The predictive value of serum procalcitonin levels in adult patients with active pulmonary tuberculosis

Jpn J Infect Dis. 2006 Jun;59(3):164-7.


The aim of our prospective study was to evaluate the predictive value of serum procalcitonin (PCT) level in comparison with C-reactive protein level and erythrocyte sedimentation rate for the diagnosis of pulmonary tuberculosis (PTB) on admission and 6 months after the administration of anti-tuberculous chemotherapy (ATCT). Seventy-five adult male patients with active PTB who were mycobacteriologically diagnosed (smear and culture positivity) were examined in this study. As a control group, 75 healthy adult males were enrolled. The measured serum PCT levels were within the normal range both in healthy individuals and in patients 6 months after ATCT. Serum PCT levels had been slightly high on admission in patients with PTB in comparison with controls (P = 0.01) and patients who had ATCT (P = 0.001), and this difference was statistically significant, but the PCT levels of most cases with PTB (58.7%) were below the usual cut-off level (0.5 ng/mL). We conclude from this study that the serum PCT level was not a reliable indicator in the diagnosis of active PTB because of its low sensitivity (41.3%), and in most cases it was not capable of overcoming the cut-off level even if statistically meaningful results were obtained. The PCT test for the presumptive diagnosis of PTB cannot be substituted for microbiological, epidemiological, clinical and radiological data.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Blood Sedimentation
  • C-Reactive Protein / metabolism
  • Calcitonin / blood*
  • Calcitonin Gene-Related Peptide
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Protein Precursors / blood*
  • Sensitivity and Specificity
  • Tuberculosis, Pulmonary / blood*


  • CALCA protein, human
  • Protein Precursors
  • Calcitonin
  • C-Reactive Protein
  • Calcitonin Gene-Related Peptide