Elevated calcitonin precursor levels are related to mortality in an animalmodel of sepsis

Background: Increased serum levels of procalcitonin (ProCT) and its compone nt peptides have been reported in humans with sepsis. Using a hamster model of bacterial peritonitis, we investigated whether serum ProCT levels are e levated and correlate with mortality and hypocalcemia. Results: Incremental increases in doses of bacteria resulted in proportiona l increases in 72 h mortality rates (0, 20, 70, and 100%) as well as increa ses in serum total immunoreactive calcitonin (iCT) levels at 12 h (250, 380 , 1960, and 4020 pg/ml, respectively, vs control levels of 21 pg/ml). Gel f iltration studies revealed that ProCT was the predominant (>90%) molecular form of serum iCT secreted. In the metabolic experiments, total iCT peaked at 12 h concurrent with the maximal decrease in serum calcium. Conclusions: In this animal model, hyper-procalcitoninemia was an early sys temic marker of sepsis which correlated closely with mortality and had an i nverse correlation with serum calcium levels.