Changes in Gene Transcription and Immunophenotypes Following Mepolizumab Treatment for Asthma

Inclusion criteria

• Age ≥ 18 years old.
• Diagnosis of SEA by a health care provider
• History of an absolute eosinophil count ≥ 300/mm^3
• Prescription for mepolizumab provided during course of routine clinical care but mepolizumab not yet started

Exclusion criteria

• Age < 18 years old.
• Pregnancy.
• Currently using or have used within 3 months of the initial baseline visit any biologic or immunomodulatory therapy with the exception of #3.
• Currently using or any prior use of rituximab.
• History of upper/lower respiratory tract infection or asthma exacerbation within the previous four weeks of the first baseline visit.
• Any prior history of malignancy, autoimmune disease, or immune deficiency.
• Any other significant medical issue as determined by the principal investigator.