LONDON: British scientists have identified a sequence of biological events that could trigger life-threatening asthma attacks in people suffering from colds - a finding that holds the potential for developing more effective medicines. In a study published in the journal Science Translational Medicine, the researchers found that a small molecule, or ‘cytokine’, called IL-25 may play a central role in the effect that viruses causing colds have on people with asthma. According to the World Health Organisation, 235 million people suffer from asthma worldwide and the condition is the most common chronic disease among children. Viruses that infect the airways are the most common cause of asthma attacks, accounting for 80 to 90 percent of cases. Most of these are rhinoviruses, which are also the main cause of common colds.–Reuters