Prediction of gram-negative bacteremia in patients with cancer and febrile neutropenia by means of interleukin-8 levels in serum: targeting empirical monotherapy versus combination therapy

Clinical features of febrile neutropenia and bloodstream infection in autologous hematopoietic cell transplantation: Comparison to those in intensive chemotherapy for acute myeloid leukemia

BACKGROUND

In autologous hematopoietic cell transplantation (HCT), myelosuppression and mucosal damage are more severe than those in conventional chemotherapy because of high-dose chemotherapy, but the duration of neutropenia is shorter due to stem cell rescue.

METHODS

We retrospectively evaluated febrile neutropenia (FN) and bloodstream infection (BSI) in 208 patients who underwent their first autologous HCT at our institution between 2007 and 2019. They were compared to those in patients who underwent intensive chemotherapy for acute myeloid leukemia (AML) (130 induction/salvage and 191 consolidation).

RESULTS

The median neutropenic period in autologous HCT, AML induction/salvage and consolidation was 9, 26.5, and 19 days, respectively. The incidence of FN was 93.8%, 92.3%, and 81.7%, and that of BSI in initial FN was 7.2%, 7.5% and 26.3%, respectively. The incidence of oral mucositis (≥ grade 2) was 63.1%, 9.2% and 12.2%, and that of diarrhea (≥ grade 2) was 53.3%, 9.2% and 6.4%, respectively. Although there were significant differences in the incidence of shaking chills, the degree of fever and the value of CRP between patients with and without BSI in initial FN of AML chemotherapy, no significant risk factors or predictive factors for BSI were identified in autologous HCT.

CONCLUSIONS

The profile of infectious complications in autologous HCT was characterized by a high incidence of FN maybe due to mucosal damage. On the other hand, the incidence of BSI was lower compared to that in AML consolidation chemotherapy.

Prospective validation of a risk prediction model for severe sepsis in children with cancer and high-risk febrile neutropenia

BACKGROUND

We previously created a risk prediction model for severe sepsis not clinically apparent during the first 24 hours of hospitalization in children with high-risk febrile neutropenia (HRFN), which identified 3 variables, age ≥ 12 years, serum C-reactive protein (CRP) ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL, evaluated at the time of admission and at 24 hours of hospitalization. The combination of these 3 variables identified a risk for severe sepsis ranging from 8% to 73% with a relative risk of 3.15 (95% confidence interval: 1.1-9.06). The aim of this study was to validate prospectively our risk prediction model for severe sepsis in a new cohort of children with cancer and HRFN.

METHODS

Predictors of severe sepsis identified in our previous model (age, CRP and interleukin-8) were evaluated at admission and at 24 hours of hospitalization in a new cohort of children with HRFN between April 2009 and July 2011. Diagnosis of severe sepsis, not clinically apparent during the first 24 hours of hospitalization, was made after discharge by a blind evaluator.

RESULTS

A total of 447 HRFN episodes were studied, of which 76 (17%) had a diagnosis of severe sepsis. The combination of age ≥ 12 years, CRP ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL at admission and/or at 24 hours in the new cohort identified a risk for severe sepsis ranging from 7% to 46% with an RR of 6.7 (95% CI: 2.3-19.5).

CONCLUSIONS

We validated a risk prediction model for severe sepsis applicable to children with HRFN episodes within the first 24 hours of admission. We propose to incorporate this model in the initial patient assessment to offer a more selective management for children at risk for severe sepsis.

IL-8 predicts pediatric oncology patients with febrile neutropenia at low risk for bacteremia

INTRODUCTION

Despite a low bacteremia rate, pediatric oncology patients are frequently admitted for febrile neutropenia. A pediatric risk prediction model with high sensitivity to identify patients at low risk for bacteremia is not available. We performed a single-institution prospective cohort study of pediatric oncology patients with febrile neutropenia to create a risk prediction model using clinical factors, respiratory viral infection, and cytokine expression.

MATERIALS AND METHODS

Pediatric oncology patients with febrile neutropenia were enrolled between March 30, 2010 and April 1, 2011 and managed per institutional protocol. Blood samples for C-reactive protein and cytokine expression and nasopharyngeal swabs for respiratory viral testing were obtained. Medical records were reviewed for clinical data. Statistical analysis utilized mixed multiple logistic regression modeling.

RESULTS

During the 12-month period, 195 febrile neutropenia episodes were enrolled. There were 24 (12%) episodes of bacteremia. Univariate analysis revealed several factors predictive for bacteremia, and interleukin (IL)-8 was the most predictive variable in the multivariate stepwise logistic regression. Low serum IL-8 predicted patients at low risk for bacteremia with a sensitivity of 0.9 and negative predictive value of 0.98.

CONCLUSIONS

IL-8 is a highly sensitive predictor for patients at low risk for bacteremia. IL-8 should be utilized in a multi-institution prospective trial to assign risk stratification to pediatric patients admitted with febrile neutropenia.

Inflammatory cytokine measurement quickly discriminates gram-negative from gram-positive bacteremia in pediatric hematology/oncology patients with septic shock

PURPOSE

We performed a prospective study to evaluate the ability of inflammatory cytokines in discriminating gram-negative from gram-positive bacteremia in septic shock.

