IL-33 blockade in asthma: a story of hype, hope and hindsight

Extract Interest in the role of interleukin (IL)-33 in asthma was sparked by genome-wide association studies linking IL-33 genetic variants with blood eosinophil counts and different asthma phenotypes [1, 2]. Both coding and non-coding IL-33 variants have been associated with protection from or risk for asthma [3, 4], but the exact mechanisms linking IL-33 with airway inflammation and hyperreactivity remain elusive. The discovery that IL-33, a member of the IL-1 cytokine family, was a ligand for IL-1R1 (ST2) and induced cytokine gene expression from T helper 2 (Th2) cells was a major advance [5].