Biomarkers for bacteremia and severe sepsis in hematological patients with neutropenic fever: multivariate logistic regression analysis and factor analysis

Nausea Predicts Bacteremia in Immunocompetent Patients with Pneumococcal Community-Acquired Pneumonia: Secondary Data Analysis from a Prospective Cohort

BACKGROUND

In pneumococcal community-acquired pneumonia (CAP), bacteremia is associated with increased mortality, but initial clinical severity scores frequently fail to identify bacteremic patients at risk. We have previously shown that gastrointestinal symptoms are common among patients admitted to the hospital with pneumococcal bacteremia. The aim of this study was to examine gastrointestinal symptoms and inflammatory responses in bacteremic and non-bacteremic pneumococcal CAP in a prospective cohort of immunocompromised and immunocompetent patients hospitalized with CAP.

METHODS

Logistic regression analysis was used to estimate the predictive value of gastrointestinal symptoms for pneumococcal bacteremia in patients with CAP. The Mann-Whitney test was used to compare inflammatory responses in patients with bacteremic vs. non-bacteremic pneumococcal CAP.

RESULTS

Eighty-one patients with pneumococcal CAP were included, of whom 21 (26%) had bacteremia. Immunocompetent patients with pneumococcal CAP had an odds ratio of 16.5 (95% CI 3.0-90.9, p = 0.001) for bacteremia if nausea was present, whereas no such association was found in the immunocompromised patients (OR 0.22, 95% CI 0.02-2.05, p = 0.18). The serum levels of C-reactive protein, procalcitonin and interleukin 6 were significantly higher in the patients with bacteremic pneumococcal CAP compared to non-bacteremic pneumococcal CAP patients (p < 0.001, p = 0.005, and p = 0.019, respectively).

CONCLUSIONS

In immunocompetent patients hospitalized with pneumococcal CAP, nausea may be a predictor of bacteremia. Bacteremic pneumococcal CAP patients display an increased inflammatory response compared to non-bacteremic pneumococcal CAP patients.

Biomarkers Predicting Tissue Pharmacokinetics of Antimicrobials in Sepsis: A Review

The pathophysiology of sepsis alters drug pharmacokinetics, resulting in inadequate drug exposure and target-site concentration. Suboptimal exposure leads to treatment failure and the development of antimicrobial resistance. Therefore, we seek to optimize antimicrobial therapy in sepsis by selecting the right drug and the correct dosage. A prerequisite for achieving this goal is characterization and understanding of the mechanisms of pharmacokinetic alterations. However, most infections take place not in blood but in different body compartments. Since tissue pharmacokinetic assessment is not feasible in daily practice, we need to tailor antibiotic treatment according to the specific patient’s pathophysiological processes. The complex pathophysiology of sepsis and the ineffectiveness of current targeted therapies suggest that treatments guided by biomarkers predicting target-site concentration could provide a new therapeutic strategy. Inflammation, endothelial and coagulation activation markers, and blood flow parameters might be indicators of impaired tissue distribution. Moreover, hepatic and renal dysfunction biomarkers can predict not only drug metabolism and clearance but also drug distribution. Identification of the right biomarkers can direct drug dosing and provide timely feedback on its effectiveness. Therefore, this might decrease antibiotic resistance and the mortality of critically ill patients. This article fills the literature gap by characterizing patient biomarkers that might be used to predict unbound plasma-to-tissue drug distribution in critically ill patients. Although all biomarkers must be clinically evaluated with the ultimate goal of combining them in a clinically feasible scoring system, we support the concept that the appropriate biomarkers could be used to direct targeted antibiotic dosing.

Fatal hemorrhagic pneumonia in patients with hematologic diseases and Stenotrophomonas maltophilia bacteremia: a retrospective study

Background

Fatal hemorrhagic pneumonia is one of the most severe manifestations of Stenotrophomonas maltophilia (SM) infections. Here, we aimed to investigate the clinical characteristics of SM bacteremia and to identify the risk factors of hemorrhagic pneumonia caused by SM in patients with hematologic diseases.

Methods

The clinical records of 55 patients diagnosed with hematologic diseases and SM bacteremia were retrospectively reviewed. We compared patients’ clinical characteristics and outcomes between the hemorrhagic pneumonia group and non-hemorrhagic pneumonia group.

