“In some moderate or severe cases, figuring out which type of asthma a child has can help doctors match patients with proper treatment. But testing options have long been limited: Typically, doctors either draw blood to measure levels of immune cells or antibodies, or have children breathe into a mouthpiece to measure the nitric oxide in their breath.

However, the tests aren’t always accurate, and they only detect T2-high asthma, and thus can’t differentiate between other subtypes.

So researchers at the University of Pittsburgh developed a more precise way to diagnose different asthma subtypes: collecting nasal swabs, then sequencing the RNA they contain. In people with two of the asthma subtypes, certain genes associated with inflammation are more highly expressed, so the researchers looked for those hallmarks. The third subtype was identified through the absence of those genetic hallmarks…

The analysis showed that the nasal swabs could accurately diagnose several asthma subtypes.”

From NBC News.