Differences in characteristics between first and breakthrough neutropenic fever after chemotherapy in patients with hematologic disease

Risk factors for resistant gram-positive bacteremia in febrile neutropenic patients with cancer

BACKGROUND

Gram-positive bacteria are frequently resistant to empirical beta-lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer.

METHODS

Episodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed. Resistant Gram-positive bacteria were defined as a pathogen susceptible only to glycopeptide or linezolid in vitro (e.g., methicillin-resistant staphylococci, penicillin-resistant viridans streptococci, and ampicillin-resistant enterococci). Episodes were compared to identify independent risk factors for resistant Gram-positive bacteremia.

RESULTS

Of 225 episodes, 78 (34.7%) involved resistant Gram-positive bacteremia. Multivariate analysis revealed that breakthrough bacteremia while being administered antibiotics (adjusted odds ratio [aOR], 6.794; 95% confidence interval [95% CI], 3.130-14.749; P < 0.001) and catheter-related infection (aOR 4.039, 95% CI 1.366-11.946; P = 0.012) were associated with resistant Gram-positive bacteremia. Chronic liver disease (aOR 0.231, 95% CI 0.059-0.905; P = 0.035) and hypotension at bacteremia (aOR 0.454, 95% CI 0.218-0.945; P = 0.035) were inversely associated with resistant Gram-positive bacteremia.

CONCLUSIONS

Resistant Gram-positive bacteria should be considered in breakthrough bacteremia and catheter-related infection in febrile neutropenic patients with cancer.

Advances in antibacterial treatment of adults with high-risk febrile neutropenia

BACKGROUND

High-risk febrile neutropenia (HR-FN) is a life-threatening complication in patients with haematological malignancies or receiving myelosuppressive chemotherapy. Since the last international guidelines were published over 10 years ago, there have been major advances in the understanding and management of HR-FN, including on antibiotic pharmacokinetics and discontinuation/de-escalation strategies.

OBJECTIVES

Summarizing major advances in the field of antibacterial therapy in patients with HR-FN: empirical therapy, pharmacokinetics of antibiotics and antibiotic stewardship.

SOURCES

Narrative review based on literature review from PubMed. We focused on studies published between 2010 and 2023 about the pharmacokinetics of antimicrobials, management of antimicrobial administration, and discontinuation/de-escalation strategies. We did not address antimicrobial prophylaxis, viral or fungal infections.

CONTENT

Several high-quality publications have highlighted important modifications of antibiotic pharmacokinetics in HR-FN, with standard dosages exposing patients to underdosing. These recent clinical and population pharmacokinetics studies help improve management protocols with optimized initial dosing and infusion rules for β-lactams, vancomycin, daptomycin and amikacin; they highlight the potential benefits of therapeutic drug monitoring. A growing body of evidence also shows that antibiotic discontinuation/de-escalation strategies are beneficial for bacterial ecology and patients' outcome. We further discuss methods and limitations for implementation of such protocols in haematology.

IMPLICATIONS

We highlight recent information about the management of antibacterial therapy in HR-FN that might be considered in updated guidelines for HR-FN management.

Tigecycline as salvage treatment of febrile neutropenia in patients with haematological malignancies-a retrospective single-centre analysis of 200 cases

Tigecycline has been used to treat patients with febrile neutropenia (FN). This study aims to analyse the effectiveness of tigecycline as salvage treatment of FN. Patients records from 09/2004 to 04/2019 were reviewed. Cases were eligible if fever persisted/recurred (p/r-FN) after 3 days of second-line treatment with a carbapenem, and were divided into three groups: switch to tigecycline (TGC group), switch to other antibiotics (OAB group), and no switch (W&W group). The primary endpoint was response rate (defervescence for ≥ 7 days or at least until discharge); the key secondary endpoint was 30-day mortality rate. Two hundred cases from 176 patients (median 59 years; 53.5% men) treated were included, mostly acute myeloid leukaemias (61.0%). 45.5% of cases were in the TGC group (in combination with an anti-pseudomonal antibiotic, mostly ceftazidime [95.6%]); 35.5% were in the OAB and 19.0% in the W&W group. There was no significant difference in response rates (TGC, 73.6%; OAB, 62.0%; W&W, 78.9%; p = 0.12) or 30-day mortality rates (TGC, 7.7%; OAB, 7.0%; W&W, 5.3%; p = 0.94). Tigecycline plus an anti-pseudomonal antibiotic does not improve response or 30-day mortality rate compared to other antibiotics in patients with p/r-FN. Also, in some cases, no switch in antibiotics may be necessary at all.

