Febrile neutropenia in allogeneic and autologous peripheral blood stem cell transplantation and conventional chemotherapy for malignancies

Evaluating Antibiotic De-escalation for Autologous Stem Cell Transplant Patients With Febrile Neutropenia in a Real-World Clinical Setting

Febrile neutropenia (FN) is a complication in approximately 90% of autologous stem cell transplant (SCT) patients. Guidelines support early broad-spectrum antibiotics (BSA) to prevent morbidity and mortality. However, in patients who are clinically stable and deemed to have a fever of unknown origin, the optimal duration of BSA is unknown. Accumulating evidence suggests that de-escalation of BSA in select patients may decrease duration of BSA exposure without compromising clinical outcomes such as infection, recurrent fever, and readmission. With this, a de-escalation protocol was implemented at Vanderbilt University Medical Center (VUMC) to identify autologous SCT patients who may benefit from early de-escalation of BSA. The objectives of this study were to analyze the impact of early empiric antibiotic de-escalation on the duration of BSA as well as its impact on the incidence of recurrent fever and documented infection in autologous SCT patients. This was a single-center, retrospective study evaluating patients older than 18 years of age who underwent autologous SCT and experienced an episode of FN from January 2018 to December 2022 at VUMC (N = 195). The protocol was initiated on January 1, 2020, to de-escalate BSA back to prophylaxis in stable neutropenic patients determined to have a fever of unknown origin. The primary outcome was the number of BSA days within 30 days. Secondary clinical outcomes included recurrent fever, documented infection, readmission, 30-day mortality, and 90-day non-relapsed mortality (NRM). Outcomes were compared across pre- and postprotocol groups with a Wilcoxon rank sum test, Pearson chi-square test, or regression analysis as appropriate. The median BSA duration was 4.7 and 2.7 days in the pre- and postprotocol groups, respectively (P < .001). Recurrent fever (14.2% versus 16.0%, P = .726), documented infection (1.7% versus 6.7%, P = .068), and readmission (13.3% versus 22.7%, P = .091) within 30 days were not significantly different between the two groups. Neither 30-day mortality (0.8% versus 1.3%, P = .736) nor 90-day NRM (0.8% versus 1.3%, P = .736) differed. The implementation of an early de-escalation protocol for autologous SCT patients who develop FN was associated with a reduction in duration of BSA compared to the preprotocol group without a significant difference in readmission, recurrent fevers, and documented infections. This study adds to existing evidence that early de-escalation of BSA in FN patients with a fever of unknown origin who are afebrile and clinically stable is safe and reduces unnecessary antibiotic use.

DNA Damage-driven Inflammatory Cytokines: Reprogramming of Tumor Immune Microenvironment and Application of Oncotherapy

DNA damage occurs across tumorigenesis and tumor development. Tumor intrinsic DNA damage can not only increase the risk of mutations responsible for tumor generation but also initiate a cellular stress response to orchestrate the tumor immune microenvironment (TIME) and dominate tumor progression. Accumulating evidence documents that multiple signaling pathways, including cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) and ataxia telangiectasia-mutated protein/ataxia telangiectasia and Rad3-related protein (ATM/ATR), are activated downstream of DNA damage and they are associated with the secretion of diverse cytokines. These cytokines possess multifaced functions in the anti-tumor immune response. Thus, it is necessary to deeply interpret the complex TIME reshaped by damaged DNA and tumor-derived cytokines, critical for the development of effective tumor therapies. This manuscript comprehensively reviews the relationship between the DNA damage response and related cytokines in tumors and depicts the dual immunoregulatory roles of these cytokines. We also summarize clinical trials targeting signaling pathways and cytokines associated with DNA damage and provide future perspectives on emerging technologies.

Utility of Urine Cultures During Febrile Neutropenia Workup in Hematopoietic Stem Cell Transplantation Recipients Without Urinary Symptoms

The utility of obtaining screening urine cultures for febrile neutropenia (FN) during hematopoietic stem cell transplant (HCT) is unknown. In 667 adult HCT patients with FN, only 40 (6%) were found with bacteriuria. Antibiotics were modified in 3 patients (0.4%) based on urine cultures and none developed urinary-associated infectious complications.

Clinical features of febrile neutropenia and bloodstream infection in autologous hematopoietic cell transplantation: Comparison to those in intensive chemotherapy for acute myeloid leukemia

BACKGROUND

In autologous hematopoietic cell transplantation (HCT), myelosuppression and mucosal damage are more severe than those in conventional chemotherapy because of high-dose chemotherapy, but the duration of neutropenia is shorter due to stem cell rescue.

METHODS

We retrospectively evaluated febrile neutropenia (FN) and bloodstream infection (BSI) in 208 patients who underwent their first autologous HCT at our institution between 2007 and 2019. They were compared to those in patients who underwent intensive chemotherapy for acute myeloid leukemia (AML) (130 induction/salvage and 191 consolidation).

RESULTS

The median neutropenic period in autologous HCT, AML induction/salvage and consolidation was 9, 26.5, and 19 days, respectively. The incidence of FN was 93.8%, 92.3%, and 81.7%, and that of BSI in initial FN was 7.2%, 7.5% and 26.3%, respectively. The incidence of oral mucositis (≥ grade 2) was 63.1%, 9.2% and 12.2%, and that of diarrhea (≥ grade 2) was 53.3%, 9.2% and 6.4%, respectively. Although there were significant differences in the incidence of shaking chills, the degree of fever and the value of CRP between patients with and without BSI in initial FN of AML chemotherapy, no significant risk factors or predictive factors for BSI were identified in autologous HCT.

CONCLUSIONS

The profile of infectious complications in autologous HCT was characterized by a high incidence of FN maybe due to mucosal damage. On the other hand, the incidence of BSI was lower compared to that in AML consolidation chemotherapy.