Results

Twenty-seven (49.1%) patients developed hemorrhagic pneumonia. The overall mortality rate of SM bacteremia was 67.3%. Hemorrhagic pneumonia (adjusted HR 2.316, 95% CI 1.140–4.705; P = 0.020) was an independent risk factor of 30-day mortality in hematological patients with SM bacteremia. Compared with the non-hemorrhagic pneumonia group, patients in the hemorrhagic pneumonia group were older and showed clinical manifestations as higher proportions of isolated SM in sputum culture, neutropenia and elevated procalcitonin (PCT). Multivariate analysis showed that neutropenia, high levels of PCT, prior tigecycline therapy within 1 month were independent risk factors associated with hemorrhagic pneumonia.

Conclusions

Neutropenia, high level of PCT and prior tigecycline therapy within 1 month were significant independent predictors of hemorrhagic pneumonia in hematologic patients with SM bacteremia. Due to no effective antibiotics to prevent hemorrhagic pneumonia, prophylaxis of SM infection and its progression to hemorrhagic pneumonia is particularly important.

Antimicrobial prophylaxis and post-chemotherapy neutropenic fever in patients with leukemia: comparisons of C-reactive protein, procalcitonin and immediate fever outcome measures between those with and without prophylaxis, and the implications for practice

Purpose

The efficacy of prophylactic antimicrobial treatment renders challenges in patients with leukemias receiving chemotherapy. The study aimed to compare differences in C-reactive protein (CRP) and procalcitonin (PCT) at presentation and the immediate outcome measures of post-chemotherapy NF between patients with and without antimicrobial prophylaxis.

Methods

A 5-year observational study included 282 NF episodes in 133 leukemia patients requiring hospital care from January 2014 to May 2019. We collected demographic characteristics, laboratory data of blood cell counts and inflammatory biomarkers, and immediate outcome measures of NF, including microbiologically diagnosed infections, presence of predominant pathogens, required modification of antibiotics during NF, adverse medical complications, total fever duration, and deaths. We evaluated data between patients with and without prophylaxis.

Results

Of patients, 77.3%, 68.4%, and 20.6% had antibiotic prophylaxis, antifungal prophylaxis, and no prophylaxis, respectively. There were totally 15 deaths—13 with antibiotic prophylaxis and 10 with antifungal prophylaxis. CRP, PCT, and immediate outcome measures of NF did not show significant differences between those with and without antimicrobial prophylaxis. Although between-group differences showed no statistical significance, higher median fever duration, CRP and PTC values, and higher proportions of NF requiring modification of antibiotics were found more frequently in those with antimicrobial prophylaxis than in those without.

Conclusion

The benefits of using antimicrobial prophylaxis were less supported. Enhancing diagnostic laboratory and medical complication surveillance and periodic evaluation of institutional data during post-chemotherapy neutropenia and NF in relation to antimicrobial prophylaxis is promising in providing insights to redefine the risk–benefit accounts of using prophylaxis.

Understanding and Managing Sepsis in Patients With Cancer in the Era of Antimicrobial Resistance

Sepsis is a frequent complication in immunosuppressed cancer patients and hematopoietic stem cell transplant recipients that is associated with high morbidity and mortality rates. The worldwide emergence of antimicrobial resistance is of special concern in this population because any delay in starting adequate empirical antibiotic therapy can lead to poor outcomes. In this review, we aim to address: (1) the mechanisms involved in the development of sepsis and septic shock in these patients; (2) the risk factors associated with a worse prognosis; (3) the impact of adequate initial empirical antibiotic therapy given the current era of widespread antimicrobial resistance; and (4) the optimal management of sepsis, including adequate and early source control of infection, optimized antibiotic use based on the pharmacokinetic and pharmacodynamics changes in these patients, and the role of the new available antibiotics.

Utility of procalcitonin as a predictor of bloodstream infections and supportive modality requirements in critically ill cancer patients

BACKGROUND

We evaluated the diagnostic utility of procalcitonin (PCT) in predicting bacterial bloodstream infections (BSI) in critically ill cancer patients with and without neutropenia. We also investigated the role of PCT as a prognostic marker of supportive modalities (vasopressors, invasive mechanical ventilation, and renal replacement therapy (RRT)) in the intensive care unit (ICU).

