Asthma Subtypes Discovery Could Lead to New Treatment Methods

New research has identified 3 distinct subsets of patients with severe asthma, a discovery that could lead to the development of new biologic therapies to target the specific inflammatory responses in individual patients.

Previous research into the efficacy of biological therapies targeting T helper 2 (Th2) cells—the cells responsible for inappropriate immune response to environmental stimuli in patients with severe asthma—revealed that only half of the patients showed Th2 inflammatory responses.

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In their recent study, researchers were able to identify 3 distinct subsets of severe asthma: those with Th2 inflammatory response, those with T helper 17 (Th17) inflammatory responses, and those with neither.

Interestingly, researchers noted that all patients with Th17 responses had been previously exposed to steroids, suggesting that steroids, by inhibiting the Th2 pathway, may promote Th17 inflammation.

Later studies using a mouse model of severe asthma confirmed that inhibiting one inflammatory response encouraged the other.  By suppressing both inflammatory responses at once, researchers were able to suppress the infmammation in the mice more than by simply targeting 1 at a time.

Further research is needed to discover whether treating both pathways could improve outcomes in patients unaffected by biological therapies that target the Th2 reactions alone, according to researchers.

—Michael Potts


Choy DF, Hart KM, Borthwick LA, et al. TH2 and TH17 inflammatory pathways are reciprocally regulated in asthma. Science Translational Medicine. 2015;7(301):301ral29