Potential use of procalcitonin as a diagnostic criterion in febrile neutropenia: experience from a multicentre study

Association of Procalcitonin with the Patient’s Infection Characteristics and Prognosis after Hematopoietic Stem Cell Transplantation

Objective

To study whether procalcitonin (PCT) is an important indicator of infection with or without agranulocytosis and to reveal whether PCT can distinguish between infected sites and affect prognosis after hematopoietic stem cell transplantation (HSCT).

Method

In the present study, 682 patients with HSCT were enrolled, and their clinical characteristics were noted. Their blood culture and inflammatory and biochemical indicators were studied. The patients were divided into respective groups according to the degree of agranulocytosis, type of bacterial infection, infected sites, and prognosis.

Results

The PCT, CRP, and D-dimer levels were significantly improved in patients with positive blood culture results compared to the case for those with negative blood culture results. The PCT level was the highest in the gram-negative group. The levels of PCT and D-dimer were significantly elevated in patients with infection and agranulocytosis after HSCT compared to those in the nonagranulocytosis cohort. Interestingly, no significant difference in the PCT level was observed among any of the eight foci. Lower PCT levels were associated with higher survival in patients with infection after HSCT.

Conclusion

Among patients that underwent HSCT, PCT levels were significantly elevated in those with infection and agranulocytosis, with the levels being specifically high in the gram-negative group. Moreover, lower PCT levels were associated with higher survival in patients with infection after HSCT.

The Clinical Value of Procalcitonin in the Neutropenic Period After Allogeneic Hematopoietic Stem Cell Transplantation

The diagnostic value of procalcitonin and the prognostic role of PCT clearance remain unclear in neutropenic period after allogeneic hematopoietic stem cell transplantation introduction. This study evaluated 219 febrile neutropenic patients (116, retrospectively; 103, prospectively) who underwent allo-HSCT from April 2014 to March 2016. The area under the receiver operator characteristic curve (AUC) of PCT for detecting documented infection (DI) was 0.637, and that of bloodstream infection (BSI) was 0.811. In multivariate analysis, the inability to decrease PCT by more than 80% within 5–7 days after the onset of fever independently predicted poor 100-day survival following allo-HSCT (P = 0.036). Furthermore, the prognostic nomogram combining PCTc and clinical parameters showed a stable predictive performance, supported by the C-index of 0.808 and AUC of 0.813 in the primary cohort, and C-index of 0.691 and AUC of 0.697 in the validation cohort. This study demonstrated the diagnostic role of PCT in documented and bloodstream infection during the neutropenic period after allo-HSCT. PCTc might serve as a predictive indicator of post-HSCT 100-day mortality. A nomogram based on PCTc and several clinical factors effectively predicted the 100-day survival of febrile patients and may help physicians identify high-risk patients in the post-HSCT neutropenic period.

Clinical utility of procalcitonin and its association with pathogenic microorganisms

In this review, we summarize the relationship of PCT with pathogens, evaluate the clinical utility of PCT in the diagnosis of clinical diseases, condition monitoring and evaluation, and guiding medical decision-making, and explore current knowledge on the mechanisms by which pathogens cause changes in PCT levels. The lipopolysaccharides of the microorganisms stimulate cytokine production in host cells, which in turn stimulates production of serum PCT. Pathogens have different virulence mechanisms that lead to variable host inflammatory responses, and differences in the specific signal transduction pathways result in variable serum PCT concentrations. The mechanisms of signal transduction have not been fully elucidated. Further studies are necessary to ascertain the PCT fluctuation range of each pathogen. PCT levels are helpful in distinguishing between certain pathogens, in deciding if antibiotics are indicated, and in monitoring response to antibiotics.

Diagnostic Accuracy of Procalcitonin, Neutrophil-to-Lymphocyte Ratio, and C-Reactive Protein in Detection of Bacterial Infections and Prediction of Outcome in Nonneutropenic Febrile Patients with Lung Malignancy

Background

Procalcitonin (PCT), C-reactive protein (CRP), and neutrophil-to-lymphocyte ratio (NLR) have emerged as important markers of inflammation, and these markers, especially PCT and CRP, have been studied in patients with neutropenia. This study was designed to evaluate their value in differentiating infectious fever from tumor fever (TF) and to investigate their role in assessing outcomes in nonneutropenic lung cancer patients (NNLCPs).

Methods

This retrospective clinical study included 588 febrile NNLCPs between January 2019 and December 2019. The levels of PCT, CRP, and conventional inflammatory markers, including white blood cells (WBC) and neutrophils (NEU), were measured. NLR was defined as the ratio of the absolute neutrophil count to the absolute lymphocyte count. Patients' clinical and bacteriological data were recorded.

Results

This study included 311 NNLCPs with bacterial infections and 277 with TF. Inflammatory markers such as PCT, CRP, WBC, and NEU levels and NLR were significantly higher in patients with bacterial infections than in those with TF (p < 0.0001). However, PCT level was the best predictor of bacterial infections, with an area under the curve (AUC) of 0.874, followed by CRP level (AUC = 0.855) and NLR (AUC = 0.792) (p < 0.0001). Additionally, PCT level was significantly elevated in patients with bacterial infections with progressive disease after radiotherapy and chemotherapy (p < 0.01).

Conclusions

The present study demonstrated the superiority of PCT over CRP and NLR in the diagnosis of febrile patients with bacterial infections. Additionally, PCT can be used to assess the clinical outcomes and cancer progression in NNLCPs.

Procalcitonin levels among patients with fever secondary to severe intracerebral infection. A cross-sectional study

BACKGROUND

Making the differential diagnosis between central fever and infectious fever is critically important among intracerebral hemorrhage patients followed up in intensive care units (ICUs). Serum procalcitonin (PCT) has been found to be a promising biomarker for the initial diagnosis of infection, even before culturing results.

OBJECTIVES

To investigate the relationship between PCT and both fever etiologies and C-reactive protein (CRP) levels among critically ill patients with suspected intracerebral hemorrhage.

DESIGN AND SETTING

Cross-sectional study in a public university hospital in Elazig, Turkey.

METHODS

ICU patients diagnosed with intracerebral hemorrhage and normal procalcitonin levels were included in this study. From clinical assessments and cultures, they were classified as presenting either infectious or central fever. The sensitivity and specificity of PCT and CRP for predicting infection were calculated using a receiver operating characteristic (ROC) curve.

RESULTS

There were 98 ICU patients with diagnoses of intracerebral hemorrhage. The median (interquartile range) PCT levels of patients with infectious and central fever were 4 (0.9-11) and 0.1 (0.1-0.4) ng/ml, respectively, with a statistically significant intergroup difference (P < 0.001). The areas under the ROC curve for predicting infectious or central fever PCT and CRP were 0.958 (P < 0.001) and 0.816 (P < 0.001), respectively. A statistically significant positive correlation was detected between PCT and CRP levels in patients with infectious fever (rho: 0.461; P = 0.003), but not in patients with central fever.

CONCLUSIONS

PCT can possibly be used as a biomarker to differentiate between infectious and central fever among ICU patients.

