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Transcription factors control genes to maintain normal hemopoiesis, and dysregulation of some factors can lead to acute lymphoblastic leukemia (ALL). Mycoviruses are known to alter the genetics of their fungal host. The present study evaluates the effects of the products of a mycovirus-containing Aspergillus flavus (MCAF), isolated from the home of a patient with ALL, on certain transcription factors of normal and ALL cell lines. Our published studies have shown that ALL patients have antibodies to MCAF, and that exposure of the mononuclear leukocytes of patients in complete remission to its products, unlike controls, results in the re-development of genetic and cell surface phenotypes characteristic of ALL. For the present study, normal, pre-B, and B-cell leukemia cell lines were exposed to the culture of MCAF. Pre- and post-exposure levels of PAX5, Ikaros, and NF-κB were assessed. Exposure to MCAF resulted in apoptosis, cell cycle changes, and complete downregulation of all transcription factors in normal cell lines. In acute leukemia cell lines, cellular apoptosis and alterations in the cell cycle were also noted; however, while there was downregulation of all tested transcription factors, residual levels were retained. The noted alterations in the transcription factors caused by MCAF are novel findings. The possible role of MCAF in leukemogenesis needs to be further investigated. Mycovirus-containing Aspergillus flavus was initially isolated from a leukemia patient's home. Our prior published studies have illuminated intriguing associations of this organism with leukemia. Unlike controls, patients diagnosed with acute lymphoblastic leukemia (ALL) harbor antibodies to this organism. Furthermore, the exposure of mononuclear cells from patients with ALL in complete remission to the products of this organism reproduced genetic and cell phenotypes characteristic of ALL. These findings underscore the potential role of environmental factors in leukemogenesis and hint at novel avenues for therapeutic intervention and preventive strategies.

Background: We employed Mendelian randomization (MR) to investigate the causal relationship between the gut microbiota and lymphoid leukemia, further exploring the causal relationships among immune cells, lymphoid leukemia, and potential metabolic mediators., Methods: We utilized data from the largest genome-wide association studies to date, encompassing 418 species of gut microbiota, 713 types of immune cells, and 1,400 serum metabolites as exposures. Summary statistics for lymphoid leukemia, acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL) were obtained from the FinnGen database. We performed bidirectional Mendelian analyses to explore the causal relationships among the gut microbiota, immune cells, serum metabolites, and lymphoid leukemia. Additionally, we conducted a two-step mediation analysis to identify potential intermediary metabolites between immune cells and lymphoid leukemia., Results: Several gut microbiota were found to have causal relationships with lymphoid leukemia, ALL, and CLL, particularly within the Firmicutes and Bacteroidetes phyla . In the two-step MR analysis, various steroid hormone metabolites (such as DHEAS, pregnenolone sulfateprogestogen derivatives, and androstenediol-related compounds) were identified as potential intermediary metabolites between lymphoid leukemia and immune cells. In ALL, the causal relationship between 1-palmitoyl-2-docosahexaenoyl-GPE (16:0/22:6) and ALL was mediated by CD62L-plasmacytoid DC%DC (mediated proportion=-2.84%, P =0.020). In CLL, the causal relationship between N6,n6,n6-trimethyllysine and CLL was mediated by HLA DR+ CD8br AC (mediated proportion=4.07%, P =0.021)., Conclusion: This MR study provides evidence supporting specific causal relationships between the gut microbiota and lymphoid leukemia, as well as between certain immune cells and lymphoid leukemia with potential intermediary metabolites., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhuang, Yin, Yang, Man, Wang, Geng and Shi.)

Introduction: Bloodstream infections (BSIs) cause treatment-related mortality in pediatric acute leukemia. We explored the potential of intestinal microbiota and fecal volatile organic compounds (VOCs) analyses to predict BSI., Methods: In this case-control study, fecal samples of pediatric acute leukemia patients were collected. Microbiota composition and fecal VOC profiles of BSI cases and matched non-BSI controls were compared., Results: In total, 6 patients were included, of which 1 developed BSI and 1 neutropenic fever. Both showed reduced microbial diversity and stability of Bacteroidetes. In the BSI case, Pantoea was identified 15 days before BSI. Significant differences in fecal VOC profiles were measured between the case and controls., Conclusion: Microbiota and fecal VOC could serve as biomarkers to predict BSI in pediatric leukemia., Competing Interests: A.E.B. has proprietary rights on the IS-pro platform technology and is cofounders of a spin-off company developing this technique. The remaining authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

There are limiteddata on long-term changes in the gut microbiome after acute lymphoblastic leukemia (ALL) therapy. We compared the gut microbial composition in stool samples of nine survivors of childhood ALL with 10 healthy sibling controls using 16S rRNA gene sequencing. Analysis of beta diversity within family units demonstrated a significant difference in bacterial strains between patients and healthy siblings. A significant difference in alpha diversity between patients and their healthy siblings was noted using Pielou's evenness. The composition of the gut microbiome differs between pediatric ALL survivors and healthy sibling controls for years after completion of therapy., (© 2021 Wiley Periodicals LLC.)

