The plasma elimination rate and urinary secretion of procalcitonin in patients with normal and impaired renal function

Background and objective The amount of procalcitonin eliminated in the urin e and the plasma disappearance rate of procalcitonin were evaluated in pati ents with normal and impaired renal function, because patients with sepsis are a main target group for procalcitonin measurement, and these patients o ften develop renal dysfunction. Methods Elimination of procalcitonin in the urine (mug 12 h(-1)) was measur ed in 76 patients. In another 67 patients, the 50% plasma disappearance rat e (t 1/2, h) was evaluated 48 h after peak concentrations (procalcitonin >2 mug L-1). Renal function was assessed by creatinine clearance. Results Procalcitonin elimination in the urine was significantly reduced in patients with severe renal dysfunction. However, the plasma disappearance rate correlated only weakly with renal dysfunction (Spearman's rank correla tion R=-0.36, P=0.004, regression t 1/2 = 49.87-0.15 creatinine clearance). The 25% quartile and median were 25.2 h and 30.0 h in patients with normal renal function, and 36.3 h and 44.7 h in patients with severely impaired r enal function (creatinine clearance <30 mt min(-1)). Conclusions Renal elimination of procalcitonin is not a major mechanism for procalcitonin removal from the plasma. Although the plasma disappearance r ate may be prolonged up to 30-50% in some patients with renal dysfunction, clinical diagnostic decisions may not be severely influenced by this modera te prolongation of procalcitonin elimination. We conclude that procalcitoni n can be used diagnostically in patients with renal failure as well as in t hose with normal renal function.