METHODS

We retrospectively analyzed 2200 PCT and blood cultures from adult cancer patients with suspected sepsis. Primary outcome was BSI, defined by positive blood culture, collected within 72 h of PCT collection.

RESULTS

Median PCT values were higher in encounters with BSI (3.2 vs 0.5 ng/ml, p < 0.001). The area under the ROC curve (AUC) was 0.726 (95%CI 0.698, 0.754). PCT > 2.0 ng/ml was significantly associated with greater likelihood of BSI and this effect was significantly stronger for neutropenic (OR 9.09, 95%CI: 4.39, 18.79) compared with non-neutropenic patients (OR 4.00 (95% CI: 3.13, 5.10), interaction p = 0.036). PCT > 2.0 was associated with vasopressor requirement on ICU admission (OR 1.82 (95% CI 1.31, 2.53), p < 0.001) and RRT (OR 2.20 (95% CI 1.24, 3.91), p = 0.007).

CONCLUSIONS

Procalcitonin is a fair discriminator of BSI in critically ill cancer patients with and without neutropenia and a PCT > 2.0 ng/ml was significantly more likely to require vasopressors and RRT in the ICU.

Biomarkers of sepsis: time for a reappraisal

INTRODUCTION

Sepsis biomarkers can have important diagnostic, therapeutic, and prognostic functions. In a previous review, we identified 3370 references reporting on 178 different biomarkers related to sepsis. In the present review, we evaluate the progress in the research of sepsis biomarkers.

METHODS

Using the same methodology as in our previous review, we searched the PubMed database from 2009 until September 2019 using the terms "Biomarker" AND "Sepsis." There were no restrictions by age or language, and all studies, clinical and experimental, were included.

RESULTS

We retrieved a total of 5367 new references since our previous review. We identified 258 biomarkers, 80 of which were new compared to our previous list. The majority of biomarkers have been evaluated in fewer than 5 studies, with 81 (31%) being assessed in just a single study. Apart from studies of C-reactive protein (CRP) or procalcitonin (PCT), only 26 biomarkers have been assessed in clinical studies with more than 300 participants. Forty biomarkers have been compared to PCT and/or CRP for their diagnostic value; 9 were shown to have a better diagnostic value for sepsis than either or both of these biomarkers. Forty-four biomarkers have been evaluated for a role in answering a specific clinical question rather than for their general diagnostic or prognostic properties in sepsis.

CONCLUSIONS

The number of biomarkers being identified is still increasing although at a slower rate than in the past. Most of the biomarkers have not been well-studied; in particular, the clinical role of these biomarkers needs to be better evaluated.

Symptom Clusters in Postchemotherapy Neutropenic Fever in Hematological Malignancy: Associations Among Sickness Behavior Symptom Cluster, Inflammatory Biomarkers of Procalcitonin and C-Reactive Protein, and Febrile Measures

CONTEXT

Little research has been conducted to investigate symptom clusters in postchemotherapy neutropenic fever (NF), their relationships with inflammatory biomarkers, and febrile outcome measures in patients with hematological malignancy, a population with high febrile rates incurring considerable costs to the health care system.

OBJECTIVES

The aim of the present study was to investigate these.

METHODS

One hundred four NF episodes were observed in patients with hematological malignancy who were enrolled in the study. Patient-reported symptoms were recorded using the M.D. Anderson Symptom Inventory. Inflammatory biomarkers of procalcitonin (PCT) and C-reactive protein (CRP), vital signs, blood specimens for cultures, blood cell counts, and biochemistry were also collected. Serious complications from NF were reviewed from medical records if documented. Exploratory factor analysis and Spearman's rank correlation were used in the data analysis.

RESULTS

Three symptom clusters-sickness behavior, chemotherapy neurotoxicity, and emesis-were identified by exploratory factor analysis. The factor score of the sickness behavior cluster was significantly correlated with CRP (P < 0.05), PCT (P < 0.01), and the highest (P < 0.05) and maximum increased in (P < 001) temperatures at the onset (first day) of neutropenic fever.

