A faulty immune reaction - where the body reacts to non-existent parasites - could trigger asthma, a study suggests. Yale University scientists found high levels of an enzyme called chitinase, produced by the immune system, soar in mice with asthma-like disease. The enzyme is linked to parasites because it breaks down chitin, found on the surfaces of parasites and insects. Writing in Science, the researchers say their findings may lead to new ways of treating asthma.
