Blood stream infection after hematopoietic stem cell transplantation is associated with increased mortality

Do oral conditions influence the incidence of bloodstream infection after hematopoietic stem cell transplantation? A retrospective study in Japan

PURPOSE

This study aimed to evaluate the incidence of bloodstream infection (BSI) among patients undergoing hematopoietic stem cell transplantation (HSCT) for teeth indicated for extraction.

METHODS

Patients who underwent HSCT at Toranomon Hospital (Tokyo, Japan) between January 2017 and December 2019 were retrospectively evaluated. The incidence of BSI among patients with teeth indicated for extraction who did not undergo extraction (oral high-risk group) and patients who did not have this risk (oral low-risk group) was compared.

RESULTS

Among the 191 consecutive patients included in this study, 119 patients were classified as undergoing high-risk transplantation. BSI after HSCT was observed in 32 out of 60 (53.3%) patients and 56 out of 131 (42.7%) patients in the oral low-risk and oral high-risk groups, respectively (p = 0.173). Multivariable analyses revealed that the presence of > 3 teeth as intraoral sources of infection and age over 50 years were determinants of BSI originating from the oral cavity after engraftment (odds ratio [OR], 9.11; 95% confidential interval [CI] 2.27-36.61]; p = 0.002; OR, 3.22; CI [1.47-7.08], p = 0.004, respectively).

CONCLUSION

In patients undergoing HSCT, the presence of less than three intraoral sources of infection did not affect the incidence of BSI after HSCT.

MicroRNAs predict early complications of autologous hematopoietic stem cell transplantation

Autologous hematopoietic stem cell transplantation (AHSCT) remains the most prevalent type of stem cell transplantation. In our study, we investigated the changes in circulating miRNAs in AHSCT recipients and their potential to predict early procedure-related complications. We collected serum samples from 77 patients, including 54 with multiple myeloma, at four key time points: before AHSCT, on the day of transplantation (day 0), and at days + 7 and + 14 post-transplantation. Through serum miRNA-seq analysis, we identified altered expression patterns and miRNAs associated with the AHSCT procedure. Validation using qPCR confirmed deviations in the levels of miRNAs at the beginning of the procedure in patients who subsequently developed bacteremia: hsa-miR-223-3p and hsa-miR-15b-5p exhibited decreased expression, while hsa-miR-126-5p had increased level. Then, a neural network model was constructed to use miRNA levels for the prediction of bacteremia. The model achieved an accuracy of 93.33% (95%CI: 68.05-99.83%), with a sensitivity of 100% (95%CI: 67.81-100.00%) and specificity of 90.91% (95%CI: 58.72-99.77%) in predicting bacteremia with mean of 6.5 ± 3.2 days before occurrence. In addition, we showed unique patterns of miRNA expression in patients experiencing platelet engraftment delay which involved the downregulation of hsa-let-7f-5p and upregulation of hsa-miR-96-5p; and neutrophil engraftment delay which was associated with decreased levels of hsa-miR-125a-5p and hsa-miR-15b-5p. Our findings highlight the significant alterations in serum miRNA levels during AHSCT and suggest the clinical utility of miRNA expression patterns as potential biomarkers that could be harnessed to improve patient outcomes, particularly by predicting the risk of bacteremia during AHSCT.

Epidemiology, Microbiology, and Risk Factors of Bacterial Bloodstream Infections in Patients After Allogeneic Hematopoietic Stem Cell Transplantation

Purpose

To investigate the clinical characteristics, etiology, and risk factors of bacterial bloodstream infection (BSI) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. This study also aimed to provide a clinical basis for early identification of high-risk patients and optimization of empirical antimicrobial treatment.

Patients and Methods

This is a retrospective study of clinical data during agranulocytosis from 331 patients with hematological malignancies who underwent allo-HSCT at our institute between January 2016 and December 2022. The incidence, distribution and drug resistance patterns, and the risk factors of BSI were analyzed.

Results

Among the 331 HSCT patients, 250 had febrile neutropenia and 45 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 18% (45/250). A total of 48 pathogens were isolated during BSI episodes, gram-negative bacteria (GNB) accounted for 70.8% (34/48), gram-positive bacteria (GPB) for 29.2% (14/48). Multivariate analysis revealed that ≥grade 2 acute graft-versus-host disease (aGVHD) and previous BSI within 6 months before HSCT were independently associated with an increased occurrence of BSI. Coagulase-negative staphylococci (CoNS) and Escherichia coli were the most commonly isolated GPB and GNB, respectively. A total of 32 GNB were tested for drug susceptibility, the detection rate of carbapenem-resistant Enterobacteriaceae (CRE) was 12.5% (4/32), and extended-spectrum β-lactamase (ESBL) accounted for 56.3% (18/32).

Conclusion

BSIs are still a common and severe complication after allo-HSCT. In our center, BSIs in allo-HSCT patients are dominated by gram-negative bacteria and the resistance rate to carbapenem drugs is high. Risk factors for BSI during agranulocytosis were previous BSI within 6 months before HSCT and ≥grade 2 aGVHD.

Results of Levofloxacin Prophylaxis Timing in Autologous and Allogeneic Stem Cell Transplantation: A Retrospective Cohort Study

Background Despite preventive measures and varying antibiotic recommendations, bacterial infections continue to pose a significant threat to individuals undergoing hematopoietic stem cell transplantation (HSCT). Levofloxacin prophylaxis is commonly used, but the optimal timing for initiation is debated. This study aims to assess infection outcomes based on timing of levofloxacin prophylaxis (initiation at the first day of conditioning vs. after infusion of stem cells) in autologous and allogeneic HSCT patients. Methods We compared infectious episodes, responsible pathogens, and clinical outcomes based on the implementation of levofloxacin prophylaxis in patients receiving autologous or allogeneic HSCT procedures. This retrospective single-center study involved a review of the medical records of autologous and allogeneic HSCT patients treated at our adult stem cell transplantation unit between 2018 and 2020. The study included 23 patients who underwent autologous HSCT and 12 patients who underwent allogeneic HSCT. We compared the demographic data, febrile neutropenia, proven bacterial infections, and 30-day survival among the autologous and allogeneic transplant groups, including those who received oral levofloxacin 500 mg/day prophylaxis. Results Positive blood cultures (26.1% vs. 75%; p = 0.011), mean neutrophil engraftment (10.6±1.2 vs. 14.8±1.3; p<0.001), and mean platelet engraftment (11.2±1.1 vs. 15.4±3.2; p = 0.004) were all lower in autologous transplant patients versus their allogeneic counterparts. When each type of HSCT was evaluated within the same type, there were no observed differences in infection frequency, infection type, or 30-day mortality between the patient groups with different levofloxacin initiation times. Conclusion Healthcare professionals should choose the most appropriate timing for initiating levofloxacin prophylaxis based on individual patient factors and clinical circumstances while considering the cost-effectiveness implications. Further research with a larger sample size and prospective design is needed to support our findings.

Gut diversity and the resistome as biomarkers of febrile neutropenia outcome in paediatric oncology patients undergoing hematopoietic stem cell transplantation

The gut microbiota of paediatric oncology patients undergoing a conditioning regimen before hematopoietic stem cell transplantation is recently considered to play role in febrile neutropenia. Disruption of commensal microbiota and evolution of opportune pathogens community carrying a plethora of antibiotic-resistance genes play crucial role. However, the impact, predictive role and association of patient´s gut resistome in the course of the therapy is still to be elucidated. We analysed gut microbiota composition and resistome of 18 paediatric oncology patients undergoing hematopoietic stem cell transplantation, including 12 patients developing febrile neutropenia, hospitalized at The Bone Marrow Transplantation Unit of the National Institute of Children´s disease in Slovak Republic and healthy individuals (n = 14). Gut microbiome of stool samples obtained in 3 time points, before hematopoietic stem cell transplantation (n = 16), one week after hematopoietic stem cell transplantation (n = 16) and four weeks after hematopoietic stem cell transplantation (n = 14) was investigated using shotgun metagenome sequencing and bioinformatical analysis. We identified significant decrease in alpha-diversity and nine antibiotic-resistance genes msr(C), dfrG, erm(T), VanHAX, erm(B), aac(6)-aph(2), aph(3)-III, ant(6)-Ia and aac(6)-Ii, one week after hematopoietic stem cell transplantation associated with febrile neutropenia. Multidrug-resistant opportune pathogens of ESKAPE, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli found in the gut carried the significant subset of patient's resistome. Over 50% of patients treated with trimethoprim/sulfamethoxazole, piperacillin/tazobactam and amikacin carried antibiotic-resistance genes to applied treatment. The alpha diversity and the resistome of gut microbiota one week after hematopoietic stem cell transplantation is relevant predictor of febrile neutropenia outcome after hematopoietic stem cell transplantation. Furthermore, the interindividual diversity of multi-drug resistant opportunistic pathogens with variable portfolios of antibiotic-resistance genes indicates necessity of preventive, personalized approach.

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.

Clinical metagenomic sequencing of plasma microbial cell-free DNA for febrile neutropenia in patients with acute leukaemia

OBJECTIVES

To evaluate the diagnostic performance and clinical impact of metagenomic next-generation sequencing (mNGS) of plasma microbial cell-free DNA (mcfDNA) in febrile neutropenia (FN).

METHODS

In a 1-year, multicentre, prospective study, we enrolled 442 adult patients with acute leukaemia with FN and investigated the usefulness of mNGS of plasma mcfDNA for identification of infectious pathogens. The results of mNGS were available to clinicians in real time. The performance of mNGS testing was evaluated in comparison with blood culture (BC) and a composite standard that incorporated standard microbiological testing and clinical adjudication.

