calca-protein--human and Gram-Positive-Bacterial-Infections

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.. A prospective study was carried out from August through November 2007. Blood for PCT levels and culture were drawn simultaneously.. 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. PCT was highly sensitive in detecting bacteremia, although not very accurate in differentiating bacteremic from non-bacteremic SIRS in adult patients.

Topics: Adult; Aged; Bacteremia; Calcitonin; Calcitonin Gene-Related Peptide; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Predictive Value of Tests; Protein Precursors; Severity of Illness Index; Treatment Outcome

Sepsis is among the most common causes of death in hospitalized patients, and early recognition followed by immediate initiation of therapy is an important concept to improve survival in these patients. According to the definition of sepsis, diagnosis of sepsis requires the recognition of the systemic inflammatory response syndrome (SIRS) caused by infection as well as recognition of possible infection-related organ dysfunctions for diagnosis of severe sepsis or septic shock. Both SIRS and organ dysfunctions may occur frequently in hospitalized patients for various reasons. However, the fast recognition of acute infection as a cause of SIRS and newly developed organ dysfunction may be a demanding task since culture-based results of microbiological samples will be available only days after onset of symptoms. Biomarkers and PCR-based pathogen detection may help the physician in differentiating SIRS from sepsis. Procalcitonin (PCT) is the best investigated biomarker for this purpose. Furthermore, the current data support the usage of PCT for guidance of antimicrobial therapy. C-reactive protein (CRP) may be used to monitor the course of infection but has only limited discriminative capabilities. Interleukin-6 is widely used for its fast response to the infectious stimulus, but conclusive data for the application of this biomarker are missing. None of the available biomarkers can by itself reliably differentiate SIRS from sepsis but can aid and shorten the decision process. PCR-based pathogen detection can theoretically shorten the recognition of the underlying pathogen to about 8 h. However, this technique is expensive and requires additional staff in the laboratory; controlled prospective studies are missing. Although current studies suggest that PCR-based pathogen detection may be useful to shorten time to adequate antimicrobial therapy and diagnose invasive Candida infections, no general recommendations about the application of PCR for the diagnosis of sepsis can be given.

Topics: Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Gram-Positive Bacterial Infections; Humans; Immunoassay; Interleukin-6; Male; Middle Aged; Molecular Diagnostic Techniques; Polymerase Chain Reaction; Protein Precursors; Severity of Illness Index; Shock, Septic

Undernutrition causes a reduction of body-fat mass and a decrease in the circulating concentration of leptin which impairs the production of proinflammatory cytokines and increases the incidence of infectious diseases. The main objective of this study was to determine whether leptin deficiency is a risk factor for ventilator-associated pneumonia (VAP).. This prospective observational case-control study was conducted in a university ICU during a 2-year period. Patients with VAP (cases) were matched (1:1) to patients without VAP (controls) according to all the following criteria: age, gender, SAPS II, and duration of ICU stay before VAP occurrence. In all patients leptin, C-reactive protein (CRP) and procalcitonin (PCT) were measured at ICU admission, and twice a week. In addition, in cases, leptin, CRP and PCT were also measured on the day of VAP diagnosis.. Eighty-six cases were matched with 86 controls. No significant difference was found in leptin and PCT levels between cases and controls. CRP level was significantly higher on the day of VAP in cases compared with controls (99 vs. 48 mg/L, P=0.001). Combination of CRP-leptin (CRP ≥78 mg/L and leptin ≥6.2 ng/mL on the day of VAP) was significantly (P=0.009) associated with VAP in univariate analysis. Multivariate analysis identified the combination of CRP-leptin (OR [95% CI] 3.08 [1.18-8.04], P=0.003), LOD score (1.27 [1.08-1.48], P=0.003), neuromuscular-blockers use (6.6 [2.03-21.7], P=0.002), and reintubation (3.3 [1.14-9.6], P=0.027) as independent risk factors for VAP.. In our study, leptin level was not associated with VAP occurrence. Further studies are needed to confirm our results, and to define the exact inflammatory role of leptin, and its interest as a biomarker in ICU patients.