Immune-responsive biodegradable scaffolds for enhancing neutrophil regeneration

Neutrophils are essential effector cells for mediating rapid host defense and their insufficiency arising from therapy-induced side-effects, termed neutropenia, can lead to immunodeficiency-associated complications. In autologous hematopoietic stem cell transplantation (HSCT), neutropenia is a complication that limits therapeutic efficacy. Here, we report the development and in vivo evaluation of an injectable, biodegradable hyaluronic acid (HA)-based scaffold, termed HA cryogel, with myeloid responsive degradation behavior. In mouse models of immune deficiency, we show that the infiltration of functional myeloid-lineage cells, specifically neutrophils, is essential to mediate HA cryogel degradation. Post-HSCT neutropenia in recipient mice delayed degradation of HA cryogels by up to 3 weeks. We harnessed the neutrophil-responsive degradation to sustain the release of granulocyte colony stimulating factor (G-CSF) from HA cryogels. Sustained release of G-CSF from HA cryogels enhanced post-HSCT neutrophil recovery, comparable to pegylated G-CSF, which, in turn, accelerated cryogel degradation. HA cryogels are a potential approach for enhancing neutrophils and concurrently assessing immune recovery in neutropenic hosts.

Protective Effect of Intestinal Blautia Against Neutropenic Fever in Allogeneic Transplant Recipients

BACKGROUND

Neutropenic fever (NF) occurs in >70% of hematopoietic cell transplant (HCT) recipients, without a documented cause in most cases. Antibiotics used to prevent and treat NF disrupt the gut microbiota; these disruptions predict a higher posttransplantation mortality rate. We hypothesized that specific features in the gut microbial community may mediate the risk of NF.

METHODS

We searched a large gut microbiota database in allogeneic HCT recipients (12 546 stool samples; 1278 patients) to find pairs with NF (cases) versus without NF (controls) on the same day relative to transplantation and with a stool sample on the previous day. A total of 179 such pairs were matched as to the underlying disease and graft source. Several other important clinical variables were similar between the groups.

RESULTS

The gut microbiota of cases on the day before NF occurrence had a lower abundance of Blautia than their matched controls on the same day after transplantation, suggesting a protective role for Blautia. Microbiota network analysis did not find any differences in community structure between the groups, suggesting a single-taxon effect. To identify putative mechanisms, we searched a gut microbiome and serum metabolome database of patients with acute leukemia receiving chemotherapy and identified 139 serum samples collected within 24 hours after a stool sample from the same patient. Greater Blautia abundances predicted higher levels of next-day citrulline, a biomarker of total enterocyte mass.

CONCLUSIONS

These findings support a model in which Blautia protects against NF by improving intestinal health. Therapeutic restoration of Blautia may help prevent NF, thus reducing antibiotic exposures and transplantation-related deaths.

Autologous hematopoietic stem cell transplantation in neuromyelitis optica spectrum disorder: A systematic review and meta-analysis

INTRODUCTION

Treatment options for neuromyelitis optica spectrum disorder (NMOSD) are corticosteroids, immunosuppressive drugs, emerging monoclonal antibodies, rituximab, eculizumab, satralizumab, and inebilizumab. Due to disabling and deadly nature of NMOSD, there is a great motivation among physicians for finding new treatment options. Recently, several studies have been conducted on the therapeutic effects of autologous hematopoietic stem cell transplantation (AHSCT) on NMOSD patients.

METHODS

Several databases including PubMed, Scopus, Web of Science, and Google scholar were searched for studies on AHSCT in NMOSD patients.

RESULTS

After screening titles and abstracts, and reviewing full texts, nine studies with 39 severe cases of NMOSD met the criteria of our study. The pooled standardized mean difference (SMD) for EDSS score before and after treatment was -0.81 (95 %CI:-1.07, -0.15; Q = 1.99, P = 0.58, I2 = 0 %). Also, the PFS and RFS were 69 % and 53 % respectively (PFS: 69 %, 95 %CI 42 %, 96 %; Q = 8.63, P = 0.01, I2 = 73.07 %; RFS: 53 %, 95 %CI 27 %, 79 %; Q = 12.33, P = 0.01, I2 = 71.87 %). Also, there were three cases with secondary autoimmune diseases including myasthenia gravis, hyperthyroidism, and thyroiditis.

CONCLUSION

According to the present study, AHSCT could be an alternative therapy for NMOSD in severe cases instead of conventional immunotherapies. However, physicians should pay attention to its serious complications. The diversity of results from the published trials on the efficacy and safety of AHSCT calls for further investigations on determining the ideal AHSCT conditioning and the characteristics of patients.

GM-CSF: A Double-Edged Sword in Cancer Immunotherapy

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that drives the generation of myeloid cell subsets including neutrophils, monocytes, macrophages, and dendritic cells in response to stress, infections, and cancers. By modulating the functions of innate immune cells that serve as a bridge to activate adaptive immune responses, GM-CSF globally impacts host immune surveillance under pathologic conditions. As with other soluble mediators of immunity, too much or too little GM-CSF has been found to promote cancer aggressiveness. While too little GM-CSF prevents the appropriate production of innate immune cells and subsequent activation of adaptive anti-cancer immune responses, too much of GM-CSF can exhaust immune cells and promote cancer growth. The consequences of GM-CSF signaling in cancer progression are a function of the levels of GM-CSF, the cancer type, and the tumor microenvironment. In this review, we first discuss the secretion of GM-CSF, signaling downstream of the GM-CSF receptor, and GM-CSF’s role in modulating myeloid cell homeostasis. We then outline GM-CSF’s anti-tumorigenic and pro-tumorigenic effects both on the malignant cells and on the non-malignant immune and other cells in the tumor microenvironment. We provide examples of current clinical and preclinical strategies that harness GM-CSF’s anti-cancer potential while minimizing its deleterious effects. We describe the challenges in achieving the Goldilocks effect during administration of GM-CSF-based therapies to patients with cancer. Finally, we provide insights into how technologies that map the immune microenvironment spatially and temporally may be leveraged to intelligently harness GM-CSF for treatment of malignancies.

