We hypothesize that there is a statistically significant difference in miRNA profiling and expression of subjects with asthma upon its exacerbation compared to patient's baseline level or following effective treatment of an exacerbation of asthma. Therefore, plasma miRNA profiling may provide noninvasive, highly specific and sensitive biomarkers for asthma exacerbation's detection and treatment follow-up.

Inclusion Criteria:

• Literacy: The subject must be able to read and comprehend English. Consent: The subject must have the ability to give informed consent. Type of subject: The subject must be seen in the outpatient setting at one of the clinics staffed by faculty members of the Division of Allergy and Immunology, Department of Internal Medicine, University of South Florida College of Medicine.
• Asthma: The subject must have a history of physician diagnosed asthma for at least 1 year and must have a current exacerbation of asthma requiring oral glucocorticosteroids. Asthma exacerbation is defined below.

Asthma exacerbation (relapse or de novo) is defined as either:

1. An increase of asthma symptoms (cough, wheeze, chest tightness, and /or shortness of breath) that does not resolve within 2 hours after the use of rescue albuterol or corticosteroids and requires a medical visit or
2. During a scheduled visit, the subject has acute worsening of asthma symptoms and a reduction of >20% in peak flow, which in the opinion of the investigator requires treatment with oral glucocorticosteroids.

Exclusion Criteria:

• Females who are pregnant or lactating.
• Any other coexistent lung disease (COPD, interstitial lung disease, allergic bronchopulmonary aspergillosis, TB, sarcoidosis).
• Any clinically significant, uncontrolled condition or disease state that, in the opinion of the investigator, would put the safety of the subject at risk through study participation or would confound the interpretation of the results if the condition/disease exacerbates during the study. The list of conditions/diseases that will result in exclusion if determined to be clinically significant includes, but is not limited to: uncontrolled hypertension; hematological, hepatic, neurological, thyroid, peptic ulcer, or renal disease; immunologic compromise; current malignancy.
• Past or current use of tobacco (<10 pack year smoking history and no smoking within the last 5 years).

Both genders of any racial or ethnic group, age 5-85 are eligible. The subjects should not have participated in any other experimental study in the last 30 days.