Topics: Aged; Biomarkers; Body Mass Index; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Case-Control Studies; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Hypoalbuminemia; Infection Control; Intensive Care Units; Leptin; Male; Malnutrition; Middle Aged; Pneumonia, Ventilator-Associated; Prospective Studies; Protein Precursors; Risk Factors; Sensitivity and Specificity; Ventilator Weaning

Sepsis is one of the leading causes of mortality in critically ill patients, and providing a timely diagnosis and early intervention is necessary for successful treatment. Procalcitonin (PCT) may be a better marker of sepsis than conventional inflammatory markers. The aim of this study was to evaluate the clinical utility of the PCT level as a marker of sepsis.. Forty-five patients with sepsis, 24 patients with pneumonia who did not meet the SIRS criteria (PN) and 56 controls were enrolled in this study. The levels of PCT and other serum markers were measured, and their utility as markers of sepsis was assessed.. The serum PCT levels exhibited statistically significant differences between the three groups (p<0.0001). The PCT levels in the sepsis group (29.3 ± 85.3 ng/mL) were significantly higher (p<0.001) than those observed in the PN group (0.34 ± 8.6 ng/mL) and the control group (0.74 ± 2.1 ng/mL), according to a post hoc analysis. There were no differences in the white blood cell (WBC) counts or C-reactive protein (CRP) levels between the three groups. Fourteen of the 45 patients with sepsis had positive microbiological blood cultures (Gram-positive cocci [GPC] in seven patients, Gram-negative rods [GNR] in six patients, other types of bacteria in one patient). The 13 patients with GNR or GPC were categorized into the GNR group or GPC group according to the identified pathogens. The serum PCT levels were significantly higher in the GNR group (149.8 ± 199.7 ng/mL) than in the GPC group (19.1 ± 41.8 ng/mL) (p<0.05), although there were no differences in the WBC counts or CRP levels between these groups. When the cut-off value for the PCT level was set at 16.9 ng/mL, the sensitivity and specificity for the detection of GNR infection were 85.7% and 83.3%, respectively.. The PCT level is a potentially useful marker of the type of causative pathogen in patients with sepsis whose measurement may facilitate the selection of appropriate empiric antibiotic treatment.

Topics: Aged; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Female; Follow-Up Studies; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Humans; Leukocyte Count; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Protein Precursors; Reproducibility of Results; ROC Curve; Sepsis

Procalcitonin (PCT) levels can distinguish between infectious and non-infectious systemic inflammatory response. However, there are some differences between Gram-negative (G-), Gram-positive (G+), and fungal bloodstream infections, particularly in different cytokine profiles, severity and mortality. The aim of current study was to examine whether PCT levels can serve as a distinguishing mark between G+, G-, and fungal sepsis as well. One hundred and sixty-six septic patients with positive blood cultures were examined on C-reactive protein (CRP) and PCT on the same date of blood culture evaluation. The median (interquartile range, IQR) of CRP and PCT in G+, G-, and fungal cohorts and comparison of measured values between groups were made using the Kruskal-Wallis test with subsequent Bonferroni's corrections, with p < 0.05. In 83/166 (50 %) of blood cultures, G+ microbes, 78/166 (47 %) G- rods, and 5/166 (3 %) fungi were detected. PCT concentrations (ng/ml) were significantly higher in G- compared to other cohorts: 8.90 (1.88; 32.60) in G-, 0.73 (0.22; 3.40) in G+, and 0.58 (0.35; 0.73) in fungi (p < 0.00001). CRP concentrations did not differ significantly in groups. Significantly higher PCT levels could differentiate G- sepsis from G+ and fungemia. In contrast to CRP, PCT is a good discriminative biomarker in different bloodstream infections.