Objectives: The aim was to identify the clinical characteristics, outcome, and antimicrobial susceptibility of healthcare-associated bloodstream infections (BSIs) in hematological patients., Methods: This retrospectively collected laboratory-based surveillance data include 3404 healthcare-associated BSIs in 2296 patients with a hematological malignancy in hospitals participating in the Finnish Hospital Infection Program from January 1, 2006, to December 31, 2016., Results: The most common underlying diseases were acute myelogenous leukemia (35%) and non-Hodgkin lymphoma (22%). Gram-positive organisms accounted for 60%-46% and gram-negative organisms for 24%-36% of BSIs in 2006-2016. The most common causative organism was coagulase-negative staphylococci (CoNS) (n = 731). The 7- and 28-day case fatality rates were 5.2% and 11.4%, respectively, and was highest in BSIs caused by Candida species (10.8% and 30.8%). The median age of patients increased from 59 years in 2006-2008 to 62 years in 2015-2016 (P < .01). Five percent of S aureus isolates were resistant to methicillin and five percent of Pseudomonas aeruginosa isolates were multidrug-resistant. Four percent of Klebsiella and seven percent of E coli isolates were resistant to ceftazidime., Conclusions: The proportion of gram-positive bacteria decreased and gram-negative bacteria increased over time. The case fatality rate was low and the median age of patients increased during the study., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The etiology of acute lymphoblastic leukemia (ALL) remains unknown. A recent "two-hit" model for the occurrence of precursor B cell acute lymphoblastic leukemia propose that this disease arises through a two-step process, including predisposing genetic mutation and exposure to infections. While several genetic mutations are proposed, no infection category has been suggested. We have isolated a certain Aspergillus Flavus from residence of an ALL patient. This organism contains mycovirus and does not produce aflatoxin. The supernatant of culture of this mycovirus containing Aspergillus Flavus (SAF) was tested on the PBMCs of ALL patients in remission and controls. Cell surface phenotypes and genetic markers were examined. The effects of its combination with Epstein-Barr virus (EBV) was also investigated. For the SAF, positive and negative controls were aflatoxin and culture of Mycocladus corymbifer, respectively. Controls for ALL were sickle cell patients undergoing exchange transfusion. Incubation of the PMBCs from ALL patients in remission, or controls, with SAF resulted in re-development of ALL cell surface phenotypes and genetic markers in ALL patients in remission and not controls. These differentiating effects were not seen with aflatoxin or culture of Mycocladus Corymbifer. Addition of EBV did not alter effects of SAF. Currently, there are no techniques to discriminately reproduce characteristic leukemic genetic markers and cell surface phenotypes in cells from ALL patients in remission and not controls. These studies may provide a test for recognition of ALL patients in remission and new prospects for the investigation of leukemogenesis., (Copyright © 2020. Published by Elsevier Ltd.)

Background: Tisagenlecleucel, an anti-CD19 chimeric antigen receptor T (CAR-T) cell therapy, has demonstrated durable efficacy and a manageable safety profile in pediatric and young adult patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) in the ELIANA pivotal trial and real-world experience. Experience from investigator-led studies prior to ELIANA suggests that infections and inflammatory conditions may exacerbate the severity of cytokine release syndrome (CRS) associated with CAR-T cell therapy, leading to extreme caution and strong restrictions for on-study and commercial infusion of tisagenlecleucel in patients with active infection. CRS intervention with interleukin (IL)-6 blockade and/or steroid therapy was introduced late in the course during clinical trials due to concern for potential negative effect on efficacy and persistence. However, earlier CRS intervention is now viewed more favorably. Earlier intervention and consistency in management between providers may promote broader use of tisagenlecleucel, including potential curative therapy in patients who require remission and recovery of hematopoiesis for management of severe infection., Main Body: Patient 1 was diagnosed with B-ALL at 23 years old. Fourteen days before tisagenlecleucel infusion, the patient developed fever and neutropenia and was diagnosed with invasive Mucorales infection and BK virus hemorrhagic cystitis. Aggressive measures were instituted to control infection and to manage prolonged cytopenias during CAR-T cell manufacturing. Adverse events, including CRS, were manageable despite elevated inflammatory markers and active infection. The patient attained remission and recovered hematopoiesis, and infections resolved. The patient remains in remission ≥1 year postinfusion.Patient 2 was diagnosed with pre-B-ALL at preschool age. She developed severe septic shock 3 days postinitiation of lymphodepleting chemotherapy. After receiving tisagenlecleucel, she experienced CRS with cardiac dysfunction and extensive lymphadenopathy leading to renovascular compromise. The patient attained remission and was discharged in good condition to her country of origin. She remained in remission but expired on day 208 postinfusion due to cardiac arrest of unclear etiology., Conclusions: Infusion was feasible, and toxicity related to tisagenlecleucel was manageable despite active infections and concurrent inflammation, allowing attainment of remission in otherwise refractory pediatric/young adult ALL. This may lead to consideration of tisagenlecleucel as a potential curative therapy in patients with managed active infections., Competing Interests: Competing interests: DEY has been an investigator on studies supported by Astellas, Chimerix, Merck, Pfizer, and Viracor-Eurofins. KJA is on the Speaker’s Bureau for and receives support from Novartis Pharmaceuticals. GDM is a consultant and is on the Speaker’s Bureau for Novartis Pharmaceuticals. EMH, RKG, AAA, GSM, SDS, TGF, IAA, WL, and RJH declare that they have no competing interests., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Microbial translocation (MT) and altered gut microbiota have been described in acute leukemic patients and contribute to immune activation and inflammation. However, phage translocation has not been investigated in leukemia patients yet. We recruited 44 leukemic patients and 52 healthy adults and quantified the levels of 3 phages in peripheral blood, which were the most positive phages screened from fecal samples. The content of 16S rRNA in plasma was detected by qPCR to assess the intestinal mucosa of these patients. Spearman's rank correlation was used to analyze the relationship between phage load and the relevant clinical data. We found the most prevalent phages in fecal samples were λ phage, Wphi phage, and P22 phage, and λ phage had the highest detection rate in plasma (68%). Phage content was affected by chemotherapy and course of disease and correlated with the levels of CRP (r = 0.43, p = 0.003), sCD14 (r = 0.37, p = 0.014), and sCD163 (r = 0.44, p = 0.003). Our data indicate that plasma phage load is a promising marker for gut barrier damage and that gut phage translocation correlates with monocyte/macrophage activation and systemic inflammatory response in leukemic patients.

Intestinal mucositis is a common side effect of chemotherapy leading to diarrhea, abdominal pain and increased risk of infections. The intestinal microbiota has been recognized as a key regulator of mucosal immune responses. Therefore, we hypothesized that intestinal microbial changes would be associated with enterocyte loss and systemic inflammation during induction treatment for childhood acute lymphoblastic leukemia (ALL). We prospectively included 51 children newly-diagnosed with ALL treated in Denmark in 2015-2018. Plasma C-reactive protein (CRP), plasma citrulline (marker of functional enterocytes mass) measurements and fecal samplings were performed on treatment Days 1, 8, 15, 22 and 29. Moreover, intestinal mucositis was scored by a trained nurse/physician. Fecal samples in patients and 19 healthy siblings were analyzed by 16S rRNA gene sequencing (V3-V4 region). Bacterial alpha diversity was lower in patients compared to siblings. It decreased from Day 1 to Days 8-22 and increased on Day 29. Shannon alpha diversity index was correlated with CRP on Days 15-29 (rho = -0.33-0.49; p < 0.05) and with citrulline on Days 15 and 29 (although with p values <0.06, rho = 0.32-0.34). The abundance of unclassified Enterococcus species (spp.) was correlated with CRP on Days 22-29 (rho = 0.42-0.49; p < 0.009), while the abundance of unclassified Lachnospiraceae spp. was correlated with citrulline on days 8-15 (rho = 0.48-0.62, p < 0.001). Systemic inflammation, enterocyte loss and relative abundance of unclassified Enterococcus spp. reached a peak around Day 15. In conclusion, specific changes in the microbiota were associated with the severity of enterocyte loss and systemic inflammation during chemotherapy., (© 2020 UICC.)