Granulocytes Negatively Regulate Secretion of Transforming Growth Factor β1 by Bone Marrow Mononuclear Cells via Secretion of Erythropoietin Receptors in the Milieu

In my previous study, I demonstrated that bone marrow-derived mononuclear cells (BM MNCs) secrete copious amounts of Transforming Growth Factor β1 (TGFβ1) in response to erythropoietin (EPO). In this study, I investigated the principal cell type involved in the process. I found that a large percentage of various marrow cells, but not their mature counterparts present in the peripheral blood, express EPO-receptors (EPO-R). Cell depletion experiments showed that depletion of Glycophorin positive erythroblasts and CD41⁺ megakaryocytes - the prime suspects - did not affect the EPO-mediated TGFβ1 secretion by the BM MNCs. However, individual depletion of CD2⁺ T lymphocytes, CD14⁺ monocyte/macrophages, and CD19⁺ B cells affected the TGFβ1 secretion by EPO-primed MNCs: depletion of CD2⁺ cells had the most striking effect. Unexpectedly, and most interestingly, depletion of CD15⁺ granulocytes led to a significant increase in the TGFβ1 secretion by both naïve and EPO-primed BM MNCs, suggesting that these cells negatively regulate the process. Mechanistically, I show that the CD15⁺ cells exert this regulatory effect via secretion of both full-length and soluble EPO-R in the milieu. Overall my results, for the first time, unravel an in-built regulatory mechanism prevailing in the BM microenvironment that regulates the secretion of TGFβ1 by controlling EPO-EPO-R interaction.My data could be relevant in understanding the pathophysiology of several conditions associated with deregulated production of TGFβ1 in the marrow compartment.

Early antimicrobial prophylaxis in autologous stem cell transplant recipients: Conventional versus an absolute neutrophil count-driven approach

BACKGROUND

Autologous hematopoietic stem cell transplantation (HSCT) recipients are at increased risk of developing life-threatening infections. There is discordance in published recommendations for timing of pre- and post-transplant antimicrobial prophylaxis in this patient population, and these recommendations are unsubstantiated by any published comparative analyses.

METHODS

An observational, pre- and post-intervention study of consecutive autologous HSCT recipients was conducted over a 2-year period. In the pre-intervention cohort, antimicrobial prophylaxis was initiated on the day prior to transplant. In the post-intervention cohort, antimicrobials were initiated once absolute neutrophil count (ANC) reached ≤500 cells/mm3 . The primary outcome assessed was frequency of febrile occurrences. Secondary outcomes included total days of prophylaxis, positive blood cultures, all-cause mortality, Clostridioides difficile infection rates, and length of stay.

RESULTS

A total of 208 patients were included in the final analysis, with 105 and 103 patients in the pre- and post-intervention cohorts, respectively. The majority of patients included were male. Lower rates of fever occurrences were observed in the post-intervention cohort (83% pre- vs. 69% post-intervention; p = 0.019). A significant reduction in the mean antibacterial days per patient was identified (9.7 vs. 4.6 days; p < 0.001). Other than lower rates of febrile neutropenia in the post-intervention cohort, no differences were identified in secondary outcomes. In multivariable analyses, ANC-driven prophylaxis was independently associated with decreased febrile events.

CONCLUSIONS

Delaying prophylaxis until severe neutropenia was not associated with increased febrile events or other secondary clinical outcomes evaluated. This approach is associated with a significant reduction in antimicrobial exposure.

De-escalation of empiric broad spectrum antibiotics in hematopoietic stem cell transplant recipients with febrile neutropenia

Febrile neutropenia (FN) is a common serious complication in patients undergoing hematopoietic stem cell transplantation (HSCT) requiring urgent evaluation and initiation of empiric broad spectrum antibiotics (BSA). The appropriate duration of BSA for FN in patients with negative cultures and no identifiable infection remains undefined. We retrospectively analyzed allogenic and autologous HSCT patients with FN and negative infectious work-up at our facility from 2012 to 2018. The early de-escalation group (EDG) included those who had BSA de-escalation to fluoroquinolone prophylaxis at least 24 h prior to absolute neutrophil count (ANC) recovery after the patient was fever-free for at least 48 h. Among 297 patients undergoing their first HSCT who experienced FN with negative infectious work-up, 83 patients were de-escalated early with the remaining 214 in the standard of care group (SCG) whose BSA were continued until ANC was > 500. Duration of broad-spectrum antibiotics was shorter in EDG compared to SCG (3.86 days vs. 4.62 days, p = 0.03). Rates of mortality, new infections, and clinical decompensation requiring intensive care unit transfer and/or pressor use within 30 days were all similar between the two groups (0% vs. 0.4% p = 1.00, 0% vs. 1.4% p = 0.56, 13.2% vs. 8.4% p = 0.27). This indicates that it is safe to de-escalate antibiotics prior to ANC recovery, leading to less BSA exposure.