Topics: Aged; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Diagnosis, Differential; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Mycoses; Protein Precursors; Retrospective Studies; Sepsis

Soluble urokinase plasminogen activator receptor (suPAR) serum concentrations have recently been described to reflect the severity status of systemic inflammation. In this study, the diagnostic accuracy of suPAR, C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) to predict bacteremia in patients with systemic inflammatory response syndrome (SIRS) was compared.. A total of 132 patients with SIRS were included. In 55 patients blood cultures had resulted positive (study group 1, Gram positive bacteria: Staphylococcus aureus and Streptococcus spp., n=15; study group 2, Gram-negative bacteria, n=40) and 77 patients had negative blood culture results (control group, n=77). Simultaneously with blood cultures suPAR, CRP, PCT, IL-6 and white blood count (WBC) were determined.. SuPAR values were significantly higher in study group 1 (median 8.11; IQR 5.78-15.53; p=0.006) and study group 2 (median 9.62; IQR 6.52-11.74; p<0.001) when compared with the control group (median 5.65; IQR 4.30-7.83). ROC curve analysis revealed an AUC of 0.726 for suPAR in differentiating SIRS patients with bacteremia from those without. The biomarkers PCT and IL-6 showed comparable results. Regarding combinations of biomarkers multiplying suPAR, PCT and IL-6 was most promising and resulted in an AUC value of 0.804. Initial suPAR serum concentrations were significantly higher (p=0.028) in patients who died within 28 days than in those who survived. No significant difference was seen for PCT, IL-6 and CRP.. In conclusion, suPAR, IL-6 and PCT may contribute to predicting bacteremia in SIRS patients.

Topics: Aged; Aged, 80 and over; Area Under Curve; Bacteremia; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Case-Control Studies; Escherichia coli; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Interleukin-6; Klebsiella; Leukocyte Count; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Protein Precursors; Receptors, Urokinase Plasminogen Activator; Reproducibility of Results; ROC Curve; Sensitivity and Specificity; Staphylococcus aureus; Systemic Inflammatory Response Syndrome

Sepsis in the early stage is a common disease in emergency medicine, and rapid diagnosis is essential. Our aim was to compare pathogen diagnosis using blood cultures (BC) and the multiplex polymerase chain reaction (PCR) test.Methods. At total of 211 patients admitted to the multidisciplinary emergency department of our university hospital between 2006 and 2009 with suspected severe infection from any origin were studied. Blood samples for BC (aerobic and anaerobic) and multiplex PCR were taken for identification of infectious microorganisms immediately after hospital admission. Results of the BC and PCR correlated with procalcitonin concentration (PCT) and clinical diagnosis of sepsis (≥2 positive SIRS criteria) as well as with severity of disease at admission and with clinical outcome measures.. Results of the BC were available in 200 patients (94.8%) and PCR were available in 119 patients (56.3%), respectively. In total, 87 BC (43.5%) were positive and identified 94 pathogens. In 45 positive PCRs, 47 pathogens (37.8%) were found. Identical results were obtained in 81.4%. In addition, BC identified 9 Gram-positive and 3 Gram-negative bacteria, while PCR added 5 Gram-negative pathogens. Coagulase-negative staphylococci were detected in blood cultures only (n=20, 21.3%), whereas PCR identified significantly more Gram-negative bacteria than BC. In patients with positive PCR results, the PCT level was significantly higher than in patients with negative PCR (15.0±23.3 vs. 8.8±32.8 ng/ml, p<0.001). This difference was not observed for BC (10.6±25.7 vs. 11.6±44.9 ng/ml, p=0.075). The APACHE II score correlated with PCR (19.2±9.1 vs. 15.8±8.9, p<0.05) and was also higher in positive BC (18.7±8.7 vs. 14.4±8.0, p<0.01). Positive PCR and BC were correlated with negative clinical outcomes (e.g., transfer to ICU, mechanical ventilation, renal replacement therapy, death).. In patients admitted with suspected severe infection, a high percentage of positive BC and PCR were observed. Positive findings in the PCR correlate with elevated levels of PCT and high APACHE II scores.

