Serum Procalcitonin in Diagnosis of Bacteremia
Ubonvan Jongwutiwes MD*, Klairung Suitharak MD**, Surapee Tiengrim MSc***, Visanu Thamlikitkul MD***
Affiliation : * Department of Internal Medicine, University of Minnesota, Minneapolis, USA ** Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Division of Infectious Diseases and Tropical Medicine, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Objective : To (a) determine the diagnostic value of procalcitonin (PCT) in differentiating sepsis with or
without bacteremia, (b) evaluate the correlation of PCT levels to severity of sepsis, (c) establish the prognostic
value in predicting the outcome of sepsis and (d) evaluate the correlation among different assays.
Material and Method: A prospective study was carried out from August through November 2007. Blood for
PCT levels and culture were drawn simultaneously.
Results : Fifty-six patients with clinical suspicious of sepsis were enrolled in the study; bacteremia (n = 30)
and non-bacteremia (n = 26). There were good correlations between the PCT levels measured by three assays
(p < 0.001). At the threshold of 0.5 ng/mL, PCT had > 90% sensitivity for diagnosis of bacteremia. Of the
bacteremic group, median PCT levels measured by Kryptor and VIDAS assays were 12.4 and 16.6 ng/mL
respectively. In the non-bacteremic group, median PCT levels measured by Kryptor and VIDAS were 4.2 and
4.9 ng/mL respectively. PCT levels were significantly higher in the bacteremic group (p = 0.04). The optimum
thresholds to discriminate between these two groups were found to be 5, 6.5 and 2 ng/mL for Kryptor, VIDAS
and PCT-Q, respectively. In addition, correlations of PCT and increasing values of the APACHE II score were
observed. PCT levels in the severe sepsis and MOD group were also found to be significantly higher.
Conclusion : PCT was highly sensitive in detecting bacteremia, although not very accurate in differentiating
bacteremic from non-bacteremic SIRS in adult patients.
Keywords : Bacteremia, Calcitonin, Procalcitonin, Protein precursors, Sepsis, Systemic inflammatory response syndrome