Anaerobic Antibiotics and the Risk of Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Certain anaerobic bacteria are important for maintenance of gut barrier integrity and immune tolerance and may influence the risk of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a single-center retrospective cohort study of allogeneic HSCT recipients to evaluate associations between receipt of antibiotics with an anaerobic spectrum of activity and GVHD outcomes. We identified 1214 children and adults who developed febrile neutropenia between 7 days before and 28 days after HSCT and compared GVHD risk and mortality among patients who received anaerobic antibiotics (piperacillin-tazobactam or carbapenems; n = 491) to patients who received only antibiotics with minimal activity against anaerobes (aztreonam, cefepime, or ceftazidime; n = 723). We performed metagenomic sequencing of serial fecal samples from 36 pediatric patients to compare the effects of specific antibiotics on the gut metagenome. Receipt of anaerobic antibiotics was associated with higher hazards of acute gut/liver GVHD (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.03 to 1.54) and acute GVHD mortality (HR, 1.63; 95% CI, 1.08 to 2.46), but not chronic GVHD diagnosis (HR, 1.04; 95% CI: .84 to 1.28) or chronic GVHD mortality (HR, .88; 95% CI, .53 to 1.45). Anaerobic antibiotics resulted in decreased gut bacterial diversity, reduced abundances of Bifidobacteriales and Clostridiales, and loss of bacterial genes encoding butyrate biosynthesis enzymes from the gut metagenome. Acute gut/liver GVHD was preceded by a sharp decline in bacterial butyrate biosynthesis genes with antibiotic treatment. Our findings demonstrate that exposure to anaerobic antibiotics is associated with increased risks of acute gut/liver GVHD and acute GVHD mortality after allogeneic HSCT. Use of piperacillin-tazobactam or carbapenems should be reserved for febrile neutropenia cases in which anaerobic or multidrug-resistant infections are suspected.

Early infectious complications after autologous hematopoietic cell transplantation for multiple myeloma

BACKGROUND

The spectrum of infectious complications in autologous hematopoietic cell transplant recipients (AHCT) with multiple myeloma has not been well described in the recent era of novel agent induction and improved supportive care.

METHODS

We conducted a retrospective cohort study of 413 adult myeloma AHCT recipients at our institution from 2007-2016 to describe the cumulative incidence and risk factors for various infections and FN occurring within the first 100 days after AHCT. Additionally, landmark analysis was done among 404 patients who survived at least 100 days after transplant admission to estimate the association of infections with subsequent non-relapse mortality (NRM), overall survival (OS), and relapse-free survival (RFS).

RESULTS

Cumulative incidences (95% CI) of infection events by day 100 were: FN 43% (38-48), any infection 21% (17-25), bacterial 17% (14-21), viral 4% (3-7) and fungal 1% (0.5-3), central line-associated blood stream infection 3% (2-6), and Clostridium difficile colitis 6% (4-8). Patients with infection had a longer initial transplant hospitalization (median 17 vs 16 days, P < 0.01), more readmissions (31% vs 8%, P < 0.01), and spent more days in hospital in first 100 days (median 18 vs 16 days, P < 0.01). A 100-day mortality was low and similar between groups (2% vs 1%, P = 0.28). In landmark analysis of 404 100-day survivors, OS was worse among patients with early infections (hazard ratio 1.54 [1.03-2.30], P = 0.03), although there was no difference in NRM and RFS.

CONCLUSIONS

Notwithstanding advances in supportive care, early infectious complications remain a relevant source of morbidity and require attention in myeloma AHCT recipients.

Febrile Neutropenia in Transplant Recipients

Febrile neutropenic patients are at increased risk of developing infections. During the initial stages of neutropenia, most of these infections are bacterial. The spectrum of bacterial infections depends to some extent on whether or not patients receive antimicrobial prophylaxis when neutropenic. Since most transplant recipients do, Gram-positive organisms predominate, due to the fact prophylaxis is directed primarily against Gram-negative organisms. Staphylococcus species (often methicillin-resistant), Streptococcus species (viridans group streptococci, beta-hemolytic streptococci), and Enterococcus species (including vancomycin-resistant strains) are isolated most often. Therefore, potent empiric Gram-positive coverage is recommended by many in this setting. Escherichia coli, Pseudomonas aeruginosa, and Klebsiella species are the most common Gram-negative pathogens isolated. Non-fermentative Gram-negative bacilli (Stenotrophomonas maltophilia, Acinetobacter species) are emerging as important pathogens. Many of these organisms acquire multiple mechanisms of resistance that render them multidrug resistant. The administration of prompt, broad-spectrum, empiric, antimicrobial therapy is essential and is generally based on local epidemiology and susceptibility/resistance patterns. Response rate to the initial regimen is generally in the range of 75–85%. Fungal infections develop in patients with prolonged neutropenia (greater than 7–10 days). Candida species and Aspergillus species are the predominant fungal pathogens, although many other fungi are opportunistic pathogens in this setting. Fungal infections are seldom documented microbiologically or on histopathology, and the administration of empiric antifungal therapy, when such infections are suspected, is the norm. Therapy is often prolonged, and outcomes are still suboptimal. The importance of infection control and antimicrobial stewardship cannot be overemphasized.

Can immune biomarkers predict infections in solid organ transplant recipients? A review of current evidence

Despite improvements in graft survival, solid organ transplantation is still associated with considerable infection induced morbidity and mortality. If we were able to show that serious infection risk was associated with excessive suppression of immune capacity, we would be justified in "personalizing" the extent of immunosuppression by carefully monitored reduction to see if we can improve immune compromize without increasing the risk of rejection. Reliable biomarkers are needed to identify this patients at an increased risk of infection. This review focuses on the currently available evidence in solid organ transplant recipients for immune non-pathogen specific biomarkers to predict severe infections with the susceptibility to particular pathogens according to the component of the immune system that is suppressed. This review is categorized into immune biomarkers representative of the humoral, cellular, phagocytic, natural killer cell and complement system. Biomarkers humoral and cellular systems of the that have demonstrated an association with infections include immunoglobulins, lymphocyte number, lymphocyte subsets, intracellular concentrations of adenosine triphosphate in stimulated CD4⁺ cells and soluble CD30. Biomarkers of the innate immune system that have demonstrated an association with infections include natural killer cell numbers, complement and mannose binding lectin. Emerging evidence shows that quantification of viral nucleic acid (such as Epstein Barr Virus) can act as a biomarker to predict all-cause infections. Studies that show the most promise are those in which several immune biomarkers are assessed in combination. Ongoing research is required to validate non-pathogen specific immune biomarkers in multi-centre studies using standardized study designs.