Topics: Adult; Aged; Bacterial Infections; Bacteriological Techniques; Blood; Calcitonin; Calcitonin Gene-Related Peptide; Cooperative Behavior; Culture Media; Early Diagnosis; Emergency Service, Hospital; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Interdisciplinary Communication; Male; Middle Aged; Multiplex Polymerase Chain Reaction; Mycoses; Predictive Value of Tests; Prospective Studies; Protein Precursors; Sepsis; Sleep, REM; Staphylococcal Infections

To examine the diagnostic usefulness of procalcitonin (PCT), C-reactive protein and immature to total neutrophil ratio (I : T) in nosocomial sepsis among neonates treated in an intensive care unit.. A retrospective analysis and comparison of diagnostic utility performed in preterm neonates using receiver operating characteristic curves for the diagnosis of culture-proven sepsis.. A total of 78 clinically suspected sepsis episodes in 73 newborns were analysed. The median values of PCT were: 0.56 ng/mL (interquartile range (IQR) 0.33-1.32) in group with aseptic blood culture (n = 15), 2.69 ng/mL (IQR 1.10-5.29) in Gram-positive (n = 47) and 9.36 ng/mL (IQR 3.11-39.35) in Gram-negative sepsis (n = 16). Only PCT values were significantly different (P < 0.01) among all groups. This was also true when correction for differences in blood withdrawal time was implemented. The positive and negative predictive values of PCT in the diagnosis of sepsis equalled 97.5% and 88.9%, respectively, for a cut-off value of 0.99 ng/mL. PCT was significantly better in diagnosis of sepsis than I : T (P = 0.03). No other significant differences in diagnostic efficacy were noted. The diagnostic efficacy was the highest for measurements made two or more hours since the onset of symptoms.. The PCT serum concentration is a valuable tool for early detection of nosocomial sepsis in infants. Highest levels of PCT were observed in Gram-negative infections.

Topics: C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Cross Infection; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Male; Protein Precursors; Retrospective Studies; ROC Curve; Sepsis; Time Factors

In the ICU, bacteremia is a life-threatening infection whose prognosis is highly dependent on early recognition and treatment with appropriate antibiotics. Procalcitonin levels have been shown to distinguish between bacteremia and noninfectious inflammatory states accurately and quickly in critically ill patients. However, we still do not know to what extent the magnitude of PCT elevation at the onset of bacteremia varies according to the Gram stain result.. Review of the medical records of every patient treated between May, 2004 and December, 2006 who had bacteremia caused by either Gram positive (GP) or Gram negative (GN) bacteria, and whose PCT dosage at the onset of infection was available.. 97 episodes of either GN bacteremia (n = 52) or GP bacteremia (n = 45) were included. Procalcitonin levels were found to be markedly higher in patients with GN bacteremia than in those with GP bacteremia, whereas the SOFA score value in the two groups was similar. Moreover, in the study population, a high PCT value was found to be independently associated with GN bacteremia. A PCT level of 16.0 ng/mL yielded an 83.0% positive predictive value and a 74.0% negative predictive value for GN-related bacteremia in the study cohort (AUROCC = 0.79; 95% CI, 0.71-0.88).. In a critically ill patient with clinical sepsis, GN bacteremia could be associated with higher PCT values than those found in GP bacteremia, regardless of the severity of the disease.

Topics: Adult; Aged; Bacteremia; Calcitonin; Calcitonin Gene-Related Peptide; Cohort Studies; Female; France; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Intensive Care Units; Logistic Models; Male; Medical Records; Middle Aged; Protein Precursors; ROC Curve; Treatment Outcome

Topics: Bacteremia; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Child; Child, Preschool; Diagnosis, Differential; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Infant; Male; Meningitis, Bacterial; Prognosis; Protein Precursors; Radioimmunoassay; Retrospective Studies; Sampling Studies; Sensitivity and Specificity; Severity of Illness Index

