Diagnostic derivation and verification trial on biomarkers for ventilator-associated pneumonia

The aim of this national collaboration is to derive and verify diagnostic biomarkers for ventilator-associated pneumonia (VAP). VAP is frequently faulty diagnosed, which leads to wrong treatment or unnecessary broad-spectrum antibiotic treatment. No existing biomarker has sufficient sensitivity and specificity to aid in the diagnosis.

Patients with expected need for mechanical ventilation for more than 48 hours (n=1000) will be enrolled and serially sampled from blood and the lung with blind mini-BAL. We expect that 10% of the enrolled patients will develop VAP. C ases with signs of VAP are identified and further sampled. A study cohort of 100 cases with VAP yields sufficient statistical power. Enrolled cases without VAP are controls.

The primary aim is to verify HBP and IL26 as diagnostic biomarkers for VAP. Specificity and sensitivity will be calculated and ROC curves generated. Demographic and clinical data will be collected from the hospital records.

For derivation of diagnostiv biomarkers for VAP, predictive biomarkers for upcoming VAP within 7 days or for antibiotic treatment failure, we will analyze the total protein content (proteome), the composition of the bacterial community (microbiome) and the bacterial gene expression (transcriptome). We expect the patient recruitment to be ongoing for 2 years.