No indication of increased infection rates using low-dose alemtuzumab instead of anti-thymocyte globulin as graft-versus-host disease prophylaxis before allogeneic stem cell transplantation

BACKGROUND

Alemtuzumab as part of the conditioning protocol is effective in reducing graft-versus-host disease (GvHD), but may be associated with increased infection rates, especially when using high doses (ie, 100 mg).

METHODS

We performed a retrospective, single-center, case-control study analyzing the rates of neutropenic fever, cytomegalovirus (CMV) reactivation, Epstein-Barr virus (EBV) reactivation, clinical manifest toxoplasmosis, and clinical manifest human herpesvirus-6 (HHV6) infection using low-dose alemtuzumab in comparison with anti-thymocyte globulin (ATG) as GvHD prophylaxis before allogeneic stem cell transplantation. Forty-four patients transplanted from unrelated donors between 2001 and 2012 were matched by age, diagnosis, and conditioning regimen and treated either with alemtuzumab 10 mg at day -2 (respectively, 20 mg in case of mismatch transplantation) or ATG. ATG Fresenius (10 mg/kg for 3 days) or Thymoglobulin (2 mg/kg for 3 days) were used.

RESULTS

Rates of CMV reactivation, EBV reactivation, and clinical manifest HHV6 infection or toxoplasmosis did not differ significantly between both groups until 2 years after transplantation. No case of post-transplant lymphoproliferative disorder was observed. Also, rates of neutropenic fever during inpatient treatment after transplantation did not differ significantly in both groups.

CONCLUSION

We saw no indication of increased infections rates when using low-dose alemtuzumab as GvHD prophylaxis before allogeneic stem cell transplantation in this retrospective analysis.

Febrile neutropenic infection occurred in cancer patients undergoing autologous peripheral blood stem cell transplantation

OBJECTIVE

The objective of this study was to investigate the incidence, risk factors, and clinical and prognostic characteristics of febrile infection that occurred during the neutropenic period in cancer patients who underwent autologous peripheral blood stem cell transplantation (APBSCT).

METHODS

Clinical data of all the APBSCT cases from 2007 to 2009 in Sun Yat-sen University Cancer Center were collected and retrospectively analyzed.

RESULTS

Eighty-nine APBSCT subjects were investigated. Neutropenia usually occurred on the 4th day (range, 0-15) after transplantation and lasted 6 (range, 3-27) days. Febrile neutropenia occurred in 78.7% patients and lasted around 3 (range, 1-20) days and no infection-related deaths were observed. For febrile episodes, 12 patients (17.1%) were diagnosed as having microbiologically documented infections (MDI). Initial empirical antimicrobial therapy was given to all cases of post-APBSCT febrile neutropenia, of which 44 cases (62.9%) were effective. Febrile neutropenia occurred in 25/34 (73.5%) patients who were given antifungal drugs for prophylaxis.

CONCLUSIONS

Neutropenic infection is still the major complication in APBSCT patients and duration of neutropenia is one of the major risk factors. Prophylactic administration of antifungal drugs seems to be invalid to reduce post-APBSCT infection. Sufficient doses of broad-spectrum antibiotics at the early stage lead to better results of initial antimicrobial treatment.

Infections After High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Infection represents an important cause of morbidity after autologous hematopoietic stem cell transplantation (HSCT). Immunodeficiency is the key risk factor and results from interplay between the underlying disease and its therapy. Various defects in the immune system coexist in HSCT recipients. In the early post-transplant period, neutropenia, oral and gastrointestinal mucositis, and the presence of central venous catheters are the main risk factors. Bacterial infections predominate, and the agents and antibiotic susceptibility profiles vary widely in different regions. Invasive candidiasis is infrequent with fluconazole use, but the incidence of invasive aspergillosis is on the rise, mainly in patients receiving purine analogues or intensive chemotherapy before transplant. In the post-engraftment period, infections are less frequent, but may contribute to significant non-relapse mortality. The dynamics of immune reconstitution drives the risk for infection in this period. The most frequent infections are varicella-zoster virus disease and respiratory tract infections. Assessment of the risk of infection in each period and the identification of patients at higher risk of specific infections are critical to the appropriate management of infectious complications after autologous hematopoietic stem cell transplantation.

Infection profile of patients undergoing autologous bone marrow transplantation in a Brazilian institution

CONTEXT AND OBJECTIVE

Hematopoietic stem cell transplantation (HSCT) has been widely used for treating oncological and hematological diseases. Although HSCT has helped to improve patient survival, the risk of developing infection during hospitalization is an important cause of morbidity and mortality. This study aimed to analyze the infection profile during hospitalization and the associated risk factors among patients undergoing autologous HSCT at the University Hospital, Universidade Federal de Juiz de Fora.

DESIGN AND SETTING

This was a cross-sectional study on patients undergoing autologous HSCT at a public university hospital.

METHODS

Patients with febrile neutropenia between 2004 and 2009 were retrospectively evaluated regarding their infection profile and associated risk factors.

RESULTS

Infection occurred in 57.2% of 112 patients with febrile neutropenia. The main source of infection was the central venous catheter (25.9%). Infection was chiefly due to Gram-positive bacteria, although Gram-negative-related infections were more severe and caused a higher death rate. Sex, age, skin color, nutritional status and underlying disease were not associated with the development of infection. Patients with severe mucositis (Grades III and IV) had a higher infection rate (P < 0.001). Patients who developed pulmonary complications during hospitalization had higher infection rates (P = 0.002). Infection was the main cause of death (57.1%) in the study sample.

CONCLUSION

Strategies aimed at reducing infection-related mortality rates among patients undergoing autologous HSCT are necessary.

