Shock and Early Death in Hematologic Patients with Febrile Neutropenia

Successful Management of Neutropenic Sepsis Is Key to Better Survival of Patients With Blood Cancer in Sri Lanka: Real-World Data From the Resource-Limited Setting

PURPOSE

Sepsis is the main cause of nonrelapse mortality, and there are no published data on applicability of supportive care protocols from high-income countries such as Sri Lanka. The aim of the study was to investigate management and mortality of neutropenic episodes among Hemato-Oncology patients.

MATERIALS AND METHODS

Retrospective analysis of clinical characteristics, management, morbidity, and mortality of neutropenic Hemato-Oncology patients presented to the Lanka Hospital Blood Cancer Centre from January 1, 2019 to December 31, 2019 was performed.

RESULTS

A total of 169 neutropenic episodes were identified; 115 (68%) of such episodes were related to chemotherapy. Acute leukemia, lymphoproliferative disorders, and plasma cell disorders accounted for 23%, 69%, and 8% of patients, respectively. The median age of patients who had sepsis was 56 years, whereas that of those who had no sepsis was 53 years (P = .49). The median time to neutropenia was 9 days for those in the sepsis group compared with 8 days in the group that had no sepsis (0.64). The median neutrophil count in the group that had sepsis was 0.06, whereas it was 0.69 in the group that had no sepsis (P ≤ .05). The median time to commencement of antibiotics was 20 minutes.

CONCLUSION

To our knowledge, this is the only documented study related to outcome and successful applicability of western supportive care protocols to Sri Lankan patients with neutropenia. In this study, we have shown that neutropenic sepsis can be successfully managed in the setting of limited resources with service development, following guidelines and staff training.

Carbapenem-resistant Klebsiella pneumoniae bloodstream infections in haematological malignances and hematopoietic stem cell transplantation: Clinical impact of combination therapy in a 10-year Brazilian cohort

Bacterial bloodstream infections (BSI) are a common threat among patients with haematological malignancies (HM) and hematopoietic stem cell transplant recipients (HSCT). The purpose of this research was to describe clinical and microbiological aspects of BSI caused by carbapenem-resistant Klebsiella pneumoniae (CRKp) and assess risk factors associated with 30-day mortality in a 10-year cohort of haematological patients. A total of 65 CRKp-BSI episodes occurring in HM patients and HSCT recipients and CRKp-BSI between January 2010 and December 2019 were retrospectively studied. Acute leukemias were the most frequently observed underlying disease (87.7%) and 18 patients (27.7%) received HSCT. Mucosal barrier injury in the gastrointestinal tract was the primary cause of bacteremia (86.1%). Also, 14 individuals (21.6%) had an Invasive Fungal Disease (IFD) throughout the episode. Regarding treatment, in 31 patients (47.7%) empirical therapy was deemed appropriate, whereas 33 (50.8%) patients received a combination therapy. Microbiological data revealed that the majority of isolates (53-58%) had the Polymyxin B co-resistance phenotype, while amikacin resistance was less common (16 samples, or 24.7%). The mortality rates at 14 and 30 days were 32.3% and 36.9%, respectively. In a multivariate Cox regression analysis, prompt appropriate antibiotic administration within three days was associated with a better outcome (Adjusted Hazard Ratio [aHR]: 0.33; 95% Confidence Interval [CI]: 0.14-0.76; p = 0.01), whereas hypotension at presentation (aHR: 3.88; 95% CI: 1.40-10.74; p = 0.01) and concurrent IFD (aHR: 2.97; 95% CI: 1.20-7.37; p = 0.02) were independently associated with death within 30 days. Additionally, a favorable correlation between combination therapy and overall survival was found (aHR: 0.18; 95%CI: 0.06-0.56; p = 0.002). In conclusion, 30-day mortality CRKp-BSI was elevated and most of the isolates were polymyxin B resistant. Early appropriate antimicrobial treatment and the use of combination therapy were linked to a better outcome.