Current use and potential role of procalcitonin in the diagnostic work up and follow up of febrile neutropenia in hematological patients

INTRODUCTION

Febrile neutropenia (FN) represents a life-threatening complication in hematological malignancies. Its etiology is most often due to infections even though FN of other origins, such as tumor-related fever and non-infectious inflammation, should rapidly be ruled out. Initially, C-reactive protein and, more recently, procalcitonin (PCT) have been proposed as useful biomarkers for differential diagnosis. PCT was shown to be a good biomarker of bacterial infections and their clinical outcomes. Definition of standard cut-offs and design of PCT-guided treatment protocols remain however to be defined. Areas covered: In this review, highlights on the current clinical use of PCT and its potential role as a diagnostic tool have been discussed by a panel of physicians from different areas of expertise. We provide current clinical evidence that PCT has been shown to be a reliable biomarker to differentiate fever of bacterial origin from other causes. Moreover, the Authors convened to a round-table to discuss their 'real-life experience' and offer their recommendations by a Delphi survey. Expert commentary: PCT has an important clinical role in FN. Issues such as the validation of a specific decision algorithm that includes PCT to monitor antibiotic choice and treatment duration will be addressed in prospective studies.

Comparison between procalcitonin and C-reactive protein in predicting bacteremias and confounding factors: a case-control study

Background:

The detection of infectious bacteria in blood culture samples is important for diagnosis and treatment, but this requires 1–2 days at least, and is not adequate as a rapid test. Therefore, we have investigated the diagnostic ability and the optimal cutoff value of procalcitonin (PCT) and C-reactive protein (CRP) for predicting the bacteremias using receiver operating characteristic (ROC) curves and relative cumulative frequency distribution (RCD) curves.

Methods:

A case-control study was performed in inpatients (852 subjects: 426 positive cultures and 426 negative cultures) from January 1 to December 31, 2014. We retrospectively investigated their blood culture and blood chemistry findings recorded in this period using electronic medical records.

Results:

Area under the ROC curve of PCT and CRP were 0.79 and 0.66, respectively. The optimal cutoff values were 0.5 μg/L with a sensitivity of 70% and specificity of 70% for PCT and 50.0 mg/L with a sensitivity of 63% and specificity of 65% for CRP. When the optimal cutoff value was treated as a reference, the odds ratio (OR) was 71.11 and the hazard ratio (HR) was 6.27 for PCT >2.0 μg/L, and the risk of blood culture positivity was markedly elevated. PCT levels were significantly higher in the population with Gram-negative rod (GNR) infections than in the population with Gram-positive coccal (GPC) infections.

Conclusions:

The elevation of CRP and PCT were significantly associated with bacteremias. PCT was superior to CRP as a diagnostic indicator for predicting bacteremias, for discriminating bacterial from nonbacterial infections, and for determining bacterial species.

Combinational approach using in situ hybridization targeting 23S ribosomal RNA genes and blood cultures for bacterial identification in patients with neutropenia and fever

BACKGROUND

A new 23S ribosomal RNA genes-targeted in situ hybridization (ISH) probe to detect global bacterial genomic DNA (59 species from 35 genera; referred to as the GB probe) phagocytized in leukocytes was recently developed. This method provided early and direct evidence of bacterial infection with high sensitivity and specificity in spontaneous bacterial peritonitis ascites. However, the utility of this method in febrile neutropenia (FN) is unknown.

METHODS

We prospectively evaluated the utility of the ISH approach using the GB probe and previously reported probes in patients with neutropenia and fever undergoing chemotherapy at our institution between June 2011 and July 2013. Blood samples for culture analysis and ISH tests were collected simultaneously at the onset of fever; the latter were performed repeatedly.

RESULTS

Fifty febrile episodes were evaluated. In 24 episodes of fever of unknown origin and 15 episodes of local infection (all negative for blood cultures), ISH tests identified causal bacteria in 21% and 13% of cases, respectively, at the onset of fever. In seven sepsis cases (all positive for blood culture), positive ISH test results at fever onset were achieved in 71%; for two patients with neutrophil counts of 0/μl and 171/μl, respectively, negative results were obtained.

CONCLUSIONS

This new ISH approach could prove useful for early detection of bacteria in patients with neutropenia and blood culture-negative, with fever of unknown etiology after chemotherapy. Using this method in combination with blood culture, even in cases with extremely low neutrophil counts, might contribute to better management of FN.

Diagnostic value of levels of presepsin (soluble CD14-subtype) in febrile neutropenia in patients with hematological disorders

BACKGROUND

Whether presepsin (soluble CD14-subtype) is better than other markers including procalcitonin (PCT), has not been adequately investigated in febrile neutropenia (FN).

METHODS

We prospectively examined the utility of presepsin in FN in Cohort 1 (C1) and 2 (C2), between November 2010 and February 2012, and between November 2013 and January 2014, respectively. The purpose of this study was to investigate 1) the relative value of serum presepsin over serum PCT in C1, and 2) the relative value of plasma presepsin as compared with serum PCT, C-reactive protein, interleukin-6 and interleukin-8 with frequent, repeated sampling in C2.

RESULTS

Seventy-nine FN episodes (C1, 75; C2, 4) were evaluable. In C1, when compared with control values, presepsin was significantly higher at onset of FN (P = 0.004), while PCT was not significantly higher (P = 0.54). The median value of serum presepsin within 72 h of onset of FN in subjects with fever of unknown origin, local infection, bacteremia and septic shock was 680 (reference 314) pg/ml, 763, 782 and 1359, respectively. In C2, the mean levels of plasma presepsin from onset of FN to 72 h were classified as negative in the two patients with no suspected site of infection, and those of the remaining two patients with clinically probable infections were positive (175, 131, 346 and 329 pg/ml, respectively). In contrast, the other markers did not discriminate between this two groups.

CONCLUSIONS

In FN, presepsin may be an earlier and more sensitive indicator of bacterial infection than PCT.

Procalcitonin-guided protocol is not useful to manage antibiotic therapy in febrile neutropenia: a randomized controlled trial

Febrile neutropenia (FN) requires immediate use of antibiotics (ATB), and procalcitonin (PCT) is proven to be useful in guiding antibiotic therapy in different settings. This study investigated the use of PCT as a guide for the duration of ATB in FN. A randomized controlled trial was carried out from January-December 2010. A total of 62 hematological adult patients with FN were randomized, in 1:1 ratio, into two groups: (1) PCT group: length of ATB guided by institutional protocol plus PCT dynamics, and (2) control group: duration of ATB in accordance with institutional protocol. There was no difference between groups regarding the use of ATB for the first episode of fever (HR 1.14, 95 % CI 0.66-1.95, p = 0.641), with equivalent median duration of ATB therapy (PCT group 9.0 days and control group 8.0 days, p = 0.67), and median number of days without ATB (0 days, IQR 0-2 days for both groups, p = 0.96). We observed no difference in clinical cure rate (p = 0.68), infection relapse (p = 1.0), superinfection (p = 0.85), length of hospitalization (p = 0.64), and mortality at 28 days (p = 0.39) and at 90 days (p = 0.72). Considering the cut-off of 0.5 ng/ml, PCT was correlated with bacteremia (sensitivity of 51.9 % and specificity of 76.5 %). In this randomized controlled trial, adding a PCT-guided protocol to the standard recommendations did not reduce the use of antibiotics in febrile neutropenia, although no apparent harm was caused. PCT proved to be a marker of bacteremia in this setting.

