C-reactive protein in diagnosis of community-acquired pneumonia in adult patients in primary care

The usefulness of non-specific inflammatory parameters for the diagnosis of community-acquired pneumonia ( CAP) in primary care is not settled. The aim of this study was to assess the value of serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white blood cell count (WBC) for this purpose. These inflammatory parameters, as well as the aetiological agents, were studied in 82 patients with radiologically confirmed CAP. CRP was elevated (> 5 mg/l) in 76 patients, with a median value of 65 mg/l. 25 patients had a value of over 100 mg/l. In 32 patients the CRP levels were < 50 mg/l and in 17 patients they were < 20 mg/l. ESR varied from 5 to 100 mm/h, with a median value of 53 mm/h; in 21 patients the value was < 30 mm/h. WBC varied from 4.4 to 21.4 x 10(9)/l, with a median value of 9.8 x 10(9)/l. No associations between the levels of the inflammatory parameters and the various aetiologies were found. It is concluded that the examined inflammatory parameters did not contribute notably in the routine diagnosis of CAP established by clinical measures.