METHODS

During the study period, the serum inflammatory cytokine levels were measured at the onset of septic shock by flow cytometry in pediatric hematology/oncology patients with septic shock.

RESULTS

One hundred episodes of septic shock were enrolled. Of 97 episodes of monomicrobial infection, 73.2 % were caused by gram-negative bacteremia and 26.8 % by gram-positive bacteremia. Interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α were closely related to the pediatric index of mortality 2 (PIM2) score and mortality. However, although the PIM2 score and mortality were comparable, the IL-6, IL-10, and TNF-α levels were significantly higher in patients with gram-negative bacteremia (GNB) than those with gram-positive bacteremia (median levels, pg/mL: IL-6: 784.1 vs. 254.4, P = 0.001; IL-10: 192.2 vs. 19.7, P < 0.001; TNF-α: 4.2 vs. 2.0, P < 0.001). Of the three cytokines, IL-10 was the most useful biomarker for GNB prediction in the derivation cohort and a cutoff value of 50 pg/mL showed a sensitivity of 70.8 % and a specificity of 80.0 %, with a positive predictive value of 89.5 %. When this cutoff value was applied to the validation cohort, the sensitivity, specificity, and positive predictive value were 80.9, 75.0, and 90.5 %, respectively.

CONCLUSIONS

Flow cytometry-based inflammatory cytokine measurement is a helpful adjuvant approach for early and quick discrimination of gram-negative from gram-positive bacteremia in pediatric hematology/oncology patients with septic shock which might be useful for evaluating the severity of shock and the selection and/or timely withdrawal or switch of antibiotics.

Prediction of community-onset bacteremia among febrile adults visiting an emergency department: rigor matters

OBJECTIVES

Bacteremia is a severe bacterial infection with significant mortality and morbidity. Clinical parameters that reliably predict the presence of community-onset bacteremia are less elucidated.

METHODS

During 96 randomly selected days between August 2006 and July 2007, a prospective study was conducted to analyze the risk factors of community-onset bacteremia among febrile adults who visited the emergency department (ED) of a medical center. Patients hospitalized in the 30 days prior to the study, patients experiencing consciousness alteration, and nursing facility residents were excluded.

RESULTS

The mean age of the 396 febrile adults enrolled in the study was 53.8 years (range, 18-95 years), and 60 (15.2%) patients had true bacteremia, with the predominance of monomicrobial Gram-negative pathogens (42 patients). In a multivariate analysis, several factors were independently associated with community-onset bacteremia, including an age of >65 years (odds ratio [OR], 2.81; 95% confidence interval [CI], 1.25-6.33), the presence of rigor (OR, 13.7; 95% CI, 4.47-42.0) or chills (OR, 6.04; 95% CI, 1.10-32.9), a body temperature >39.9 °C (OR, 2.68; 95% CI, 1.03-6.94), blood urea nitrogen >20 mg/dL (OR, 5.56; 95% CI, 2.03-15.7), a blood urea nitrogen/creatinine ratio >16 (OR, 2.29; 95% CI, 1.03-5.11), and thrombocytopenia (OR, 6.09; 95% CI, 1.84-20.0). After scoring each risk factor, a logistic regression model for the prediction of bacteremia was developed, and the area under the receiver operating characteristic curve was 0.91.

CONCLUSIONS

Some easily determined clinical parameters were independently associated with community-onset bacteremia among febrile adults, and the most significant predictor was the presence of rigor. Although the proposed predictive model needs further validation, it may be of use for the early identification of bacteremic episodes in ED practice.

Prognostic evaluation of febrile neutropenia in apparently stable adult cancer patients

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BACKGROUND

Predictive models to identify low-risk febrile neutropenia (FN) have been developed with heterogeneous samples, which included stable and unstable patients, solid tumours, acute leukaemia and bone marrow transplantation. These models fail to recognise 5-15% of cases with unexpected complications, and literature specifically addressing apparently stable patients (ASPs) is scarce.

METHODS

We reviewed 861 episodes of FN in outpatients with solid tumours, including 692 (80%) episodes with apparent clinical stability. We aimed to investigate the prognosis of this latter group and explore the possibility of stratifying it according to the presenting features. A case-control study was performed and the MASCC index was evaluated.

RESULTS

The rates of complications and bacteraemia in ASPs were 7.3% and 6.2%, respectively. The MASCC index yielded a low sensitivity to detect complications (36%). Prognostic factors were identified: ECOG performance status ≥2, chronic bronchitis, chronic heart failure, stomatitis NCI grade ≥2, monocytes <200 mm(-3) and stress hyperglycaemia.

CONCLUSION

A very simple assessment is useful to classify the patients with FN according to the risk of complications. A few additional variables may predict the clinical course of the patients. We additionally show that the MASCC index applied to this specific group has a low sensitivity to predict complications.

Pitfalls in using serum C-reactive protein to predict bacteremia in febrile adults in the ED

OBJECTIVES

The diagnostic performance of serum C-reactive protein (CRP) in prediction of bacteremia among febrile patients visiting an emergency department (ED) was analyzed.

METHODS

During randomly selected 96 days between August 2006 and July 2007, a prospective study of febrile adults visiting the ED of a medical center was conducted to analyze the clinical characters associated with bacteremia.