The RNA m6A demethylase ALKBH5 drives emergency granulopoiesis and neutrophil mobilization by upregulating G-CSFR expression

Emergency granulopoiesis and neutrophil mobilization that can be triggered by granulocyte colony-stimulating factor (G-CSF) through its receptor G-CSFR are essential for antibacterial innate defense. However, the epigenetic modifiers crucial for intrinsically regulating G-CSFR expression and the antibacterial response of neutrophils remain largely unclear. N6-methyladenosine (m6A) RNA modification and the related demethylase alkB homolog 5 (ALKBH5) are key epigenetic regulators of immunity and inflammation, but their roles in neutrophil production and mobilization are still unknown. We used cecal ligation and puncture (CLP)-induced polymicrobial sepsis to model systemic bacterial infection, and we report that ALKBH5 is required for emergency granulopoiesis and neutrophil mobilization. ALKBH5 depletion significantly impaired the production of immature neutrophils in the bone marrow of septic mice. In addition, Alkbh5-deficient septic mice exhibited higher retention of mature neutrophils in the bone marrow and defective neutrophil release into the circulation, which led to fewer neutrophils at the infection site than in their wild-type littermates. During bacterial infection, ALKBH5 imprinted production- and mobilization-promoting transcriptome signatures in both mouse and human neutrophils. Mechanistically, ALKBH5 erased m6A methylation on the CSF3R mRNA to increase the mRNA stability and protein expression of G-CSFR, consequently upregulating cell surface G-CSFR expression and downstream STAT3 signaling in neutrophils. The RIP-qPCR results confirmed the direct binding of ALKBH5 to the CSF3R mRNA, and the binding strength declined upon bacterial infection, accounting for the decrease in G-CSFR expression on bacteria-infected neutrophils. Considering these results collectively, we define a new role of ALKBH5 in intrinsically driving neutrophil production and mobilization through m6A demethylation-dependent posttranscriptional regulation, indicating that m6A RNA modification in neutrophils is a potential target for treating bacterial infections and neutropenia.

Vancomycin resistant enterococcus risk factors for hospital colonization in hematological patients: a matched case-control study

BACKGROUND

Vancomycin-resistant enterococcus (VRE) was the fastest growing pathogen in Europe in 2022 (+ 21%) but its clinical relevance is still unclear. We aim to identify risk factors for acquired VRE rectal colonization in hematological patients and evaluate the clinical impact of VRE colonization on subsequent infection, and 30- and 90-day overall mortality rates, compared to a matched control group.

METHODS

A retrospective, single center, case-control matched study (ratio 1:1) was conducted in a hematological department from January 2017 to December 2020. Case patients with nosocomial isolation of VRE from rectal swab screening (≥ 48 h) were matched to controls by age, sex, ethnicity, and hematologic disease. Univariate and multivariate logistic regression compared risk factors for colonization.

RESULTS

A total of 83 cases were matched with 83 controls. Risk factors for VRE colonization were febrile neutropenia, bone marrow transplant, central venous catheter, bedsores, reduced mobility, altered bowel habits, cachexia, previous hospitalization and antibiotic treatments before and during hospitalization. VRE bacteraemia and Clostridioides difficile infection (CDI) occurred more frequently among cases without any impact on 30 and 90-days overall mortality. Vancomycin administration and altered bowel habits were the only independent risk factors for VRE colonization at multivariate analysis (OR: 3.53 and 3.1; respectively).

CONCLUSIONS

Antimicrobial stewardship strategies to reduce inappropriate Gram-positive coverage in hematological patients is urgently required, as independent risk factors for VRE nosocomial colonization identified in this study include any use of vancomycin and altered bowel habits. VRE colonization and infection did not influence 30- and 90-day mortality. There was a strong correlation between CDI and VRE, which deserves further investigation to target new therapeutic approaches.