CONCLUSION

This study identified symptom clusters of sickness behavior, chemotherapy neurotoxicity, and emesis and highlighted significant associations between sickness behavior cluster, PCT, CRP, and febrile temperatures at the onset of postchemotherapy NF. These areas have lacked exploration in previous research. Monitoring and analyzing patient-reported sickness behavior symptoms, PCT, CRP, and temperature data would provide significant complementary data for the management and surveillance of postchemotherapy NF in hematological malignancy.

Procalcitonin and C-Reactive Protein As Markers of Bacteremia in Patients With Febrile Neutropenia Who Receive Chemotherapy for Acute Leukemia: A Prospective Study From Nepal

PURPOSE

The purpose of this study was to evaluate the clinical significance of the biomarkers procalcitonin (PCT) and C-reactive protein (CRP) in patients with febrile neutropenia (FN) undergoing chemotherapy for acute leukemia.

METHODS

We conducted a prospective, observational study in patients who developed FN while undergoing chemotherapy for acute leukemia. PCT and CRP were obtained in patients who presented with FN. Blood cultures also were obtained. The primary goals were to evaluate the ability of PCT and CRP to predict bacteremia in patients with FN. The secondary goals were to assess the prognostic role of PCT and CRP and to assess the microbiologic profile and culture sensitivity patterns in the study population.

RESULTS

A total of 124 episodes of FN that involved 67 patients with acute leukemia occurred in the study. PCT was superior to CRP in the prediction of bacteremia. The median PCT level in the bacteremia group was 3.25 ng/mL compared with 0.51 ng/mL in the group without bacteremia (P < .01). The median values of CRP in the bacteremia and without-bacteremia groups were 119.3 mg/L and 94.5 mg/L, respectively (P = .07). There were no differences in median PCT and CRP in patients who died and those who improved. Of the 42 positive cultures, Gram-negative bacteremia was common (86%), and Escherichia coli was the most frequent organism isolated. Carbapenem resistance was seen in 39% of positive cultures.

CONCLUSION

PCT is an effective biomarker to predict bacteremia in patients with FN undergoing chemotherapy for acute leukemia.

Biomarkers of Sepsis and Bloodstream Infections: The Role of Procalcitonin and Proadrenomedullin With Emphasis in Patients With Cancer

Sepsis and bloodstream infections remain a leading cause of death in immunocompromised patients with cancer. The management of these serious infections consist of empiric use of antimicrobial agents which are often overused. Procalcitonin and proadrenomedullin are biomarkers that have been extensively evaluated in the general populations but with little emphasis in the population immunocompromised patients with cancer, where they may have promising roles in the management of febrile patients. In this review, we summarize the available evidence of the potential role of these available biomarkers in guiding antimicrobial therapy to optimize the use of resources in the general patient population. Special emphasis is given to the role of these 2 biomarkers in the immunocompromised and critically ill patients with cancer, highlighting the distinctive utility of each.

Interleukin-1 receptor antagonist as a biomarker of sepsis in neutropenic haematological patients

OBJECTIVE

The study aim was to compare the performance of interleukin-1 receptor antagonist (IL-1Ra) to C-reactive protein (CRP) and procalcitonin (PCT) in early prediction of the clinical course of febrile neutropenia.

METHODS

The study population consisted of 86 consecutive patients with febrile neutropenia who received intensive chemotherapy for haematological malignancy between November 2009 and November 2012 at the adult haematology ward of Kuopio University Hospital. Twenty-three (27%) patients had acute myeloid leukaemia and 63 (73%) patients were autologous stem cell transplant recipients. IL-1Ra, CRP and procalcitonin were measured at the onset of fever (d0), on day 1 (d1) and on day 2 (d2).

RESULTS

Eight patients developed severe sepsis, including three patients with septic shock. Eighteen patients had bacteraemia. After the onset of febrile neutropenia Youden´s indices (with their 95% confidence intervals) to identify severe sepsis were for IL-1Ra on d0 0.57 (0.20-0.71) and on d1 0.65 (0.28-0.78), for CRP on d0 0.41 (0.04-0.61) and on d1 0.47 (0.11-0.67) and for PCT on d0 0.39 (0.05-0.66) and on d1 0.52 (0.18-0.76).

