BACKGROUND:
Bacteremia is a
life-threatening
infection, and
prognosis is highly dependent on early recognition and
treatment with appropriate
antimicrobial agents. We investigated the diagnostic performance of
serum procalcitonin (PCT) for differentiation between contaminants and true pathogens in
blood cultures.
METHODS:
Serum PCT,
C-reactive protein (CRP) and
blood culture were performed for 473
patients between February 2008 and October 2008. We retrospectively reviewed the
patients' clinical characteristics and
laboratory results based on
medical records.
RESULTS:
The mean concentration of PCT was significantly different between the two negative and positive
blood culture groups (6.45 ng/mL vs 28.77 ng/mL, P<0.001).
Procalcitonin levels were found to be markedly higher in those with Gram-negative bacilli (mean+/-SD; 59.58+/-67.00 ng/mL)
bacteremia than in those with
Gram-positive cocci (mean+/-SD; 17.75+/-42.88 ng/mL)
bacteremia (P<0.001). The areas under the
receiver operating characteristic curves (95%
confidence interval) for PCT and CRP were 0.880 (0.820~0.940) and 0.637 (0.538~0.736), respectively. The use of a PCT level of 2 ng/mL as a cutoff value yielded an 83.6%
positive predictive value and a 77.4%
negative predictive value for the
detection of
bacteremia pathogens.
CONCLUSION:
Serum PCT is a helpful diagnostic marker for rapidly and accurately distinguishing between contaminants and pathogens in
blood cultures.