Low utilization of vancomycin in febrile neutropenia: real-world evidence from 4 Brazilian centers

PURPOSE

The prompt initiation of a betalactam antibiotic in febrile neutropenic patients is considered standard of care, while the empiric use of vancomycin is recommended by guidelines in specific situations, with a low level of evidence. The objective of this study was to assess the utilization of vancomycin in the management of febrile neutropenia within four Brazilian medical centers that implemented more stringent criteria for its administration.

METHODS

A comprehensive retrospective analysis was performed encompassing all instances of febrile neutropenia observed during the period from 2013 to 2019. The primary focus was to identify the reasons for initiating vancomycin therapy.

RESULTS

A total of 536 consecutive episodes of febrile neutropenia were documented, involving 384 patients with a median age of 52 years (range 18-86). Chemotherapy preceded febrile neutropenia in 59.7% of cases, while 40.3% occurred after hematopoietic stem cell transplantation. The most prevalent underlying diseases were acute myeloid leukemia (26.5%) and non-Hodgkin's lymphoma (22%). According to international guidelines, vancomycin should have been initiated at the onset of fever in 145 episodes (27%); however, it was administered in only 27 cases (5.0%). Three episodes were associated with Staphylococcus aureus bacteremia, two of which were methicillin resistant. The 15-day and 30-day mortality rates were 5.0% and 9.9%, respectively.

CONCLUSIONS

The results of this study underscore the notably low utilization rate of vancomycin in cases of febrile neutropenia, despite clear indications outlined in established guidelines. These findings emphasize the importance of carefully implementing guideline recommendations, considering local epidemiological factors, especially when the strength of recommendation is weak.

Antimicrobial Stewardship on Patients with Neutropenia: A Narrative Review Commissioned by Microorganisms

The emergence of antibiotic resistance poses a global health threat. High-risk patients such as those with neutropenia are particularly vulnerable to opportunistic infections, sepsis, and multidrug-resistant infections, and clinical outcomes remain the primary concern. Antimicrobial stewardship (AMS) programs should mainly focus on optimizing antibiotic use, decreasing adverse effects, and improving patient outcomes. There is a limited number of published studies assessing the impact of AMS programs on patients with neutropenia, where early appropriate antibiotic choice can be the difference between life and death. This narrative review updates the current advances in strategies of AMS for bacterial infections among high-risk patients with neutropenia. Diagnosis, drug, dose, duration, and de-escalation (5D) are the core variables among AMS strategies. Altered volumes of distribution can make standard dose regimens inadequate, and developing skills towards a personalized approach represents a major advance in therapy. Intensivists should partner antibiotic stewardship programs to improve patient care. Assembling multidisciplinary teams with trained and dedicated professionals for AMS is a priority.

Combination of Interleukin-6, C-Reactive Protein and Procalcitonin Values as Predictive Index of Sepsis in Course of Fever Episode in Adult Haematological Patients: Observational and Statistical Study

Haematological patients represent a vulnerable population to opportunistic infections, mainly due to the disease itself and chemotherapy-induced neutropenia. The level of immune suppression strongly increases the importance of timely antibiotic treatment in order to prevent sepsis-related mortality. During the initial fever episode, serum biomarkers are usually used to estimate the probability of blood stream infection prior to the results of microbial diagnosis. A new serum biomarker combination study on a febrile haematological population, including C-reactive protein (CRP), interleukin-6 (IL-6) and procalcitonin (PCT), is proposed in order to improve their predictive accuracy. In our prospective study, CRP, IL-6 and PCT were evaluated in 34 immunosuppressed haematological patients immediately after the onset of 51 fever episodes, either during the course of standard chemotherapy or high-dose chemotherapy and autologous stem cell transplant. The fever episodes were divided into documented infections and fever alone. Receiver operating characteristic analysis (ROC) was performed for each biomarker and a combination of all three biomarkers (multiROC) to define a new predictive index. Significant differences were evidenced between the two groups (documented infection and no infection) for both PCT and IL-6 (p = 0.03 and p = 0.035, respectively), but none for CRP (p = 0.1). The composite parameter is more reliable than any single biomarker alone, with an area under the curve (AUC) of 79% and with high sensitivity and specificity. IL-6 gave the closest response compared to the composite index. Composite parameters of serum biomarkers could be used for an early diagnosis of infection at fever onset in haematological patients.