Role of Biomarkers as Predictors of Infection and Death in Neutropenic Febrile Patients after Hematopoietic Stem Cell Transplantation

An ideal marker in the neutropenic population after HSCT is the one which positivetes at the onset of fever, or at most up to 24 hours after its onset, the patients at potential risk for infection due to bacterial and fungi and mortality. Several biomarkers have been used in HSCT patients in the last decade. However, it seems that C-RP and Il-6 are the most useful markers to early detected infection and risk for death

Procalcitonin and C-reactive protein in differantiating to contamination from bacteremia

Procalcitonin (PCT) and C-reactive protein (CRP) are important biological markers used in the diagnosis of severe infections. The aim of this study was to evaluate the consistency of blood culture with PCT and CRP in differentiating contamination and non-bacteremia from true bacteremia. In this study blood samples were obtained from 809 febrile patients and analyzed using BACTEC 9120 system. All of positive blood cultures were performed Gram staining. The microorganisms were identified with conventional methods and automated systems. Antibiotic susceptibility tests were made by disc diffusion. PCT levels were analyzed by mini VIDAS device and PCT kit. PCT and CRP levels were analyzed with blood cultures in same times. Kruskal Wallis test, Mann-Whitney U test, Spearman’s rho test and ROC curve were used for statistical analyses. The bacteremia group was found to be significantly different from non-bacteremia group and contamination group in terms of both PCT and CRP (p<0.0001). The p values of PCT and CRP in differentiating bacteremia from non-bacteremia were p<0.001 for PCT, p=0.002 for CRP and in differentiating bacteremia from contamination were p<0.001 for PCT, p<0.001 for CRP. PCT is a more useful marker than CRP in the differentiating of true bacteremia from contamination according to the results of this study.

Does procalcitonin, C-reactive protein, or interleukin-6 test have a role in the diagnosis of severe infection in patients with febrile neutropenia? A systematic review and meta-analysis

PURPOSE

The study aims to determine the usefulness of procalcitonin (PCT) and other blood markers for identification of bacterial infection among patients with febrile neutropenia (FN).

METHODS

The Medline, EMBASE, and Cochrane databases were searched for articles from 1966 to December 2012. We performed a search to identify articles that examined the diagnostic accuracy of PCT in patients with FN. Statistical analyses (fixed- or random-effect models) were conducted to summarize and calculate the sensitivity, specificity, likelihood ratios, and 95 % confidence intervals (CIs).

RESULTS

Twenty-seven studies were included (1960 febrile episodes) for PCT analysis, 13 (1712 febrile episodes) for C-reactive protein (CRP) analysis, and five (314 febrile episodes) for interleukin (IL)-6 analysis. Increased PCT levels (odds ratio [OR] 11.5; 95 % CI 7.6 to 17.3), raised CRP levels (3.3; 2.7 to 4.2), and raised IL-6 levels (10.0; 5.5 to 18.0) were significantly associated with bacterial infection. Overall positive likelihood ratio was 5.49 (4.04-7.45) for PCT, 1.82 (1.42-2.33) for CRP, and 3.68 (2.41-5.60) for IL-6. Overall negative likelihood ratio was 0.40 (0.31-0.51) for PCT, 0.40 (0.26-0.61) for CRP, and 0.33 (0.23-0.46) for IL-6.

CONCLUSIONS

Of the three potentially useful markers, PCT had the best positive likelihood ratio and can be used to confirm the diagnosis of bacterial infections in patients with FN. Due to unacceptably high negative likelihood ratio, medical decision for stopping antibiotics based on PCT alone in this high-risk population may not be possible.

Do proinflammatory cytokine levels predict serious complication risk of infection in pediatric cancer patients?

Determination of risk of severe bacterial infection complication in children with cancer is important to diminish the cost of hospitalization and therapy. In this study, children with cancer (leukemia excluded) were evaluated for risk of severe infection complication, success of therapy and the relation between clinical and inflammatory parameters during neutropenic fever attacks. Children who fulfilled the criteria of neutropenic fever with cancer were enrolled in the study. During admission, together with clinical and laboratory parameters; interleukin-6, interleukin-8, soluble tumor necrosis factor receptor II, and soluble interleukin 2 reseptor ve procalcitonin levels were detected. Empirical therapy was started with piperacillin/tazobactam and relation between the inflammatory cytokine levels and therapy response parameters were evaluated. The study population included 31 children and 50 neutropenic attacks were studied. In 48% of the attacks, absolute neutrophile count was >100/mm(3) and infectious agents were shown microbiologically in 12% of the attacks. In the study group with piperacillin/tazobactam monotherapy, the success rate without modification was 58%. In the therapy modified group mean duration of fever, antibiotherapy and hospitalization were significantly longer than the group without modification. Inflammatory cytokines' levels during admission (interleukin-6, interleukin-8, soluble tumor necrosis factor reseptor II) were higher in patients with fever >3 days and in multiple regression analysis, it has been shown that they have a determinative role on fever control time. Other cytokines did not show any significant relationship with risk of severe bacterial infection complication and success of therapy.

Diagnostic performance of serum high-sensitivity procalcitonin and serum C-reactive protein tests for detecting bacterial infection in febrile neutropenia

PURPOSE

Although a few prospective studies have addressed the question as to which biomarker of infection in adult patients with febrile neutropenia (FN) is superior, procalcitonin (PCT) or C-reactive protein (CRP), the results have been inconsistent and inconclusive. This was possibly due to the poor sensitivity of previous PCT tests that have a functional sensitivity of 0.5 ng/ml.

METHODS

Between November 2010 and February 2012, we prospectively compared the diagnostic utility of serum high-sensitivity (hs) PCT (lower limit of detection, 0.02 ng/ml) and CRP levels for detecting bacterial infection in patients with FN. Serum was collected within 72 h after the onset of FN in patients with hematological disorders.

RESULTS

Seventy-five febrile episodes were evaluable. The areas under the receiver operating characteristic curves for life-threatening infection defined as septic shock and bacteremia caused by non-coagulase negative staphylococcus were 0.824 (95% CI 0.711-0.937; P = 0.001) for hsPCT and 0.673 (0.505-0.842; P = 0.068) for CRP, respectively. In contrast, CRP, but not hsPCT, tended to increase significantly with the clinical severity, as indicated by the diagnostic classification (P = 0.002 for trend).

CONCLUSIONS

The serum hsPCT test may be more useful than the serum CRP test in the detection of life-threatening infection at an early phase after the onset of FN. In contrast, the serum CRP test may be more useful in diagnosing the severity of infection. However, neither of these tests was able to differentiate the cause of FN with a low probability of fatal outcome.