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer with high cure rates leading to rising numbers of long-term survivors. Adult survivors of childhood ALL are at increased risk of obesity, cardiovascular disease, and other chronic illnesses. We hypothesize that ALL therapy is associated with long-term gut microbiome alterations that contribute to predisposition to chronic medical conditions. We conducted a pilot study to test whether differences can be detected between stool microbiota of pediatric ALL survivors and their siblings. Stool samples were collected from 38 individuals under age 19 who were at least 1 year after completion of therapy for ALL. Stool samples collected from 16 healthy siblings served as controls. 16S ribosomal RNA gene sequencing was performed on the stool samples. Comparing microbiota of survivors to sibling controls, no statistically significant differences were found in alpha or beta diversity. However, among the top 10 operational taxonomic units (OTUs) from component 1 in sparse partial least squares discriminant analysis (sPLS-DA) with different relative abundance in survivors versus siblings, OTUs mapping to the genus Faecalibacterium were depleted in survivors. Differences in gut microbial composition were found between pediatric survivors of childhood ALL and their siblings. Specifically, the protective Faecalibacterium is depleted in survivors, which is reminiscent of gut microbiota alteration found in adult survivors of childhood ALL and reported in obesity, suggesting that microbiota alterations in pediatric ALL survivors start in childhood and may play a role in predisposition to chronic illness in later years of survivorship.

A 5-year-old patient treated for acute lymphoblastic leukaemia (ALL) developed proven pulmonary invasive fungal disease (IFD) due to Actinomucor elegans. While completing ALL treatment according to AIEOP ALL protocol 2009 for further 15 months, antifungal treatment with liposomal amphotericin B and intermittent additional posaconazole was continued until immune reconstitution 7 months after the end of ALL treatment. Repeated imaging guided treatment decisions. Twenty-six and 19 months after the end of ALL treatment and antifungal treatment, respectively, the patient is still in the first complete remission and shows no signs of active invasive fungal disease (IFD).

Enterobacterales represent a serious threat to transplant patients due to their increase frequency of carbapenem resistance and wide spreading. We present a case of an infant with acute lymphoblastic leukemia undergoing hematopoietic stem cell transplantation. Before transplantation an unusual double colonization of the gastrointestinal tract with extremely resistant Escherichia coli and Klebsiella pneumoniae strains producing metallo-beta-lactamase was diagnosed. Respective epidemiologic management was implemented, based on the strict reverse isolation in patient-protective environment, and intensified antimicrobial surveillance. After granulocyte recovery, no extremely drug-resistant strains were found, and no case of isolation and/or transmission of carbapenem-resistant bacteria has been identified in the transplant center during the following 6 months.

Saccharomyces cerevisiae is an emerging pathogen within the immunocompromised. We present a 4-year-old boy with acute lymphoblastic leukemia presenting with polymerase chain reaction-confirmed hepatosplenic S. cerevisiae infection and significant immune reconstitution symptoms. We explore the challenges of monitoring treatment efficacy using C-Reactive protein, β-D-glucan, and imaging and the administration of chemotherapy alongside antifungals and steroids for control of immune reconstitution syndrome.

Hematological malignancies are the most common type of pediatric cancers, and acute lymphocytic leukemia (ALL) is the most frequently occurring hematological malignancy during childhood. A major cause of mortality in leukemia is bloodstream infection (BSI). The aim of the current study was to explore the gut microbiota in ALL and its potential functional alterations. High-throughput sequencing was used to characterize the bacterial and fungal microbiota in feces and their predicted functional characteristics in a xenotransplant pediatric ALL mouse model. Our work shows that gut microbiota significantly changes in leukemia, which may result in functional alterations. This study may provide potential therapeutic or preventive strategies of BSI in ALL., (© 2019 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.)

Background: Invasive fungal infections are a life-threatening complication of cancer treatments, especially in hemato-oncological patients. Mucormycosis is the third leading cause of invasive fungal infections after Aspergillus and Candida infections. The first clinical symptoms are usually non-specific, which can lead to a late diagnosis and delayed therapy., Purpose: The objective of this report is to summarize data in the literature about mucormycosis and to present a case report of a patient with acute lymphoblastic leukemia, who developed this infection at our center. Risk factors for the development of mucormycosis, clinical symptoms, radiology, laboratory results, and outcome were retrospectively evaluated., Case: We describe a 6-years-old female patient with acute lymphoblastic leukemia. During the induction phase of therapy, the patient developed febrile neutropenia and did not respond to therapy with a combination of antibiotics and supportive treatment. Pansinusitis and orbitocellulitis developed. Examination of the biological material revealed that the etiological agent was a Rhizopus sp. The patient was treated with a combination of antimycotic drugs, but the infection disseminated to the central nervous system. She underwent radical surgical resection of the affected tissue. At this time, she is still under treatment with antimycotic and oncology agents, but is in remission of the main diagnosis and in good clinical condition., Conclusion: Mucormycosis is an invasive fungal infection with high morbidity and mortality. Early diagnosis and initiation of effective therapy using a combination of amphotericin B administration and surgery are necessary to obtain a favorable outcome. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

Background: Alteration in gut microbiota has been recently linked with childhood leukemia and the use of chemotherapy. Whether the perturbed microbiota community is restored after disease remission and cessation of cancer treatment has not been evaluated. This study examines the chronological changes of gut microbiota in children with acute lymphoblastic leukemia (ALL) prior to the start-, during-, and following cessation of chemotherapy., Methodology: We conducted a longitudinal observational study in gut microbiota profile in a group of paediatric patients diagnosed with ALL using 16 s ribosomal RNA sequencing and compared these patients' microbiota pattern with age and ethnicity-matched healthy children. Temporal changes of gut microbiota in these patients with ALL were also examined at different time-points in relation to chemotherapy., Results: Prior to commencement of chemotherapy, gut microbiota in children with ALL had larger inter-individual variability compared to healthy controls and was enriched with bacteria belonging to Bacteroidetes phylum and Bacteroides genus. The relative abundance of Bacteroides decreased upon commencement of chemotherapy. Restitution of gut microbiota composition to resemble that of healthy controls occurred after cessation of chemotherapy. However, the microbiota composition (beta diversity) remained distinctive and a few bacteria were different in abundance among the patients with ALL compared to controls despite completion of chemotherapy and presumed restoration of normal health., Conclusion: Our findings in this pilot study is the first to suggest that gut microbiota profile in children with ALL remains marginally different from healthy controls even after cessation of chemotherapy. These persistent microbiota changes may have a role in the long-term wellbeing in childhood cancer survivors but the impact of these changes in subsequent health perturbations in these survivors remain unexplored.

