The role of biomarkers in community-acquired pneumonia: predicting mortality and response to adjunctive therapy

Patients with community-acquired pneumonia (CAP) in the hospital setting exhibit markedly abnormal levels of various biomarkers of infection, inflammation and coagulation. CAP is a well characterized disease, relatively homogeneous and amenable to management according to defined protocols. Hence, this group of patients represents an opportunity to investigate further these biomarkers as a means of determining disease severity and identifying candidates for new therapies. Changes in biomarker levels during the course of disease may enable physicians to identify those patients who are most at risk for deterioration and progression toward severe CAP and who are in greatest need of early intervention. Subgroup analysis of the placebo-controlled OPTIMIST trial of tifacogin in severe sepsis revealed a trend toward benefit in patients with procalcitonin levels of 2 ng/ml or greater and in those with high baseline markers of activated coagulation. Biomarker studies are being undertaken as part of the ongoing CAPTIVATE study. This study includes patients with severe CAP and will compare the efficacy and safety of recombinant tissue factor pathway inhibitor (tifacogin) versus placebo. In the future it may also be possible to use genomic markers to identify patients at greatest risk for deterioration or complications.