Procalcitonin as a prognostic marker for sepsis: a prospective observational study

Background

Procalcitonin is useful for the diagnosis of sepsis but its prognostic value regarding mortality is unclear. This prospective observational study was designed to study the prognostic value of procalcitonin in prediction of 28 day mortality in patients of sepsis. Fifty-four consecutive patients of sepsis, severe sepsis and septic shock defined using the 2001 Consensus Conference SCCM/ESICM/ACCP/ATS/SIS criteria from medical Intensive Care Unit (ICU) of a tertiary care center in New Delhi, India were enrolled from July 2011 to June 2013. Procalcitonin (PCT), C-reactive protein (CRP) measurements were recorded on day 1, day 7 and day 28 of follow up.

Results

Procalcitonin value was a better predictor of all-cause short-term mortality than C-reactive protein. Those patients with Procalcitonin levels <7 ng/ml showed higher cumulative survival than those with level [greater than or equal to]7 ng/ml (69.1% vs. 39.5%, p = 0.02). No such effect was observed in relation to C-reactive protein. Procalcitonin levels [greater than or equal to]7 ng/ml predicted mortality with a hazard ratio of 2.6(1.1-6.3).

Conclusions

A Procalcitonin value [greater than or equal to]7 ng/ml obtained at the time of admission to the ICU is a predictor of short-term mortality and thus may allow the identification of those septic patients at increased mortality risk, and help improve their treatment.

Procalcitonin and quantitative C-reactive protein role in the early diagnosis of sepsis in patients with febrile neutropenia

Background:

Neutropenia with fever is a common syndrome in patients with hematologic malignancies who have a high risk of infectious diseases. As early diagnosis of infection in such patients is really important, the aim of this study was to investigate the sensitivity and specificity of procalcitonin (PCT) and C-reactive protein (CRP) in the diagnosis of sepsis in febrile neutropenic patients in a referral malignant care center of Isfahan in 2010-2011.

Materials and Methods:

In this analytical cross-sectional study, all the febrile neutropenic patients who were admitted in the referral malignant care center in 2010-2011 were evaluated. The data from every individual, including sex, age, admission time, and duration of fever before taking antibiotics were collected. Sixty-four subjects were involved in the study. Blood samples of the subjects were obtained and the levels of PCT, CRP, Absolute neutrophil count (ANC), and white blood cell count were measured, and blood cultures were obtained. According to the test results, the 64 subjects were divided into two groups including patients with sepsis and without sepsis.

Results:

Mean value of PCT in the sepsis group was 28.65 ± 2.68 and in the non-sepsis group was 2.48 ± 0.66, with a P value of 0.000. In case of CRP, the sepsis group had a mean of 159.48 ± 9.73 and the non-sepsis group had a mean of 126.17 ± 10.63 (P = 0.015). Sensitivity and specificity were analyzed by using receiver operating characteristic (ROC) curve and were found to be 92.5% and 97.3%, respectively, for PCT and 70.5% and 42.1%, respectively, for CRP.

Conclusion:

PCT can be considered as a predictive factor and a diagnostic marker for the diagnosis of sepsis in febrile neutropenic patients.

Procalcitonin and C-reactive protein in the diagnosis and prediction of spontaneous bacterial peritonitis associated with chronic severe hepatitis B

Background

Procalcitonin (PCT), C-reactive protein (CRP), and white blood cells (WBCs) are inflammatory markers used to diagnose severe bacterial infections. We evaluated the diagnostic role of these markers and compared their accuracy for spontaneous bacterial peritonitis (SBP) associated with chronic severe hepatitis B (CSHB).

Methods

PCT and CRP concentrations, WBC count, and other hematological parameters were measured in serum from 84 well-characterized patients with CSHB, of whom 42 had SBP. Receiver operating characteristics (ROC) curve analysis was performed to assess the diagnostic accuracy.

Results

PCT and CRP concentrations were significantly higher in the CSHB patients with SBP (n=42) than CSHB patients without SBP (n=42). PCT and CRP concentrations were more accurate than WBC count for the diagnosis of CSHB-associated SBP. The optimal cutoff value of PCT was 0.48 ng/mL. The PCT concentration was significantly correlated with the CRP concentration and WBC count.

Conclusions

Serum PCT and CRP seems to be better markers than WBC for the diagnosis of CSHB patients with SBP.

Predictive factors for poor prognosis febrile neutropenia

PURPOSE OF REVIEW

Most patients with chemotherapy-induced febrile neutropenia recover rapidly without serious complications. However, it still remains a life-threatening treatment-related toxicity, and is associated with dose reductions and delays of chemotherapeutic agents that may compromise treatment outcomes. Recent developments of risk stratification enabled early discharge with oral antibiotics for low-risk patients. However, even in low-risk patients, medical complications including bacteremia could happen. The authors reviewed recent literature to provide an update on research regarding predictive factors for poor prognosis in patients with febrile neutropenia.

RECENT FINDINGS

Various prognostic factors have been suggested with controversies. Hematological parameters, prophylactic measurements and patient-specific risk factors showed inconsistent results. MASCC risk-index score, which was originally developed to identify low-risk patients, in turn showed that the lower the MASCC score, the poorer the prognosis of febrile neutropenia, with very low levels (<15), the rate of complications was high. Patients with severe sepsis and septic shock commonly had procalcitonin concentration above 2.0 ng/ml, and this level should be considered at high risk of poor prognosis.

SUMMARY

Lower MASCC score and higher procalcitonin concentration can predict poor outcomes in febrile neutropenia. More research is required with regard to the other factors showing controversies.

Evaluation of circulating soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) to predict risk profile, response to antimicrobial therapy, and development of complications in patients with chemotherapy-associated febrile neutropenia: a pilot study

The soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) is a useful marker of infection in patients with sepsis, but has not been adequately evaluated in patients with chemotherapy-associated febrile neutropenia (FN). The value of sTREM-1 in this setting has been tested in a retrospective, pilot study using stored serum from 48 cancer patients with documented FN. On presentation, patients were categorized according to the Talcott risk-index clinical score. Circulating soluble sTREM-1 was measured using an ELISA procedure, while procalcitonin (PCT) or interleukins 6 (IL-6) and 8 (IL-8), included for comparison, were measured using an immunoluminescence-based assay and Bio-Plex® suspension bead array system, respectively. Circulating concentrations of both sTREM-1 and PCT were significantly (P < 0.05) elevated in patients at high risk for complications or death, as predicted by the Talcott score and were significantly lower in patients who responded to empiric antimicrobial agents. Neither IL-6 nor IL-8 accurately predicted serious complications in patients with FN. These observations, albeit from a pilot study, demonstrate that sTREM-1 is indeed elevated in high-risk patients with FN and is potentially useful to predict their clinical course, either together with, or as an alternative to PCT.

The usefulness of procalcitonin and C-reactive protein as early diagnostic markers of bacteremia in cancer patients with febrile neutropenia

Purpose

Procalcitonin (PCT) and C-reactive protein (CRP) are well known inflammatory markers. This study was designed to determine whether PCT and CRP are useful as early diagnostic markers for bacteremia in cancer patients with febrile neutropenia (FN) in the emergency department (ED).