Outcome of hematopoietic stem cell transplant in children with congenital heart disease

CHD is the most commonly occurring birth defect in the United States. Improvements in supportive care for CHD result in increasing numbers of survivors who may develop benign or malignant conditions for which HSCT is indicated. However, the ability of individuals with CHD to tolerate HSCT is unknown. Retrospective medical record review of 1031 patients who underwent HSCT at Children's Hospital Boston between 1989 and 2007 identified those with CHD. Ten patients with CHD that required repair or palliation before or after HSCT, or with CHD that would have required repair had they survived HSCT, were identified. These patients tolerated chemotherapy and/or radiation therapy uneventfully. Although half experienced febrile neutropenia and two had documented bacteremia, no endocarditis was observed. During the first 100 days post-HSCT, combined rates of grade 3, 4, and 5 cardiac, renal, and pulmonary toxicity for these patients were 10%, 0%, and 10%, respectively. In children with underlying CHD, there was no clinical evidence of impaired ability to tolerate febrile neutropenia, volume challenge, or other regimen-related toxicities that might require significant cardiac reserve. CHD alone should not be considered an absolute contraindication for indicated HSCT.

Continuous multi-parameter heart rate variability analysis heralds onset of sepsis in adults

BACKGROUND

Early diagnosis of sepsis enables timely resuscitation and antibiotics and prevents subsequent morbidity and mortality. Clinical approaches relying on point-in-time analysis of vital signs or lab values are often insensitive, non-specific and late diagnostic markers of sepsis. Exploring otherwise hidden information within intervals-in-time, heart rate variability (HRV) has been documented to be both altered in the presence of sepsis, and correlated with its severity. We hypothesized that by continuously tracking individual patient HRV over time in patients as they develop sepsis, we would demonstrate reduced HRV in association with the onset of sepsis.

METHODOLOGY/PRINCIPAL FINDINGS

We monitored heart rate continuously in adult bone marrow transplant (BMT) patients (n = 21) beginning a day before their BMT and continuing until recovery or withdrawal (12+/-4 days). We characterized HRV continuously over time with a panel of time, frequency, complexity, and scale-invariant domain techniques. We defined baseline HRV as mean variability for the first 24 h of monitoring and studied individual and population average percentage change (from baseline) over time in diverse HRV metrics, in comparison with the time of clinical diagnosis and treatment of sepsis (defined as systemic inflammatory response syndrome along with clinically suspected infection requiring treatment). Of the 21 patients enrolled, 4 patients withdrew, leaving 17 patients who completed the study. Fourteen patients developed sepsis requiring antibiotic therapy, whereas 3 did not. On average, for 12 out of 14 infected patients, a significant (25%) reduction prior to the clinical diagnosis and treatment of sepsis was observed in standard deviation, root mean square successive difference, sample and multiscale entropy, fast Fourier transform, detrended fluctuation analysis, and wavelet variability metrics. For infected patients (n = 14), wavelet HRV demonstrated a 25% drop from baseline 35 h prior to sepsis on average. For 3 out of 3 non-infected patients, all measures, except root mean square successive difference and entropy, showed no significant reduction. Significant correlation was present amongst these HRV metrics for the entire population.

CONCLUSIONS/SIGNIFICANCE

Continuous HRV monitoring is feasible in ambulatory patients, demonstrates significant HRV alteration in individual patients in association with, and prior to clinical diagnosis and treatment of sepsis, and merits further investigation as a means of providing early warning of sepsis.

Bloodstream infections in haematology: risks and new challenges for prevention

Bloodstream infections are an important cause of morbidity and mortality in the haematology population, and may contribute to delayed administration of chemotherapy, increased length of hospitalisation, and increased healthcare expenditure. For gram-positive, gram-negative, anaerobic and fungal infections, specific risk factors are recognised. Unique host and environmental factors contributing to pathogenesis are acknowledged in this population. Trends in spectrum and antimicrobial susceptibility of pathogens are examined, and potential contributing factors are discussed. These include the widespread use of empiric antimicrobial therapy, increasingly intensive chemotherapeutic regimens, frequent use of central venous catheters, and local infection control practices. In addition, the risks and benefits of prophylaxis, and spectrum of endemic flora are identified as relevant factors within individual centres. Finally, challenges are presented regarding prevention, early detection, surveillance and prophylaxis. To reduce the rate and impact of bloodstream infections multifaceted and customised strategies are required within individual haematology units.

The influence of infection early after allogeneic stem cell transplantation on the risk of leukemic relapse and graft-versus-host disease

An infection after allogeneic stem cell transplantation (SCT) can affect the activity of immune cells and increase the level of proinflammatory cytokines. Further, a post-SCT infection may influence the milieu of the graft-versus-leukemia (GVL) effect and graft-versus-host disease (GVHD). We performed a retrospective study of patients with acute leukemia who had undergone allogeneic SCT using the same preparative regimens and bone marrow as the stem cell source to determine if early post-transplant infection was associated with the risk of leukemic relapse and GVHD. The analysis revealed that patients who had a febrile infection (FI) before post-transplant day 21 (FI group) had a lower actuarial probability of leukemic relapse (P < 0.001) and a higher relapse-free survival rate (P = 0.012) than those patients who did not have a FI before post-transplant day 21 (non-FI group). The experience of early post-transplant FI (HR = 0.316; 95% CI = 0.174-0.575; P < 0.001), together with the presence of chronic GVHD and high risk cytogenetics, were independent predictive factors for post-transplant leukemic relapse. The FI group had a trend towards a higher lymphocyte count on post-transplant day 21 than the non-FI group (P = 0.063), despite the delayed recovery of the platelet count and a trend towards delayed recovery of the neutrophil count. These findings suggest that a change in the immunologic network by infectious diseases in the early post-transplant period favors the milieu of the GVL effect. The specific immunologic change during FI, which can potentiate the GVL effect, remains to be determined.

