The natural elimination rate of procalcitonin in patients with normal and impaired renal function

Objective: Procalcitonin (PCT) plasma concentrations and its kinetic can be used as a diagnostic tool in critically ill patients and patients with sepsis. Since renal dysfunction is a frequent complication in these patients, and PCT is a protein with a low molecular weight, we have measured the half-life time of PCT after peak concentrations in patients with normal and impaired renal function. We also have analyzed the influence of patients age and gender on PCT elimination kinetic. Design: Prospective clinical study. Renal dysfunction was assessed by plasma creatinine. The half-life time of PCT was evaluated 24 and 48 h after acute induction of PCT, when the focus of PCT induction has rapidly been eliminated. Setting: Intensive care unit of our University hospital, a tertiary health care institution. Patients: 69 patients were included into the study, Interventions: None, Measurements and results: The half-life-time of PCT was not significantly altered during renal dysfunction (26.1-33.1 h, 25-50 percentiles, creatinine clearance < 30 ml/min) when compared with normal renal function (22.3-28.9 h), IL neither correlated with creatinine clearance (p = 0.14), nor age (p = 0.99) or gender (p = 0.90, Pearson product-moment correlation). Conclusions: The data of the present study demonstrate that assement of PCT kinetic can also be used for diagnostic and prognostic reasons in patients with renal dysfunction. It may, however exceed 24 h also in patients with normal renal function. As to the present knowledge, renal secretion does not contribute as a main pathway to PCT elimination.