RESULTS

In comparison with BC, the positive and negative agreements of mNGS were 81.91% (77 of 94) and 60.92% (212 of 348), respectively. By clinical adjudication, mNGS results were categorized by infectious diseases specialists as definite (n = 76), probable (n = 116), possible (n = 26), unlikely (n = 7), and false negative (n = 5). In 225 mNGS-positive cases, 81 patients (36%) underwent antimicrobials adjustment, resulting in positive impact on 79 patients and negative impact on two patients (antibiotics overuse). Further analysis indicated that mNGS was less affected by prior antibiotics exposure than BC.

DISCUSSION

Our results indicate that mNGS of plasma mcfDNA increased the detection of clinically significant pathogens and enabled early optimization of antimicrobial therapy in patients with acute leukaemia with FN.

Epidemiologic and microbiologic evaluation of catheter-line bloodstream infection in a pediatric hematopoietic stem cell transplant center

BACKGROUND

Children who underwent hematopoietic stem cell transplant (HSCT) transplants are at high risk of developing central-line-associated bloodstream infections (CLABSIs). The present study aimed to identify possible risk factors for mortality by analyzing the clinical and laboratory characteristics of patients diagnosed with CLABSI in our pediatric hematopoietic stem cell transplant unit.

METHODS

The initial CLABSI episodes of 102 children were analyzed. Medical records of the patients were evaluated by preformed standardized surveys. Univariate analysis and multivariate logistic regression analysis were performed to identify risk factors for mortality.

RESULTS

Thirty-five patients (34.3%) were female. The median age was 48 months (3-204). The median time to onset of CLABSI was 19 days (4-150). The gram-negative and gram-positive bacteria ratio among the causative agents was 57.8% to 34.3%. The mortality rate was 12.6%. The presence of severe neutropenia, initiation of inappropriate empirical antibiotic therapy, the presence of hypotension, persistent bacteremia, pediatric intensive care unit admission, growth of carbapenemase-positive gram-negative microorganism and multidrug-resistant bacteria were significantly high in the mortality group when compared to survivors. The presence of hypotension, inappropriate empirical antibiotic therapy, and persistent bacteremia were found to be independent risk factors for mortality.

CONCLUSIONS

Rational use of antibiotics, active surveillance and screening of patients together with improved infection control practices may reduce the incidence and the consequences of CLABSIs.

Dual-Activity Fluoroquinolone-Transportan 10 Conjugates Offer Alternative Leukemia Therapy during Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) is often considered a last resort leukemia treatment, fraught with limited success due to microbial infections, a leading cause of mortality in leukemia patients. To address this critical issue, we explored a novel approach by synthesizing antileukemic agents containing antibacterial substances. This innovative strategy involves conjugating fluoroquinolone antibiotics, such as ciprofloxacin (CIP) or levofloxacin (LVX), with the cell-penetrating peptide transportan 10 (TP10). Here, we demonstrate that the resultant compounds display promising biologic activities in preclinical studies. These novel conjugates not only exhibit potent antimicrobial effects but are also selective against leukemia cells. The cytotoxic mechanism involves rapid disruption of cell membrane asymmetry leading to membrane damage. Importantly, these conjugates penetrated mammalian cells, accumulating within the nuclear membrane without significant effect on cellular architecture or mitochondrial function. Molecular simulations elucidated the aggregation tendencies of TP10 conjugates within lipid bilayers, resulting in membrane disruption and permeabilization. Moreover, mass spectrometry analysis confirmed efficient reduction of disulfide bonds within TP10 conjugates, facilitating release and activation of the fluoroquinolone derivatives. Intriguingly, these compounds inhibited human topoisomerases, setting them apart from traditional fluoroquinolones. Remarkably, TP10 conjugates generated lower intracellular levels of reactive oxygen species compared with CIP and LVX. The combination of antibacterial and antileukemic properties, coupled with selective cytostatic effects and minimal toxicity toward healthy cells, positions TP10 derivatives as promising candidates for innovative therapeutic approaches in the context of antileukemic HCT. This study highlights their potential in search of more effective leukemia treatments. SIGNIFICANCE STATEMENT: Fluoroquinolones are commonly used antibiotics, while transportan 10 (TP10) is a cell-penetrating peptide (CPP) with anticancer properties. In HCT, microbial infections are the primary cause of illness and death. Combining TP10 with fluoroquinolones enhanced their effects on different cell types. The dual pharmacological action of these conjugates offers a promising proof-of-concept solution for leukemic patients undergoing HCT. Strategically designed therapeutics, incorporating CPPs with antibacterial properties, have the potential to reduce microbial infections in the treatment of malignancies.

Risk Factors for Carbapenem-Resistant Enterobacteriaceae Colonization and the Effect on Clinical Outcomes and Prognosis in Allogeneic Hematopoietic Stem Cell Transplanted Patients

Purpose

The current study assesses which are the main risk factors, clinical outcome and prognosis following the colonization of CRE in patients that underwent allo-HSCT.

Patients and Methods

A total of 343 patients subjected to allo-HSCT in the period comprised between June 2021 and June 2022 were enrolled in this retrospective study. The CRE colonization was diagnosed by clinical history and routine microbial culture of perirectal swab. In this regard, a clinical prediction model was designed based on independent risk factors underlying the pre-transplantation CRE colonization using a backward stepwise logistic regression, followed by the evaluation of its discrimination and calibration efficacies, along with clinical usefulness. Furthermore, univariate and multivariate Cox regression analyses were then conducted to assess the risk factors for post-transplantation clinical outcomes.

Results

Out of 343 patients enrolled in this study, 135 (39.3%) reported CRE colonization. The independent risk factor variables for CRE colonization were incorporated into the nomogram to build a prediction model, which showed an area under the curve of 0.767 (95% CI: 0.716-0.818), and well-fitted calibration curves (χ2 = 1.737, P = 0.9788). The patients with CRE colonization reported a significantly lower platelet engraftment rate with a higher risk of post-transplantation BSI when compared with the non-CRE colonization group (P = 0.02 and P < 0.001; respectively). The non-relapse mortality (NRM) value was higher in the CRE patients (P < 0.05), consistently with a survival probability that was thus significantly lower for the same timeframe (P < 0.05).

Conclusion

A reliable clinical prediction model for pre-transplantation CRE colonization was developed that demonstrated that the CRE colonization negatively affects platelet engraftment and survival outcomes following allo-HSCT.

A Primed Neutrophil Subset Predicts the Risk of Bloodstream Infections in Allogeneic Hematopoietic Stem-Cell Transplant Patients: A Prospective Study

BACKGROUND

Bloodstream infections (BSIs) are the most common infectious complication in patients who receive allogeneic hematopoietic stem-cell transplants (allo-HSCTs). Polymorphonuclear neutrophils (PMNs) are quantified to monitor the susceptibility to BSIs; however, their degree of activation is not. We previously identified a population of primed PMNs (pPMNs) with distinct markers of activation representing approximately 10% of PMNs in circulation. In this study, we investigate whether susceptibility to BSIs is related to the proportion of pPMNs rather than strictly PMN counts.

METHODS

In this prospective observational study, we used flow cytometry to assess pPMNs in blood and oral rinse samples collected from patients receiving an allo-HSCT over the course of their treatment. We used the proportion of pPMNs in the blood on day 5 post-transplant to categorize patients into a high- or a low-pPMN group (>10% or <10% pPMNs). These groups were then used as a predictor of BSIs.

RESULTS

A total of 76 patients were enrolled in the study with 36 in the high-pPMN group and 40 in the low-pPMN group. Patients in the low-pPMN group had lower expression of PMN activation and recruitment markers and displayed a delay in PMN repopulation of the oral cavity after the transplant. These patients were more susceptible to BSIs compared with patients in the high-pPMN group with an odds ratio of 6.5 (95% confidence interval, 2.110-25.07; P = .002).

CONCLUSIONS

In patients who receive an allo-HSCT, having <10% pPMNs early in the post-transplant phase can be an independent predictor of BSI in allo-HSCT patients.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

Microbiology and Clinical Outcome of Bloodstream Infections in Patients After Hematopoietic Stem Cell Transplantation

Purpose

Patients after hematopoietic stem cell transplantation (HSCT) are often followed by bloodstream infections (BSIs). BSI is an important cause of non-relapse mortality (NRM) in HSCT patients.

Methods

We conducted a retrospective cohort study of patients (aged >14 years) who underwent HSCT at our hospital from 2017 to 2021. Population characteristics, BSI microbiology, resistance to common antibiotics, and 30-day all-cause mortality were analyzed.

Results

Of 3054 patients, 169 (5.5%) had BSIs after HSCT. Male, not in complete remission at transplantation and longer duration of neutropenia were risk factors for the development of BSI after HSCT. These BSIs were Gram-negative bacterial (n=123, 69.49%), Gram-positive bacterial (n=27, 15.25%), fungal (n=11, 6.36%), and polymicrobial (n=16, 9.25%). Among the Gram-negative bacteria, the proportions of isolates resistant to ceftazidime, cefepime, and piperacillin-tazobactam were similar (72.93%, 74.80%, and 77.42%, respectively). The overall drug resistance rates of amikacin and imipenem were 16.13% and 43.90%, respectively. Staphylococcus isolates were methicillin-resistant. In Enterococcus isolates, the penicillin resistance rate was 84.62%. Eleven isolates of Candida tropicalis were resistant to fluconazole and were sensitive to amphotericin B and flucytosine. The 30-day all-cause mortality rate of the 169 patients with BSIs was 8.88%. The 30-day all-cause mortality of patients with Gram-negative bacterial BSIs was 7.32%, 25.00% for polymicrobial BSIs, and 36.36% for fungal BSIs. The 30-day all-cause mortality of patients with fungal BSIs was significantly higher than that of patients with Gram-negative (P=0.0023) and Gram-positive bacteria (P=0.0023). Fungal BSI and non-Hodgkin's lymphoma (NHL) were associated with higher 30-day mortality.