RESULTS

Of the total 454 febrile adults enrolled, their mean age was 54.1 years, and 232 (54.6%) were women. Major comorbidities included cardiovascular disease (137 patients, or 30.1%) and diabetes mellitus (105, or 23.1%). Seventy-four patients (16.2%) had true bloodstream infections with the predominance of monomicrobial gram-negative bacteremia in 49 patients (10.7%). Four risk factors, including low platelet count (<100 000/mm(3); odds ratio [OR], 4.19; 95% confidence interval [CI], 1.85-9.47; P = .001), high blood urea nitrogen (>20 mg/dL; OR, 4.61; 95% CI, 2.56-8.31; P < .001), high fever (>39.0°C; OR, 3.67; 95% CI, 2.05-6.59; P < .001), and high Pittsburg bacteremia scores (≧4 points; OR, 2.95; 95% CI, 1.01-8.57; P = .04) were independently associated with bacteremic episodes. Of note, high CRP (>150 mg/dL; OR, 1.75; 95% CI, 0.73-3.99; P = .21) was not an independent risk factor. In further analysis, the difference of serum CRP levels between bacteremic and nonbacteremic adults was significant only when the period from fever onset to ED arrival was more than 12 hours.

CONCLUSIONS

The CRP level was not reliable to distinguish the bacteremia from nonbacteremic infection, whereas duration after fever onset was less than 12 hours. Clinicians must consider the history of fever onset to improve the accuracy of early prediction of serum CRP before the microbiological results of blood cultures is available.

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.

The diagnostic value of CRP, IL-8, PCT, and sTREM-1 in the detection of bacterial infections in pediatric oncology patients with febrile neutropenia

Purpose

In this study, we evaluated C-reactive protein (CRP), interleukin (IL)-8, procalcitonin (PCT), and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) as predictors for bacterial infection in febrile neutropenia, plus their usefulness in febrile neutropenia during chemotherapy-induced gastrointestinal mucositis.

Methods

Plasma was obtained from pediatric oncology patients at presentation with febrile neutropenia (n = 43) and 24–48 h later (n = 17). The patients were classified as having or not having a bacterial infection. Plasma was also obtained of patients in the absence and in the presence of mucositis (n = 26).

Results

At presentation with febrile neutropenia, median IL-8 and PCT levels were significantly increased in patients with a bacterial infection, in contrast to CRP and sTREM-1. IL-8 was the most sensitive marker for the early detection of bacterial infection, in combination with clinical parameters or PCT the sensitivity reached 100%. After 24–48 h, only PCT was significantly elevated during bacterial infection. IL-8 levels were significantly increased during mucositis. Mucositis did not cause considerable changes in PCT levels.

Conclusions

IL-8 is the most useful marker for the early detection of bacterial infections, compared with CRP, PCT, and sTREM-1. IL-8 in combination with clinical parameters or PCT might be even more useful. Gastrointestinal mucositis alone does not affect PCT levels, in contrast to IL-8 levels, and therefore, PCT might be more useful for the detection of bacterial infections during mucositis than IL-8.

Predicting febrile neutropenic patients at low risk using the MASCC score: does bacteremia matter?

BACKGROUND

Febrile neutropenic cancer patients represent a heterogeneous population with a limited proportion at risk of serious medical complications. The Multinational Association for Supportive Care in Cancer (MASCC) score has been developed and validated for identifying low-risk patients at the onset of febrile neutropenia. Since bacteremia, although not documented at baseline, is a predictor of pejorative outcome, the purpose of this study was to investigate the possible interaction between the MASCC score and bacteremic status and to assess whether, assuming that bacteremic status could be predicted at onset of febrile neutropenia, adding bacteremia as a covariate in a risk model would improve the accuracy of low-risk patients identification.

METHODS

Two consecutive multicentric observational studies were carried out from 1994 till 2005 involving 2,142 febrile neutropenic patients. The study data bases were retrospectively used for the present analysis.

RESULTS

A predictive value was found for the MASCC score in all strata obtained by stratification for the bacteremic status with odds ratios for successful outcome being, in patients with a score ≥21, respectively, 6.06 (95%CI: 4.51-8.15), 3.42 (95%CI: 1.95-5.98), and 6.04 (95%CI: 3.01-12.09) in patients without bacteremia, gram-positive bacteremia, and gram-negative bacteremia. No interaction between the MASCC score and the bacteremic status was present. A clinical prediction rule integrating the MASCC score and the bacteremic status was not helpful in improving the identification of low-risk patients. This rule may then be used in a general population of patients with febrile neutropenia without having concerns for a lower predictive value in bacteremic patients.

CONCLUSIONS

Our results suggest that the knowledge, provided we could find a model to predict it at fever onset, of a bacteremic etiology of the fever would be of little additional value to the MASCC score when attempting to identify low-risk patients.

Cytokine concentrations are not predictive of bacteremia in febrile neutropenic patients

Assay of cytokines and C reactive protein (CRP) in different periods of febrile neutropenia may be helpful for early defining the risk in severe infections. We determined serum interleukin-6 (IL-6), interleukin-8 (IL-8), soluble interleukin-2 receptor (sIL-2R), tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1beta), and CRP in 22 previously untreated patients with various malignancies. Samples were obtained in four different clinical periods of febrile neutropenia; prior to chemotherapy, afebrile neutropenic period after chemotherapy, febrile neutropenic period, and recovery period. When compared to sex-and age-matched group of healthy subjects, IL-6, IL-8, sIL-2R, and CRP levels were found to be elevated in all periods. The highest levels were encountered in the febrile neutropenic period. For predictivity purposes, the afebrile neutropenic period was the most important period. Serum sIL-2R, IL-6, IL-8 and CRP levels were elevated in this period. IL-8 levels showed the most stable elevation through different stages of febrile neutropenia. Serum IL-8 levels were found to have the most reliable and stable elevation in different clinical stages of febrile neutropenia. Nevertheless, IL-8 is not able to discriminate among risk groups and cannot be used as a predictive factor.

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.

Interleukin-8 as a stratification tool for interventional trials involving pediatric septic shock

RATIONALE

Interventional clinical trials involving children with septic shock would benefit from an efficient preenrollment stratification strategy.

OBJECTIVES

To test the predictive value of interleukin (IL)-8 for 28-day mortality in pediatric septic shock.

METHODS

A training data set (n = 40) identified a serum IL-8 of greater than 220 pg/ml as having a 75% sensitivity and specificity for predicting 28-day mortality. This cutoff was then subjected to a series of validation steps.

MEASUREMENTS AND MAIN RESULTS

Subjects were drawn from two large, independent pediatric septic shock databases. Prospective application of the IL-8 cutoff to validation data set 1 (n = 139) demonstrated 78% sensitivity and 64% specificity for 28-day mortality. A serum IL-8 level of 220 pg/ml or less, however, had a negative predictive value for 28-day mortality of 95% in validation data set 1, which was subsequently applied to an independently generated data set of children with septic shock (validation set 2, n = 193). A serum IL-8 level of 220 pg/ml or less had a negative predictive value for 28-day mortality of 94% when applied to validation set 2.

CONCLUSIONS

A serum IL-8 level of 220 pg/ml or less, obtained within 24 hours of admission, predicts a high likelihood of survival in children with septic shock. We propose that IL-8 can be used to exclude such patients from interventional clinical trials and ultimately derive a study population with a more favorable risk to benefit ratio when subjected to a study agent.

Admission clinical and laboratory factors associated with death in children with cancer during a febrile neutropenic episode

BACKGROUND

Early identification of children with cancer at risk for death during a febrile neutropenic (FN) episode may increase their possibility for survival. Our aim was to identify at the time of admission, clinical and laboratory variables differing significantly among children who survived or died during a FN episode.

METHODS

In a prospective, multicenter study, children admitted with a high-risk FN episode were uniformly evaluated at enrollment and managed according to a national consensus protocol. Medical charts of children who died were evaluated to determine whether the death could be associated with an infection. Admission clinical and laboratory variables significantly associated with death were identified.

RESULTS

A total of 393 (70%) of 561 FN episodes evaluated from June 2004 to December 2005 were classified as high risk for invasive bacterial infection, of which 14 (3.6%) resulted in an infectious-related death. Deaths occurred from 2 to 27 days after admission, and most dying children were admitted with relapse of acute lymphocytic leukemia (36%), hypotension (71%), and a diagnosis of sepsis (79%), compared with surviving children (16%, 20%, and 5% respectively, P < 0.001). Children who died were admitted with lower absolute neutrophil count (P < 0.001) and absolute monocytes count levels (P = 0.008), higher blood urinary nitrogen (P = 0.03) and C-reactive protein values (P < 0.001), and had more positive cultures (79% versus 32%, P = 0.008).

CONCLUSIONS

We identified early clinical and laboratory findings significantly associated with death occurring at a later stage. Routine evaluation of these variables may prove to be useful in the early identification of children with a high-risk FN episode at risk for death.

Polymorphisms in Genes Involved in Innate Immunity Predispose Toward Mycetoma Susceptibility

Madurella mycetomatis is the main causative agent of mycetoma, a tumorous fungal infection characterized by the infiltration of large numbers of neutrophils at the site of infection. In endemic areas the majority of inhabitants have Abs to M. mycetomatis, although only a small proportion of individuals actually develop mycetomal disease. It therefore appears that neutrophils are unable to clear the infection in some individuals. To test this hypothesis, 11 single nucleotide polymorphisms involved in neutrophil function were studied in a population of Sudanese mycetoma patients vs geographically and ethnically matched controls. Significant differences in allele distribution for IL-8 (CXCL8), its receptor CXCR2, thrombospondin-4 (TSP-4), NO synthase 2 (NOS2), and complement receptor 1 (CR1) were found. Further, the NOS2(Lambaréné) polymorphism was clearly associated with lesion size. The genotypes obtained for CXCL8, its receptor CXCR2, and TSP-4 all predisposed to a higher CXCL8 expression in patients, which was supported by the detection of significantly elevated levels of CXCL8 in patient serum. The NOS2 genotype observed in healthy controls was correlated with an increase in NOS2 expression and higher concentrations of nitrate and nitrite in control serum. We present the first evidence of human genetic predisposition toward susceptibility to mycetoma, a neglected infection of the poor.

The diagnostic value of C-reactive protein, interleukin-8, and monocyte chemotactic protein in risk stratification of febrile neutropenic children with hematologic malignancies

BACKGROUND AND AIM

Recent advances in febrile neutropenia have highlighted the value of risk stratification especially that it can have important implications in terms of management. We aimed to identify a serum marker that may help to stratify febrile neutropenic pediatric patients treated for hematologic malignancies at the time of first evaluation. Thus, C-reactive protein (CRP), interleukin-8 (IL-8), and monocyte chemotactic protein-1-alpha (MCP-1-alpha) were evaluated for their predictive and diagnostic relevance in febrile episodes of cancer patients.

PATIENTS AND METHODS

Within 24 hours of fever, CRP, IL-8, and MCP-1 serum levels were measured and the levels of these markers were related to the clinical findings of the patients. For this purpose, we collected and analyzed clinical data of 85 fever episodes occurring in 76 patients with hematologic malignancies, presenting to the Department of Pediatric Oncology, National Cancer Institute, Cairo University, during a 6-month period.

RESULTS

Neutropenic children with febrile episodes were classified into 2 groups, a group with unexplainable fever (group I, n=26) and another group with either blood culture positive, and/or fever periods with a documented clinical sepsis and/or local infection (group II, n=59). Clinically, local sites of infection were encountered in 39 cases (45.9%), whereas a positive blood culture was detected in 20 cases. CRP, IL-8, and MCP-1 levels were significantly lower in group I versus group II (P value <0.001). There were overlaps of values between groups. CRP > or =90 mg/L was significantly associated with chemotherapy-related neutropenia and fever owing to bacteremia (P=0.038). The sensitivity, specificity, negative and positive predictive values of CRP, MCP-1, and IL-8 were (70%, 73%, 51%, and 85%), (64%, 92%, 53%, and 95%), and (71%, 77%, 54%, and 88%), respectively. Combining 2 or 3 markers improved the diagnostic performance of these test, as 78% of group II had elevated 2 or 3 markers versus 16% of the group with no evident infection.

CONCLUSIONS

Low levels of CRP, MCP-1, and IL-8 could identify patients with unexplainable fever; whereas, high levels of these markers were of help in the diagnosis of infectious episodes. A model combining more than 1 marker is recommended in the assessment of febrile neutropenia.

Comparison of whole blood interleukin-8 and plasma interleukin-8 as a predictor for sepsis in postoperative patients

OBJECTIVE

Interleukin-8 (IL-8, also known as neutrophil-activating peptide 1, NAP1 and CXCL8, CXC chemokine ligand 8) is recognized as a potent effector of neutrophil functions. IL-8 is a major response factor following NfkB activation by cytokines or lipopolysaccharide and several different cell types T lymphocytes, monocytes, epithelial and endothelial cells secrete this polypeptide. IL-8 is not to be determined at significant concentrations in plasma due to its receptor binding but may play a major role in tissues. The prediction of sepsis is a major and current field of research in the treatment of surgical patients. The aim of this study was to compare the determination of IL-8 in whole blood cell lysates (whole blood IL-8) and in plasma for the prediction of sepsis in postoperative intensive care.

DESIGN

Whole blood IL-8, IL-8 in plasma, and CRP were measured in the daily routine monitoring of 84 patients in a surgical intensive care unit. Sepsis was defined by the criteria of the Society of Critical Care Medicine (SCCM). For comparison the APACHE II score (APACHE=Acute Physiology and Chronic Health Evaluation) was calculated. The diagnostic value of the three tests was compared by receiver operating characteristic (ROC) curves.

RESULTS

Whole blood IL-8 showed higher areas under the curve (AUC) than IL-8 in plasma and CRP. The ROC curves for the APACHE II scores gave similar results.

CONCLUSIONS

Sepsis is a complex disease and is induced by systemic infection of patients suffering from systemic inflammatory response syndromes (SIRS). Therefore, the identification of infection or the host response to infection is of crucial importance. The prediction of an individual marker or interleukin or its binding to surface proteins is not necessarily indicative for sepsis. In cases with unequivocally identified bacterial infections, the current results suggest that whole blood IL-8 may have a similar diagnostic accuracy as plasma levels. Of note, this technique needs less blood and is not being affected by hemolysis.

The role of oral mucositis on the systemic inflammation parameter IL-8 in febrile neutropenic cancer patients

PURPOSE

Cancer patients treated with cytostatic drugs often develop oral mucositis, considered to be a mucosal injury in which various cytokines, such as interleukin 8 (IL-8), may play a role. Plasma IL-8 is a systemic inflammatory response parameter. This study investigated whether oral mucositis affects plasma IL-8 levels in febrile neutropenic cancer patients.

PATIENTS AND METHODS

Patients (n = 57) who were hospitalized with chemotherapy-induced neutropenic fever were scored for oral mucositis on the second day of hospitalization according to a validated oral mucositis assessment scale (OMAS) and WHO toxicity grading. Patients (n = 20) with a clinical sepsis or local bacterial infection were excluded from this evaluation. The remaining 37 patients were divided in groups with and without oral mucositis.

RESULTS

The difference in plasma IL-8 level between patients with and without mucositis was not significant (P = 0.7). Similarly no difference was observed in the degree and duration of granulocytopenia.

CONCLUSION

These results indicate that low-grade oral mucositis is not related to the systemic plasma IL-8 level in febrile neutropenic cancer patients without a clinical sepsis or local bacterial infection.

Sedimentation characteristics of leucocytes can predict bacteraemia in critical care patients

BACKGROUND

Early detection of blood stream infection can be lifesaving, but the results of blood cultures are not usually available before 24 hours after blood sampling. An earlier indication would lead to the initiation of immediate and adequate antibiotic treatment with obvious advantages for the patient.

OBJECTIVE

To evaluate the ability of leucocyte count, serum procalcitonin (PCT) concentration, erythrocyte sedimentation rate (ESR), and leucocyte antisedimentation rate (LAR) in predicting the blood culture results in critical care patients.

METHODS

39 consecutive patients with their first febrile episode were investigated prospectively. LAR was determined as the percentage of leucocytes crossing the midline of a blood column upward during one hour of gravity sedimentation. The relevance of the different variables was estimated by likelihood ratio tests and area under receiver operating characteristic curves (AUC).

RESULTS

23 patients had positive blood culture results and 16 negative. LAR was significantly higher in bacteraemic patients than in non-bacteraemic patients (p = 0.001), but leucocyte count, ESR and PCT level failed to show significant differences. Leucocyte count, PCT, and ESR yielded low discriminative values with the AUCs of 0.66, 0.64, and 0.52, respectively. LAR provided a likelihood ratio of 3.6 and an AUC of 0.80 (95% confidence interval, 0.64 to 0.95) (p = 0.002).

CONCLUSIONS

The simple LAR test can predict blood culture results and support urgent treatment decisions in critical care patients in their first febrile episode.

Risk assessment and treatment of low-risk patients with febrile neutropenia

Progress has been made in the development and validation of rules that attempt ito predict a low risk (<10%) of severe infection or clinical complications in patients with cancer, fever, and neutropenia. It is uncertain, however, which model is optimal, with respect to test characteristics, applicability, and interinstitutional reliability, and prospective model validation in a multicenter context among outpatients has not been performed. Clinical criteria, such as comorbidities and performance status, remain critical in the risk-assessment process and probably are used by most physicians caring for patients with cancer who are febrile and neutropenic. Clinical prediction rules might be improved in the future by including measurements of inflammatory markers, such as procalcitonin. Reliable prediction of the risk of medical complications may be relevant for decisions regarding parenteral versus oral antimicrobial therapy, but it is definitely needed for decisions regarding site of care. Site-of-care decisions require thorough assessment not only of medical criteria, but also of psychosocial and organizational and/or logistic criteria. If the appropriate infrastructure to provide follow-up is available, home-based therapy with oral (or parenteral) antibiotics is an acceptable option in the care of patients with cancer who have intercurrent febrile neutropenia and a predicted low risk for medical complications.

Feasibility of withholding antibiotics in selected febrile neutropenic cancer patients

PURPOSE

To investigate the feasibility of withholding antibiotics and early discharge for patients with chemotherapy-induced neutropenia and fever at low risk of bacterial infection by a new risk assessment model.

PATIENTS AND METHODS

Outpatients with febrile neutropenia were allocated to one of three groups by a risk assessment model combining objective clinical parameters and plasma interleukin 8 level. Patients with signs of a bacterial infection and/or abnormal vital signs indicating sepsis were considered high risk. Based on their interleukin-8 level, remaining patients were allocated to low or medium risk for bacterial infection. Medium-risk and high-risk patients received standard antibiotic therapy, whereas low-risk patients did not receive antibiotics and were discharged from hospital after 12 hours of a febrile observation. End points were the feasibility of the treatment protocol.

RESULTS

Of 196 assessable episodes, 76 (39%) were classified as high risk, 84 (43%) as medium risk, and 36 (18%) as low risk. There were no treatment failures in the low-risk group (95% CI, 0% to 10%). Therefore, sensitivity of our risk assessment model was 100% (95% CI, 90% to 100%), the specificity, positive, and negative predictive values were 21%, 13%, and 100%, respectively. Median duration of hospitalization was 3 days in the low-risk group versus 7 days in the medium- and high-risk groups (P < .0001). The incremental costs of the experimental treatment protocol amounted to a saving of 471 (US $572) for every potentially low-risk patient.

CONCLUSION

This risk assessment model appears to identify febrile neutropenic patients at low risk for bacterial infection. Antibiotics can be withheld in well-defined neutropenic patients with fever.

Assessment of systemic inflammation markers to differentiate a stable from a deteriorating clinical course in patients with febrile neutropenia

In this study, we evaluated the predictive values of procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6) and serum amyloid A (SAA) for determining the clinical course in febrile neutropenic patients. Daily plasma analyses during the fever course were performed in 101 episodes with fever and chemotherapy-induced neutropenia (neutrophil count <0.5 x 10(9)/L). Procalcitonin (PCT) and IL-6 values were significantly higher in febrile episodes in patients who developed complications. Procalcitonin with a cut-off value of < or =0.4 ng/mL or IL-6 < or =50 pg/mL 3 d after fever onset indicated daily high negative predictive values (NPVs) (91-100%) for episodes with complications. No marker could predict deterioration; however, daily low plasma concentrations of PCT or IL-6 during the first 8 d of fever were found to be a good predictor of no subsequent complications in neutropenic patients and therefore to be a helpful tool for limiting anti-microbial therapy.

Impact of fluoroquinolone prophylaxis on reduced infection-related mortality among patients with neutropenia and hematologic malignancies

BACKGROUND

Fluoroquinolone prophylaxis during neutropenia in patients with cancer has been associated with decreased incidence of gram-negative bacteremia. Bacterial antimicrobial resistance is likely to cause a progressive lack of efficacy of fluoroquinolones, but no convincing evidence from clinicoepidemiologic observations has proved this hypothesis.

METHODS

This prospective observational study assessed the impact of discontinuing fluoroquinolone prophylaxis on the incidences of fever and bacteremia and on mortality among patients with neutropenia, after chemotherapy for hematologic malignancies.

RESULTS

After a 12-month baseline period of levofloxacin prophylaxis, a period of discontinuation of fluoroquinolone prophylaxis was planned but was stopped prematurely after 9 neutropenic episodes over 3 weeks, because the mortality rate (33.3%) was higher than that with routine fluoroquinolone prophylaxis (2.9%) (odds ratio [OR], 16.6; 95% confidence interval [CI], 3.6-77.2). Fewer patients had gram-negative bacteremia during the baseline period (4.8%; n=15) than during the discontinuation period (44.4%; n=4) (OR, 16.9; 95% CI, 4.1-70.0). After levofloxacin therapy was reintroduced, the incidence of gram-negative bacteremia and the mortality rate were comparable to those during the first period. Escherichia coli isolated during the discontinuation period was susceptible to levofloxacin in vitro, whereas all E. coli isolates isolated during both prophylaxis periods were resistant. Bloodstream infections were caused by a single agent when the patient had received levofloxacin prophylaxis, whereas most cases of gram-negative bacteremia were polymicrobial after discontinuation.

CONCLUSIONS

These findings suggest that, despite increasing rates of antimicrobial resistance, levofloxacin prophylaxis during neutropenia may have a beneficial impact on morbidity and infection-related mortality. Continued monitoring of the rate of gram-negative bacteremia is warranted for timely detection of the loss of efficacy of fluoroquinolone prophylaxis.

Management of infections in critically ill neutropenic cancer patients

Because of improving antineoplastic treatment options with increasing cure rates, prolonging survival, and improving quality of life, the reluctance to admit patients with malignant disease to an intensive care unit is not justified; thus, the number of patients with malignancies treated in intensive care units rises. The use of more aggressive anticancer regimens leads to an increase of attendant infections, which are the most frequent and often life-threatening complications in cancer patients. A multidisciplinary practical approach to evaluation and treatment is needed to optimize treatment results and to meet the various diagnostic and therapeutic challenges in this subset of patients on an intensive care unit.

Role of endogenous macrophage inflammatory protein-2 in regulating fever induced by bacterial endotoxin in normal and immunosuppressed rats

During myelosuppressive chemotherapy, Gram-negative bacterial infection with consequent exposure to lipopolysaccharide (LPS) is one of the most important causes of persistent fever. The classical model of the pathogenesis of fever suggests that pro-inflammatory cytokines, produced by leucocytes in the bloodstream in response to exogenous pyrogens such as bacterial LPS, represent the distal mediators of the febrile response. Neutrophils are the first effectors cells and the most prominent leucocyte population involved in acute bacterial infection. Macrophage inflammatory protein (MIP)-2 plays a crucial role in influencing early cell trafficking and neutrophil activation during pathophysiological processes and serves the same chemotactic function as human interleukin-8. In the present study, we investigated the role of MIP-2 in the development of a febrile response induced by LPS in immunocompetent and leukopenic rats. Intraperitoneal injection of LPS in leukopenic rats elicited a biphasic febrile response of rapid onset, the magnitude and duration of which were significantly greater than in immunocompetent animals. The febrile responses to LPS were accompanied by a pronounced induction of serum MIP-2 levels at 1, 2 and 4 h compared with their respective controls. In both normal and leukopenic rats, neutralization of endogenous MIP-2 bioactivity by systemic administration of antirat MIP-2 antibody caused a significant attenuation of the early phase of LPS fever. However, in contrast with normal rats, the second phase of fever was unimpaired by anti-MIP-2 in leukopenic rats. These findings suggest that circulating MIP-2 is involved in the generation of the early phase of LPS fever that contributes to the maintenance of the later phase of fever in immunocompetent, but not leukopenic, rats. Our data support a regulatory role for endogenous MIP-2 in initiating the fever responses to LPS. Furthermore, these results provide evidence that different cellular and humoral mechanisms are implicated in the development of a febrile response triggered by Gram-negative bacterial infections in leukopenic hosts.

Clinical Features of the Neutropenic Host: Definitions and Initial Evaluation

Initial evaluation of patients with febrile neutropenia includes a thorough history and physical examination; a complete blood cell count; measurement of serum creatinine, blood urea nitrogen, transaminases, and C-reactive protein; and culture of blood (samples from a peripheral vein and/or catheter). Chest radiography is indicated for patients with respiratory signs or symptoms. Signs and symptoms of inflammation may be minimal or absent. However, a search should be undertaken in the sites most commonly infected, including the periodontium, pharynx, lower esophagus, lung, perineum, eyes, and skin. Blood samples, including samples from catheter lumen(s), if present, and a peripheral vein, should be obtained for cultures for bacteria and fungi. Urine culture is indicated in the presence of signs or symptoms of urinary tract infection, a urinary catheter in place, or abnormal results of urinalysis. Fever is defined as a single axillary temperature measurement of > or =37.5 degrees C (oral temperature of > or =38.0 degrees C). Neutropenia is defined as a neutrophil count of <1000 cells/mm3.