Since neutropenic patients with hematological malignancies are at high risk of contracting life-threatening infections, specific markers of infection are needed in cases of febrile neutropenia. The study presented here assessed serum concentrations of C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) in samples obtained from 31 febrile neutropenic patients. A total of 53 episodes were evaluated, and 18 of these were associated with positive blood culture results. Procalcitonin and IL-6 concentrations differed significantly between bacteremic and non-bacteremic episodes. Procalcitonin values were 0.22 ng/ml [interquartile range (IR), 0.15-1.9] for patients with pneumonia without bacteremia, 0.22 ng/ml (IR, 0.16-0.55) for patients with fever of unknown origin, 0.2 ng/ml (IR, 0.13-0.57) for patients with non-microbial fever and 1.8 ng/ml (IR, 0.35-5.3) for patients with bacteremia. The differences between bacteremic and non-bacteremic episodes had a P-value of 0.003 using the Mann-Whitney test. For IL-6 the median values were 301 pg/ml (IR, 152-1,879) for patients with pneumonia without bacteremia, 207 pg/ml (IR, 94-445) for patients with fever of unknown origin, 177 pg/ml (IR, 142-208) for patients with non-microbial fever and 942 pg/ml (IR, 181-2,807) for patients with bacteremia. Using the Mann-Whitney test, the differences between bacteremic and non-bacteremic episodes were P=0.006. No differences were found in CRP concentrations. Cutoff levels to distinguish between bacteremic and non-bacteremic episodes were chosen using receiver operating characteristic curves: 0.62 ng/ml for PCT and 297 pg/ml for IL-6. Negative predictive values were 84% for PCT and 70% for IL-6. The results indicate that PCT and IL-6 are more reliable markers than CRP for predicting bacteremia in patients with febrile neutropenia.

Topics: Adult; Aged; Analysis of Variance; Bacteremia; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Chi-Square Distribution; Cohort Studies; Female; Fever; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Hematologic Neoplasms; Humans; Interleukin-6; Male; Middle Aged; Neutropenia; Predictive Value of Tests; Probability; Prognosis; Protein Precursors; Risk Assessment; ROC Curve; Sensitivity and Specificity; Severity of Illness Index; Statistics, Nonparametric

Sensitive, reliable and early parameters of bacterial infection are extremely valuable in diagnosis of nosocomial infections in neonatal intensive care unit. In this study procalcitonin (PCT) and C-reactive protein (CRP) were evaluated for their diagnostic relevance in neonatal late onset sepsis.. Clinical study. We analysed inflammatory parameters in 48 newborn infants admitted to the Intensive Care Unit of Institute of Paediatrics in Lodz who suffered from nosocomial sepsis. They were sampled for PCT and CRP levels at the time of the onset of signs and 24 hours later. CRP was determined by an nephelometric method and PCT was determined by an immunoluminometric assay.. At the onset of Gram negative sepsis 14 from 17 contaminated newborns had significantly increased CRP levels and 15 of them had increased levels of PCT After 24 hours 100% of them had elevated PCT and CRP levels. At the onset of Gram positive sepsis only 18 from 31 neonates with positive blood culture had increased CRP levels and 28 of them had elevated concentrations of PCT. This difference was statistically significant. After 24 hours 26 of them had elevated CRP and 100% had increased PCT concentrations--this difference was not significant.. Measurement of procalcitonin concentrations may be useful for early diagnosis of late onset sepsis in neonates.

Topics: Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Infant; Infant, Newborn; Protein Precursors; Severity of Illness Index; Systemic Inflammatory Response Syndrome

