Sterols in asthma

Among patients with asthma, those with severe asthma have difficult to control symptoms that can be life threatening. Type 17/neutrophilic infiltration is often observed in severe asthma and is associated with lack of responsiveness to currently available treatments. Sterols and oxysterols promote the differentiation of Th17 lymphocytes that promote neutrophilic inflammation associated with severe asthma. Although statin clinical trials largely show no benefit, large population studies show protection against severe symptoms. We propose that statins may provide a therapeutic opportunity for patients with severe asthma endotypes. While sterols regulate immune processes key to the pathogenesis of asthma, inhibition of sterols with statin drugs has shown conflicting results in human asthma. Here, a novel understanding of the impact of sterols on type 17 immune responses and asthma lead us to hypothesize that sterols and statins may be relevant to severe asthma endotypes with neutrophil infiltration. While sterols regulate immune processes key to the pathogenesis of asthma, inhibition of sterols with statin drugs has shown conflicting results in human asthma. Here, a novel understanding of the impact of sterols on type 17 immune responses and asthma lead us to hypothesize that sterols and statins may be relevant to severe asthma endotypes with neutrophil infiltration.