Respiratory failure in a patient with exhaled nitric oxide >300 ppb and subsequent response to dupilumab.

Multiple biologic agents are approved for the treatment of severe persistent asthma not controlled by inhaled corticosteroid/beta-agonist therapy. Appropriate phenotyping can aid in picking the right biologic for the right patient. Here is a unique case of a patient with severe asthma and respiratory arrest, with fraction of exhaled nitric oxide >300 ppb whose asthma became completely controlled with dupilumab. KEY POINTS: Elevated fraction of exhaled nitric oxide (FeNO) levels reflect type-2 inflammation mediated by interleukin (IL)-13. Elevated FeNO levels predict enhanced response to inhaled corticosteroids as well as to dupilumab, which blocks IL-4 and IL-13 signaling. [ABSTRACT FROM AUTHOR]