Materials and Methods

In this retrospective study, 286 episodes of FN in the ED were consecutively included between June 2009 and August 2010. From medical records, clinical characteristics including PCT and CRP were extracted and analyzed.

Results

Bacteremia was identified in 38 (13.3%) of the 286 episodes. The median values of PCT (2.8 ng/mL vs. 0.0 ng/mL, p=0.000) and CRP (15.9 mg/dL vs. 5.6 mg/dL, p=0.002) were significantly higher in the group with bacteremia compared to the group without bacteremia. In univariate analysis, elevated PCT (>0.5 ng/mL) and CRP (>10 mg/dL) as well as older age, hypotension, tachycardia, tachypnea, and high body temperature were significantly associated with bacteremia. On multivariate analysis, elevated PCT (>0.5 ng/mL) (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.4 to 9.2; p<0.01) and tachypnea (OR, 3.4; 95% CI, 1.4 to 8.5; p<0.01) were independent early diagnostic markers for bacteremia in FN patients. The area under the curve of PCT was 74.8% (95% CI, 65.1 to 84.6%) and that of CRP was 65.5% (95% CI, 54.8 to 76.1%). With a PCT cut-off value of 0.5 ng/mL, sensitivity and specificity were 60.5% and 82.3%, respectively, while the sensitivity and specificity were 57.6% and 67.3%, respectively, with a CRP cutoff of 10 mg/dL.

Conclusion

These findings suggest that PCT is a useful early diagnostic marker for the detection of bacteremia in FN at the ED and has better diagnostic value than CRP.

The mild inflammatory response in febrile neutropenic lymphoma patients with low risk of complications is more pronounced in patients receiving tobramycin once daily compared with three times daily

We evaluated inflammatory markers in febrile neutropenic lymphoma patients undergoing high-dose chemotherapy with autologous stem cell support. Based on MASCC scores, our patients had a low risk of serious complications and a perspective of a benign initial clinical course of the febrile neutropenia. We also studied the impact of tobramycin given once versus three times daily on these immune markers. Sixty-one patients participating in a Norwegian multicentre prospective randomized clinical trial, comparing tobramycin once daily versus three times daily, given with penicillin G to febrile neutropenic patients, constituted a clinically homogenous group. Four patients had bacteraemia, all isolates being Gram-positive. Thirty-two patients received tobramycin once daily, and 29 patients received tobramycin three times daily. Blood samples were taken at the onset of febrile neutropenia and 1-2 days later. All samples were frozen at -70 °C and analysed at the end of the clinical trial for C-reactive protein (CRP), procalcitonin (PCT), complement activation products, mannose-binding lectin (MBL) and 17 cytokines. We found a mild proinflammatory response in this series of patients. CRP was non-specifically elevated. Ten patients with decreased MBL levels showed the same mild clinical and proinflammatory response. Patients receiving tobramycin once daily showed a more pronounced proinflammatory response compared with patients receiving tobramycin three times daily. Overall, febrile neutropenic cancer patients with a benign clinical course show a mild proinflammatory immune response.

Diagnostic accuracy of procalcitonin in critically ill immunocompromised patients

Background

Recognizing infection is crucial in immunocompromised patients with organ dysfunction. Our objective was to assess the diagnostic accuracy of procalcitonin (PCT) in critically ill immunocompromised patients.

Methods

This prospective, observational study included patients with suspected sepsis. Patients were classified into one of three diagnostic groups: no infection, bacterial sepsis, and nonbacterial sepsis.

Results

We included 119 patients with a median age of 54 years (interquartile range [IQR], 42-68 years). The general severity (SAPSII) and organ dysfunction (LOD) scores on day 1 were 45 (35-62.7) and 4 (2-6), respectively, and overall hospital mortality was 32.8%. Causes of immunodepression were hematological disorders (64 patients, 53.8%), HIV infection (31 patients, 26%), and solid cancers (26 patients, 21.8%). Bacterial sepsis was diagnosed in 58 patients and nonbacterial infections in nine patients (7.6%); 52 patients (43.7%) had no infection. PCT concentrations on the first ICU day were higher in the group with bacterial sepsis (4.42 [1.60-22.14] vs. 0.26 [0.09-1.26] ng/ml in patients without bacterial infection, P < 0.0001). PCT concentrations on day 1 that were > 0.5 ng/ml had 100% sensitivity but only 63% specificity for diagnosing bacterial sepsis. The area under the receiver operating characteristic (ROC) curve was 0.851 (0.78-0.92). In multivariate analyses, PCT concentrations > 0.5 ng/ml on day 1 independently predicted bacterial sepsis (odds ratio, 8.6; 95% confidence interval, 2.53-29.3; P = 0.0006). PCT concentrations were not significantly correlated with hospital mortality.

Conclusion

Despite limited specificity in critically ill immunocompromised patients, PCT concentrations may help to rule out bacterial infection.

C-reactive protein in critically ill cancer patients with sepsis: influence of neutropenia

INTRODUCTION

Several biomarkers have been studied in febrile neutropenia. Our aim was to assess C-reactive protein (CRP) concentration in septic critically ill cancer patients and to compare those with and without neutropenia.

METHODS

A secondary analysis of a matched case-control study conducted at an oncologic medical-surgical intensive care unit (ICU) was performed, segregating patients with severe sepsis/septic shock. The impact of neutropenia on CRP concentrations at admission and during the first week of ICU stay was assessed.

RESULTS

A total of 154 critically ill septic cancer patients, 86 with neutropenia and 68 without, were included in the present study. At ICU admission, the CRP concentration of neutropenic patients was significantly higher than in non-neutropenic patients, 25.9 ± 11.2 mg/dL vs. 19.7 ± 11.4 mg/dL (P = 0.009). Among neutropenic patients, CRP concentrations at ICU admission were not influenced by the severity of neutropenia (< 100/mm3 vs. ≥ 100/mm3 neutrophils), 25.1 ± 11.6 mg/dL vs. 26.9 ± 10.9 mg/dL (P = 0.527). Time dependent analysis of CRP from Day 1 to Day 7 of antibiotic therapy showed an almost parallel decrease in both groups (P = 0.335), though CRP of neutropenic patients was, on average, always higher in comparison to that of non-neutropenic patients.

CONCLUSIONS

In septic critically ill cancer patients CRP concentrations are more elevated in those with neutropenia. However, the CRP course seems to be independent from the presence or absence of neutropenia.

Monitoring procalcitonin in febrile neutropenia: what is its utility for initial diagnosis of infection and reassessment in persistent fever?

Background

Management of febrile neutropenic episodes (FE) is challenged by lacking microbiological and clinical documentation of infection. We aimed at evaluating the utility of monitoring blood procalcitonin (PCT) in FE for initial diagnosis of infection and reassessment in persistent fever.

