The pathophysiology of the adrenal insufficiency of patients with critical diseases remains unclear. In a prior exploratory study investigating patients with exacerbation of chronic obstructive pulmonary disease (COPD), the investigators demonstrated a highly significant correlation between the expression level of Defensin-alpha 4 (DEFA4) mRNA in blood and the adrenal function assessed via low-dose ACTH tests. The aim of this prospective study is to demonstrate that DEFA4 measured both at the mRNA level (RT-PCR) and at the protein level (Western blot/Elisa) is a reliable biomarker for the prediction of adrenal insufficiency in inflammatory lung diseases (patients with COPD and pneumonia).

Inclusion Criteria:

• Patients 18-80 yo
• Patients diagnosed with pneumonia or exacerbated COPD
• Healthy controls 18-80yo
• Signed informed consent

Exclusion Criteria:

• Pregnant or lactating females
• Life threatening severe disease
• Known primary or secondary adrenal insufficiency
• Systemic steroid therapy in the last 8 weeks
• Systemic therapy with opioid
• Systemic therapy with Ketoconazol, Mitotane, Metopyron, Etomidat, Rifampicin
• In healthy controls: relevant respiratory disease or known adrenal insufficiency or indication of infection
• Allergic reaction to ACTH
• Missing informed consent

Pneumonia patients (n=30) COPD patients (n=30) Healthy controls (n=15)