CONCLUSIONS

In haematological patients, IL-1Ra has a comparable capacity with CRP and PCT to predict severe sepsis at the early stages of febrile neutropenia.

Soluble CD14 as a Diagnostic and Prognostic Biomarker in Hematological Patients with Febrile Neutropenia

Objective

Elevated levels of a cell surface glycoprotein, soluble cluster of differentiation 14 (sCD14), have been observed in patients with sepsis. Only scarce data are available on sCD14 in hematological patients with chemotherapy-induced febrile neutropenia. The study aim was to investigate sCD14 as an early biomarker in febrile neutropenia after intensive chemotherapy to detect a rapidly deteriorating clinical course early enough to avoid serious infectious complications.

Patients and Methods

This prospective study included 87 adult hematological patients at the start of febrile neutropenia after intensive chemotherapy for acute myeloid leukemia or after autologous stem cell transplantation. The study endpoints were septic shock, severe sepsis, and positive blood culture findings. sCD14 was analyzed from day 0 to day 2, and its prognostic capacity was compared to that of C-reactive protein and procalcitonin.

Results

Plasma level of sCD14 predicted the development of septic shock on day 1 (p = 0.001) and day 2 but not the development of severe sepsis or blood culture positivity in hematological patients with chemotherapy-induced febrile neutropenia.

Conclusions

Soluble CD14 did not predict an overall complicated course at the early stages of febrile neutropenia. However, it was helpful in predicting the progression of the clinical course of neutropenic fever to septic shock.

Diagnostic value of serum procalcitonin, lactate, and high-sensitivity C-reactive protein for predicting bacteremia in adult patients in the emergency department

BACKGROUND

Few studies compared the diagnostic value of procalcitonin with a combination of other tests including lactate and high-sensitivity C-reactive protein in the prediction of pathogenic bacteremia in emergency department adult patients.

METHODS

We performed a retrospective study assessing the differences in performances of procalcitonin at a cutoff of 0.5 ng/mL, lactate at a cutoff of 19.8 mg/dL, high-sensitivity C-reactive protein at a cutoff of 0.8 mg/dL and their combinations for predicting bacteremia in emergency department adult patients. Sensitivity, specificity, overall accuracy, positive-test and negative-test likelihood, and diagnostic odds ratio with 95% confidence interval for each test combination were calculated for comparison. The receiver operating characteristic curve for every single test were compared using DeLong's method. We also performed a sensitivity analysis in two expanded patient cohorts to assess the discriminative ability of procalcitonin or test combination.

RESULTS

A total of 886 patients formed the initial patient cohort. The area under the receiver operating characteristic curve for discriminating positive blood culture was: procalcitonin = 0.72 (95% CI [0.69-0.75]) with a derived optimal cutoff at 3.9 ng/mL; lactate 0.69 (0.66-0.72) with an optimal cutoff at 17.9 mg/dL; high-sensitivity C-reactive protein 0.56 (0.53-0.59) with an optimal cutoff of 13 mg/dL; with pairwise comparisons showing statistically significant better performance of either procalcitonin or lactate outperforming high-sensitivity C-reactive protein. To predict positive blood cultures, the diagnostic odds ratio for procalcitonin was 3.64 (95% CI [2.46-5.51]), lactate 2.93 (2.09-4.14), and high-sensitivity C-reactive protein 0.91 (0.55-1.55; P = 0.79). About combined tests, the diagnostic odds ratio for procalcitonin and lactate increases were 3.98 (95% CI [2.81-5.63]) for positive blood culture prediction. Elevated procalcitonin level rendered a six-fold increased risk of positive gram-negative bacteremia with a diagnostic odds ratio of 6.44 (95% CI [3.65-12.15]), which showed no further improvement in any test combinations. In the sensitivity analysis, as a single test to predict unspecified, gram-negative and gram-positive bacteremia, procalcitonin performed even better in an expanded cohort of 2,234 adult patients in terms of the diagnostic odds ratio.