Conclusion

Our study reveals the microbiological characteristics and 30-day all-cause mortality in patients with bloodstream infections after HSCT. Our data provides strong support for empirical antimicrobial therapy and infection prevention strategies for patients with BSIs after HSCT.

Clinical impact and early prediction of carbapenem-resistant Pseudomonas aeruginosa bacteraemia in allogeneic hematopoietic stem cell transplantation recipients

OBJECTIVE

Although antipseudomonal agents are administered in high-risk patients, no reports have focused on the risk of carbapenem-resistant (CR) Pseudomonas aeruginosa bacteraemia in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients.

METHODS

We retrospectively studied a cohort of adult allo-HSCT recipients with P. aeruginosa bacteraemia, focusing on a comparison between carbapenem-sensitive (CS) and CR P. aeruginosa after initiating conditioning chemotherapy at our institute between January 2005 and December 2020. The incidence, all-cause 30-d mortality of P. aeruginosa bacteraemia, and risk factors for carbapenem resistance among patients with P. aeruginosa bacteraemia in allo-HSCT recipients were evaluated.

RESULTS

Forty-eight patients with P. aeruginosa bacteraemia were included, with an incidence of 3.84/100 recipients (CS = 1.92 vs. CR = 1.92). The all-cause 30-d mortality was significantly higher in CR P. aeruginosa bacteraemia (CS = 4.2% vs. CR = 39.1%; P = 0.003). The factor significantly associated with CR P. aeruginosa bacteraemia was carbapenem use for at least 3 d within 30 d before the onset of bacteraemia (odds ratio = 8.92; 95% confidence interval: 1.35-58.90). Inappropriate antimicrobial selection was significantly more frequent in CR P. aeruginosa bacteraemia (CS = 0% vs. CR = 29.2%; P ˂ 0.009).

CONCLUSION

Empirical combination therapy with reference to antimicrobial susceptibility profiles in each institution should be considered when CR P. aeruginosa bacteraemia is suspected in allo-HSCT recipients based on the risk of carbapenem exposure.

Epidemiology, antimicrobial resistance, and mortality risk factors of carbapenem resistant gram-negative bacteria in hematopoietic stem cell transplantation recipients

Introduction

Carbapenem resistant gram-negative bacteria (CRGNB) infection is more and more frequent in patients after hematopoietic stem cell transplantation (HSCT), and the prognosis is very poor. The purpose of this study was to investigate the clinical characteristics and risk factors for mortality with CRGNB infection in HSCT recipients, and to provide useful information for guiding the application of antibiotics and improving the prognosis in the future.

Methods

Electronic medical records of CRGNB infected patients who underwent HSCT in Xiangya Hospital from January 1, 2015 to June 30, 2022 were collected. At the same time, 1:1 case-control matching was performed according to gender, age and disease type. The epidemiological characteristics and drug resistance of patients with CRGNB infection and non-CRGNB infection were compared. Logistic regression and Cox regression analysis were used to determine the risk factors for CRGNB acquisition and death respectively, and a prediction model of overall survival was constructed by R language.

Results and Discussion

The crude infection rate of CRGNB in HSCT recipients was 7.42%, and the mortality rate was 47.1%. CRGNB was resistant to most commonly used antibiotics. Time interval from diagnosis to transplantation >180 days (HR=7.886, 95% CI 2.624-23.703, P=0.000), septic shock (HR=6.182, 95% CI 2.605-14.671, P=0.000), platelet count < 20 × 10⁹/L (HR=2.615, 95% CI 1.152-5.934, P=0.022) and total bilirubin > 34.2 μmol/L (HR=7.348, 95% CI 2.966-18.202, P=0.000) at the initial stage of infection were 4 independent risk factors associated with mortality. CRGNB infection has become a serious threat to HSCT recipients. Clinicians should pay high attention to it and actively seek personalized treatment strategies suitable for local medical conditions.

Bacterial Bloodstream Infections in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation With Post-Transplantation Cyclophosphamide

This study investigates the incidence and predictors for bacterial bloodstream infection (BSI) in 330 adults undergoing allo-HCT, and explores the effect of post-transplantation cyclophosphamide (PTCY) on the probability of presenting this complication. All patients received levofloxacin during the aplastic phase. Only the first episode of BSI was counted as an event. Patients were classified into 2 groups: PTCY-based (n = 200) versus other prophylaxis (n = 130). One hundred twenty-four patients were diagnosed with a first episode of BSI, most of them during the first 30 days (70.2%). Proportions of BSIs caused by Gram-positive bacteria were comparable to those caused by Gram-negative bacteria (48.3% versus 45.9%). The cumulative incidence of BSI was higher in patients receiving PTCY than in those receiving other prophylaxis (days 30 and 100: 35.0% and 37.0% versus 13.1% and 18.5%, P < .001). At day 30, the likelihood of BSI was 2.41 (P = .012) times higher in the PTCY group than in the non-PTCY group. The 30-day mortality rate in all patients with BSI was 8.0%, lower (P = .002) in the PTCY group (2.3%) than in the non-PTCY group (21.6%). Finally, the overall survival of patients receiving PTCY and diagnosed with BSI was similar to that of patients without presenting this complication. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Clinical Characteristics, Microbiology, and Risk Factors for Mortality of Pre-Engraftment and Post-Engraftment Bloodstream Infection in Hematopoietic Stem Cell Transplantation Recipients

BACKGROUND

Bloodstream infection (BSI) is a common and serious complication that may lead to high mortality during the different phases after hematopoietic stem cell transplant (HSCT). We investigated BSI in patients undergoing HSCT to provide an appropriate clinical anti-infection experience and improve the prognosis of recipients with BSI after HSCT.

METHODS

A total of 105 patients with BSI after HSCT at our center from January 2015 to June 2020 were included in this retrospective study. We analyzed the clinical and microbiological data, and the risk factors for mortality at 3 months after BSI.

RESULTS

Of the 1141 HSCT recipients, 105 (9.2%) patients presented with 122 episodes of BSI, of which we isolated 85 (65.9%) gram-negative bacteria, 32 (24.8%) gram-positive bacteria and 12 (9.3%) fungi. Multidrug-resistant bacteria (MDR) were more than 70% of all pathogens and carbapenem-resistant organisms (CRO) were 25.6%. There were 55 episodes of BSI in the pre-engraftment phase and 67 episodes in the post-engraftment phase. The mortality of post-engraftment BSI was significantly higher than that of pre-engraftment (56.7% vs 32.7%, p = 0.005). Through multivariate analysis, the independent risk factors for all-cause mortality at 3 months after BSI were higher levels of procalcitonin (PCT), failure to cover appropriate antibiotics timely, and CRO BSI in pre-engraftment period or multidrug-resistant gram-negative bacteria (MDRGNB) BSI in post-engraftment period.

CONCLUSION

Although the incidence of BSI was lower after HSCT, MDR-dominated BSI had a high mortality rate. Rapid identification of infection or pathogens' classification with various testing methods and the more sensible and timely antibiotic cover are critical to the outcome of BSI after HSCT.

Impact of Discontinuing Levofloxacin Prophylaxis on Bloodstream Infections in Neutropenic Hematopoietic Stem Cell Transplantation Patients

Multidrug-resistant pathogens have emerged worldwide. We have driven the hypothesis that the non-use of fluoroquinolone prophylaxis during neutropenia could reduce antibiotic resistance in Gram-negative bacteria that cause bloodstream infections (BSIs) in hematopoietic stem cell transplantation (HSCT) patients and that this change in resistance pattern could lead to an impact on BSI mortality. This is a quasi-experimental study comparing BSI incidence, resistance patterns of bacteria that cause BSI, and BSI mortality when levofloxacin prophylaxis was routine for neutropenic HSCT patients (2016–2018) to when fluoroquinolone prophylaxis was discontinued in our center (2019). Bivariate comparisons and multivariate logistic regression models were used for analyses. A total of 310 HSCTs (66 (21%) allogeneic and 244 (79%) autologous) were performed during the study period. Sixty (19%) patients had BSIs, 30 in each evaluated period. The discontinuation of levofloxacin prophylaxis was associated with an increase in BSI incidence and a decrease in the resistance rates of causative BSI bacteria and in BSI 30-day mortality. The increase in the rate of resistant bacteria causing BSI and in BSI mortality might outweigh the benefits of a decrease in BSI incidence caused by fluoroquinolone prophylaxis in neutropenic HSCT patients. We suggest that the routine use of fluoroquinolone in this context be revisited.

The Impact of Human Microbiotas in Hematopoietic Stem Cell and Organ Transplantation

The human microbiota heavily influences most vital aspects of human physiology including organ transplantation outcomes and transplant rejection risk. A variety of organ transplantation scenarios such as lung and heart transplantation as well as hematopoietic stem cell transplantation is heavily influenced by the human microbiotas. The human microbiota refers to a rich, diverse, and complex ecosystem of bacteria, fungi, archaea, helminths, protozoans, parasites, and viruses. Research accumulating over the past decade has established the existence of complex cross-species, cross-kingdom interactions between the residents of the various human microbiotas and the human body. Since the gut microbiota is the densest, most popular, and most studied human microbiota, the impact of other human microbiotas such as the oral, lung, urinary, and genital microbiotas is often overshadowed. However, these microbiotas also provide critical and unique insights pertaining to transplantation success, rejection risk, and overall host health, across multiple different transplantation scenarios. Organ transplantation as well as the pre-, peri-, and post-transplant pharmacological regimens patients undergo is known to adversely impact the microbiotas, thereby increasing the risk of adverse patient outcomes. Over the past decade, holistic approaches to post-transplant patient care such as the administration of clinical and dietary interventions aiming at restoring deranged microbiota community structures have been gaining momentum. Examples of these include prebiotic and probiotic administration, fecal microbial transplantation, and bacteriophage-mediated multidrug-resistant bacterial decolonization. This review will discuss these perspectives and explore the role of different human microbiotas in the context of various transplantation scenarios.

