Clinical significance of serum procalcitonin in patients with community-acquired lobar pneumonia.

BACKGROUND Community-acquired pneumonia (CAP) is a common respiratory disorder in children, which necessitates hospitalization. Bacterial pneumonia, especially lobar pneumonia and parapneumonic effusions, is associated with considerably severe clinical course and extensive alveolar infiltrates. Serum procalcitonin (PCT) level has been used to distinguish bacterial from viral infections, but its usefulness is disputed. The diagnostic accuracy and usefulness of PCT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count were determined by comparing their values in the patients with CAP with those in healthy controls. METHODS The serum PCT levels, as well as CRP level, ESR, and WBC counts, were measured in 76 hospitalized patients with CAP (lobar pneumonia, 16; bronchopneumonia, 60) and 18 healthy controls. Serum PCT level was measured using VIDAS BRAHMS PCT (Biomerieux, France), and ROC curve analysis was performed to evaluate its diagnostic accuracy. RESULTS Serum PCT levels were higher in the patients with CAP than in healthy controls, especially in the patients with lobar pneumonia than in those with bronchopneumonia. Serum CRP level was also significantly elevated in the patients with CAP, especially in those with lobar pneumonia. The diagnostic accuracy of serum PCT level for the diagnosis of lobar pneumonia was better than those of serum CRP level and ESR. The serum PCT level was significantly correlated with the CRP level, ESR, and WBC count. CONCLUSIONS Serum PCT level was a better marker than CRP level or ESR for the diagnosis of lobar pneumonia in children with CAP.