Diagnostic and prognostic performances of serum procalcitonin in patients with bloodstream infections: A parallel, case-control study comprising adults and elderly.

Abstract

To examine the diagnostic and prognostic performances of serum procalcitonin (PCT) in adult and elderly patients with bloodstream infections (BSIs).A total of 176 patients with culture-proven BSIs and 200 healthy counterparts were studied prospectively. Participants were studied in two adult (age?65 years, n=92) and elderly (age>65 years, n=84) groups. Admission serum PCT level was measured using a standard enzyme-linked immunosorbent assay (ELISA) technique.The mean serum PCT level (in ng/mL) was significantly higher in cases than in controls (0.18 vs. 0.07, p=0.01 in adults; 0.20 vs. 0.07, p=0.002 in elderly). At cut-off values of 0.09 ng/mL in adults and 0.08 ng/mL in the elderly, the corresponding sensitivity and specificity were 82.6 and 82.0% in adults, and 69.1 and 70.0% in elderly, respectively. At a cut-off value of 0.2 ng/mL, the sensitivity and specificity of serum PCT in predicting 28-day mortality were 81 and 81.7% in adults, and 75 and 80.4% in elderly, respectively.Although admission serum PCT is a sensitive and specific biomarker for the diagnosis of BSIs in patients younger than 65 years old, its short-term prognostic value is comparable between adults and the elderly.