Incidence, etiology, risk factors and outcomes of pre-engraftment bloodstream infections after first and second allogeneic hematopoietic cell transplantation

INTRODUCTION

With increasing number of allogeneic hematopoietic cell transplantations (allo-HCT) bloodstream infections (BSI) are still among the most common and serious complications. This study aimed to analyze the incidence, etiology, risk factors, and outcomes of pre-engraftment BSI after the first and the second allo-HCT.

MATERIALS AND METHODS

This is a retrospective study of 284 patients who underwent first allo-HCT and 37 patients after the second allo-HCT at the National Research Center for Hematology in Moscow, Russia, from January 2018 till September 2021.

RESULTS

Cumulative incidence of pre-engraftment BSI was 29.9% after the first allo-HCT and 35.1% after the second (p = 0,805). Median time to the first BSI was 9 days (range 0-61 days) after the first and 16 days (range 1-28 days) after the second allo-HCT (p = 0.014). A total of 113 pathogens were isolated during 94 BSI episodes after the first allo-HCT (gram-negative bacteria 52.2%; gram-positive bacteria 47.7%). Fourteen pathogens were isolated during 14 BSI episodes after the second allo-HCT (gram-negative bacteria 50.0%; gram-positive bacteria 50.0%). The only significant difference was found in the rate of carbapenem-resistant gram-negative bacteria, which was higher after the second allo-HCT compared to the first (57.1% vs. 13.6%; p = 0.048). Mismatched unrelated donor (HR 3.01; 95% CI:1.62-5.60; p<0.0001) and haploidentical donor transplantations (HR 1.84; 95% CI:1.02-3.33; p = 0.042) were the only independent risk factors associated with the higher risk of pre-engraftment BSI. Overall 30-day survival after all BSI episodes was 94.4%,. Survival was lower after BSI during the second allo-HCT compared to the first (71.4% vs. 97.9%; p<0,0001), particularly after BSI caused by carbapenem-resistant gram-negative bacteria (25.0% vs. 100.0%; p = 0.0023). Non-relapse mortality rate at day +60 was 4.0%, and the risk was highly associated with primary graft failure (HR 9.62; 95% CI: 1.33-71.43), second allo-HCT (HR 6.80; 95% CI: 1.36-34.48), and pre-engraftment BSI caused by carbapenem-resistant gram-negative bacteria (HR 32.11; 95% CI: 4.91-210.15).

CONCLUSIONS

Pre-engraftment BSI is still a common complication after allo-HCT, particularly after mismatched unrelated and haploidentical donor transplantations. BSI incidence was slightly higher after the second allo-HCT with significantly higher rate of carbapenem-resistant BSI. Although pre-engraftment BSI would generally follow benign clinical course, survival was dramatically lower during the second allo-HCT especially after carbapenem-resistant BSI. This article is protected by copyright. All rights reserved.

Bacteremia in Hematopoietic Stem Cell Recipients Receiving Fluoroquinolone Prophylaxis: Incidence, Resistance, and Risk Factors

Background

Bacteremia is a common complication in hematopoietic stem cell transplant (HSCT) recipients. Prophylactic fluoroquinolone is recommended and used in these individuals. Breakthrough infections can occur with fluoroquinolone-resistant strains. We aimed to identify the incidence, resistance, and risk factors for bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis.

Materials and Methods

This retrospective study was performed on patients who received fluoroquinolone prophylaxis and underwent autologous and allogeneic HSCT between 2015 and 2019. The incidence of bacteremia, comorbidity, treatment, and invasive procedures was compared in these patients with and without bacteremia.

Results

There were 553 patients included in the study, 68 (12.3%) had bacteremia. The incidence of bacteremia is 8.2% of autologous HSCT recipients and 18.4% of allogeneic HSCT recipients. The significant risk factors associated with bacteremia were steroid-using (odds ratio [OR]:13.83, 95% confidence interval [CI]: 2.88 - 66.40), higher Charlson Comorbidity Index (CCI)-mean (OR: 1.57, 95% CI: 1.15 - 2.16), diabetes mellitus (OR: 4.29, 95% CI: 1.11 - 16.48) in autologous HSCT, steroid-using (OR: 6.84, 95% CI: 1.44 - 32.33), longer duration of neutropenia (OR: 1.05, 95% CI: 1.01 - 1.09) using central venous catheter (OR: 7.81, 95% CI: 1.00 - 61.23) in allogeneic HSCT. Seventy-three pathogens were isolated from a total of 68 bacteremia episodes. The most commonly occurring agents were Escherichia coli, Klebsiella pneumoniae and Enterococcus spp. Resistance to fluoroquinolones was 87.2%, 70.0% and 60.0% among these strains, respectively.

Conclusion

High CCI, diabetes mellitus, use of steroids and long-term neutropenia and use of central venous catheters were significantly associated with the breakthrough bacteremia in HSCT recipients receiving fluoroquinolone prophylaxis. Fluoroquinolone prophylaxis may reduce the incidence of bacteremia but may select strains resistant to fluoroquinolone.

Analysis of incidence and risk factors of the multidrug resistant gastrointestinal tract infection in children and adolescents undergoing allogeneic and autologous hematopoietic cell transplantation: a nationwide study

The aim of this multi-center study was to evaluate the incidence, clinical course, and risk factors for bacterial multidrug-resistant (MDR) gastrointestinal tract infections (GTI) among children undergoing allogeneic and autologous hematopoietic cell transplantation. A total number of 175 pediatric patients (aged 1–18 years), transplanted between January 2018 and December 2019, who were tested for bacterial colonization/infection were enrolled into this multi-center analysis. Episodes of MDR GTI occurred in 77/175 (44%) patients. In multivariate analysis for higher GTI incidence, the following factors were significant: matched-unrelated donor (MUD) transplantation, HLA mismatch, presence of graft-versus-host disease (GVHD), and gut GVHD. The most common GTI were Clostridium difficile (CDI), multidrug-resistant Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli extended-spectrum β-lactamase), and Enterococcus HLAR (high-level aminoglycoside-resistant). No MDR GTI–attributed deaths were reported. MDR GTI is a frequent complication after HCT among children, causes prolonged hospitalization, but rarely contributes to death. We identified risk factors of MDR GTI development in children, with focus on GVHD and unrelated donor and HLA mismatch. We conclude that the presence of Clostridiales plays an important anti-inflammatory homeostatic role and decreases incidence of GVHD or alleviate its course.

Bloodstream Infections and Outcomes Following Allogeneic Hematopoietic Cell Transplantation: A Single-Center Study

This study investigated the single-center incidence and risk factors for bloodstream infections (BSIs) in 651 adults who underwent allogeneic hematopoietic cell transplantation (alloHCT) between 2015 and 2019 and explored the impact of these BSIs on post-transplantation outcomes. Antibiotic prophylaxis with ciprofloxacin was given during the aplastic phase. Overall, the median patient age was 57 years, 79.7% of patients received an alternative donor graft, and 68.7% received post-transplantation cyclophosphamide (PTCy) as part of their graft-versus-host disease (GVHD) prophylaxis. Of the 651 patients, 358 (55.0%) had at least 1 episode of BSI, and the overall mortality rate secondary to this complication was 7.5% (12.6% among those diagnosed with at least 1 episode of BSI). BSI was more often diagnosed during the first 30 days (58.7%), and gram-positive bacteria were the most prevalent microorganisms isolated during the entire post-transplantation follow-up (62%). A high Disease Risk Index (hazard ratio [HR], 1.47; P < .029) and receipt of PTCy-based GVHD prophylaxis (HR, 3.33; P < .001) were identified as risk factors for BSI. Additionally, univariate analysis showed that patients diagnosed with a BSI during post-transplantation follow-up had worse overall survival (HR, 2.48; P < .001) and higher nonrelapse mortality (HR, 2.68; P < .001) than those without BSI. In conclusion, alloHCT recipients with a BSI had a higher risk of mortality compared with those who did not develop BSI. The inclusion of PTCy as part of GVHD prophylaxis was identified as an independent risk factor for BSI during early post-transplantation follow-up. Single-center analyses focused on reporting the incidence and risk factors for BSI highlight the need for active implementation of preemptive strategies to decrease BSI incidence in the alloHCT setting. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Severe acute graft-versus-host disease increases the incidence of blood stream infection and mortality after allogeneic hematopoietic cell transplantation: Japanese transplant registry study

This study aimed to clarify the risk factors and prognosis associated with blood stream infection (BSI) in allogeneic hematopoietic cell transplantation (allo-HCT), and the relationship between BSI and acute graft-versus-host disease (aGVHD). This retrospective analysis included 11,098 patients in the Japanese national transplant registry. A total of 2172 patients developed BSI after allo-HCT, with 2332 identified pathogens. The cumulative incidences of BSI were 15.5% at 30 days and 20.9% at 100 days after allo-HCT. In a multivariate analysis, severe (grade III-IV) aGVHD was associated with a higher risk of BSI (vs. grade 0-I aGVHD: hazard ratio [HR] 3.34 [95% confidence interval (CI), 2.85-3.92; P < 0.001]). In a multivariate analysis, severe aGVHD before BSI was associated with a higher risk of overall mortality after BSI (vs. grade 0-I aGVHD: HR 2.61 [95% CI 2.18-3.11; P < 0.001]). In addition, BSI (vs. no-BSI: HR 1.20 [95% CI, 1.12-1.29; P < 0.001]) and severe aGVHD (vs. grade 0-I aGVHD: HR 1.97 [95% CI, 1.83-2.12; P < 0.001]) were independent risk factors for overall mortality after allo-HCT. In the setting of allo-HCT, severe aGVHD was associated with increases in both BSI incidence and post-BSI overall mortality. Furthermore, BSI was an independent risk factor for overall mortality.