Purpose: Infections are a frequent complication during childhood leukemia treatment. Little is known about the infectious risk in survivors. We compared the relative rate (RR) of infections after treatment completion between pediatric leukemia survivors and the general population., Methods: We performed a retrospective, population-based cohort study of children diagnosed with leukemia between 1992 and 2015 in Ontario, Canada, who were alive and relapse free 30 days after treatment completion (index date). Leukemia survivors were matched 5:1 with the general population by year of birth, sex, and rural status and stratified by initial treatment, including and excluding hematopoietic stem-cell transplantation (HSCT). The primary outcome was time to infections, as identified using validated diagnostic codes from administrative databases. Individuals were censored at the earliest of death, first relapse, loss to follow-up, or end of study., Results: A total of 2,204 leukemia survivors were included and matched with 11,020 controls. The rate of infections was elevated after treatment completion compared with controls (RR, 1.51; 95% CI, 1.45 to 1.57) and at less than 1 year (RR, 1.77; 95% CI, 1.69 to 1.86); 1 to 4.99 years (RR, 1.66; 95% CI, 1.62 to 1.71), and 5 or more years (RR, 1.29; 95% CI, 1.22 to 1.36) from the index date. Among those whose initial treatment excluded HSCT, the rate remained elevated more than 5 years from the index date (RR, 1.29; 95% CI, 1.23 to 1.35). Infection-related death was significantly increased in leukemia survivors both among the entire cohort (hazard ratio, 149.3; 95% CI, 20.4 to 1,091.9) and among those without HSCT (hazard ratio, 92.7; 95% CI, 12.4 to 690.7)., Conclusion: A significant association was found between a history of leukemia therapy and an increased risk of infections. Additional study is needed to establish which exposures in patients with leukemia lead to late infections.

Invasive fusariosis (IF) most commonly occurs in patients with hematologic malignancies and severe neutropenia, particularly during concomitant corticosteroid use. Breakthrough infections can occur in high-risk patients despite Aspergillus-active antifungal prophylaxis. We describe a patient with rapid acute lymphoblastic leukemia (ALL) progression who presented with multifocal skin nodules thought to be choloromatous disease. These lesions were ultimately diagnosed as IF and the patient had two simultaneously active disease processes. This case highlights the importance of pathologic diagnosis of new skin lesions in ALL patients, even during leukemia progression, and demonstrates that IF can occur despite normal neutrophil counts and Aspergillus-active prophylaxis., (© 2019 Wiley Periodicals, Inc.)

Background: Osteonecrosis is a common toxicity associated with glucocorticoid (e.g., dexamethasone and prednisone) treatment of children with acute lymphoblastic leukemia (ALL), but risk factors are incompletely defined. Infections are also a common complication of ALL therapy. Lipopolysaccharide (LPS) is used experimentally to mimic infection-related systemic effects. To our knowledge, the contribution of systemic infections to the risk of glucocorticoid-induced osteonecrosis has not been investigated., Procedure: Patients with ALL on St. Jude Total Therapy XV (n = 365) were assessed for documented bacteremia prior to development of osteonecrosis, which was confirmed by MRI, and graded using the National Cancer Institute's Common Terminology for Adverse Events (version 3.0). In a preclinical model, Balb/cJ mice treated with dexamethasone plus or minus LPS were assessed for frequency and severity of osteonecrosis and arteriopathy., Results: We found that patients with ALL who experienced bacteremia had a higher frequency of symptomatic osteonecrosis (≥grade 2) than those who did not (OR: 1.88; 95% CI, 1.03-3.41, P = 0.038). LPS exacerbated experimental dexamethasone-induced osteonecrosis. Mice treated with dexamethasone plus LPS had a higher incidence of osteonecrosis (P = 0.00086) and arteriopathy (P = 0.0047) than did those treated with dexamethasone alone, and the severity of osteonecrosis (P = 0.00045) and arteriopathy (P = 0.0048) was also more pronounced with the addition of LPS treatment. The increase in osteonecrosis was not explained by any alteration of dexamethasone pharmacokinetics by LPS., Conclusions: These data identify systemic infection during ALL therapy as a novel risk factor in the development of glucocorticoid-induced osteonecrosis., (© 2019 Wiley Periodicals, Inc.)

Bloodstream infection (BSI) is the major cause of mortality in acute lymphocytic leukemia (ALL). Causative pathogens in BSI originate from the gut microbiota due to an increase in intestinal permeability, a process known as bacterial translocation (BT). The gut microbiota in physiological conditions is controlled by a large number of immune cells as part of the gut-associated lymphoid tissue (GALT).The aim of the current study was to investigate the mechanism of bacterial translocation in leukemia by identifying and characterizing alterations in the GALT in leukemic mouse model. Our studies revealed a severe impairment of the GALT characterized by a loss of lymphatic cells in ALL, which eventually led to BSI. We identified differentially expressed genes in the intraepithelium and the lamina propria, which may contribute to BT and to the impairment of lymphocyte migration., Competing Interests: The authors have declared that no competing interests exist.