Acute Abdominal Complications in Deeply Neutropenic Onco-Hematology Patients: A Retrospective Series of 105 Cases

BACKGROUND

Acute abdominal complications (AAC) in patients with deep neutropenia (DN) is challenging to manage because of the expected influence of AAC on oncological prognosis and higher surgical complication rate in a period of DN. In practice, these parameters are difficult to appreciate. This study reported our experience in managing these patients.

METHODS

All consecutive patients treated in our tertiary care cancer center between 2010 and 2020 who developed AAC in the context of a DN were retrospectively analyzed. AAC was defined as an infection (intra-abdominal, perineal, or cutaneous), bowel obstruction, or intra-abdominal hemorrhage.

FINDINGS

Among 105 patients, 18 (17%) required emergent surgery (group 1), 34 patients had a complication requiring surgical oversight (group 2), and 53 patients had a non-surgical etiology (group 3). Fifteen patients underwent surgery in the group 1, three in group 2, and one in group 3. Overall, 28 patients died during hospitalization. Mortality was statistically different between the groups (p = 0·01), with a higher rate in group 1 (n = 9/18, 50%) than in group 2 (n = 11/34, 32%) and group 3 (n = 8/53, 15%). All groups together had a median overall survival (OS) of 14 months and disease-free survival (DFS) of 10 months. OS was not comparable between the groups, and the median length of survival in group 1 was 6 months versus 8 months in group 2 and 23 months in group 3. In group 1, five patients (5/18, 28%) did not relapse at the end of the follow-up compared to 13 in group 2 (13/34, 38%) and 25 in group 3 (25/53, 47%). After discharge, OS and DFS were similar between the groups.

INTERPRETATION

The advent of an AAC necessitating surgery in the context of DN is a deadly event associated with a 50% mortality; nonetheless, in case of unpostponable emergencies, surgery can provide long-term survival in selected patients.

Effect of Combination Antibiotic Empirical Therapy on Mortality in Neutropenic Cancer Patients with Pseudomonas aeruginosa Pneumonia

To assess the effect of combination antibiotic empirical therapy on 30-day case-fatality rate in neutropenic cancer patients with Pseudomonas aeruginosa (PA) bacteremic pneumonia. This was a multinational, retrospective cohort study of neutropenic onco-hematological patients with PA bloodstream infection (BSI) (2006−2018). The effect of appropriate empirical combination therapy, appropriate monotherapy and inappropriate empirical antibiotic therapy [IEAT] on 30-day case-fatality was assessed only in patients with PA bacteremic pneumonia. Among 1017 PA BSI episodes, pneumonia was the source of BSI in 294 (28.9%). Among those, 52 (17.7%) were caused by a multidrug-resistant (MDR) strain and 68 (23.1%) received IEAT, mainly when the infection was caused by an MDR strain [38/52 (73.1%) vs. 30/242 (12.4%); p < 0.001]. The 30-day case-fatality rate was higher in patients with PA bacteremic pneumonia than in those with PA BSI from other sources (55.1% vs. 31.4%; p < 0.001). IEAT was associated with increased 30-day case-fatality (aHR 1.44 [95%CI 1.01−2.03]; p = 0.042), whereas the use of appropriate combination empirical treatment was independently associated with improved survival (aHR 0.46 [95%CI 0.27−0.78]; p = 0.004). Appropriate empirical monotherapy was not associated with improved overall survival (aHR 1.25 [95%CI 0.76−2.05]; p = 0.39). Combination antibiotic empirical therapy should be administered promptly in febrile neutropenic patients with suspected pneumonia as the source of infection.