A study of incidence and characteristics of infections in 476 patients from a single center undergoing autologous blood stem cell transplantation

Infectious complications are a major cause of morbidity and mortality in patients who undergo autologous stem cell transplantation (ASCT). We examined 476 patients with hematologic malignancies (401) or solid tumors (75) who underwent ASCT between February 1990 and May 2005. Anti-infectious prophylaxis consisted of different combinations of ciprofloxacin, cotrimoxazole, fluconazole, aerosolized amphotericin B, acyclovir, and intravenous immunoglobulins. Overall, 454 patients (95%) developed fever in the first 60 days after ASCT. In the majority of patients, initial antibiotic therapy consisted of broad-spectrum beta-lactamic with or without amikacin. A glycopeptide was administered as initial therapy in 86 cases. Overall, there were 132 (29%) clinically documented infections (37 pneumonias), 79 (17%) microbiologically documented infections (65 bacteremias), and 243 (54%) fevers of unknown origin. Coagulase-negative staphylococci (18, 25%) and E coli (18, 25%) were the organisms most frequently isolated. The pattern of infection did not change throughout the study except for a significantly higher incidence of bacteremia due to gram-positive bacteria in the first 5 years of the study. Infection-related mortality was 5% (21 cases), with pneumonia the most frequent cause of death. ASCT should be considered a low-risk procedure, although new therapeutic approaches for patients developing severe respiratory infections are still needed.

Evaluation of potential risk factors for early infectious complications after autologous peripheral blood stem cell transplantation in patients with lymphoproliferative diseases

A number of risk factors for the occurrence of neutropaenic fever after haematopoietic stem cell transplantation (HSCT) have been proposed. We were interested in whether these factors remain valid for several early infection-related outcomes when applied to a homogeneous group of patients in uni- and multivariate analyses. Therefore, we analysed 144 consecutive patients with lymphoproliferative disorders receiving autologous peripheral blood HSCT. Variables tested as potential risk factors for the occurrence of fever, documented infection (DI), microbiologically documented infection (MDI) or failure of first-line antimicrobial therapy were sex, conditioning regimen, prolonged neutropaenia, low number of CD34+ cells transplanted, purging, lack of selective gut decontamination, higher age and increased body mass index. In uni- and multivariate analyses, conditioning including total body irradiation was the only risk factor for the occurrence of fever, and neutropaenia >or=10 days was the only factor associated with failure of first-line antimicrobial therapy. None of the variables tested was associated with an increased risk for DI or MDI. This analysis suggests that a number of previously proposed risk factors actually are of minor clinical relevance for early infections in the majority of patients receiving autologous HSCT.

Development of early neutropenic fever, with or without bacterial infection, is still a significant complication after reduced-intensity stem cell transplantation

Little information is available on the clinical characteristics of infectious complications that occur in the early period after reduced-intensity stem cell transplantation (RIST). We retrospectively investigated the clinical features of neutropenic fever and infectious episodes within 30 days after RIST in 76 patients who had received fluoroquinolones as part of their antibacterial prophylaxis. Preparative regimens included cladribine 0.66 mg/kg or fludarabine 180 mg/m2 plus busulfan 8 mg/kg. All but 1 patient survived 30 days after transplantation, and 75 patients (99%) became neutropenic within a median duration of 9 days. Neutropenic fever was observed in 29 patients (38%), and bacterial infection was confirmed in 15 (20%) of these, including bacteremia (n = 13), bacteremia plus pneumonia (n = 1), and urinary tract infection (n = 1). The causative organisms were gram-positive (n = 9) and gram-negative organisms (n = 7), with a mortality rate of 6%. Neither viral nor fungal infection was documented. Multivariate analysis showed that the presence of neutropenia at the initiation of preparative regimens was an independent risk factor for subsequent documented bacterial infections (P =.026; 95% confidence interval, 1.25-35.1). We conclude that neutropenic fever and bacteremia remain common complications in RIST.

Infectious complications in patients receiving mobilization chemotherapy for autologous peripheral blood stem cell collection

The purpose of this retrospective study was to evaluate infectious complications in patients receiving mobilization chemotherapy for stem cell collection prior to autologous peripheral blood stem cell transplantation. An additional goal was to evaluate risk factors associated with the development of infectious complications. At the Medical College of Georgia BMT center, 54 patients were administered mobilization chemotherapy for the purpose of collecting stem cells between June, 1997, and May, 2002. All patients received Filgrastim in addition to chemotherapy, and 50 of 54 patients received prophylactic acyclovir, fluconazole, and ciprofloxacin until neutrophil recovery. The median duration to neutrophil recovery was 11 days. Fourteen of 54 (26%) patients developed fever/infections during the mobilization phase. One patient developed both a catheter-related infection and Clostridium difficile colitis, increasing the total number of infectious episodes to 15. Twelve patients had a documented site of infection whereas 2 patients had neutropenic fever with no identifiable source. Eight of the 15 (55%) infections were Gram-positive catheter infections. All the patients were treated successfully with antibiotics. No systemic fungal infections were identified and none of the patients died from complications related to mobilization chemotherapy. Logistic regression was applied for univariate and multivariate analysis and showed that age, sex, diagnosis, neutrophil recovery, disease status, use of salvage chemotherapy, and mobilization regimen used did not affect the infection rate. In our series of 54 patients, 14 patients developed fever/infections during mobilization. Although there is a substantial risk of infectious complications among patients who receive mobilization chemotherapy, it is not clear that prophylactic antibiotics decrease infectious complications. Because the vast majority of infections are Gram-positive catheter infections, it appears reasonable to employ Gram-positive prophylaxis. Controlled studies should be conducted to define the optimum mobilization regimens as well as the optimum combination of prophylactic antibiotics.

Infectious complications following T-cell depleted hematopoietic stem-cell transplantation

BACKGROUND

Although sepsis is a common complication during stem-cell transplantation, the prevalence of infections after hematopoietic recovery is less well known.