High Throughput Analysis Reveals Changes in Gut Microbiota and Specific Fecal Metabolomic Signature in Hematopoietic Stem Cell Transplant Patients

There is mounting evidence for the emerging role of gut microbiota (GM) and its metabolites in profoundly impacting allogenic hematopoietic stem cell transplantation (allo-HSCT) and its subsequent complications, mainly infections and graft versus host-disease (GvHD). The present study was performed in order to investigate changes in GM composition and fecal metabolic signature between transplant patients (n = 15) and healthy controls (n = 18). The intestinal microbiota was characterized by NGS and gas chromatography-mass spectrometry was employed to perform untargeted analysis of fecal metabolites. We found lower relative abundances of Actinobacteria, Firmicutes, and Bacteroidetes and a higher abundance of Proteobacteria phylum after allo-HSCT. Particularly, the GvHD microbiota was characterized by a lower relative abundance of the short-chain fatty acid-producing bacteria, namely, the Feacalibacterium, Akkermansia, and Veillonella genera and the Lachnospiraceae family, and an enrichment in multidrug-resistant bacteria belonging to Escherichia, Shigella, and Bacteroides. Moreover, network analysis showed that GvHD was linked to a higher number of positive interactions of Blautia and a significant mutual-exclusion rate of Citrobacter. The fecal metabolome was dominated by lipids in the transplant group when compared with the healthy individuals (p < 0.05). Overall, 76 metabolites were significantly altered within transplant recipients, of which 24 were selected as potential biomarkers. Furthermore, the most notable altered metabolic pathways included the TCA cycle; butanoate, propanoate, and pyruvate metabolisms; steroid biosynthesis; and glycolysis/gluconeogenesis. Specific biomarkers and altered metabolic pathways were correlated to GvHD onset. Our results showed significant shifts in gut microbiota structure and fecal metabolites characterizing allo-HSCT.

Therapeutics for paediatric oncological emergencies

Background

With advancements in the field of oncology, cancer survival rates have improved dramatically but modern cancer treatments also come with an increasing number of disease and treatment-associated complications. This article provides an updated narrative review on the pathophysiology, clinical presentations and latest management strategies for common paediatric oncological emergencies.

Methods

An extensive PubMed^® search of all human studies in the English literature was performed in Clinical Queries for different oncology syndromes and conditions using the following Medical Subject Headings: “tumour lysis syndrome”, “hyperleukocytosis”, “disseminated intravascular coagulation”, “superior mediastinal syndrome”, “superior vena cava syndrome”, “sepsis”, “severe inflammatory response syndrome”, “acute respiratory distress syndrome”, “posterior reversible encephalopathy syndrome” and “reversible posterior leukoencephalopathy syndrome”. Categories were limited to clinical trials and reviews for ages from birth to 18 years.

Results

The general description, presentation and management of these oncologic emergencies are systematically described. Early recognition along with prompt and proactive treatment can reduce the chances of potential complications and improve the clinical outcomes, thereby improving not only survival rates in oncology patients but also their clinical outcomes and quality of life.

Conclusions

Oncologic emergencies are associated with significant mortality and morbidity. Healthcare professionals involved with the care of oncology patients must be vigilant of these emergencies.

Secular trends of Blood stream infections in allogeneic hematopoietic cell transplant recipients 72 hours prior to death

INTRODUCTION

Blood stream infections (BSI) frequently cause morbidity and mortality in allogeneic (allo) hematopoietic cell transplant (HCT) recipients. Characteristics of causative organisms shortly before death have not been previously described. Early treatment with antimicrobial agents targeting the recent surge in multidrug-resistant (MDR) pathogens may lead to better outcomes.

METHODS

This is retrospective study including 529 allo HCT recipients who died between 2000 and 2013. All patients who had BSI that happened 72 hours before death were included. BSI and criteria for antimicrobial resistance were defined according to the Centers for Disease Control and Prevention and the National Healthcare Safety Network surveillance criteria.

RESULTS

Overall, 104 BSI were identified from 91 patients. Bacterial infections accounted for 87% of the infections which were comprised by 37% gram-negative organisms and 50% gram-positive bacteria. The most common species were Enterococcus (30%), Staphylococcus (16%), and Pseudomonas (16%). Most enterococci were vancomycin resistant (87%), 100% of staphylococci were resistant to methicillin, and 64% of Pseudomonas were MDR. Over time there was a significant increase in vancomycin-resistant enterococcal (P = .01) and gram-negative BSI (P = .01). Blood stream infections were either the primary or secondary cause of death in 53% of patients.

CONCLUSIONS

In allo HCT recipients, vancomycin-resistant enterococcal infections caused the majority of BSI 72 hours prior to death. Our findings provide information that may guide empiric antibiotic coverage in critically ill HCT recipients.

Risk Factors for Mortality in Hematopoietic Stem Cell Transplantation Recipients with Bloodstream Infection: Points To Be Addressed by Future Guidelines

In recent years, important epidemiologic changes have been described in hematopoietic stem cell transplantation (HSCT) recipients with bloodstream infection (BSI), with increases in gram-negative bacilli and multidrug resistant (MDR) gram-negative bacilli. These changes have been linked to a worrisome increase in mortality. We aimed to define the risk factors for mortality of HSCT patients experiencing BSI. All episodes of BSI in patients with HSCT between 2008 and 2017 were prospectively collected. Multivariate analyses were performed. A total of 402 BSI episodes were documented in 293 patients who had undergone HSCT (75.4% allogenic, 32.3% autologous, 19.3% second HSCT). The median time from HSCT to BSI was 62 days (interquartile range, 9 to 182 days). Gram-positive cocci accounted for 56.7% of the episodes; gram-negative bacilli, for 42%. The most common microorganisms were coagulase-negative staphylococci (30.6%) and Pseudomonas aeruginosa (15.9%). MDR gram-negative bacilli caused 11.9% of all episodes. Clinical characteristics, source of BSI, etiology, and outcomes changed depending on time since HSCT. Globally, 26.6% of episodes were treated with inappropriate empiric antibiotic therapy, more frequently in BSI episodes caused by P. aeruginosa, MDR P. aeruginosa, and MDR gram-negative bacilli. The 30-day mortality was 19.2%. Independent risk factors for mortality were BSI occurring ≥30 days after HSCT (odds ratio [OR], 11.21; 95% confidence interval [CI], 4.63 to 27.19), shock (OR, 7.10; 95% CI, 2.98 to 16.94), BSI caused by MDR P. aeruginosa (OR, 4.45; 95% CI, 1.12 to 17.72), and inappropriate empiric antibiotic therapy for gram-negative bacilli or Candida spp. (OR, 3.73; 95% CI, 1.27 to 10.89). HSCT recipients experiencing BSI have high mortality related to host and procedure factors, causative microorganism, and empiric antibiotic therapy. Strategies to identify HSCT recipients at risk of MDR P. aeruginosa and reducing inappropriate empiric antibiotic therapy are paramount to reduce mortality.

The impact of graft cell source on bloodstream infection in the first 100 days after allogeneic hematopoietic cell transplantation

Bloodstream infection (BSI) is a major infectious complication after allogeneic hematopoietic cell transplantation (HCT). To clarify the impact of graft cell source on the incidence of BSI after transplantation, we retrospectively examined 782 adult patients receiving their first allogeneic HCT: 122 recipients of related peripheral blood stem cells or bone marrow, 215 recipients of unrelated bone marrow, and 445 recipients of unrelated umbilical cord blood (U-CB). The cumulative incidence of BSI was 42.5% at 100 days after transplantation (95% confidence interval, 39.0-46.0). Gram-positive cocci were present in 64.2% of detected isolates. Among the pre-transplant factors including age, performance status, primary disease, disease status, graft cell source, sex and ABO blood type matching, and the intensity of conditioning regimen, U-CB use was identified as the most significant risk factor for BSI by multivariate analysis (hazard ratio, 1.76; 95% confidence interval, 1.40-2.22; p < 0.00001). Among the U-CB recipients, those who are not in remission at the time of transplantation were at the greatest risk of BSI (hazard ratio, 1.69; 95% confidence interval, 1.14-2.50; p < 0.01). The study makes it clear that graft cell source has an impact on BSI development after allogeneic HCT.

Inappropriate Empirical Antibiotic Treatment in High-risk Neutropenic Patients With Bacteremia in the Era of Multidrug Resistance

BACKGROUND

We aimed to describe the current rates of inappropriate empirical antibiotic treatment (IEAT) in oncohematological patients with febrile neutropenia (FN) and its impact on mortality.

METHODS

This was a multicenter prospective study of all episodes of bloodstream infection (BSI) in high-risk FN patients (2006-2017). Episodes receiving IEAT were compared with episodes receiving appropriate empirical therapy. Adherence to Infectious Diseases Society of America (IDSA) recommendations was evaluated. Multivariate analysis was performed to identify independent risk factors for mortality in Pseudomonas aeruginosa episodes.

RESULTS

Of 1615 episodes, including Escherichia coli (24%), coagulase-negative staphylococci (21%), and P. aeruginosa (16%), 394 (24%) received IEAT despite IDSA recommendations being followed in 87% of cases. Patients with multidrug-resistant gram-negative bacilli (MDR-GNB), accounting for 221 (14%) of all isolates, were more likely to receive IEAT (39% vs 7%, P < .001). Overall mortality was higher in patients with GNB BSI who received IEAT (36% vs 24%, P = .004); when considering individual microorganisms, only patients with infection caused by P. aeruginosa experienced a significant increase in mortality when receiving IEAT (48% vs 31%, P = .027). Independent risk factors for mortality in PA BSI (odds ratio [95% confidence interval] were IEAT (2.41 [1.19-4.91]), shock at onset (4.62 [2.49-8.56]), and pneumonia (3.01 [1.55-5.83]).