DISCUSSIONS

For adult emergency patients, procalcitonin has an acceptable discriminative ability for bacterial blood culture and a better discriminative ability for gram-negative bacteremia when compared with lactate and high-sensitivity C-reactive protein. High-sensitivity C-reactive protein at a cutoff of 0.8 mg/dL performed poorly for the prediction of positive bacterial culture.

Relationship of serum mannose-binding lectin levels with the development of sepsis: a meta-analysis

Many studies have evaluated the association between serum levels of mannose-binding lectin (MBL) and sepsis; however, the findings are inconclusive and conflicting. For a better understanding of MBL in sepsis, we conducted a comprehensive meta-analysis. Potential relevant studies were identified covering Science Citation Index, the Cochrane Library, PubMed, Embase, CINAHL, and Current Contents Index databases. Two reviewers extracted data and assessed studies independently. Statistical analyses were conducted with the version 12.0 STATA statistical software. Ten papers were collected for meta-analysis. Results identified that sepsis patients had considerably lower MBL level than those in the controls (standardized mean difference (SMD) = 1.59, 95 % confidence interval (95%CI) = 0.86∼2.31, P < 0.001). Ethnicity-subgroup analysis showed that sepsis patients were associated with decreased serum MBL level in contrast to the healthy controls in Asians (SMD = 3.07, 95%CI = 1.27∼4.88, P = 0.001) and Caucasians (SMD = 1.00, 95%CI = 0.35∼1.65, P = 0.003). In the group-stratified subgroup analysis, subjects with lower serum MBL level did underpin susceptibility to sepsis in the infants subgroup (SMD = 2.57, 95%CI = 1.59∼3.55, P < 0.001); however, this was not the case in the adults subgroup (SMD = 0.13, 95%CI = -1.30∼1.55, P = 0.862). Our study suggests an important involvement of serum MBL level in sepsis patients considering their lower level compared to controls, especially among infants.

L-Asparaginase lowers plasma antithrombin and mannan-binding-lectin levels: Impact on thrombotic and infectious events in children with acute lymphoblastic leukemia

BACKGROUND

L-asparaginase, a key therapeutic agent in the management of patients with acute lymphoblastic leukemia (ALL), dramatically impairs hepatic protein synthesis. We investigated the effects of prolonged exposure to L-asparaginase on antithrombin (AT), fibrinogen and mannan-binding-lectin (MBL) levels, and on the occurrence of thrombotic events (TE) and febrile neutropenia episodes (FN) in pediatric patients.

PROCEDURE

Protein levels were measured in 97 children during 30 weeks of chemotherapy with L-asparaginase and up to 1 year following remission. TE and FN episodes were recorded during this period.

RESULTS

Median AT level decreased from 0.96 IU/mL prior to treatment (range: 0.69-1.38) to 0.55 IU/mL (0.37-0.76) during therapy. Fibrinogen and MBL decreased from 3.18 g/L (1.29-7.28) and 1,177 ng/mL (57-5,343) to 1.56 g/L (0.84-2.13) and 193 ng/mL (57-544), respectively. All three proteins had recovered 1-4 weeks after L-asparaginase cessation. TE were reported in 22 (23%) patients. Of these, 11 occurred after a median of 10 administrations of L-asparaginase. Fifty-one FN were associated with infections, of which 36 occurred during treatment with L-asparaginase. Patients with low levels of MBL at diagnosis were at higher risk of FN associated with infections (RR = 1.59, 95%CI: 1.026-2.474). Both AT and MBL decreases were moderately correlated with fibrinogen (r = 0.51 and 0.58, respectively).

CONCLUSIONS

Children with ALL are exposed to significant decrease in AT, fibrinogen and MBL levels, and concomitant increased risk of thrombosis and FN with infection during L-asparaginase treatment. Measuring plasma levels of these liver-derived proteins could help predict the occurrence of adverse events.

Sepsis biomarkers in neutropaenic systemic inflammatory response syndrome patients on standard care wards

BACKGROUND

Neutropaenic patients are at a high risk of contracting severe infections. In particular, in these patients, parameters with a high negative predictive value are desirable for excluding infection or bacteraemia. This study evaluated sepsis biomarkers in neutropaenic patients suffering from systemic inflammatory response syndrome (SIRS). Further, the predictive capacities of evaluated biomarkers in neutropaenic SIRS patients were compared to non-neutropaenic SIRS patients.

