the study.