Methods

PCT kinetics was prospectively monitored in 194 consecutive FE (1771 blood samples): 65 microbiologically documented infections (MDI, 33.5%; 49 due to non-coagulase-negative staphylococci, non-CNS), 68 clinically documented infections (CDI, 35%; 39 deep-seated), and 61 fever of unexplained origin (FUO, 31.5%).

Results

At fever onset median PCT was 190 pg/mL (range 30–26'800), without significant difference among MDI, CDI and FUO. PCT peak occurred on day 2 after onset of fever: non-CNS-MDI/deep-seated-CDI (656, 80–86350) vs. FUO (205, 33–771; p<0.001). PCT >500 pg/mL distinguished non-CNS-MDI/deep-seated-CDI from FUO with 56% sensitivity and 90% specificity. PCT was >500 pg/ml in only 10% of FUO (688, 570–771). A PCT peak >500 pg/mL (1196, 524–11950) occurred beyond 3 days of persistent fever in 17/21 (81%) invasive fungal diseases (IFD). This late PCT peak identified IFD with 81% sensitivity and 57% specificity and preceded diagnosis according to EORTC-MSG criteria in 41% of cases. In IFD responding to therapy, median days to PCT <500 pg/mL and defervescence were 5 (1–23) vs. 10 (3–22; p = 0.026), respectively.

Conclusion

While procalcitonin is not useful for diagnosis of infection at onset of neutropenic fever, it may help to distinguish a minority of potentially severe infections among FUOs on day 2 after onset of fever. In persistent fever monitoring procalcitonin contributes to early diagnosis and follow-up of invasive mycoses.

Plasma levels of procalcitonin and eight additional inflammatory molecules in febrile neutropenic patients

OBJECTIVE

This study aimed to examine the association between different inflammatory markers and specific clinical endpoints in patients with febrile neutropenia.

METHOD

We prospectively evaluated the expression of procalcitonin (PCT), interleukin 8 (IL-8), induced protein-10, tumor necrosis factor alpha (TNF-α), two soluble TNF-α receptors (sTNF-R I and sTNF-R II), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 alpha, and eotaxin in 37 episodes of febrile neutropenia occurring in 31 hospitalized adult onco-hematologic patients. Peripheral blood samples were collected in the morning at inclusion (day of fever onset) and on days 1, 3, and 7 after the onset of fever. Approximately 2-3 ml of plasma was obtained from each blood sample and stored at -80 °C.

RESULTS

The sTNF-R II level at inclusion (day 1), the PCT level on the day of fever onset, and the change (day 3 - day 1) in the IL-8 and eotaxin levels were significantly higher in patients who died during the 28-day follow-up. A requirement for early adjustment of antimicrobial treatment was associated with higher day 3 levels of IL-8, sTNF-R II, PCT, and MCP-1.

CONCLUSION

Procalcitonin, sTNF-R II, IL-8, MCP-1, and eotaxin could potentially be used to assess the risk of death and the requirement for early adjustment of antimicrobial treatment in febrile, neutropenic onco-hematologic patients. The levels of the other markers showed no association with any of the evaluated endpoints.

Infectious background of febrile advanced lung cancer patients who received chemotherapy

The study aimed to determine the diagnostic utility of procalcitonin (PCT) in order to discriminate between infective fever and fever due to inflammation in febrile advanced lung cancer patients treated with cytotoxic chemotherapy. A total of 121 patients with advanced lung cancer, treated with a cytotoxic chemotherapy regimen between September 2007 and September 2008 at Kyoto University Hospital, were recruited. Blood samples were obtained on the first day of the fever. Serum c-reactive protein (CRP) and PCT levels were measured. At least two blood cultures were performed, and sputum was taken for Gram staining and culture. There were 71 episodes in 61 patients in the 12 months of the study, representing 50.4% of our study population. A total of 41 patients (57.7%) were diagnosed with pneumonia using imaging modalities, 6 (8.5%) with bacteremia using blood culture and 4 (5.6%) with urinary tract infections using urine culture. Among the 41 pneumonia cases, culture from sputum revealed pathologic bacteria in 21 (51.2%) and fungal disease in 14 (34.1%) cases. Among the 71 febrile episodes, serum procalcitonin and CRP were measured in 50 episodes. Serum procalcitonin-positive patients showed poor outcomes on antibiotics therapy (Fisher's exact test, p=0.042). Furthermore, serum procalcitonin positivity was able to discriminate infective fever from fever due to inflammation (Chi-square test, p=0.001). We showed the causative organisms of febrile advanced lung cancer patients who received cytotoxic chemotherapy, as well as the possibility of PCT to discriminate infective fever from fever due to inflammation.

Pro- and synbiotics to control inflammation and infection in patients with multiple injuries

BACKGROUND

A recent randomized clinical trial of our group disclosed considerable reduction of the infective sequelae after administration of a synbiotic formula, namely Synbiotic 2000FORTE, in patients with multiple injuries, the latter being a preparation of four probiotics. The mechanism of action of synbiotics was studied.

METHODS

A total of 72 patients with severe multiple injuries were allocated to a 15-day administration of either placebo or the synbiotic formula. The association of bloodstream infections, ventilator-associated pneumonia (VAP), serum levels of C-reactive protein (CRP), and endotoxins (LPS) were studied.

RESULTS

Sepsis in the field of bacteremia occurred in 13 patients treated with placebo (36.1%) compared with 5 patients treated with Synbiotic 2000FORTE (13.9%, p = 0.028 between groups). The time to progression to primary bacteremia was longer among patients treated with Synbiotic 2000FORTE compared with placebo (p = 0.0237 between groups). Twelve (33.3%) and five (13.9%) placebo-treated and probiotic-treated patients, respectively, developed ventilator-associated pneumonia with Acinetobacter baumannii as a bacterial cause (p = 0.047 between groups). Treatment with synbiotics was accompanied by reduction of white blood cell counts and LPS and CRP levels in either patients who did or did not develop sepsis.

CONCLUSIONS

Synbiotics contained in the studied formula decrease significantly the risk for sepsis by bloodstream infections and the occurrence of VAP by A. baumannii. The mechanisms of action might involve direct immunomodulatory effect, prevention of bacterial translocation, or most likely a combination of both.

Procalcitonin as a predictive marker of infections in chemoinduced neutropenia

PURPOSE

This study was designed to determine the usefulness of procalcitonin (PCT) as a predictive marker of infections in neutropenic patients following chemotherapeutic treatments.

METHODS

Over a 6-month period, 65 patients (34 affected by a solid tumor, 31 by a hematological disorder) were enrolled. Serum PCT concentrations were measured by an automated immunoassay on the leucocytes nadir and on the third day, when patients were checked for any sign of infection.

RESULTS

Procalcitonin values were not affected by gender, age, therapeutic approach, use of G-CSF or performance status and did not differ between patients who subsequently developed a localized infection and those who did not. PCT concentrations resulted higher in patients affected by hematological disorders than in those affected by solid tumors (mean value 0.09 vs. 0.05 microg/L; p < 0.0015) and in those who were hospitalized than in the outpatient group (0.10 vs. 0.05 microg/L; p < 0.0013). PCT levels correlated with the type of neoplastic disease (p = 0.016), the highest concentrations being detected in patients affected by acute leukemia.