CONCLUSIONS

IEAT is frequent in high-risk patients with FN and BSI, despite high adherence to guidelines. This inappropriate treatment primarily impacts patients with P. aeruginosa-related BSI mortality and in turn is the only modifiable factor to improve outcomes.

Epidemiological surveillance of health care-associated infections in a pediatric hematopoietic stem cell transplantation unit in South Brazil

BACKGROUND

Pediatric hematopoietic stem cell transplantation (HSCT) recipients represent a vulnerable population with regard to health care-associated infections (HAI) with a differentiated profile of etiologic agents.^1,2 There are few reports in the literature regarding HAI in the pediatric population submitted to HSCT.

METHODS

This is a retrospective study conducted in a pediatric HSCT unit in Curitiba, Brazil between February 2013 and December 2017 that evaluated 109 pediatric patients. The variables analyzed were: age, gender, baseline disease, type of transplantation, infection topography, etiologic agent, time of HAI occurrence, antimicrobial prophylaxis, period of neutropenia, length of stay, and outcomes RESULTS: Of 113 HSCT procedures, 91 (83.5%) were allogenic and 18 were autologous (16.5%). The mean age of the patients was 7.9 years, with a median of 8.1 years (4.0 months-17.3 years); 71 (65.1%) were male; 55 (50.5%) presented with an oncologic diagnosis, 32 (29.4%) with a hematological diagnosis, 17 (15.6%) with immunodeficiencies, and 5 (4.6%) with other causes. During hospitalization after HSCT, 86 episodes of HAI were detected in 66 patients, with an infection density of 16.5 infections/1000 patient days, 86% of which occurred after allogeneic transplants, appearing, on average, 15.3 days after transplantation. The main topographies were bloodstream infection (BSI), with 24 (27.9%) cases, and central line-associated bloodstream infection (CLABSI), with 11 (12.8%). Gram-positive bacteria predominated in cultures and HAI was more frequent in patients diagnosed with immunodeficiencies and other non-oncologic and non-hematologic conditions. Among the Gram-positive bacteria, Staphylococcus epidermidis was the main agent identified (77.7%), possibly because of colonization. However, Gram-negative bacteria, with a resistance profile, comprised 40% of the cases of bacterial infections, most of them represented by Klebsiella pneumoniae (66.6%). Of the 66 patients who presented HAI, 59 patients (89.4%) were discharged, and 7 (10.6%) died.

CONCLUSION

The main topographies were CLABSI and BSI. Patients with immunodeficiencies presented a higher risk for HAI Staphylococcus epidermidis was the main agent identified. However, Klebsiella pneumoniae posed a higher risk for Pediatric Intensive Care Unit admission and death.

Characteristics of gram-negative bacteremia during febrile neutropenia among allogeneic hematopoietic stem cell transplant recipients on levofloxacin prophylaxis

The aim of this study is to clarify the characteristics of gram-negative bacteremia (GNB), including extended-spectrum β-lactamase (ESBL)-producing pathogens, among allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients on levofloxacin (LVFX) prophylaxis. A retrospective analysis on GNB at the first episode of febrile neutropenia (FN) was conducted among allo-HSCT recipients (age ≥ 20 years) on 500 mg/day of oral LVFX prophylaxis. Epidemiological and microbiological features of GNB were investigated and compared between the inappropriate and appropriate empiric therapy groups. In total, FN occurred in 414 allo-HSCT cases, and bacteremia at the first episode of FN occurred in 169 cases. Overall, 29 GNB cases were documented, and the causative organisms identified were Escherichia coli in 21 cases (including 10 ESBLs), Klebsiella pneumoniae in 2, Pseudomonas aeruginosa in 2, and other in 4. The crude 30-day mortality rate was not significantly different among cases of GNB (6.9%), gram-positive bacteremia (GPB) (7.1%), or non-bacteremia (5.4%; P = 0.78). Cefepime (CFPM) was administered in all cases in the inappropriate empiric therapy group, and all causative organisms were ESBL-producing E. coli (ESBL-EC). All patients in the inappropriate empiric therapy group had a low Pitt bacteremia score (≤ 2). Thirty-day mortality did not differ significantly between the inappropriate and appropriate empiric therapy groups (1/10 vs. 1/15, P = 0.61). In conclusion, GNB was not a significant cause of death. In LVFX breakthrough ESBL-EC bacteremia among allo-HSCT recipients, the administration of CFPM as empiric therapy did not lead to significantly poor prognosis. Empiric CFPM administration might be an acceptable strategy.

Intercontinental study on pre-engraftment and post-engraftment Gram-negative rods bacteremia in hematopoietic stem cell transplantation patients: Risk factors and association with mortality

OBJECTIVES

We present here data on Gram-negative rods bacteremia (GNRB) rates, risk factors and associated mortality.

METHODS

Data on GNRB episodes were prospectively collected in 65 allo-/67 auto-HSCT centers in 24 countries (Europe, Asia, Australia). In patients with and without GNRB, we compared: demography, underlying disease, HSCT-related data, center` fluoroquinolone prophylaxis (FQP) policy and accreditation status, and involvement of infection control team (ICT).

RESULTS

The GNRB cumulative incidence among 2818 allo-HSCT was: pre-engraftment (pre-eng-allo-HSCT), 8.4 (95% CI 7-9%), post-engraftment (post-eng-allo-HSCT), 5.8% (95%CI: 5-7%); among 3152 auto-HSCT, pre-eng-auto-HSCT, 6.6% (95%CI: 6-7%), post-eng-auto-HSCT, 0.7% (95%CI: 0.4-1.1%). GNRB, especially MDR, was associated with increased mortality. Multivariate analysis revealed the following GNRB risk factors: (a) pre-eng-allo-HSCT: south-eastern Europe center location, underlying diseases not at complete remission, and cord blood source; (b) post-eng-allo-HSCT: center location not in northwestern Europe; underlying non-malignant disease, not providing FQP and never accredited. (c) pre-eng-auto-HSCT: older age, autoimmune and malignant (vs. plasma cell) disease, and ICT absence.

CONCLUSIONS

Benefit of FQP should be explored in prospective studies. Increased GNRB risk in auto-HSCT patients transplanted for autoimmune diseases is worrying. Infection control and being accredited are possibly protective against bacteremia. GNRB are associated with increased mortality.

Allogeneic hematopoietic stem cell transplantation in aplastic anemia: current indications and transplant strategies

Treatment options for newly diagnosed aplastic anemia (AA) patient includes upfront allogeneic hematopoietic stem cell transplant (HSCT) or immunosuppressive therapy (IST). With recent advances in supportive care, conditioning regimens and post-transplant immunosuppression the overall survival for HSCT approaches 70-90%. Transplant eligibility needs to be assessed considering age, comorbidities, donor availability and probability of response to immunosuppressive therapy (IST). Upfront HSCT should be offered to children and young adults with matched related donor (MRD). Upfront HSCT may also be offered to children and young adults with rapidly available matched unrelated donor (MUD) who require urgent HSCT. Bone marrow (BM) graft source and cyclosporine (CsA) plus methotrexate (MTX) as graft versus host disease (GVHD) prophylaxis are preferable when using anti-thymocyte globulin (ATG) based conditioning regimens. Alemtuzumab is an acceptable alternative to ATG and is used with CsA alone and with either BM or peripheral blood stem cells (PBSC). Cyclophosphamide (CY) plus ATG conditioning is preferable for patients receiving MRD transplant, while Fludarabine (Flu) based conditioning is reserved for older adults, those with risk factors of graft failure and those receiving MUD HSCT. For haploidentical transplant, use of low dose radiotherapy and post-transplant cyclophosphamide has resulted in a marked reduction in graft failure and GVHD.

Improving Oral Health and Modulating the Oral Microbiome to Reduce Bloodstream Infections from Oral Organisms in Pediatric and Young Adult Hematopoietic Stem Cell Transplantation Recipients: A Randomized Controlled Trial

Bloodstream infections (BSIs) from oral organisms are a significant cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients. There are no proven strategies to decrease BSIs from oral organisms. The aim of this study was to evaluate the impact of daily xylitol wipes in improving oral health, decreasing BSI from oral organisms, and modulating the oral microbiome in pediatric HSCT recipients. This was a single-center 1:1 randomized controlled trial in pediatric HSCT recipients age >2 years. Age-matched healthy children were enrolled to compare the oral microbiome. The oral hygiene standard of care (SOC) group continued to receive the standard oral hygiene regimen. The xylitol group received daily oral xylitol wipes (with .7 g xylitol) in addition to the SOC. The intervention started from the beginning of the transplantation chemotherapy regimen and extended to 28 days following transplantation. The primary outcome was oral health at interval time points, and secondary outcomes included BSIs from oral organisms in the first 30 days following transplantation, oral microbiome abundance, and diversity and oral pathogenic organism abundance. The study was closed early due to efficacy after an interim analysis of the first 30 HSCT recipients was performed (SOC group, n = 16; xylitol group, n = 14). The xylitol group had a significantly lower rate of gingivitis at days 7, 14, and 28 following transplantation (P = .031, .0039, and .0005, respectively); oral plaque at days 7 and 14 (P = .045 and .0023, respectively); and oral ulcers >10 mm at day 14 (P = .049) compared with the SOC group. The xylitol group had no BSI from oral organisms compared with the SOC group, which had 4 (P = .04). The xylitol group had significantly lower abundance of potential BSI pathogens, such as Staphylococcus aureus (P = .036), Klebsiella pneumoniae (P = .033), and Streptococcus spp (P = .011) at the day after transplantation compared with the SOC group. Healthy children and young adults had significantly increased oral microbiome diversity compared with all HSCT recipients (P < .001). The addition of xylitol to standard oral care significantly improves oral health, decreases BSI from oral organisms, and decreases the abundance of pathogenic oral organisms in pediatric and young adult HSCT recipients.