Background: A thorough understanding of local and contemporary invasive fungal infection (IFI) epidemiology in immunocompromised children is required to provide a rationale for targeted prevention and treatment strategies., Methods: Retrospective data over 10 years from four tertiary pediatric oncology and hematopoietic stem cell transplant (HSCT) units across Australia were analyzed to report demographic, clinical, and mycological characteristics of IFI episodes, and crude IFI prevalence in select oncology/HSCT groups. Kaplan-Meier survival analyses were used to calculate 180-day overall survival., Results: A total of 337 IFI episodes occurred in 320 children, of which 149 (44.2%), 51 (15.1%), and 110 (32.6%) met a modified European Organization for Research and Treatment of Cancer (mEORTC) criteria for proven, probable, and possible IFI, respectively. There were a further 27 (8.0%) that met a "modified possible IFI" criteria. Median age at IFI diagnosis was 8.4 years. Crude mEORTC IFI prevalence in acute lymphoblastic leukemia, acute myeloid leukemia, solid tumor, and allogeneic HSCT cohorts was 10.6%, 28.2%, 4.4%, and 11.7%, respectively. Non-Aspergillus species represented 48/102 (47.1%) molds identified, and non-albicans Candida represented 66/93 (71.0%) yeasts identified. There were 56 deaths among 297 children who met mEORTC criteria, with 180-day overall survival for proven, probable, and possible IFIs of 79.7%, 76.2%, and 84.4%, respectively., Conclusion: Non-Aspergillus molds and non-albicans Candida contributed substantially to pediatric IFI in our study, with high IFI prevalence in leukemia and allogeneic HSCT cohorts. Inclusion of IFIs outside of European Organization for Research and Treatment of Cancer criteria revealed an IFI burden that would go otherwise unrecognized in published reports., (© 2018 Wiley Periodicals, Inc.)

Objective: Few data are available on the clinical significance of 18-fluorodeoxyglucose positron emission tomography (FDG-PET/CT) results in patients with leukemia. We investigated the utility of FDG-PET/CT at the time of relapsed/refractory disease in pediatric patients with leukemia., Methods: Medical records of 28 children with suspected leukemia progression or recurrence during/after chemotherapy or allogeneic stem cell transplantation (allo-SCT) were retrospectively reviewed to determine the utility of FDG-PET/CT., Results: Twenty-two of the 28 patients have documented abnormal imaging findings during clinical follow-up, while six had were interpreted as not demonstrating signal consistent with active leukemia. Of the 22 patients with abnormal FDG-PET/CT studies 14 were found to have FDG-PET/CT reported as consistent with active leukemia and increased leukemia blasts on bone marrow biopsy. Regarding the eight patients without positive FDG-PET/CT and proven leukemia relapse, four had discordant findings on FDG-PET/CT and biopsy, and four had FDG-PET/CT reported as infection. Mean maximum standardized uptake values (SUVmax) were significantly higher among patients whose FDG-PET/CT findings were positive for leukemia as opposed to infectious disease (p < .05). Mean SUVmax was also significantly higher among patients with multifocal lesions on FDG-PET/CT than among those with diffuse lesions (p < .05)., Conclusions: The findings suggest that FDG-PET/CT may be a complementary imaging modality that could be combined with bone marrow examination to improve detection of subtle leukemic infiltration in children with suspected leukemia progression or recurrence after chemotherapy or allo-SCT.

Aspergillus terreus causes invasive aspergillosis (IA) in immunocompromised patients. Treatment is complicated by intrinsic resistance to amphotericin B and thereby contributing to a high mortality. Therefore, we conducted in vitro studies to investigate the effectivity of adjunctive recombinant interferon-γ immunotherapy. We describe a pediatric patient with A. terreus IA who received adjunctive recombinant interferon-γ (rIFNγ) immunotherapy. In vitro studies were conducted to investigate the capacity of rIFNγ to improve antifungal host defense in terms of fungal killing ability and the release of pro-inflammatory cytokines in cells of the patient as well as healthy controls. An 8-year-old female pediatric patient with leukemia developed A. terreus IA. She clinically deteriorated and had high serum galactomannan levels despite broad antifungal therapy. Therefore, adjunctive immune stimulatory therapy with rIFNγ was initiated. After 3 weeks of treatment, galactomannan levels decreased and the patient clinically showed improvement. Addition of rIFNγ boosted the capacity of monocytes of healthy volunteers to mount TNFα and IL-1β cytokine responses to Escherichia coli LPS, and increased TNFα response to both A. terreus and Aspergillus fumigatus. Monocytes isolated from the patient's blood demonstrated a similar augmented cytokine induction in response to rIFNγ. In addition, rIFNγ increased the capacity of monocytes from healthy volunteers as well as monocytes from the patient to kill A. terreus spores. Adjuvant immunotherapy with rIFNγ might be a promising additional treatment strategy that could be used to improve outcome in patients with refractory invasive A. terreus infections or other resistant invasive Aspergillus infections.

Clostridium difficile infection (CDI) is one of the most common causes of nosocomial infectious diarrhea in children during anticancer therapy or undergoing hematopoietic stem cell transplantation (HSCT) in Europe. Immunosuppression in these patients is a risk factor for CDI. Malignant diseases, age, acute graft-versus-host disease (aGVHD), HLA mismatch, or use of total body irradiation may play an important role in CDI course. The aim of this study was to evaluate the incidence, course, and outcome of CDI in children treated for malignancy or undergoing HSCT. Between 2012 and 2015, a total number of 1846 patients were treated for malignancy in Polish pediatric oncological centers (PHO group) and 342 underwent transplantation (HSCT group). In PHO group, episodes of CDI occurred in 210 patients (14%). The incidence of CDI was higher in patients with hematological malignancies in comparison to that with solid tumors. Patients with acute myeloblastic leukemia had shorter time to episode of CDI than those with acute lymphoblastic leukemia. Patients over 5 years and treated for acute leukemia had more severe clinical course of disease in PHO group. In HSCT group, CDI occurred in 29 (8%) patients. The incidence of CDI was higher in patients transplanted for acute leukemia. The recurrence rate was 14.7% in PHO and 20.7% in HSCT patients. CDI incidence was highest in patients with hematological malignancies. Most of patients experienced mild CDI. Age < 5 years and diagnosis other than acute leukemia were the positive prognostic factors influencing clinical CDI course.

The patients with hematologic malignancies and hematopoietic stem cell transplantation (HSCT) recipients are at high risk for invasive fungal diseases (IFDs) mainly due to the severe and prolonged neutropenia related to high-dose chemotherapy. Voriconazole prophylaxis is recommended for possible IFDs. Mucormycosis is a fulminant infection, which may occur after voriconazole prophylaxis for invasive aspergillosis in immunocompromised hosts. Here, we report mucormycosis after 4 months of voriconazole prophylaxis in a young patient with relapsed acute lymphoblastic leukemia and hematopoietic stem cell transplant failure and discuss the clinical manifestation, imaging, laboratory findings and therapeutic regimens. Clinician's awareness of this entity and timely diagnosis using conventional and molecular methods are the promising approach for the management of this devastating infection., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Background/aim: The aim of this article is to study the spectrum, changing prevalence, and predictors for mortality of invasive fungal disease (IFD) in pediatric leukemia in a resource-limited setting., Observations: Prevalence was 7% (proven, 69%; probable, 16.4%; possible, 14.6%) and did not differ between acute lymphoblastic leukemia and acute myeloid leukemia. Lungs were frequently involved (46%). Aspergillus was the commonest fungus (47%). Visceral abscesses were frequent with candidiasis as compared with invasive molds (P=0.016). IFD resulted in a prolonged admission (mean, 12.6±2 d; P=0.014) and death (44%) (Aspergillus, 50%; Candida, 50%; Mucor, 34%). Diagnosis of acute myeloid leukemia predicted mortality (P=0.03)., Conclusions: IFD was an important cause of treatment related mortality in pediatric leukemia (odds ratio, 8.39). Protocolled use of computed tomography-chest and galactomannan-assay aided diagnosis (P<0.05).