Infective endocarditis especially where blood culture is negative frequently causes problems in diagnosis despite of many nonspecific inflammation parameters. Procalcitonin (PCT) concentration is a new marker of severe bacterial and fungal infection. The aim of this study was to evaluate the usefulness of PCT concentration assessment in the diagnosis of uncomplicated infective endocarditis of bacterial etiology. The study group consisted of 30 patients with ongoing infective endocarditis in the course of acquired valvular heart disease. The diagnosis of bacterial endocarditis was established according to the Duke criteria on the basis of: clinical examination, laboratory investigations (inflammatory parameters, transthoracic and transesophageal echocardiography) and positive blood cultures. Patients with sepsis, concomitant infections and in an early postoperative period were excluded. Two control groups consisted of: 10 patients without endocarditis and other infections and another 10 patients without endocarditis and with an urinary tract infection. Serum procalcitonin concentrations were measured by an immunoluminometric assay (LUMItest PCT set). Mean serum PCT concentrations in patients with endocarditis (0.12 +/- 0.13, range 0-0.4 ng/ml) were significantly higher than in control group without infection (0.03 +/- 0.05, range 0-0.1 ng/ml) and higher than in control group with an urinary tract infection (0.02 +/- 0.04, range 0-0.1 ng/ml). However in 12 patients (of 30) were below sensitivity of the method and in the rest were within normal range (< 0.5 ng/ml).. Serum PCT concentration assessment seems to have no value in the diagnosis of uncomplicated infective endocarditis.

Topics: Adult; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Case-Control Studies; Endocarditis, Bacterial; Female; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Heart Valve Diseases; Humans; Male; Middle Aged; Protein Precursors; Sensitivity and Specificity; Urinary Tract Infections

The ability of measurement of serum procalcitonin (PCT) levels to differentiate bacteremic from nonbacteremic infectious episodes in patients hospitalized for community-acquired infections was assessed. Serum samples were obtained from adult inpatients with fever to determine the serum PCT level, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). Of 165 patients, 22 (13%) had bacteremic episodes and 143 (87%) had nonbacteremic episodes. PCT levels, CRP levels, and ESRs were significantly higher in bacteremic patients than in nonbacteremic patients (P<.001,.007, and.024, respectively). The best cutoff value for PCT was 0.4 ng/mL, which was associated with a negative predictive value of 98.8%. Area under the receiver operating characteristic curve was 0.83 for PCT, which was significantly higher than that for CRP (0.68; P<.0001) and ESR (0.65; P<.05). A serum PCT level of <0.4 ng/mL accurately rules out the diagnosis of bacteremia. The use of PCT assessment could help physicians limit the number of blood cultures to be processed and the number of antibiotic prescriptions.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Bacteremia; Biomarkers; Calcitonin; Calcitonin Gene-Related Peptide; Community-Acquired Infections; Diagnosis, Differential; Female; Fever; Fever of Unknown Origin; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Male; Middle Aged; Predictive Value of Tests; Protein Precursors; Sensitivity and Specificity

We assessed the predictive value of procalcitonin (PCT) serum levels in neutropenic patients with fever and various types of infection, using a prospective 3 times weekly blood sampling protocol during 103 patient episodes. Compared with pre-fever levels, median PCT levels increased after fever onset from 0.16 ng/ml (day -1) to 0.34 ng/ml (day +1). In samples obtained within 32 h after fever onset, PCT levels differed significantly between (clinically or microbiologically) documented infection and unexplained fever (median 0.51 vs. 0.26 ng/ml), between bacteraemia and non-bacteraemic infection (median 0.8 vs. 0.27 ng/ml) and between Gram-negative bacteraemia and all other episodes (median 1.28 vs. 0.31 ng/ml). Receiver-operating-characteristic (ROC) curves indicated that the discriminatory power of PCT was best for predicting bacteraemia vs. non-bacteraemic infection (sensitivity 73%; specificity 86%; area under the ROC curve 0.795; cut-off value 0.5 ng/ml). Compared with interleukin-8 (IL-8) serum levels, test characteristics were similar in the prediction of bacteraemia vs. non-bacteraemic infection and in the prediction of documented infection vs. unexplained fever, while IL-8 was better than PCT in the prediction of Gram-negative bacteraemia (area under the ROC curve 0.965 vs. 0.758).

Topics: Adolescent; Adult; Aged; Bacteremia; Calcitonin; Calcitonin Gene-Related Peptide; Fever of Unknown Origin; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Interleukin-8; Middle Aged; Neutropenia; Predictive Value of Tests; Prospective Studies; Protein Precursors; Sensitivity and Specificity