Last update:
10-Dec-2008

Procalcitonin is a precursor of the hormone calcitonin, which is involved in calcium homeostasis. It is produced by the C-cells of thyroid gland where it is cleaved into calcitonin, katacalcin and a protein residue. It is not released into the blood stream of healthy individuals, but with the derangements that a severe infection with associated systemic response syndrome brings, the blood levels of procalcitonin may rise to particularly high values. In the blood procalcitonin has a half-life of 25 to 30 hours. Measurement of procalcitonin can be used as a marker of severe infections or sepsis and generally correlates well with the degree of sepsis. Procalcitonin has the greatest sensitivity (85%) and specificity (91%) for differentiating between patients with systemic inflammatory response syndrome (SIRS) and those with sepsis, when compared with IL-2, IL-6, IL-8, CRP and TNF-α. An ideal marker for bacterial infections should permit early diagnosis, provide information about the course and prognosis of the disease and facilitate therapeutic decisions. Procalcitonin covers these features better than other, more commonly used, biomarkers and thus the current enthusiasm for procalcitonin has a solid scientific basis. In spite of its advantages, the test is not used routinely and has yet to gain widespread acceptance.

Key words: Endotoxin, Infections, Procalcitonin, Sepsis, Septic shock.