We report a case of a patient with acute lymphoblastic leukemia (ALL), who developed a disseminated infection by Fusarium verticillioides during chemotherapy-induced neutropenia. He was successfully treated only after combination therapy with voriconazole plus amphotericin B deoxycolate was used, but not when these compounds were used in an isolated form.

Background: Acute leukemia (AL) is a heterogeneous group of malignant hematopoietic diseases and is divided into two basic types: acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Patients with these diseases are highly immunosuppressed and therefore at a high risk of serious infections. This study aimed to perform active surveillance of enterobacteria, which cause these infections, and to determine their antibiotic resistance in patients with AL who were hospitalized at the Hemato-Oncology Center of University Hospital Olomouc., Materials and Methods: This study involved 49 patients with AL, of whom 37 had AML (16 women and 21 men) and 12 had ALL (6 women and 6 men). The mean age of the patients was 50.5 years. Samples of clinical material were obtained over 12 months (September 2015 to August 2016) and subjected to standard microbiological examinations. Bacterial strains were identified by MALDI-TOF MS, and their antibiotic susceptibility was established by microdilution method., Results: A total of 292 samples were obtained from patients with AL. Some of these samples were excluded from analysis to prevent the inclusion of identical strains from the same patient. Consequently, 146 clinical samples obtained from the following nine types of clinical materials were analyzed - throat swabs (n = 47), stools (n = 40), urine (n = 33), hemocultures (n = 11), buccal swabs (n = 5), perianal swabs (n = 4), wound swabs (n = 3), sputum (n = 2), and puncture fluid (n = 1). The most prevalent enterobacteria was Escherichia coli (n = 42), followed by Klebsiella spp. (n = 46), specifically Klebsiella pneumoniae (n = 34) and Klebsiella oxytoca (n = 12), and Enterobacter cloacae (n = 19). The most of enterobacteria were highly resistant to many tested antibiotics., Conclusions: Antibiotic-resistant enterobacteria colonize patients with hemato-oncological diseases and can cause serious infections. These antibiotic-resistant microorganisms are a serious and frequent problem. These findings together with the high level of immunosuppression mean that patients with hemato-oncological diseases are at a high risk of developing serious infections and consequently active surveillance is crucial.

Background: Inotuzumab ozogamicin (InO), an anti-CD22 antibody-calicheamicin conjugate, demonstrated superior clinical activity versus standard-of-care (SOC) chemotherapies for relapsed/refractory B-cell acute lymphoblastic leukemia in the phase 3 randomized controlled INO-VATE trial. The authors assessed patient-reported outcomes (PROs) from that study., Methods: Patients were randomized to receive either InO (1.8 mg/m 2 per cycle for ≤6 cycles) or SOC (fludarabine/cytarabine [ara-C]/granulocyte colony-stimulating factor, or ara-C plus mitoxantrone, or high-dose ara-C for ≤4 cycles) and completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and the EuroQoL 5 Dimensions Questionnaires at baseline, on day 1 of each cycle, and at the end of treatment. Treatment differences in PROs were assessed using longitudinal mixed-effects models with random intercepts and slopes., Results: Questionnaire completion rates in the InO (n = 164) and SOC (n = 162) arms were 85% and 65%, respectively. Baseline scores were similar between arms. Patients who received InO reported better quality of life (QoL), functioning, and symptom scores (except for constipation and emotional functioning). Least-squares mean (95% confidence interval [CI]) differences in physical, role, and social functioning and in appetite loss were significant (6.9 [95% CI, 1.4-12.3], 11.4 [95% CI, 3.2-19.5], 8.4 [95% CI, 0.7-16.1], and -8.7 [95% CI, -16.0 to -1.4], respectively; all P < .05) and had exceeded the minimally important difference of 5. Mean treatment differences in favor of InO on the EuroQoL visual analog scale and the global health status/QoL, dyspnea, and fatigue scales reached or approached the minimally important difference of 5, although without statistical significance. No dimensions were significantly worse with InO versus SOC., Conclusions: The current PRO data support the favorable benefit/risk ratio of InO for the treatment of relapsed/refractory acute lymphoblastic leukemia, with superior clinical efficacy and better QoL. Cancer 2018;124:2151-60. © 2018 American Cancer Society., (© 2018 American Cancer Society.)

Spontaneous remission of untreated pediatric leukemia is an extremely rare occurrence. The underlying mechanism may be because of an immune-mediated process or increased cortisol production during stress or infection. We describe a rare case of terminal deoxynucleotidyl transferase negative B-acute lymphoblastic leukemia with concurrent infection that went into remission without treatment with chemotherapy or corticosteroids. Though B-acute lymphoblastic leukemia can rarely go into spontaneous remission, these patients require close follow-up as most patients will eventually develop recurrence.

Introduction: Bacteremia is a frequent complication in children with cancer, which is associated with greater severity, prolonged hospitalization and mortality. Prolonged hospitalization conditions greater morbidity and risk of acquisition of intranosocomial infections., Aim: To describe risk factors for prolonged hospital length of stay in children with leukemia and bacteremia., Methods: Cohort study. Episodes of bacteremia in patients with leukemia at Garrahan Hospital from 1/1/2015 to 31/12/2016 were reviewed. We compared data from patients with a LOS of 14 days or more with those admitted for less than 14 days. Bivariate and logistic regression analysis was performed. We used Stata 13 statistical package., Results: n = 121. Median age 59 months.81 patients (67%) had a diagnosis of acute lymphoblastic leukemia, followed by acute myeloid leukemia in 40 (33%). 96 patients (79%) had a central venous catheter (CVC), 94 patients (78%) were neutropenic. Blood cultures were positive for Enterobacteriaceae in 55 cases (45%), coagulase-negative staphylococci in 28 cases (23%), Group viridans Streptococcus in 19 (16%), Pseudomonas aeruginosa in 8 (7%). (9%). By the multivariate analysis, three factors remained significantly associated with length of stay of more than 14 days: CVC associated bacteremia (OR 21,73; CI95% 1.2-43.2; p 0.04), severe neutropenia (OR 1.75; CI95% 1.82-1.28; p 0.03) and coinfection (OR 27.4; CI95% 2.8-260.8; p 0.004)., Conclusion: CVC associated bacteremia, severe neutropenia and viral coinfection were associated with hospital LOS of more than 14 days.

