Abstract
Pulmonary tuberculosis (PTB) and community-acquired pneumonia (CAP) are common causes of lower respiratory tract infections and may have similar clinical and radiological features.We investigated the utility of serum C-reactive protein (CRP) and procalcitonin (PCT) for differentiating pulmonary tuberculosis from bacterial CAP.
METHODS:We conducted a prospective study, enrolling 102 participants with suspected CAP in pulmonary department. We assessed serum PCT in consecutive patients diagnosed with pulmonary tuberculosis or community-acquired pneumonia (CAP) on admission to discriminate between PTB and CAP, and examined the value of prognostic factors in PTB.
RESULTS:
Of the patients, 72 had bacterial CAP and 30 had pulmonary TB. The median age of the bacterial CAP and pulmonary TB groups was 43,58years (range, 18 to 81) and 47,88 years (range, 25 to 67), respectively.
The median CRP concentration was 138,36mg/L (range 44to 486) in patients with bacterial CAP and 43,39 mg/L (range, 7 to 156) in those with pulmonary TB (p<0.001). The median PCT level was 6,65 ng/mL (range, 0.05 to 27.47) with bacterial CAP and 0.215 ng/mL (range, 0.05 to 1,27) with pulmonary TB (p<0.001).). Pulmonary TB patients had significantly lower
WBC count than CAP patients (6908 versus 15076 cells/ml-1; p<0.01) No difference was detected in the discriminative values of CRP and PCT.
CONCLUSIONS:
The concentrations of CRP and PCT differed significantly in patients with pulmonary TB and bacterial CAP. The high sensitivity and negative predictive value for differentiating pulmonary TB from bacterial CAP suggest a supplementary role of CRP and PCT in the diagnostic exclusion of pulmonary TB from bacterial CAP.
- © 2014 ERS