Eosinophils in the Spotlight: Finding the link between obesity and asthma

How eosinophils function in different tissues during health and disease is not completely understood. On the one hand, they seem to be crucial in inflammatory disorders, which suggests that pathways related to their activation and regulation may be potential therapeutic targets. In asthma, the role of these cells is well known; however, airway inflammation owing to increased eosinophils in lung tissue in nonallergic asthma has only recently started to be in the limelight. In 'Bedside to Bench', Guy G. Brusselle, Tania Maes and Ken R. Bracke peruse the disease pathway triggering eosinophilic inflammation in nonallergic eosinophilic asthma and the potential targets that may lead to effective therapies. The authors also discuss a clinical study that highlights the need to phenotype patients using cellular and molecular markers to improve treatment responses. However, on the other hand, a recent study has also shown a homeostatic role of eosinophils in metabolism in fat tissue. In 'Bench to Bedside', Clare M. Lloyd and Sejal Saglani examine evidence that hints at the crucial role of the location of eosinophils in different tissues such as lung, where they cause inflammation, and visceral fat, where they improve glucose homeostasis. Clinical data that correlate lung tissue eosinophilia with obesity may spur new research to shed light on the role of these inflammatory cells in obese individuals with asthma and on how to improve treatments in these patients.