Fusarium spp. are an uncommon cause of fungaemia in immunocompromised and neutropenic patients that may hematogenously disseminate to the eyes. Herein, we describe a patient with acute lymphoblastic leukaemia and a prior history of extensive corticosteroid exposure who developed disseminated Fusarium solani infection following chemotherapy despite posaconazole prophylaxis. She was successfully treated with combination liposomal amphotericin B and voriconazole, intraocular injections of voriconazole, topical amphotericin B and bilateral vitrectomy. We also review published literature describing the management of endogenous Fusarium endophthalmitis in immunocompromised hosts., (© 2017 Blackwell Verlag GmbH.)

Invasive aspergillosis of the lungs and the central nervous system and Legionella pneumophilia serotype 1 infection of the lungs were diagnosed in a 22-month old child during inpatient induction treatment for T-lymphoblastic leukemia. Environmental investigations i.e. samples from the hospital water system did not reveal any Legionella. The patient may have been exposed to waterborne pathogens despite terminal water filtration due to a technical device to release residual tap water from the hose after showering. A sodium chloride nose spray was found to be contaminated with the A. fumigatus isolate of the patient., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

In this study, we present a rare case of fatal breakthrough Candida tropicalis infection in a patient with acute lymphoblastic leukemia (ALL) while on posaconazole prophylaxis. Then, we explore the mechanisms underlying azole resistance by focusing on enhanced efflux pumps and changes in the azole target enzyme Erg11p, which was encoded by the ERG11 gene. Our study demonstrates that Y132C substitution of Erg11p combined with MDR1 overexpression may be the pan-azole resistance mechanisms in Candida tropicalis ., (Copyright © 2017 You et al.)

Background: Adult survivors of childhood cancers such as acute lymphoblastic leukemia (ALL) have health problems that persist or develop years after cessation of therapy. These late effects include chronic inflammation-related comorbidities such as obesity and type 2 diabetes, but the underlying cause is poorly understood., Results: We compared the anal microbiota composition of adult survivors of childhood ALL (N = 73) with healthy control subjects (N = 61). We identified an altered community with reduced microbial diversity in cancer survivors, who also exhibit signs of immune dysregulation including increased T cell activation and chronic inflammation. The bacterial community among cancer survivors was enriched for Actinobacteria (e.g. genus Corynebacterium) and depleted of Faecalibacterium, correlating with plasma concentrations of IL-6 and CRP and HLA-DR+CD4+ and HLA-DR+CD8+ T cells, which are established markers of inflammation and immune activation., Conclusions: We demonstrated a relationship between microbial dysbiosis and immune dysregulation in adult ALL survivors. These observations suggest that interventions that could restore microbial diversity may ameliorate chronic inflammation and, consequently, development of late effects of childhood cancer survivors.

Saprochaete capitata (S. capitata) is a very rare fungal pathogen that causes disseminated opportunistic infections in patients with hematologic malignancies. Fever resistant to broad-spectrum antibiotic and antifungal treatment is common in the presence of fungemia during the period of profound neutropenia. We describe three cases of leukemic children who died from S. capitata fungemia following a first febrile neutropenic episode after the induction of chemotherapy. S. capitata fungemia is an emergent infection associated with high mortality and low susceptibility to fluconazole and echinocandins. Awareness of this emergent infection is needed to ensure that it can be properly treated.

We describe the management of a 4-year-old child with acute lymphoblastic leukaemia (ALL) who presented with febrile neutropenia, Cryptosporidium and subsequently developed refeeding syndrome. Febrile neutropenia is common and can be life-threatening and we highlight the identification of well low-risk neutropenic children with resolved febrile illnesses suitable for early discharge. We also discuss the potential management strategies for Cryptosporidium Refeeding syndrome is not common, but should be considered as a cause of acute inpatient deterioration and is a significant risk, with potential morbidity, in children who have undergone a period of catabolism. This article reviews the current literature and provides useful guidance on these issues., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: An estimated 15,000 children and adolescents under the age of 19 years are diagnosed with leukemia, lymphoma and other tumors in the USA every year. All children and adolescent acute leukemia patients will undergo chemotherapy as part of their treatment regimen. Fortunately, survival rates for most pediatric cancers have improved at a remarkable pace over the past three decades, and the overall survival rate is greater than 90 % today. However, significant differences in survival rate have been found in different age groups (94 % in 1-9.99 years, 82 % in ≥10 years and 76 % in ≥15 years). ALL accounts for about three out of four cases of childhood leukemia. Intensive chemotherapy treatment coupled with prophylactic or therapeutic antibiotic use could potentially have a long-term effect on the resident gastrointestinal (GI) microbiome. The composition of GI microbiome and its changes upon chemotherapy in pediatric and adolescent leukemia patients is poorly understood. In this study, using 16S rRNA marker gene sequences we profile the GI microbial communities of pediatric and adolescent acute leukemia patients before and after chemotherapy treatment and compare with the microbiota of their healthy siblings., Results: Our study cohort consisted of 51 participants, made up of matched pediatric and adolescent patients with ALL and a healthy sibling. We elucidated and compared the GI microbiota profiles of patients and their healthy sibling controls via analysis of 16S rRNA gene sequencing data. We assessed the GI microbiota composition in pediatric and adolescent patients with ALL during the course of chemotherapy by comparing stool samples taken before chemotherapy with stool samples collected at varying time points during the chemotherapeutic treatment. The microbiota profiles of both patients and control sibling groups are dominated by members of Bacteroides, Prevotella, and Faecalibacterium. At the genus level, both groups share many taxa in common, but the microbiota diversity of the patient group is significantly lower than that of the control group. It was possible to distinguish between the patient and control groups based on their microbiota profiles. The top taxa include Anaerostipes, Coprococcus, Roseburia, and Ruminococcus2 with relatively higher abundance in the control group. The observed microbiota changes are likely the result of several factors including a direct influence of therapeutic compounds on the gut flora and an indirect effect of chemotherapy on the immune system, which, in turn, affects the microbiota., Conclusions: This study provides significant information on GI microbiota populations in immunocompromised children and opens up the potential for developing novel diagnostics based on stool tests and therapies to improve the dysbiotic condition of the microbiota at the time of diagnosis and in the earliest stages of chemotherapy.

