Role of C-reactive protein and procalcitonin in differentiation of tuberculosis from bacterial community acquired pneumonia.
OBJECTIVE
We investigated the utility of serum C-reactive protein (CRP) and procalcitonin (PCT) for differentiating pulmonary tuberculosis (TB) from bacterial community-acquired pneumonia (CAP) in South Korea, a country with an intermediate TB burden.


METHODS
We conducted a prospective study, enrolling 87 participants with suspected CAP in a community-based referral hospital. A clinical assessment was performed before treatment, and serum CRP and PCT were measured. The test results were compared to the final diagnoses.


RESULTS
Of the 87 patients, 57 had bacterial CAP and 30 had pulmonary TB. The median CRP concentration was 14.58 mg/dL (range, 0.30 to 36.61) in patients with bacterial CAP and 5.27 mg/dL (range, 0.24 to 13.22) in those with pulmonary TB (p<0.001). The median PCT level was 0.514 ng/mL (range, 0.01 to 27.75) with bacterial CAP and 0.029 ng/mL (range, 0.01 to 0.87) with pulmonary TB (p<0.001). No difference was detected in the discriminative values of CRP and PCT (p=0.733).


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 in areas with an intermediate prevalence of pulmonary TB.
Kang
Young Ae
YA
Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
Kwon
Sung-Youn
SY
Yoon
Ho Il
HI
Lee
Jae Ho
JH
Lee
Choon-Taek
CT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000097:blood / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000097:blood / Q000175:diagnosis*; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012720:Severity of Illness Index; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis*
C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide