Serum vascular endothelial growth factor in adult haematological patients with neutropenic fever: a comparison with C-reactive protein

Novel biomarkers to identify complicated course of febrile neutropenia in hematological patients receiving intensive chemotherapy

Febrile neutropenia (FN) is a common consequence of intensive chemotherapy in hematological patients. More than 90% of the patients with acute myeloid leukemia (AML) develop FN, and 5%-10% of them die from subsequent sepsis. FN is very common also in autologous stem cell transplant recipients, but the risk of death is lower than in AML patients. In this review, we discuss biomarkers that have been evaluated for diagnostic and prognostic purposes in hematological patients with FN. In general, novel biomarkers have provided little benefit over traditional inflammatory biomarkers, such as C-reactive protein and procalcitonin. The utility of most biomarkers in hematological patients with FN has been evaluated in only a few small studies. Although some of them appear promising, much more data is needed before they can be implemented in the clinical evaluation of FN patients. Currently, close patient follow-up is key to detect complicated course of FN and the need for further interventions such as intensive care unit admission. Scoring systems such as q-SOFA (Quick Sequential Organ Failure Assessment) or NEWS (National Early Warning Sign) combined with traditional and/or novel biomarkers may provide added value in the clinical evaluation of FN patients.

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.

Novel Biomarker Candidates for Febrile Neutropenia in Hematological Patients Using Nontargeted Metabolomics

Background

Novel potential small molecular biomarkers for sepsis were analyzed with nontargeted metabolite profiling to find biomarkers for febrile neutropenia after intensive chemotherapy for hematological malignancies.

Methods

Altogether, 85 patients were included into this prospective study at the start of febrile neutropenia after intensive chemotherapy for acute myeloid leukemia or after autologous stem cell transplantation. The plasma samples for the nontargeted metabolite profiling analysis by liquid chromatography-mass spectrometry were taken when fever rose over 38° and on the next morning.

Results

Altogether, 90 differential molecular features were shown to explain the differences between patients with complicated (bacteremia, severe sepsis, or fatal outcome) and noncomplicated courses of febrile neutropenia. The most differential compounds were an androgen hormone, citrulline, and phosphatidylethanolamine PE(18:0/20:4). The clinical relevance of the findings was evaluated by comparing them with conventional biomarkers like C-reactive protein and procalcitonin.

Conclusion

These results hold promise to find out novel biomarkers for febrile neutropenia, including citrulline. Furthermore, androgen metabolism merits further studies.

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.

Asymmetric dimethylarginine in the assessment of febrile neutropenia in hematological patients

Asymmetric dimethylarginine (ADMA) has been recognized as an independent prognostic factor for sepsis mortality in intensive care units. No data are available on kinetics or prognostic value of ADMA in hematological patients. We evaluated the ability of ADMA to act as a predictor for complicated course of febrile neutropenia, defined as bacteremia and/or septic shock in adult hematological patients receiving intensive chemotherapy. This prospective study included 87 adult hematological patients with febrile neutropenia after an intensive chemotherapy for acute myeloid leukemia (AML) or after an autologous stem cell transplantation (ASCT). Plasma ADMA and serum C-reactive protein (CRP) levels were measured from the onset of fever (d0) and for 2 days (d1-d2) thereafter. The levels of ADMA were stable or had only minimal changes during the study period. There was no difference between the levels at any time-point in patients having complicated course compared to those without it. On the other hand, CRP levels were significantly higher on d1 (p = 0.016) in patients with bacteremia and/or septic shock than in those without. ADMA was not able to differentiate hematological patients with a complicated course from those without complications. Elevated ADMA levels are probably associated with organ dysfunction, which is rare in this group of patients, of whom about 95% can be successfully managed at the hematology ward.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Infectious complications of stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for a variety of hematologic malignancies. The profound immunosuppression these patients experience adversely affects their risk of infection. This risk is much higher than in the general population and requires aggressive diagnostic and therapeutic interventions. The chapter will outline the major infections after HSCT.

A high angiopoietin-2/angiopoietin-1 ratio is associated with a high risk of septic shock in patients with febrile neutropenia

Introduction

Endothelial barrier breakdown is a hallmark of septic shock, and proteins that physiologically regulate endothelial barrier integrity are emerging as promising biomarkers of septic shock development. Patients with cancer and febrile neutropenia (FN) present a higher risk of sepsis complications, such as septic shock. Nonetheless, these patients are normally excluded or under-represented in sepsis biomarker studies. The aim of our study was to validate the measurement of a panel of microvascular permeability modulators as biomarkers of septic shock development in cancer patients with chemotherapy-associated FN.

Methods

This was a prospective study of diagnostic accuracy, performed in two distinct in-patient units of a university hospital. Levels of vascular endothelial growth factor A (VEGF-A), soluble fms-like tyrosine kinase-1 (sFlt-1) and angiopoietin (Ang) 1 and 2 were measured after the onset of neutropenic fever, in conditions designed to mimic the real-world use of a sepsis biomarker, based on our local practice. Patients were categorized based on the development of septic shock by 28 days as an outcome.

Results

A total of 99 consecutive patients were evaluated in the study, of which 20 developed septic shock and 79 were classified as non-complicated FN. VEGF-A and sFlt-1 levels were similar between both outcome groups. In contrast, Ang-2 concentrations were increased in patients with septic shock, whereas an inverse finding was observed for Ang-1, resulting in a higher Ang-2/Ang-1 ratio in patients with septic shock (5.29, range 0.58 to 57.14) compared to non-complicated FN (1.99, range 0.06 to 64.62; P = 0.01). After multivariate analysis, the Ang-2/Ang-1 ratio remained an independent factor for septic shock development and 28-day mortality.

Conclusions

A high Ang-2/Ang-1 ratio can predict the development of septic shock in cancer patients with febrile neutropenia.

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.

Time-course of sFlt-1 and VEGF-A release in neutropenic patients with sepsis and septic shock: a prospective study

Background

Septic shock is the most feared complication of chemotherapy-induced febrile neutropenia. So far, there are no robust biomarkers that can stratify patients to the risk of sepsis complications. The VEGF-A axis is involved in the control of microvascular permeability and has been involved in the pathogenesis of conditions associated with endothelial barrier disruption such as sepsis. sFlt-1 is a soluble variant of the VEGF-A receptor VEGFR-1 that acts as a decoy receptor down-regulating the effects of VEGF-A. In animal models of sepsis, sFlt-1 was capable to block the barrier-breaking negative effects of VEGF-A and to significantly decrease mortality. In non-neutropenic patients, sFlt-1 has been shown to be a promising biomarker for sepsis severity.

Methods

We prospectively evaluated concentrations of sFlt-1 and VEGF-A at different time-points during febrile neutropenia, and evaluated the association of these levels with sepsis severity and septic shock development.

Results

Neutropenic patients that evolved with septic shock (n = 10) presented higher levels of sFlt-1 and VEGF-A measured 48 hours after fever onset than patients with non-complicated sepsis (n = 31) and levels of these biomarkers correlated with sepsis severity scores. Estimation of the diagnostic accuracy of sFlt-1 levels for the discrimination of patients that evolved to septic shock yielded promising results in our study population.

Discussion

Our data suggest that sFlt-1 and VEGF-A could be useful biomarkers for sepsis severity in patients with febrile neutropenia. In addition, the kinetics of sFlt-1 release in patients that evolve to septic shock suggest that the sFlt-1 could be a salvage compensatory mechanism in patients with septic shock, but that the magnitude of the sFlt-1 release observed in human sepsis is not sufficient to reproduce the beneficial anti-VEGF-A effects observed in animal models of sepsis.

Elevated procalcitonin predicts Gram-negative sepsis in haematological patients with febrile neutropenia

OBJECTIVE

To compare semi-quantitative procalcitonin with C-reactive protein in predicting bacteraemia in haematological patients with neutropenic fever.

METHODS

A total of 77 patients treated with intensive chemotherapy for haematological malignancy at Kuopio University Hospital were candidates for study entry. Eleven of these patients did not fulfil the criteria for neutropenic fever, and 66 patients were finally included. Nineteen patients had acute myeloid leukaemia and 47 had received high-dose chemotherapy supported by autologous stem cell transplant. Ninety neutropenic fever episodes in these 66 patients fulfilled the study entry criteria, with microbiological cultures, procalcitonin and C-reactive protein measurements available. Serum procalcitonin and C-reactive protein were analyzed at the onset of each neutropenic fever episode on day 0, and then daily from days 1 to 4.

RESULTS

Bacteraemia was observed in 21 episodes (23%) and the criteria for severe sepsis were fulfilled in 13 episodes (14%). Half of the bacteraemic episodes were caused by Gram-negative bacteria. The kinetics of procalcitonin and C-reactive protein were similar, with increasing levels for 2 to 4 days after the onset of fever. The procalcitonin level on days 1, 2, 3 and 4 was associated with bacteraemia and Gram-negative bacteraemia, but not with the development of severe sepsis. On day 1, a procalcitonin level above 0.5 ng/ml had a sensitivity of 57% and 70% and specificity of 81% and 77% to predict bacteraemia and Gram-negative bacteraemia, respectively.

CONCLUSIONS

An elevated level of procalcitonin within 24 h after the onset of neutropenic fever predicts bacteraemia and Gram-negative bacteraemia in haematological patients.