CONCLUSIONS

These findings suggest that PCT is not a useful predictive marker of infection in oncohematologic neutropenic patients, even though higher serum PCT concentrations are associated with hematological tumors as well as in-hospital admission.

Procalcitonin and C-reactive protein serum levels as markers of infection in a pediatric population with febrile neutropenia and cancer

BACKGROUND

Procalcitonin and C-reactive-protein are inflammatory markers for sepsis. The authors evaluated their sensitivity and specificity in pediatric patients with cancer and febrile neutropenia.

PROCEDURE

Serum procalcitonin and C-reactive-protein were evaluated. Patients (n = 54) were divided into 2 groups, with severe infection (n = 18) or without documented infection (n = 36).

RESULTS

Procalcitonin and C-reactive protein were significantly higher in the high-risk group. Procalcitonin displayed 72.2% sensitivity and 80.5% specificity. C-reactive-protein had a sensitivity of 77.7% and specificity of 77.2%.

CONCLUSIONS

Procalcitonin is an accurate predictor of bacterial infection in neutropenic children, while C-reactive-protein may be a better screening test in emergency settings.

Marked increase of procalcitonin after the administration of anti-thymocyte globulin in patients before hematopoietic stem cell transplantation does not indicate sepsis: a prospective study

Introduction

Procalcitonin (PCT) and C-reactive protein (CRP) are established markers of infection in the general population. In contrast, several studies reported falsely increased PCT levels in patients receiving T-cell antibodies. We evaluated the validity of these markers in patients scheduled for hemopoietic stem cell transplantation receiving anti-thymocyte globulin (ATG) during conditioning. We also assessed renal and liver functions and their relationship to PCT and CRP changes.

Methods

Twenty-six patients without clinical signs of infection were prospectively studied. ATG was administered in up to three doses over the course of 5 days. PCT, CRP, white blood cell (WBC) count, urea, creatinine, glomerular filtration rate, bilirubin, alanin amino-transferase (ALT), and gamma-glutamyl transferase (GGT) were assessed daily during ATG administration. Pharyngeal, nose, and rectal swabs and urine samples were cultured twice weekly. Blood cultures were obtained if clinical symptoms of infection were present.

Results

Baseline (BL) levels of both PCT and CRP before ATG administration were normal. WBC count decreased after ATG administration (P = 0.005). One day after ATG administration, both PCT and CRP levels increased significantly, returning to BL levels on day 4. Microbiological results were clinically unremarkable. There was no interrelationship between PCT levels and BL markers of renal or liver functions (P > 0.05 for all comparisons). Bilirubin and GGT were increased on days 2 to 5 and ALT was increased on day 3 (P < 0.05 versus BL). No difference in renal functions was observed. Three patients developed bacterial infection on days 7 to 11 with different dynamics of PCT and CRP. There was no association between the number of ATG doses and PCT levels or between the risk of developing infection and previous PCT levels.

Conclusions

ATG triggered a marked early surge in PCT and CRP followed by a steady decrease over the course of 3 days. The dynamics of both PCT and CRP were similar and were not associated with infection. PCT levels were independent of renal and liver functions and were not predictive of further infectious complications. A direct effect of ATG on T lymphocytes could be the underlying mechanism. Hepatotoxic effect could be a contributing factor. Neither PCT nor CRP is a useful marker that can identify infection in patients receiving ATG.

Prediction of outcome in cancer patients with febrile neutropenia: comparison of the Multinational Association of Supportive Care in Cancer risk-index score with procalcitonin, C-reactive protein, serum amyloid A, and interleukins-1beta, -6, -8 and -10

The primary objective of the study was to compare the predictive potential of procalcitonin (PCT), C-reactive protein (CRP), serum amyloid A (SAA), and interleukin (IL)-1beta, IL-6, IL-8, and IL-10, with that of the Multinational Association of Supportive Care in Cancer (MASCC) risk-index score in cancer patients on presentation with chemotherapy-induced febrile neutropenia (FN). Seventy-eight consecutive FN episodes in 63 patients were included, and MASCC scores, as well as concentrations of CRP, SAA, PCT, and IL-1beta, IL-6, IL-8 and IL-10, and haematological parameters were determined on presentation, 72 h later and at outcome. Multivariate analysis of data revealed the MASCC score, but none of the laboratory parameters, to be an accurate, independent variable (P < 0.0001) for prediction of resolution with or without complications and death. Of the various laboratory parameters, PCT had the strongest association with the MASCC score (r = -0.51; P < 0.0001). In cancer patients who present with FN, the MASCC risk-index score is a useful predictor of outcome, while measurement of PCT, CRP, SAA, or IL-1beta, IL-6, IL-8 and IL-10, is of limited value.

Predictors of severe sepsis not clinically apparent during the first twenty-four hours of hospitalization in children with cancer, neutropenia, and fever: a prospective, multicenter trial

BACKGROUND

Severe sepsis is not clinically apparent during the first 24 hours of hospitalization in most children with cancer and febrile neutropenia (FN), delaying targeted interventions that could impact mortality. The aim of this study was to prospectively evaluate biomarkers obtained within 24 hours of hospitalization as predictors of severe sepsis before it becomes clinically evident.

METHODS

Children with cancer, admitted with FN at high risk for an invasive bacterial infection in 6 public hospitals in Santiago, Chile, were monitored throughout their clinical course for occurrence of severe sepsis. Clinical, demographic and 6 biomarkers [eg, blood urea nitrogen, serum glucose, lactic dehydrogenase, serum C-reactive protein (CRP), interleukin (IL)-8, and procalcitonin] were obtained at the time of admission and after 24 hours. Biomarkers independently associated with severe sepsis diagnosed after the first 24 hours of hospitalization were identified by logistic regression analysis.

RESULTS

A total of 601 high risk FN episodes were enrolled between June 2004 and October 2006; 151 (25%) developed severe sepsis of which 116 (77%) were not clinically apparent during the first 24 hours of hospitalization. Risk factors for severe sepsis were age > or =12 years [odds ratio (OR): 3.85; 95% confidence interval (CI): 2.41-6.15], admission CRP > or =90 mg/L (OR: 2.03; 95% CI: 1.32-3.14), admission IL-8 > or =200 pg/mL (OR: 2.39; 95% CI: 1.51-3.78), 24-hour CRP > or =100 mg/L (OR: 3.06; 95% CI: 1.94-4.85), and 24-hour IL-8 > or =300 pg/mL (OR: 3.13; 95% CI 1.92-5.08).

CONCLUSIONS

Age > or =12 years and admission or 24-hour values of CRP > or =90/100 mg/L and IL-8 > or =200/300 pg/mL are predictors of sepsis not clinically apparent during the first 24 hours of hospitalization.

Procalcitonin assay in systemic inflammation, infection, and sepsis: clinical utility and limitations

OBJECTIVE

The use of procalcitonin (ProCT) as a marker of several clinical conditions, in particular, systemic inflammation, infection, and sepsis, will be clarified, and its current limitations will be delineated. In particular, the need for a more sensitive assay will be emphasized. For these purposes, the medical literature comprising clinical studies pertaining to the measurement of serum ProCT in various clinical settings was examined.