Background and Objectives: We undertook the present study to ascertain the contributing risk factors and explore the epidemiological and mycological characteristics of opportunistic candidemia among patients with hematological malignancies., Design and Settings: Observational cross-sectional study in a tertiary care center., Patients and Methods: Consecutive patients with hematological malignancies reporting to the collaborating medical and pediatric units with a febrile episode were recruited and screened for candidemia by blood culture. Recovered Candida isolates were speciated and antifungal susceptibility testing was performed as per Clinical and Laboratory Standards Institute guideline (CLSI) guidelines M44-A. Further analysis was done for potential risk factors and compared between culture positive and negative patients., Results: Of 150 patients recruited, the majority (n=27) were between 51 and 60 years and the male to female ratio was 1.63:1. Fifteen patients (10%) were culture positive. The culture positivity was significantly higher in acute lymphocytic leukemia (ALL) than in non-ALL patients (p=0.03). There was significant association of candidaemia with leucopenia, chemotherapeutic drugs, corticosteroids and presence of indwelling devices. Duration of disease (p=0.032) and duration of hospitalization (p=0.003) were significantly prolonged in culture positive patients. C. tropicalis was the commonest isolate (46.67%), with non- Candida albicans outnumbering C. albicans in all categories of hematological malignancies (2.75:1). All isolates of C. albicans were uniformly sensitive to all the azoles, but only 50% were sensitive to amphotericin B and none to nystatin and flucytosine., Conclusions: This observational study identifies ALL and chronic lymphocytic leukemia (CLL) as the forms of hematological malignancy predominantly associated with candidemia; specifies risk factors and chemotherapeutic agents predisposing patients towards its occurrence; reports a preponderance of C. tropicalis among the causative agents and finds voriconazole to be the most effective antifungal agent against the recovered isolates. This information could assist in tailoring prophylactic and therapeutic antifungal practices for this infection, according to local epidemiological and mycological characteristics., (Copyright © 2015. Published by Elsevier B.V.)

The fungi of the order Mucorales cause mucormycosis, which usually presents as an invasive fungal disease with rapid angioinvasion in immunocompromised patients. Rhinocerebral is the most common presentation. The lipid formulations of amphotericin B are used as primary treatment in invasive mucormycosis; the combined use of posaconazole could allow a reduction in the dose of amphotericin B improving tolerance and adherence to treatment. Caspofungin and amphotericin B association has been shown to be synergistic in vitro and effective in murine models. We present the case of a preschool patient that during the debut of acute lymphoblastic leukemia developed a rhinocerebral mucormycosis successfully responding to antifungal treatment with the combination of liposomal amphotericin and caspofungin.

Background: The isolation of vancomycin-resistant Enterococcus spp (ERV) has increased significantly within the last few years, along with the risk of infection and dissemination of these bacteria. Our aim was to determine risk factors (RF) for intestinal colonization in hospitalized pediatric patients with oncological disease at Hospital de Niños Roberto del Río., Methods: Between January 2012 and December 2013 a transversal study was performed with 107 rectal swabs and processed with a PCR for ERV. The patients were classified as "colonized with ERV" and "not colonized with ERV" and we evaluated possible RF for intestinal colonization in both groups., Results: VRE colonization was found in 51 patients (52%). The median of time elapsed between oncological diagnosis and VRE colonization was 35 days. The significant RF associated with VRE colonization were days of hospitalization prior to study, neutropenia and treatment with antibiotics within 30 days prior to study and mucositis., Conclusions: According to the RF revealed in this study we may suggest prevention standards to avoid ERV colonization. This is the first investigation in our country in hospitalized pediatric patients with oncological disease and processed with a multiplex PCR for ERV, therefore it is a great contribution about this subject in Chile.

We present the case of a 3-year-old boy who was diagnosed with cerebral abscesses due to Aspergillus nidulans infection on day 28 of induction chemotherapy for acute lymphoblastic leukemia. He responded well to treatment with voriconazole and caspofungin, making a full recovery. There are very few cases of invasive aspergillosis reported in children during induction chemotherapy for acute leukemia and A. nidulans is rare in the absence of chronic granulomatous disease.

Unlabelled: In a prospective multicentre study of bloodstream infection (BSI) from November 01, 2007 to July 31, 2010, seven paediatric cancer centres (PCC) from Germany and one from Switzerland included 770 paediatric cancer patients (58% males; median age 8.3 years, interquartile range (IQR) 3.8-14.8 years) comprising 153,193 individual days of surveillance (in- and outpatient days during intensive treatment). Broviac catheters were used in 63% of all patients and Ports in 20%. One hundred forty-two patients (18%; 95% CI 16 to 21%) experienced at least one BSI (179 BSIs in total; bacteraemia 70%, bacterial sepsis 27%, candidaemia 2%). In 57%, the BSI occurred in inpatients, in 79% after conventional chemotherapy. Only 56 % of the patients showed neutropenia at BSI onset. Eventually, patients with acute lymphoblastic leukaemia (ALL) or acute myeloblastic leukaemia (AML), relapsed malignancy and patients with a Broviac faced an increased risk of BSI in the multivariate analysis. Relapsed malignancy (16%) was an independent risk factor for all BSI and for Gram-positive BSI., Conclusion: This study confirms relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. On a unit level, data on BSIs in this high-risk population derived from prospective surveillance are not only mandatory to decide on empiric antimicrobial treatment but also beneficial in planning and evaluating preventive bundles., What Is Known: • Paediatric cancer patients face an increased risk of nosocomial bloodstream infections (BSIs). • In most cases, these BSIs are associated with the use of a long-term central venous catheter (Broviac, Port), severe and prolonged immunosuppression (e.g. neutropenia) and other chemotherapy-induced alterations of host defence mechanisms (e.g. mucositis). What is New: • This study is the first multicentre study confirming relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. • It describes the epidemiology of nosocomial BSI in paediatric cancer patients mainly outside the stem cell transplantation setting during conventional intensive therapy and argues for prospective surveillance programmes to target and evaluate preventive bundle interventions.