The discovery could lead to better therapies for ailments such as chronic bronchitis and emphysema, researchers said. These conditions can fail to respond to the most widely used treatments, glucocorticoid drugs (GCs).
The University of Edinburgh said its study shed new light on the complex biological processes that cause lung inflammation, the immune system's response to disease caused by bacterial infection.
Scientists analysed blood samples, focusing on the vital role that certain white blood cells, called neutrophils, play in fighting infection. Neutrophils normally only have a life-span of a few hours but, when they are called into action at sites of inflammation, they can survive for several days to carry out their protective functions. To do so they absorb more oxygen than usual.
But the Edinburgh scientists found that GCs could be ineffective because, at inflammation sites, there was not enough oxygen. Treatments that are less reliant on oxygen supply are therefore more likely to be effective.