Eosinopenia in Severe COPD Exacerbation

Inclusion criteria

• Admitted to hospital with primary clinical diagnosis of exacerbation of COPD\*
• Smoking history of at least 10 pack years
• Airflow obstruction: FEV1/FVC ratio \< 0.7 confirmed on historic or inpatient spirometry
• Capacity to give informed consent to participate

Exclusion criteria

• Parasitic infection, systemic fungal infection (excluding infection limited to nails or skin), eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome or other conditions associated with a high eosinophil count#
• Active malignancy
• Maintenance oral prednisolone or other systemic steroids, anti-interleukin 5 therapy or other medication known to influence eosinophils
• Patients with poor venous access
• Investigator confirmed history of asthma
• Non-COPD related health problems which in the view of the primary investigator may compromise the conduct and completion of the study
• ADDITIONAL CRITERIA FOR THE TIME TO RECOVERY FROM EOSINOPENIA ANALYSIS ONLY
• Inclusion criteria:
• Eosinopenia on admission
• Uneventful recovery\*
• Eosinopenia on admission who do not receive a further course of systemic corticosteroids or require emergency hospital admission for an acute illness in the six weeks following admission to hospital with a severe exacerbation of COPD.