Impact of empirical antibiotic regimens on mortality in neutropenic patients with bloodstream infection presenting with septic shock

Objectives: We analyzed risk factors for mortality in febrile neutropenic patients with bloodstream infections (BSI) presenting with septic shock and assessed the impact of empirical antibiotic regimens. Methods: Multicenter retrospective study (2010-2019) of two prospective cohorts comparing BSI episodes in patients with or without septic shock. Multivariate analysis was performed to identify independent risk factors for mortality in episodes with septic shock. Results: Of 1563 patients with BSI, 257 (16%) presented with septic shock. Those patients with septic shock had higher mortality than those without septic shock (55% vs 15%, p<0.001). Gram-negative bacilli caused 81% of episodes with septic shock; gram-positive cocci, 22%; and Candida species 5%. Inappropriate empirical antibiotic treatment (IEAT) was administered in 17.5% of septic shock episodes. Empirical β-lactam combined with other active antibiotics was associated with the lowest mortality observed. When amikacin was the only active antibiotic, mortality was 90%. Addition of empirical specific gram-positive coverage had no impact on mortality. Mortality was higher when IEAT was administered (76% vs 51%, p=0.002). Age >70 years (OR 2.3, 95% CI 1.2-4.7), IEAT for Candida spp. or gram-negative bacilli (OR 3.8, 1.3-11.1), acute kidney injury (OR 2.6, 1.4-4.9) and amikacin as the only active antibiotic (OR 15.2, 1.7-134.5) were independent risk factors for mortality, while combination of β-lactam and amikacin was protective (OR 0.32, 0.18-0.57). Conclusions: Septic shock in febrile neutropenic patients with BSI is associated with extremely high mortality, especially when IEAT is administered. Combination therapy including an active β-lactam and amikacin results in the best outcomes.

Early Warning of Infection in Patients Undergoing Hematopoietic Stem Cell Transplantation Using Heart Rate Variability and Serum Biomarkers

Early warning of infection is critical to reduce the risk of deterioration and mortality, especially in neutropenic patients following hematopoietic stem cell transplantation (HCT). Given that heart rate variability (HRV) is a sensitive and early marker for infection, and that serum inflammatory biomarkers can have high specificity for infection, we hypothesized their combination may be useful for accurate early warning of infection. In this study, we developed and evaluated a composite predictive model using continuous HRV with daily serum biomarker measurements to provide risk stratification of future deterioration in HCT recipients. A total of 116 ambulatory outpatients about to undergo HCT consented to collection of prospective demographic, clinical (daily vital signs), HRV (continuous electrocardiography [ECG] monitoring, laboratory [daily serum samples frozen at -80 °C]), and infection outcome variables (defined as the time of escalation of antibiotics), all from 24 hours pre-HCT to the onset of infection or 14 days post-HCT. Indications for antibiotic escalation were adjudicated as "true infection" or not by 2 blinded HCT clinicians. A composite time series of 8 HRV metrics was created for each patient, and the probability of deterioration within the next 72 hours was estimated using logistic regression modeling of composite HRV and serum biomarkers using a rule-based naïve Bayes model if the HRV-based probability exceeded a median threshold. Thirty-five patients (30%) withdrew within <24 hours owing to intolerability of ECG monitoring, leaving 81 patients, of whom 48 (59%) had antibiotic escalation adjudicated as true infection. The combined HRV and biomarker (TNF-α, IL-6, and IL-7) predictive model began increasing at ∼48 hours on average before the diagnosis of infection, could distinguish between high risk of impending infection (>90% incidence of subsequent infection within 72 hours), average risk (∼50%), and low risk (<10%), with an area under the receiver operating characteristic curve of 0.87. However, given that prophylactic predictive ECG monitoring and daily serum collection proved challenging for many patients, further refinement in measurement is necessary for further study.