New approaches to management of fever and neutropenia in high-risk patients

PURPOSE OF REVIEW

Patients receiving treatment for acute leukaemia and haematopoietic cell transplantation (HCT) have prolonged neutropenia and are at high risk of neutropenic fever, with bacterial and particularly invasive fungal infections as feared complications, possessing potentially serious consequences including intensive care admission and mortality. Concerns for these serious complications often lead to long durations of broad-spectrum antimicrobial therapy and escalation to even broader therapy if fever persists. Further, the default approach is to continue neutropenic fever therapy until count recovery, leaving many patients who have long defervesced on prolonged antibiotics.

RECENT FINDINGS

This article details recent progress in this field with particular emphasis on early discontinuation studies in resolved neutropenic fever and improved imaging techniques for the investigation of those with persistent neutropenic fever. Recent randomized controlled trials have shown that early cessation of empiric neutropenic fever therapy is well tolerated in acute leukaemia and autologous HCT patients who are clinically stable and afebrile for 72 h. Delineation of the best approach to cessation (timing and/or use of fluoroquinolone prophylaxis) and whether this approach is well tolerated in the higher risk allogeneic HCT setting is still required. Recent RCT data demonstrate utility of FDG-PET/CT to guide management and rationalize antimicrobial therapy in high-risk patient groups with persistent neutropenic fever.

SUMMARY

Acute leukaemic and autologous HCT patients with resolved neutropenic fever prior to count recovery can have empiric therapy safely discontinued or de-escalated. There is an emerging role of FDG-PET/CT to support decision-making about antibiotic and antifungal use in high-risk persistent/recurrent neutropenic fever patients.

What, where and why: exploring fluorodeoxyglucose-PET's ability to localise and differentiate infection from cancer

PURPOSE OF REVIEW

To review the utility of FDG-PET imaging in detecting the cause of fever and infection in patients with cancer.

RECENT FINDINGS

FDG-PET has been shown to have high sensitivity and accuracy for causes of neutropenic fever, leading to higher diagnostic certainty in this group. Recent advances in pathogen-specific labelling in PET to identify Aspergillus spp. and Yersinia spp. infections in mice, as well as differentiating between Gram-positive, Gram-negative and mycobacterial infections are promising.

SUMMARY

Patients with cancer are vulnerable to infection and fever, and the causes of these are frequently unclear using conventional diagnostic methods leading to high morbidity and mortality, length of stay and costs of care. FDG-PET/CT, with its unique complementary functional and anatomical information as well as its whole-body imaging capability, has demonstrated use in detecting occult infection in immunocompromised patients, including invasive fungal and occult bacterial infections, as well as defining extent of infection. By demonstrating disease resolution following treatment and allowing earlier cessation of therapy, FDG-PET acts as a key tool for antimicrobial and antifungal stewardship. Limitations include at times poor differentiation between infection, malignancy and sterile inflammation, however, exciting new technologies specific to infectious pathogens may help alleviate that issue. Further prospective randomised research is needed to explore these benefits in a nonbiased fashion.

Early discontinuation of empirical antibacterial therapy in febrile neutropenia: the ANTIBIOSTOP study

INTRODUCTION

Immediate empirical antibiotic therapy is mandatory in febrile chemotherapy-induced neutropenia, but its optimal duration is unclear, especially in patients with fever of unknown origin (FUO).

