Procalcitonin as an Acute Phase Marker

Abstract

Procalcitonin is a 14-kDa protein encoded by the Calc-I gene along with calcitonin and katacalcin. The function and regulation of this protein are quite different from those of the other gene products. Blood concentrations of procalcitonin are increased in systemic inflammation, especially when this is caused by bacterial infection. Studies of its behaviour in patients with bacterial sepsis have led to the proposal that it may be a useful marker of systemic bacterial infection, with greater specificity and sensitivity than acute phase proteins such as C-reactive protein.

Role of Procalcitonin in Infectious Gastroenteritis and Inflammatory Bowel Disease

“…Procalcitonin level was measured using an immunofluorescent assay (PCT-sensitive Kryptor; Brahms Diagnostica, Germany) with a lowest detection limit of 0.04 ng/ml. Based on prior studies, the normal value for PCT was defined as \0.5 ng/ml, with a cut-point C0.5 ng/ ml being indicative of bacterial sepsis [17]. The normal limits for other inflammatory variables based on our laboratory reference were: CRP \0.2 mg/l, ESR \15 mm/h, TWC 4-10 9 10 9 /l, and platelet count 150-450 910 9 /l.…”

“…It has been found to be an excellent marker of bacterial infection in patients in post-surgical and intensive care settings as well as neonatal patients with sepsis [16,17]. Procalcitonin has obvious advantages as an inflammatory marker because it is stable, and the test is relatively easy to perform, with a rapid turn-around time of 2 h for results [18].…”

Calcitonin gene related peptide and N-procalcitonin modulate CD11b upregulation in lipopolysaccharide activated monocytes and neutrophils

“…These different effects might explain why neutralization of PCT increased survival in an animal model of sepsis [44]. Given the time-courses after endotoxin, TNF or OKT3 antibodies injections [16,17,18,19,45] where PCT peaks followed (or were induced by) high TNF levels, PCT is likely released in response to an elevation in inflammatory cytokines. In addition, its synthesis after endotoxin administration in humans is modulated when soluble TNF receptors are given before LPS injection [46].…”

“…Of these peptides PCT has been the most studied in clinical situations, and there is now a growing body of works supporting its use [7,15]. Nevertheless, much remains to be learned and widespread adoption of PCT in monitoring septic patients would be premature since we are lacking fundamental data about PCT, and because well-designed multicenter studies have yet not been conducted [16]. Increased PCT has also been reported independently of any bacterial stimulus in clinical situations in which tumor necrosis factor-α (TNF) is massively released [16,17].…”

“…Nevertheless, much remains to be learned and widespread adoption of PCT in monitoring septic patients would be premature since we are lacking fundamental data about PCT, and because well-designed multicenter studies have yet not been conducted [16]. Increased PCT has also been reported independently of any bacterial stimulus in clinical situations in which tumor necrosis factor-α (TNF) is massively released [16,17]. On the basis of these observations some authors have demonstrated that the elevated serum levels of PCT are directly induced by TNF [18,19].…”