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.

How I Treat Febrile Neutropenia

The management of febrile neutropenia is a backbone of treating patients with hematologic malignancies and has evolved over the past decades. This article reviews my approach to the evaluation and treatment of febrile neutropenic patients. Key topics discussed include antibacterial and antifungal prophylaxis, the initial workup for fever, the choice of the empiric antibiotic regimen and its modifications, and criteria for discontinuation. For each of these questions, I review the literature and present my perspective.

Infectious Disease Complications in Patients with Cancer

Critically ill patients with cancer are vulnerable to infections because of the underlying malignancy, tumor-directed therapy, immunosuppression, breaches in mucosa or skin, malnutrition, and other factors. Neutropenia remains the most important risk factor for infection. Infectious complications occurring in critically ill patients with cancer can affect the bloodstream, lungs, gastrointestinal tract, central nervous system, urinary tract, and the skin. Pneumonias are the leading cause of infection in patients with cancer admitted to the intensive care unit. Consideration of opportunistic pathogens in the differential diagnosis is important in patients with impaired cellular and/or humoral immunity or compromised splenic function.

Analysis of blood stream infections, antibiograms and clinical outcomes in haematological patients with febrile neutropenia: data from a tertiary care haematology institute in India

Timely administration of appropriate empirical antibiotics in febrile neutropenia is crucial for favourable patient outcomes. There are guidelines in place recommending such antibiotics. However, regional variations and local epidemiological data must be evaluated to tailor the antibiotics for best possible and rational use. In this study, we audited the clinical and microbiological data of febrile neutropenic episodes occurring at a tertiary care haematology institution. Three hundred and ninety-three febrile neutropenic episodes occurring in 123 patients over a 1-year period were analysed for microbial profile, sensitivity and resistance patterns, and finally clinical outcomes. Gram-negative bacilli (GNB) blood stream infections (46.9%) were more prevalent as compared to gram-positive infections (41.9%). Overall mortality due to complicated neutropenic sepsis was 19.5% (24/123 patients). Increased resistance to carbapenems, beta-lactam beta-lactamase inhibitor combinations, aminoglycosides, fluoroquinolones, and cephalosporins were observed. Cefepime and tigecycline resistance were seen in 20% and 15% GNB isolates, respectively. Chest was the most frequent focus of infection, and acute myeloid leukaemia (AML) was the most common underlying disorder which correlated with the likelihood of death (p < 0.01). Multidrug-resistant GNB (esp. Klebsiella sp.) are still most worrisome isolates in neutropenic patients. Single-agent cefepime or piperacillin-tazobactam/tigecycline combination may be considered empirical agents. Chest infections and AML were independent predictors of poor clinical outcome in neutropenic patients. Regular audit of infections and antibiotic susceptibility data is needed to improve clinical outcomes in patients with febrile neutropenia.

Disseminated Corynebacterium jeikeium Infection in Cancer Patients

Corynebacterium jeikeium is a multidrug-resistant gram-positive bacterium of the human skin flora and one of the most clinically important nondiphtherial corynebacteria in the acute care setting. C. jeikeium can cause different forms of infections, especially in immunocompromised patients with underlying risk factors and comorbidities. C. jeikeium was initially described in 1976 as a highly resistant coryneform bacteria causing severe sepsis in patients with hematologic malignancies and profound neutropenia. C. jeikeium infection has also been reported in the setting of endocarditis, septicemia, meningitis, pneumonia, and soft tissue infections. Management of disseminated C. jeikeium infection in immunocompromised cancer patients can be challenging due to its high virulence and rapid skin colonization. We present two cases of disseminated C. jeikeium infection in patients with acute myelogenous leukemia (AML) and underlying comorbidities. Both patients presented with neutropenic fever resistant to initial standard empiric antibiotic therapy.