Asthma is a heterogeneous disease with varying degrees of airway inflammation and variable response to treatment with inhaled corticosteroids. Woodruff and Arron describe experiments to develop a biomarker to detect asthma subtypes and determine which patients are likely to benefit from anti-inflammatory treatments.



In the first of these lectures, Prescott Woodruff explains that while asthma may be episodic in nature, it is a chronic disorder characterized by airway hypersensitivity and bronchial inflammation. Although asthma is a heterogeneous disease, treatment is typically based upon clinical severity rather than the underlying molecular phenotype. Woodruff describes how he and Dr. Arron and their colleagues were able to distinguish two distinct groups of asthma patients, one of with higher levels of T helper 2 cytokines and one with lower levels, by measuring specific gene expression patterns. Patients with different levels of Th2 cytokines responded differently to inhaled steroid treatment. This finding suggests that developing biomarkers that could indicate whether patients were Th2-high or low would help guide anti-inflammatory treatment.