Inflammatory biomarkers for the diagnosis, monitoring and follow-up of community-acquired pneumonia: clinical evidence and perspectives.

Community-acquired pneumonia (CAP) is defined as an infection of the alveolar or gas-exchanging portions of the lungs occurring outside the hospital, with clinical symptoms accompanied by the presence of an infiltrate in the chest radiograph. Due to the high prevalence and the large demand of healthcare resources, an accurate clinical and therapeutic decision making is crucial in patients with CAP. As such, there is increasing interest on the use of traditional and innovative biomarkers such as procalcitonin (PCT) and C-reactive protein (CRP). At variance with other traditional inflammatory and innovative biomarkers, PCT might help limiting unnecessary antibiotic use, reduce bacterial resistance and decrease medical costs and drug-related adverse events. PCT however carries some additional advantages over CRP, such as the greater specificity for infections and a more narrow range of normal concentrations.