Severity of enterocolitis is predicted by IL-8 in paediatric oncology patients

Enterocolitis in oncology patients remains an important complication, but there is a lack of insight into its likely severity from microbial, pathological and inflammatory aspects. Paediatric oncology patients admitted with neutropenic fever, who developed abdominal pain and diarrhoea, were monitored by the takers of rectal biopsies, cultures, and inflammatory marker measurements. Twenty-five patients were included (mean age 7.1 years). 8 patients (32%) needed intensive care treatment, 3 (12%) patients died. Gram-positive bacteraemia was diagnosed in 4 patients (16%). Most patients had negative blood and stool cultures. Predictors of a severe clinical course of the enterocolitis were an increased serum interleukin-8 (IL-8) (>1000 pg/ml) level and an increased serum C-reactive protein level (CRP) (>150 mg/l) level, both measured on the first day of clinical illness. Relative risks (RR) for admission to an Intensive Care Unit (ICU) were 11.3 (95% Confidence Interval (CI) 1.6-77.9) for elevated IL-8 levels and 6.4 (95% (CI) 0.92-45.1) for increased CRP levels. Rectal biopsies and pathology could not predict outcome (P=0.22). IL-8 analysis at the onset of enterocolitis symptoms can identify high-risk patients, which might be used clinically to design future intervention trials.

Endothelial cells are main producers of interleukin 8 through Toll-like receptor 2 and 4 signaling during bacterial infection in leukopenic cancer patients

Cancer patients who are leukopenic due to chemotherapy are susceptible to bacterial infections. Normally, clinical conditions during bacterial infections are caused by pathogen-associated molecular patterns, which are components that bind to Toll-like receptor (TLR) 2 (TLR-2) and TLR-4 on leukocytes, resulting in the production of inflammatory cytokines. The mechanism of this inflammatory response in cancer patients with diminished numbers of leukocytes is not completely clear. The levels of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha measured in the circulation of leukopenic cancer patients are lower than those measured in that of nonleukopenic patients during bacterial infections, whereas plasma interleukin 8 (IL-8) levels show distinct identical increases during bacterial infections in both leukopenic and nonleukopenic patients. Normally, these cytokines are mainly secreted by leukocytes. In cancer patients with bacterial infections and a diminished number of leukocytes, other sources of IL-8 production, such as endothelial cells, might be expected. Endothelial cells instead of leukocytes become the most important producers of IL-8 during bacterial infections in patients with chemotherapy-induced leukopenia through TLR-2 and TLR-4 signaling. Whole blood samples from six cancer patients were stimulated with lipopolysaccharide (LPS), and then IL-8 concentrations in supernatants were measured. Further, human umbilical vein endothelial cells (HUVECs) were incubated with sera from leukopenic cancer patients with or without bacterial infections, and then IL-8 concentrations in supernatants were measured (n = 6). In addition, the same HUVEC experiment was performed with the addition of neutralizing antibodies against TLR-2 and TLR-4. During leukopenia (<10(9) cells/liter), LPS stimulation of whole blood did not result in an increase in IL-8 levels. However, when endothelial cells were incubated with sera from leukopenic cancer patients during bacterial infections, a three- to eightfold increase in IL-8 production was found, compared to the IL-8 production found after incubation with sera from patients without signs of infections. This increase did not reflect a higher level of IL-8 already present in the sera. Further, we demonstrated that IL-8 production induced in endothelial cells by sera from patients with documented gram-negative infections could be reduced significantly by up to 40% when the cells were incubated with neutralizing antibodies against TLR-4 (P = 0.028). The addition of TLR-2 antibodies slightly enhanced the reduction of IL-8 production. These results suggest that during bacterial infections in cancer patients with markedly diminished numbers of leukocytes, endothelial cells become important producers of IL-8 through TLR-4 signaling and, to a lesser extent, TLR-2 signaling.

Risk assessment and risk-based therapeutic strategies in febrile neutropenia

Different approaches have developed over time regarding the empirical antimicrobial therapy of fever in neutropenic patients. The use of intravenous antibiotics remains the standard approach. Clinical criteria and 'low-risk' prediction rules have been developed that help select patients in whom oral therapy is well tolerated and who may be eligible for outpatient management. Comorbidity and clinical status at presentation remain important criteria in the risk-assessment process. Outpatient management requires additional assessment of non-medical criteria. Patients without documented infection and who have responded to initial therapy may benefit from simplified therapy such as a switch to oral drugs and/or outpatient management. Discontinuation of therapy may be considered in selected cases. Risk assessment in neutropenic patients with persistent unexplained fever is challenging. Available data suggest that broadening of the antibacterial coverage is of limited value. Instead, definition of the risk of fungal infection by using clinical criteria, imaging and laboratory studies, as well as the identification of those patients likely to benefit from antifungal therapy, appear to be of critical importance.