MATERIAL AND METHODS

In this prospective observational cohort study, patients with clinically suspected sepsis were screened. The predictive capacities of procalcitonin (PCT), C-reactive protein and lipopolysaccharide-binding protein (LBP) in neutropaenic SIRS patients were evaluated in terms of their potential to identify infection or bacteraemia and were compared to results for non-neutropaenic SIRS patients. To select an appropriate control cohort, propensity score matching was applied, balancing confounding factors between neutropaenic and non-neutropaenic SIRS patients.

RESULTS

Of 3370 prospectively screened patients with suspected infection, 51 patients suffered from neutropaenic SIRS. For the identification of infection, none of the assessed biomarkers presented a clinically relevant discriminatory potency. Lipopolysaccharide-binding protein and PCT demonstrated discriminatory capacity to discriminate between nonbacteraemic and bacteraemic SIRS in patients with neutropaenia [receiver-operating characteristics-area under the curves (ROC-AUCs): 0.860, 0.818]. In neutropaenic SIRS patients, LBP had a significantly better ROC-AUC than in a comparable non-neutropaenic patient cohort for identifying bacteraemia (P = 0.01).

CONCLUSION

In neutropaenic SIRS patients, none of the evaluated biomarkers was able to adequately identify infection. LBP and PCT presented a good performance in identifying bacteraemia. Therefore, these markers could be used for screening purposes to increase the pretest probability of blood culture analysis.

Bacteremia in Swedish hematological patients with febrile neutropenia: bacterial spectrum and antimicrobial resistance patterns

BACKGROUND

The etiology of bacteremia in hematological patients with febrile neutropenia differs geographically and changes over time. Since efficient empirical antibiotic treatment depends on relevant knowledge of the bacterial panorama, the aim of this study was to describe the prevalence of bacteremia, the bacterial spectrum, and the resistance patterns of the isolates in this group today.

METHODS

In a cross-sectional study, routine blood cultures from febrile episodes occurring in adult patients with hematological disorders and neutropenia presenting to Karolinska University Hospital, Stockholm, Sweden during a 24-month period, were analyzed.

RESULTS

A total of 142 febrile neutropenic episodes occurring in 124 hematological patients were included in the study. Bacteremia was documented in 27% of the episodes, and of these, 58% were due to Gram-positive pathogens. The most common isolates were viridans streptococci, coagulase-negative staphylococci, and Escherichia coli. Low levels of antibiotic resistance were detected. The underlying diagnosis of non-Hodgkin's lymphoma (NHL) was independently negatively associated with documented bacteremia (p < 0.01).

CONCLUSIONS

The prevalence of bacteremia and the bacterial spectrum were consistent with recent Scandinavian reports. Substantially lower levels of antimicrobial resistance were registered compared to those found in other European centers. Patients with NHL were less likely to have documented bacteremia in this study.

Plasma copeptin in the assessment of febrile neutropenia

Copeptin, the surrogate marker of arginine vasopressin (AVP), has been suggested to be a useful biomarker in monitoring sepsis reflecting hemodynamic imbalance and stress state. This prospective study conducted at a hematology ward in a Finnish University Hospital aimed to investigate whether plasma copeptin predicts the development of complicated course of neutropenic fever (bacteremia or need for treatment at intensive care unit) in 100 hematological patients experiencing their first neutropenic fever episode after intensive chemotherapy for hematological malignancy. Contrary to study presumptions, not elevated copeptin but the lack of a proper initial increase of plasma copeptin (<0.02 ng/mL from day 0 to day 1) predicted blood culture positive sepsis (p=0.023) and gram-negative bacteremia (p=0.045). No correlation was observed with plasma sodium, blood pressure or evaluated osmolality. Plasma copeptin correlated inversely with the same day pentraxin 3 on day 0-day 2 (all p-values <0.001) and with C-reactive protein on day 1 (p=0.015). In conclusion, copeptin did not correlate with disease severity, but the lack of a proper initial increase was associated with bacteremic complications of febrile neutropenia in hematological patients. The findings suggest the possibility of central dysregulation of AVP release and do not support the use of copeptin as a biomarker of septic complications in this patient group.