DATA SOURCE AND SELECTION

A PubMed search (1965 through November 2007) was conducted, including manual cross-referencing. Pertinent complete publications were obtained using the MeSH terms procalcitonin, C-reactive protein, sepsis, and biological markers. Textbook chapters were also read and extracted.

DATA EXTRACTION AND SYNTHESIS

Available clinical and other patient data from these sources were reviewed, including any data relating to precipitating factors, clinical findings, associated illnesses, and patient outcome. Published data concerning sensitivity, specificity, and reproducibility of ProCT assays were reviewed.

CONCLUSIONS

Based on available data, the measurement of serum ProCT has definite utility as a marker of severe systemic inflammation, infection, and sepsis. However, publications concerning its diagnostic and prognostic utility are contradictory. In addition, patient characteristics and clinical settings vary markedly, and the data have been difficult to interpret and often extrapolated inappropriately to clinical usage. Furthermore, attempts at meta-analyses are greatly compromised by the divergent circumstances of reported studies and by the sparsity and different timing of the ProCT assays. Although a high ProCT commonly occurs in infection, it is also elevated in some noninfectious conditions. Thus, the test is not a specific indicator of either infection or sepsis. Moreover, in any individual patient, the precipitating cause of an illness, the clinical milieu, and complicating conditions may render tenuous any reliable estimations of severity or prognosis. It also is apparent that even a febrile septic patient with documented bacteremia may not necessarily have a serum ProCT that is elevated above the limit of functional sensitivity of the assay. In this regard, the most commonly applied assay (i.e., LUMItest) is insufficiently sensitive to detect potentially important mild elevations or trends. Clinical studies with a more sensitive ProCT assay that is capable of rapid and practicable day-to-day monitoring are needed and shortly may be available. In addition, investigations showing that ProCT and its related peptides may have mediator relevance point to the need for evaluating therapeutic countermeasures and studying the pathophysiologic effect of hyperprocalcitonemia in serious infection and sepsis.

Procalcitonin as a diagnostic aid in diabetic foot infections

The diagnosis of diabetic foot infection (DFI) is usually a challenge to the clinician. Procalcitonin (PCT), a 116-amino acid propeptide of calcitonin, is a new marker of bacterial infections and sepsis. We evaluated the serum value of PCT as a marker of bacterial infection in diabetic patients with foot ulcers. Forty-nine diabetic patients with foot ulcers were consecutively enrolled into the study. DFI was diagnosed clinically by the presence of purulent secretions or at least two of the symptoms of inflammation including redness, warmth, swelling, and pain. According to these criteria, DFI was determined in 27 patients (DFI group) and not detected in 22 patients (NDFI group). The blood samples were taken for biochemical analysis on admission. PCT, white blood cell count (WBC) and erythrocyte sedimentation rate (ESR), but not C-reactive protein (CRP), was found significantly higher in DFI group compared with NDFI group. The best cut-off value, sensitivity and specificity were 0.08 ng/ml, 77% and 100% for PCT, 32.1 mg/dl, 29% and 100% for CRP, 8.6 10(9)/L, 70% and 72% for WBC and 40.5 mm/h, 77% and 77% for ESR, respectively. The area under the receiver operating characteristic curve for infection identification was greatest for PCT (0.859; p < 0.001), followed by WBC (0.785; p = 0.001), ESR (0.752; p = 0.003), and finally CRP (0.625; p = 0.137). These results suggest that PCT may be a useful diagnostic marker for DFI. Additional research is needed to better define the role of PCT in DFI.

Procalcitonin (PCT) and C-reactive protein (CRP) as severe systemic infection markers in febrile neutropenic adults

Background

Procalcitonin (PCT) is an inflammatory marker that has been used as indicator of severe bacterial infection. We evaluated the concentrations of PCT as a marker for systemic infection compared to C-reactive protein (CRP) in patients neutropenic febrile.

Methods

52 adult patients were enrolled in the study. Blood sample was collected in order to determine the serum concentrations of PCT, CRP and other hematological parameters at the onset of fever. The patients were divided into 2 groups, one with severe infection (n = 26) and the other in which the patients did not present such an infection (n = 26). Then PCT and CRP concentrations at the fever onset were compared between groups using non parametric statistical tests, ROC curve, sensitivity, specificity, likelihood ratio, and Spearman's correlation coefficient.

Results

The mean of PCT was significantly higher in the group with severe infection (6.7 ng/mL versus 0.6 ng/mL – p = 0.0075) comparing with CRP. Serum concentrations of 0.245 ng/mL of PCT displayed 100% de sensitivity and 69.2% specificity. PCT concentrations of 2,145 ng/mL presented a likelihood ratio of 13, which was not observed for any concentration of CRP.

Conclusion

PCT seems to be an useful marker for the diagnosis of systemic infection in febrile neutropenic patients, probably better than CRP.

Procalcitonin for the clinical laboratory: a review

Procalcitonin measurement has been claimed as a helpful marker in bacterial infection and sepsis. It has obtained FDA approval and is now widely marketed in the United States and Europe. This review summarises the current assays available, the evidence for its use and possible future applications of the assay.

Procalcitonin Test in the Diagnosis of Bacteremia: A Meta-analysis

STUDY OBJECTIVE

We seek to evaluate the diagnostic performance of the procalcitonin test for the diagnosis of bacteremia in the emergency department (ED) population.

METHODS

We conducted a search of MEDLINE, bibliographies of previous systemic reviews, and pertinent national meeting research abstracts. We included studies that assessed the diagnostic accuracy of procalcitonin for bacteremia, with blood culture as the reference standard. We included prospective investigations of adults and children with suspected infection studied in the ED or at admission. Two authors independently extracted data and assessed study quality; consensus was reached by conference. The analysis was based on the I2 statistic for heterogeneity, unweighted summary receiver-operating characteristic curve, and random-effects pooled sensitivity and specificity across studies using the same test threshold.

RESULTS

The search yielded 348 publications and 1 unpublished study. Seventeen studies met the inclusion criteria and provided a sample of 2,008 subjects. There was a substantial degree of inconsistency (I2=64%). The unweighted summary receiver-operating characteristic curve provided the best overall estimate of test performance, with an area under the curve of 0.84 (95% confidence interval [CI] 0.75 to 0.90). Sensitivity analysis based on study quality did not significantly change the results. Subgroup analysis including only studies that used a test threshold of 0.5 or 0.4 ng/mL yielded pooled estimates for sensitivity and specificity of 76% (95% CI 0.66 to 0.84) and 70% (95% CI 0.60 to 0.79), respectively.

CONCLUSION

We found the diagnostic performance of the procalcitonin test for identifying bacteremia in ED patients to be moderate. Future research designed to determine the utility of the procalcitonin test as a diagnostic tool used in isolation for detecting bacteremia in ambulatory patients is needed before widespread clinical use.