Increased circulating procalcitonin concentration 2019-02-14T10:46:33Z An elevated concentration of procalcitonin in the blood circulation. Procalcitonin is a 116 amino acid peptide that has an approximate MW of 14.5 kDa and belongs to the calcitonin (CT) superfamily of peptides. It can be divided into 3 sections including the amino terminus of the PCT region, immature calcitonin, and calcitonin carboxyl-terminus peptide-1 (CCP-1). Procalcitonin is encoded by CALC-1 gene located on chromosome 11. Cleavage in 1 site of the primary transcript of CALC-1 gene produces pre-PCT, which further undergoes proteolytic cleavage of its signal sequence to produce PCT. The synthesized PCT then undergoes post-translational processing to produce small peptides and mature CT. PCT is a biomarker that exhibits greater specificity than other proinflammatory markers (eg, cytokines) in identifying patients with sepsis and can be used in the diagnosis of bacterial infections. The short half-life (25-30 hours in plasma) of PCT, coupled with its virtual absence in health and specificity for bacterial infections, gives it a clear advantage over the other markers of bacterial infection. Increased circulating procalcitonin level Abnormal circulating calcium-phosphate regulating hormone concentration