Negative predictive value of serum-Procalcitonin (PCT) for active tuberculosis

Background: Procalcitonin (PCT) is a precursor peptide for calcitonin. Beside thyroid tissue the most important sources for PCT are lung and liver parenchyma, kidney tissue and skeletal muscles. While PCT is released by neutrophils it proved to be an excellent marker for bacterial pulmonary infections. In patients with inflammatory pulmonary infiltrates mycobacterial infection should always be considered as one of the differential diagnosis. As defence mechanisms against mycobacteria are lymphocyte driven elevated serum levels of procalcitonin may not to be expected. Hypothesis: PCT levels are significantly lowe…