Effectiveness of Bath Wipes After Hematopoietic Cell Transplantation: A Randomized Trial

Objective: Bacteremia is a leading cause of morbidity and mortality in children undergoing hematopoietic cell transplantation (HCT). Infections of vancomycin-resistant enterococci (VRE) and multidrug resistant (MDR) gram-negative rods (GNRs) are common in this population. Our objective was to assess whether experimental bath wipes containing silver were more effective than standard bath wipes containing soap at reducing skin colonization by VRE and MDR GNRs, and nonmucosal barrier injury bacteremia. Study Design: Patients undergoing autologous or allogeneic HCT in a tertiary referral center were randomized to receive experimental or standard bath wipes for 60 days post-HCT. Skin swabs were collected at baseline, discharge, and day +60 post-HCT. The rate of VRE colonization was chosen as the marker for efficacy. Results: Experimental bath wipes were well tolerated. Before the study, the rate of colonization with VRE in HCT recipients was 25%. In an interim analysis of 127 children, one (2%) patient in the experimental arm and two (3%) in the standard arm were colonized with VRE. Two (3%) patients had nonmucosal barrier injury bacteremia in the standard arm, with none in the experimental arm. MDR GNRs were not isolated. The trial was halted because the interim analyses indicated equivalent efficacy of the two methods. Conclusions: Skin cleansing with silver-containing or standard bath wipes resulted in very low and equivalent rates of bacteremia and colonization with VRE and MDR GNRs in children post-HCT. Future studies in other high-risk populations are needed to confirm these results.

Insertion site of central venous catheter correlates with catheter-related infectious events in patients undergoing intensive chemotherapy

Patients undergoing intensive chemotherapy are usually in need for central venous catheters (CVC). Due to contradictory study results, relation of insertion site and CVC-associated complication rate in these patients is not clear. We therefore retrospectively analyzed CVC-related data of all patients undergoing intensive chemotherapy with high risk of febrile neutropenia according to NCCN criteria, who received a CVC at our bone marrow transplantation unit between May 2016 and December 2019. In total, 210 patients received 281 CVC. CVC were placed via either the subclavian-vein (SCV, n = 58; 20%) or the internal-jugular-vein (IJV, n = 223; 80%). Median duration of CVC-lifetime and neutropenic days per CVC were comparable between the two groups (IJV vs SCV: 23 days vs 21 days (p = 0.16) and 12 days vs 11 days (p = 0.65)). Both, time to CVC removal due to local inflammation and time to central line-associated bloodstream infection was significantly shorter in patients with SCV catheters (p = 0.013 and p = 0.045). CVC placed in the IJV were associated with significantly less catheter-related infectious events compared with CVC placed in the SCV. This difference was consistent across different subgroups including 88 patients undergoing allogeneic stem cell transplantation.

Bloodstream Infections and Delayed Antibiotic Coverage Are Associated With Negative Hospital Outcomes in Hematopoietic Stem Cell Transplant Recipients

BACKGROUND

Bloodstream infections (BSIs) are common after hematopoietic stem cell transplantation (HSCT) and are associated with increased long-term morbidity and mortality. However, short-term outcomes related to BSI in this population remain unknown. More specifically, it is unclear whether choices related to empiric antimicrobials for potentially infected patients are associated with patient outcomes.

RESEARCH QUESTION

Are potential delays in appropriate antibiotics associated with hospital outcomes among HSCT recipients with BSI?

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study at a large comprehensive inpatient academic cancer center between January 2014 and June 2017. We identified all admissions for HSCT and prior recipients of HSCT. We defined potential delay in appropriate antibiotics as > 24 h between positive blood culture results and the initial dose of an antimicrobial with activity against the pathogen.

RESULTS

We evaluated 2,751 hospital admissions from 1,086 patients. Of these admissions, 395 (14.4%) involved one or more BSIs. Of these 395 hospitalizations, 44 (11.1%) involved potential delays in appropriate antibiotics. The incidence of mortality was higher in BSI hospitalizations than in those without BSI (23% vs 4.5%; P < .001). In multivariable analysis, BSI was an independent predictor of mortality (OR, 8.14; 95% CI, 5.06-13.1; P < .001). Mortality was higher for admissions with potentially delayed appropriate antibiotics than for those with appropriate antibiotics (48% vs 20%; P < .001). Potential delay in antibiotics was also an independent predictor of mortality in multivariable analysis (OR, 13.8; 95% CI, 5.27-35.9; P < .001).

INTERPRETATION

BSIs were common and independently associated with increased morbidity and mortality. Delays in administration of appropriate antimicrobials were identified as an important factor in hospital morbidity and mortality. These findings may have important implications for our current practice of empiric antibiotic treatment in HSCT patients.

Monocenter study on epidemiology, outcomes, and risk factors of infections in recipients of 166 allogeneic stem cell transplantations during 1 year

OBJECTIVES

During allogeneic hematopoietic stem cell transplantation (allo-SCT), infections significantly contribute to morbidity and mortality. A monocentric prospective analysis was performed to assess epidemiology, risk factors, and outcomes of infections during the peri-transplant period.

METHODS

Data were recorded prospectively using a predefined questionnaire.

RESULTS

In 2015, 163 consecutive patients, 37.4% female, median age 59 (range 18-79) years received 166 allo-SCT. Median duration of leukopenia <10⁹ /L was 14.5 days (range 4-43 days). Fever of unknown origin (FUO) occurred in 118/166 patients (71.1%). Severe sepsis developed in 95, and septic shock developed in 26 patients. Intensive diagnostic workup helped to identify causative microorganisms only in a small number of infectious courses. All but 13 patients needed antibiotic therapy, each according to the standard operating procedures of the department. Cumulative incidence of death by infection after 1 year was 16.6% (95% CI: 11.3-22.7). The only risk factor for FUO in neutropenia was duration of neutropenia </≥14 days (55.4% vs 85.5%, P < .001).

CONCLUSION

Results of an elaborate diagnostic workup of infections in the peri-transplant period are scarce. Attention to risk factors might help to identify patients at risk for severe infections.

Fluoroquinolone Prophylaxis in Autologous Stem Cell Transplantation: Worthy of a Second Look

Prophylaxis with fluoroquinolone (FQ) for patients undergoing autologous stem cell transplantation (ASCT) remains controversial. We performed a retrospective review of patients undergoing ASCT with and without bacterial prophylaxis to compare endpoints of interest. In accordance with institutional policy, patients undergoing ASCT for multiple myeloma routinely receive levofloxacin prophylaxis during their period of neutropenia, whereas patients undergoing the ASCT for lymphoma do not. We retrospectively examined patients with multiple myeloma (MM) or lymphoma undergoing ASCT between July 2015 and July 2018 for evidence of positive blood cultures. A total of 172 patients underwent ASCT for lymphoma and 343 underwent ASCT for MM. The 2 cohorts were similar in terms of baseline characteristics. Almost 20% (35 of 172) of the patients with lymphoma and 5.2% (18 of 342) of those with MM had a bloodstream infection (BSI). BSI occurred an average of 2 days earlier in patients with lymphoma compared with patients with MM (day +5 versus day +7; P = .0003). The 2 cohorts recovered absolute neutrophil count at the same time. Hospital length of stay was 2 days shorter for patients with MM (median, 20 days versus 18 days; P = .01). The majority of the organisms were gram-negative in both cohorts. Of the organisms commonly tested for FQ sensitivity, only 1 of 25 was resistant in the lymphoma cohort, compared with 7 of 9 in the MM cohort (P < .0001), with 4 being multidrug resistant. The odds of developing a BSI were 4.6 times greater in the lymphoma cohort compared with the MM cohort (95% confidence interval [CI], 2.52 to 8.40; P < .0001). In total, 23 of 172 patients with lymphoma (13.4%) and 28 of 342 patients with MM (8.2%) developed Clostridium difficile infection (odds ratio, 1.73; 95% CI, .96 to 3.11; P = .066). Two infection-related deaths occurred in the MM cohort. Our data indicate that FQ prophylaxis reduces the risk of BSI in patients undergoing ASCT but increases the incidence of resistant organisms. We recommend routine antimicrobial prophylaxis in patients undergoing ASCT to reduce the risk of BSI, along with a systematic and regular review of outcomes.

Incidence, risk factors, and outcome of blood stream infections during the first 100 days post-pediatric allogeneic and autologous hematopoietic stem cell transplantations

Bloodstream infections (BSI) are a frequently observed complication after hematopoietic stem cell transplant (HSCT). Retrospective analysis of clinical and microbiological data during the first 100 days from 302 consecutive pediatric patients who underwent HSCT for a malignant disease at our institute between January 2013 and June 2017. A total of 164 patients underwent autologous and 138 allogeneic HSCT. The overall incidence of BSI was 37% with 92% of infectious episodes occurring during the pre-engraftment phase. Gram-positive bacteria (GPB) accounted for 54.6% of the isolated pathogens, gram-negative bacteria (GNB) for 43.9%, and fungi for 1.4%. Coagulase-negative staphylococci and Escherichia coli were the most commonly isolated GPB and GNB, respectively. Forty-five percent of GNB were extended-spectrum beta-lactamase producers and 21% were multidrug-resistant organisms. Fluoroquinolone resistance was 92% and 68%, among GPB and GNB, respectively. Risk factors for BSI in univariate analysis were allogeneic HSCT, delayed time to engraftment more than 12 days, previous BSI before HSCT, and alternative donor. In multivariate analysis, only HSCT type (allogeneic vs autologous P = .03) and previous BSI within 6 months before HSCT (P = .016) were significant. Overall survival at day 100 was 98% and did not differ significantly between patients with and without BSI (P = .76). BSI is common in children undergoing HSCT for malignant diseases. Allogeneic HSCT recipients and previous BSI within 6 months before HSCT are associated with increased risk of post-transplant BSI. With current supportive measures, BSI does not seem to confer an increased risk for 100-day mortality.

