Ex Vivo Stimulation of Whole Blood as a Means to Determine Glucocorticoid Sensitivity to Mild-to-Moderate and Refractory Asthmatics

Inclusion criteria: To be eligible for the study, subjects must meet all of the following criteria: * Age ≥ 18 years old * Physician diagnosis of asthma confirmed through medical record documentation. * Documented history of 12% FEV1 reversibility post-bronchodilator and/or Methacholine PC 20 score of 16mg/ml or less. * Non-smoker for \> 6 months before enrollment into the trial * Less than 5 pack year smoking history defined as the average packs smoked per day multiplied by the years of active smoking. * Willing and able to adhere to the study visit schedule and other protocol-specified procedures. Exclusion criteria: Subjects meeting any of the following criteria may not be enrolled in the study: * Existence of lung disease (other than asthma) * Recent asthma exacerbation requiring hospital admissions, unexpected healthcare visits, or prednisone courses in the previous 4 weeks. * Non-English speaking. * Participation in another interventional research trial * Self-reported pregnancy * Inability or unwillingness to provide consent * Febrile illness (\>38.0˚ C or 100.4˚ F) within 24 hours of visit.