Biomarkers in stable and acute exacerbations of COPD

Chronic Obstructive Pulmonary Disease (COPD) is a chronic disorder of airways and lung tissue that causes suffering and death and recurrent exacerbations are an important driver of progression of disease. Exacerbations are treated with antibiotics if patient report sputum purulence, but not all patients need antimicrobial treatment that in turn leads to emerging antimicrobial resistance. We tried to reduce antimicrobials for patients with exacerbations of COPD admitted to hospital, comparing two strategies - patient reported sputum purulence-guidance, or C-Reactive Protein (CRP) (cut-off ≥50 mg/l) guided antimicrobial treatment. The CRP-guided regimen resulted in a reduction of 14.5% in antimicrobial use without compromising patient safety. Additionally in a subgroup analysis we showed that eosinophilic granulocytes in blood are a risk factor for recurrent exacerbations yet their absence in peripheral blood is associated with early treatment failure. Besides we performed a Chest CT in 100 participants of the trial mentioned above. 24 patients had infiltrative changes not detected by regular chest x-ray. Although inflammatory biomarkers where increased in patients with changes on chest CT, they were not able to reliable predict these changes.
In our second trial investigated the anti-inflammatory properties of doxycycline in patients with stable COPD. We performed a double blind randomized controlled trial investigating the effect of a 3-week course of doxycycline on sputum and systemic inflammatory parameters in stable COPD. Doxycycline did not influence sputum inflammatory markers nor did it influence systemic inflammation.