Incidence, Risk Factors, and Outcomes of Patients Who Develop Mucosal Barrier Injury-Laboratory Confirmed Bloodstream Infections in the First 100 Days After Allogeneic Hematopoietic Stem Cell Transplant

IMPORTANCE

Patients undergoing hematopoietic stem cell transplant (HSCT) are at risk for bloodstream infection (BSI) secondary to translocation of bacteria through the injured mucosa, termed mucosal barrier injury-laboratory confirmed bloodstream infection (MBI-LCBI), in addition to BSI secondary to indwelling catheters and infection at other sites (BSI-other).

OBJECTIVE

To determine the incidence, timing, risk factors, and outcomes of patients who develop MBI-LCBI in the first 100 days after HSCT.

DESIGN, SETTING, AND PARTICIPANTS

A case-cohort retrospective analysis was performed using data from the Center for International Blood and Marrow Transplant Research database on 16 875 consecutive pediatric and adult patients receiving a first allogeneic HSCT from January 1, 2009, to December 31, 2016. Patients were classified into 4 categories: MBI-LCBI (1481 [8.8%]), MBI-LCBI and BSI-other (698 [4.1%]), BSI-other only (2928 [17.4%]), and controls with no BSI (11 768 [69.7%]). Statistical analysis was performed from April 5 to July 17, 2018.

MAIN OUTCOMES AND MEASURES

Demographic characteristics and outcomes, including overall survival, chronic graft-vs-host disease, and transplant-related mortality (only for patients with malignant disease), were compared among groups.

RESULTS

Of the 16 875 patients in the study (9737 [57.7%] male; median [range] age, 47 [0.04-82] years) 13 686 (81.1%) underwent HSCT for a malignant neoplasm, and 3189 (18.9%) underwent HSCT for a nonmalignant condition. The cumulative incidence of MBI-LCBI was 13% (99% CI, 12%-13%) by day 100, and the cumulative incidence of BSI-other was 21% (99% CI, 21%-22%) by day 100. Median (range) time from transplant to first MBI-LCBI was 8 (<1 to 98) days vs 29 (<1 to 100) days for BSI-other. Multivariable analysis revealed an increased risk of MBI-LCBI with poor Karnofsky/Lansky performance status (hazard ratio [HR], 1.21 [99% CI, 1.04-1.41]), cord blood grafts (HR, 2.89 [99% CI, 1.97-4.24]), myeloablative conditioning (HR, 1.46 [99% CI, 1.19-1.78]), and posttransplant cyclophosphamide graft-vs-host disease prophylaxis (HR, 1.85 [99% CI, 1.38-2.48]). One-year mortality was significantly higher for patients with MBI-LCBI (HR, 1.81 [99% CI, 1.56-2.12]), BSI-other (HR, 1.81 [99% CI, 1.60-2.06]), and MBI-LCBI plus BSI-other (HR, 2.65 [99% CI, 2.17-3.24]) compared with controls. Infection was more commonly reported as a cause of death for patients with MBI-LCBI (139 of 740 [18.8%]), BSI (251 of 1537 [16.3%]), and MBI-LCBI plus BSI (94 of 435 [21.6%]) than for controls (566 of 4740 [11.9%]).

CONCLUSIONS AND RELEVANCE

In this cohort study, MBI-LCBI, in addition to any BSIs, were associated with significant morbidity and mortality after HSCT. Further investigation into risk reduction should be a clinical and scientific priority in this patient population.

Bacteremia in pediatric patients with hematopoietic stem cell transplantation

BACKGROUND

This study aimed to describe the incidence, microbiological profile, and risk factors associated with bacteremia in pediatric patients with hematopoietic stem cell transplantation (HSCT).

METHODS

A retrospective cohort study was performed on patients under 18 years old who underwent HSCT due to any indication, between January 2012 and January 2017. The patient data were collected from the first 100 days post-HSCT. Bacteremia was defined as the isolation of bacteria from at least one blood culture. The relation between bacteremia and associated risk factors was evaluated using univariate and multivariate analysis.

RESULTS

We enrolled a total of 111 pediatric patients who received HSCT during the period of study. The total number of patients who developed at least one episode of bacteremia was 46 (41.4%), and the total number of bacteremia episodes was 62. Rectal swabs were performed in 44 patients to detect prior colonization and this showed that 25% of them were positive, the main pathogen isolated being carbapenem-resistant enterobacteriaceae. The Gram-negative bacteria cases accounted for 60% of 62 events. The main Gram-negative bacteria isolated were Klebsiella pneumoniae and Escherichia coli and the majority were resistant strains. The mortality rate on day +100 for the whole cohort was 18% (n=20). Regarding the patients with bacteremia, the mortality rate on day +100 was 30% (n=14), and the cause of death was related to infection in 10 of them. We did not find any statistically significant risk factor for the development of bacteremia.

CONCLUSION

Bacteremia is common after HSCT, and there is a high frequency of resistant Gram-negative infections which is related to high mortality.

Outcomes after bloodstream infection in hospitalized pediatric hematology/oncology and stem cell transplant patients

BACKGROUND

Pediatric hematology/oncology (PHO) patients receiving therapy or undergoing hematopoietic stem cell transplantation (HSCT) often require a central line and are at risk for bloodstream infections (BSI). There are limited data describing outcomes of BSI in PHO and HSCT patients.

METHODS

This is a multicenter (n = 17) retrospective analysis of outcomes of patients who developed a BSI. Centers involved participated in a quality improvement collaborative referred to as the Childhood Cancer and Blood Disorder Network within the Children's Hospital Association. The main outcome measures were all-cause mortality at 3, 10, and 30 days after positive culture date; transfer to the intensive care unit (ICU) within 48 hours of positive culture; and central line removal within seven days of the positive blood culture.

RESULTS

Nine hundred fifty-seven BSI were included in the analysis. Three hundred fifty-four BSI (37%) were associated with at least one adverse outcome. All-cause mortality was 1% (n = 9), 3% (n = 26), and 6% (n = 57) at 3, 10, and 30 days after BSI, respectively. In the 165 BSI (17%) associated with admission to the ICU, the median ICU stay was four days (IQR 2-10). Twenty-one percent of all infections (n = 203) were associated with central line removal within seven days of positive blood culture.

CONCLUSIONS

BSI in PHO and HSCT patients are associated with adverse outcomes. These data will assist in defining the impact of BSI in this population and demonstrate the need for quality improvement and research efforts to decrease them.

Peripherally inserted central catheter in haematopoietic stem cell transplantation. Infusion of haematopoietic cells and complications

AIMS

To analyze the incidence of complications related to the central peripheral insertion catheter and the viability of the infusion of haematopoietic stem cells through volumetric perfusion pumps.

METHOD

Prospective descriptive study that includes all patients who received a haematopoietic transplant in the Haematology Service of the Hospital Clínico de Valencia between January and December 2016 (n=73). All of them received a central peripheral insertion catheter. SPSS™ v22 was used to perform the descriptive analysis of the main variables using a confidence interval of 95%. The student's t-test was used to compare the means of two independent samples assuming unequal variances.

RESULTS

The 63% (n=73) of the catheters remained without problems throughout the procedure. Fever of unknown origin (28.8%) was the main cause of catheter removal. The median number of days for haematological recovery was 12.5 for the autologous transplants and 15 for the allogeneic transplants.

CONCLUSIONS

The central peripheral insertion catheter presents few complications related to insertion. The administration of haematopoietic cells through these catheters with volumetric perfusion pumps does not imply a delay in haematological recovery. Good acceptance by the patient is confirmed.

Contribution of specific pathogens to bloodstream infection mortality in neutropenic patients with hematologic malignancies: Results from a multicentric surveillance cohort study

Bloodstream infection (BSI) remains a serious complication in patients with hematologic malignancies and neutropenia. The risk factors for mortality after BSI and the contributions of BSI pathogens to mortality remain incompletely understood. We evaluated first BSI among adult neutropenic patients undergoing high-dose chemotherapy for hematologic malignancies in the setting of (a) an early disease stage of autologous (auto-HSCT) or allogeneic (allo-HSCT) hematopoietic stem cell transplantation or (b) for acute leukemia. Risk factors for intensive care admission and all-cause mortality were analyzed by multivariable logistic regression 7 and 30 days after onset of the first BSI in the first neutropenic episode. Between 2002 and 2015, 9080 patients met the study inclusion criteria, and 1424 (16%) developed BSIs, most of them during the first week of neutropenia. Mortality during neutropenia within 7 days and 30 days after BSI onset was 2.5% and 5.1%, respectively, and differed considerably between BSI pathogens. Both 7-day and 30-day mortalities were highest for Pseudomonas aeruginosa BSI (16.7% and 26.7%, respectively) and lowest for BSI due to coagulase-negative Staphylococcus spp. (CoNS) and Streptococcus spp. BSI pathogens were independently associated with 7-day mortality included P aeruginosa, Klebsiella spp., Enterobacter spp., Serratia spp., and enterococci. Only gram-negative BSI and candidemia were associated with admission to intensive care within 7 days after BSI onset. BSI caused by P aeruginosa continues to carry a particularly poor prognosis in neutropenic patients. The unexpected association between enterococcal BSI and increased mortality needs further study.