OBJECTIVES

The primary objective of this 20-month prospective observational study was to evaluate the feasibility and safety of short-term antibiotic treatment in afebrile or febrile patients exhibiting FUO, irrespective of their neutrophil count. The secondary objective was to describe the epidemiology of all episodes of febrile neutropenia.

METHODS

In the first phase of the study, empirical antibiotic therapy in FUO patients was stopped after 48 h of apyrexia, in accordance with European Conference on Infections in Leukaemia guidelines (n = 45). In the second phase of the study, antibiotics were stopped no later than day 5 for all FUO patients, regardless of body temperature or leukocyte count (n = 37).

RESULTS

Two hundred and thirty-eight cases of febrile neutropenia in 123 patients were included. Neither the composite endpoint (p = .11), nor each component (in-hospital mortality (p = .80), intensive care unit admission (p = 0.48), relapse of infection ≤48 h after discontinuation of antibiotics (p = .82)) differed between the two FUO groups. Violation of protocol occurred in 17/82 episodes of FUO without any major impact on statistical results. Twenty-six (57.3%) and 22 (59.5%) FUO episodes did not relapse during hospital-stay (p = 1), and nine (20%) and five (13.5%) presented another FUO, respectively. One hundred and fifty-six episodes of febrile neutropenia (65.5%) were clinically or microbiologically documented, including 85 bacteremia.

CONCLUSIONS

These results suggest that early discontinuation of empirical antibiotics in FUO is safe for afebrile neutropenic patients.

Bloodstream infections due to extended-spectrum β-lactamase-producing Enterobacteriaceae among patients with malignancy: a systematic review and meta-analysis

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) are an increasing cause of resistant infections among patients with malignancy. This study sought to estimate the prevalence of bloodstream infections (BSIs) caused by ESBL-PE in this population and to examine regional and temporal differences. The PubMed and EMBASE databases (to 30 April 2016) were searched to identify studies reporting ESBL-PE BSI rates among patients with malignancies. Of 593 non-duplicate reports, 22 studies providing data on 5650 BSI cases satisfied the inclusion criteria. Among all BSIs the pooled prevalence of ESBL-PE was 11% (95% CI 8-15%) and among Gram-negative BSIs it was 21% (95% CI 16-27%). Among patients with haematological malignancies, the pooled ESBL-PE prevalence was 11% (95% CI 8-15%), whereas no studies providing specific data on patients with solid tumours were identified. Stratifying per geographic region, the pooled prevalence was 7% each in Europe (95% CI 5-11%), the Eastern Mediterranean region (95% CI 4-11%) and South America (95% CI 2-14%), 10% in the Western Pacific region (95% CI 4-19%) and 30% in Southeast Asia (95% CI 18-44%). Importantly, there was a 7.1% annual increase in the ESBL-PE incidence (P = 0.004). Overall, ca. 1 in 10 BSIs in patients with malignancy is caused by ESBL-PE and in some areas this rate can be as high as 1 in 3 cases. Additionally, the incidence of these resistant infections is rising. These findings should be considered when selecting empirical antimicrobial therapy and should prompt strict adherence to antimicrobial stewardship.

Colonization and infection with extended-spectrum beta-lactamase producing Enterobacteriaceae in patients with malignancy

INTRODUCTION

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) constitute a global threat and are prevalent in both nosocomial and community settings. These pathogens have been associated with delays in initiation of appropriate antimicrobial therapy and worse clinical outcomes. Patients with solid or hematologic malignancy represent a high-risk population for both colonization and infection with ESBL-PE. Areas covered: A description of the microbiology and epidemiology of the ESBL-PE is presented. Also, we explore studies on ESBL-PE colonization and infection, and examine areas where future research is needed. Expert commentary: ESBL-PE constitute an increasing threat to patients with malignancy. Unfortunately, substantial geographic variations as well as knowledge gaps in certain regions of the world limit our ability to reach conclusions that are valid globally. Furthermore, there is limited evidence regarding the optimal ways to prevent and manage infections caused by ESBL-PE. Research is urgently needed to elucidate these areas and allow the institution of appropriate infection control and antimicrobial stewardship policies and recommendations.