Diagnostic markers of infection: comparison of procalcitonin with C reactive protein and leucocyte count

Abstract

Background-Procalcitonin has been advocated as a marker of bacterial infection.Objective-To evaluate diagnostic markers of infection in critically ill children, comparing procalcitonin with C reactive protein and leucocyte count in a paediatric intensive care unit (PICU). Methods-Procalcitonin, C reactive protein, and leucocyte count were measured in 175 children, median age 16 months, on admission to the PICU. Patients were classified as: non-infected controls (43); viral infection (14); localised bacterial infection without shock (25); bacterial meningitis/encephalitis (10); or septic shock (77). Six children with "presumed septic shock" (without suYcient evidence of infection) were analysed separately. Optimum sensitivity, specificity, predictive values, and area under the receiver operating characteristic (ROC) curve were evaluated. Results-Admission procalcitonin was significantly higher in children with septic shock (median 94.6; range 3.3-759.8 ng/ ml), compared with localised bacterial infection (2.9; 0-24.3 ng/ml), viral infection (0.8; 0-4.4 ng/ml), and non-infected controls (0; 0-4.9 ng/ml). Children with bacterial meningitis had a median procalcitonin of 25.5 (7.2-118.4 ng/ml). Area under the ROC curve was 0.96 for procalcitonin, 0.83 for C reactive protein, and 0.51 for leucocyte count. Cut oV concentrations for optimum prediction of septic shock were: procalcitonin > 20 ng/ml and C reactive protein > 50 mg/litre. A procalcitonin concentration > 2 ng/ml identified all patients with bacterial meningitis or septic shock. Conclusion-In critically ill children the admission procalcitonin concentration is a better diagnostic marker of infection than C reactive protein or leucocyte count. A procalcitonin concentration of 2 ng/ml might be useful in diVerentiating severe bacterial disease in infants and children. (Arch Dis Child 1999;81:417-421)

Comparison of serum amyloid A concentrations with those of C-reactive protein and procalcitonin in diagnosis and follow-up of neonatal sepsis in premature infants

“…In our previous study, serum PCT levels seemed to be superior to serum CRP levels in terms of early diagnosis of neonatal sepsis, in detecting the severity of the illness, and in evaluation of the response to antibiotic treatment. 25 This was similar to findings of some, 26,27 but not all 28,29 studies. Therefore, in some studies multiple comparisons were made between CRP, PCT and other cytokines such as IL-6, IL-8 and tumor necrosis factor-a.…”

Sensitivity and specificity of serum procalcitonin level compared to leucocyte count for diagnosis of surgical site infection on patients undergoing major surgery

“…Procalcitonin is one of the applicable markers to detect bacterial infection in children and adults. 6 Plasma PCT level is comparable with specific response of bacterial infection, particularly for invasive or probably-invasive bacteria. High concentration of PCT indicates sepsis, severe sepsis or even septic shock condition.…”

“…A procalcitonin concentration of 2 ng/ mL might be useful in differentiating severe bacteri al di sease i n i nf ants and chi l dren. 6 Another study conducted in Department of Anesthesiology and Critical Care, and Department of Pharmacy, Military Hospital, Tunis University, Tunis to compare the accuracy of PCT to diagnose postoperative infection after cardiac surgery and compare it with those of C-reactive protein, white blood cell count, and interleukins 6 and 8 concluded that PCT is a valuable marker of bacterial infections after cardiac surgery. 8 This study was conducted to evaluate the sensitivity of PCT compared to leucocyte count in the diagnosis of bacterial infection after surgery in patients who underwent major surgery at Dr. Sardjito General Hospital, Yogyakarta.…”

Flow cytometric methods for prenatal and neonatal diagnosis

“…A reliable marker of infection or a set of markers that can quickly and accurately diagnose these infections using small volumes of peripheral blood could lead to faster, more effective treatment. A variety of biomarkers have been studied that include hematologic parameters such as immature/total neutrophil ratio (Rodwell et al, 1988 andBerger et al, 1995), C-reactive protein (Berger et al, 1995;Ng et al, 1997;Wagle et al, 1994;and Hatherill et al, 1999), procalcitonin (Hatherill et al, 1999;Gendrel et al, 1996), TNF-α (Ng et al, 1997), IL-1β (Ng et al, 1997), soluble IL-1ra (Küster et al, 1998), IL-2 receptor (Jurges and Henderson, 1996), IL-6 (Ng et al, 1997 andKüster et al, 1998), IL-8 (Franz et al, 1999 andBerner et al, 2000), IL-10 (van der Poll et al, 1997) and markers of complement activation (Zilow et al, 1993). Each of these markers offers some utility to the clinician during acute care of the infant, but they have yet to become a routine test for care of acutely ill infants in most settings.…”