Usefulness of acute-phase proteins in community-acquired pneumonia

BACKGROUND AND OBJECTIVE: We aimed to study the usefulness of acute-phase proteins in the evolution and microbial diagnosis of community-acquired pneumonia (CAP). PATIENTS AND METHOD: One-year prospective study of CAP. Plasma levels of C reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fibrinogen were measured on admission in all patients with CAP. RESULTS: 240 cases of CAP were included in the study. ESR was higher in patients who developed pleural effusion (p = 0.03). A value of ESR > 120 mm/h was associated with a higher likelihood of having a CAP complicated with pleural effusion (odds ratio = 3.80; 95% confidence interval, 1.37-10.49, p = 0.006). Baseline concentrations of CRP, ESR and fibrinogen were higher in patients who developed empyema. CRP and fibrinogen levels were significantly higher in patients with Legionella pneumophila pneumonia, while pneumococcal pneumonia was associated with a higher ESR value. CONCLUSIONS: Some frequently used acute-phase proteins can be useful in the prediction of pleural complications and in the approach to the etiological diagnosis of CAP.