The diagnostic value of serum levels of C-reactive protein and procalcitonin in differentiation between active pulmonary TB and CAP

C-reactive protein (CRP) and procalcitonin (PCT) levels are elevated in patients with community-acquired pneumonia (CAP), but PCT does not increase in patients with pulmonary tuberculosis (TB). To evaluate the diagnostic value of serum levels of CRP and PCT in differentiating between active pulmonary TB and CAP. The present study was carried out on 90 individuals divided into the following groups: group I included 10 control participants, group II included 40 patients with active pulmonary TB, and group III included 40 patients with CAP. Serum levels of CRP and PCT were measured. CRP was significantly increased in group III compared with groups I and II. PCT was significantly increased in group III compared with groups I and II; also, there was a significant increase in group II compared with group I. The cut-off value of CRP between group II and group III was more than 24 (mg/dl), with a sensitivity of 100%, a specificity of 70%, and that of PCT was more than 530 (pg/ml), with a sensitivity of 67% and a specificity of 97.5%. Measurements of CRP and PCT were complementary to each other to differentiate between pulmonary TB and CAP.