METHODS

We undertook a retrospective analysis of infectious episodes in patients who underwent allogeneic BM (n = 77) or PBSC (n = 29) grafting from HLA identical siblings. T-cell depletion of the stem-cell grafts with anti CD 52 (CAMPATH-1) Abs was employed for the prevention of GvHD.

RESULTS

Patients' median age was 30 (4-54) years. Antibiotic prophylaxis was with oral amphotericin, ofloxacin and i.v. or oral acyclovir. Fever was treated empirically with a third generation cephalosporin and aminoglucosides until results of microbiological cultures became available. Six patients died of graft failure. GvHD was observed in 18% but in no case was it > Grade II. Only seven patients did not develop pyrexia during the initial admission or within 60 days following graft infusion. Median duration of pyrexia was 10 (range 2-49) days. A microbial source was detected in 42% and it was Gram (+) in 86%, Gram (-) in 11% and fungal in 3%. In 16 patients, indwelling venous catheters were removed due to severe infection. Subsequent to the recovery of the blood parameters, the most prevalent infection was by herpes varicella/zoster in 20; another 17 developed herpes simplex. In total 40/102 were re-hospitalized for pyrexia, which in four cases was of unknown origin. Bacterial infections with Staphylococcus Aureus and S. Epidermitis were seen in 10 and seven patients respectively. CMV was detected in seven patients. Thirteen patients died of sepsis and in 10, it was related to GvHD or graft failure. Another 20 died following recurrence of the malignancy. Overall, 39 patients died and 63% survived at a median DFS of 1992 (range 623-5092) days.

DISCUSSION

We conclude that during the initial neutropenic period the dominant infections are by Gram (+) organisms, often associated with indwelling catheters. Once the BM has recovered, the main morbidity is by viral infections, but Gram+ organisms still remain common bacterial pathogens.

Early infections in adults undergoing matched related and matched unrelated/mismatched donor stem cell transplantation: a comparison of incidence

We compared the incidence of early infectious complications between matched related (MR) and matched unrelated/mismatched (MU/MM) allogeneic stem cell transplant (allo-SCT) recipients in a single centre over a 6-year period in 214 consecutive adult patients. Early infections were defined as occurring from hospital admission for SCT until discharge. One hundred and fifty-nine patients received an allograft from MR donors and 55 patients received MU/MM allo-SCT. One hundred and eight of 214 patients had 147 episodes of fever. Ninety-three episodes (63%) were due to clinically or microbiologically documented infections and 54 episodes (37%) to fever not related to infection. Patients undergoing MU/MM transplantation tended to have more documented infections compared to recipients of MR allo-SCT (P = 0.06). Significantly more MU/MM transplant recipients had breakthrough infections with Herpes simplex virus type 1 (HSV-1, P = 0.003), and more CMV reactivation (P = 0.015). The mortality rate in all patients during hospitalisation post-SCT was 6.3% in MR and 18.2% in MU/MM allo-SCT recipients (P = 0.009). Early mortality was associated with infection in 70% of the patients, with a similar distribution between MR and MU/MM transplant recipients. However, MU/MM transplant recipients had significantly more early deaths due to toxic causes (P < 0.001). We conclude that early post-transplant MU/MM transplant recipients tend to have more documented infections, and have significantly more breakthrough infections with HSV-1 and more CMV reactivation. MU/MM transplant recipients are at higher risk of early mortality, especially due to toxic causes.

Risk of neutropenic fever and early infectious complications after autologous peripheral blood stem cell transplantation for malignant diseases

Autologous peripheral blood stem cell transplantation (auto-PBSCT) has facilitated high-dose chemotherapy for the treatment of various types of malignancy, but the factors affecting the treatment outcome have not been well defined. We evaluated patients who underwent auto-PBSCT (46 patients with hematological malignancies and 39 with solid tumors) to elucidate the risks of background factors, including age, in association with infectious complications. In contrast to former reports, faster engraftment did not influence the incidence of documented infection or neutropenic fever, whereas high age (age > or = 50 years old) and delayed platelet recovery (> or = 18 days) were demonstrated to be positively involved. The odds ratio (OR) for documented infection in elderly patients was 4.94 (95% confidence interval, 1.22-15.8). Another risk factor of infection was the HD-ICE regimen (ifosfamide, carboplatin, etoposide) given to patients with solid tumors (OR, 8.00; 95% confidence interval, 1.61-39.7). In conclusion, we found that elderly patients and patients on the HD-ICE regimen have a higher risk of infectious complications even after auto-PBSCT. Although the clinical indications for auto-PBSCT can be extended to elderly patients, thorough precautions should be taken against infectious complications during the pre-engraftment phase.

Aerobic bacterial and fungal infections in peripheral blood stem cell transplants

Allogeneic and autologous peripheral blood stem cell transplants are frequently complicated by infections. This study was performed to evaluate early and late infections in 74 patients who underwent peripheral blood stem cell transplantation (PBSCT). Fifty-eight patients received allogeneic and 16 autologous PBSCT. All patients received fluconazole, ciprofloxacin and acyclovir prophylaxis. 93.1% of alloPBSCT patients and 87.5% of autoPBSCT patients developed fever. Febrile episodes were commonly seen in the week of transplantation (66%). There was a median of 3 days with fever in alloPBSCT, and 2 days in autoPBSCT. Period of neutropenia was 15 days for AlloPBSCT and 12 days for AutoPBSCT. The microbiological identification rate was 47% (32/68). Gram-positive infections dominated the early period (50%) and Gram-negative bacterial infections dominated the late period (50%). All our patients had Hickman-type catheters and 26 infections involving catheters were seen. Sixteen occurred in the early, and 10 in the late period. Ten of 14 (71.4%) late bacterial infections were catheter-related. The dominance of Gram-positive infections and high rates of methicillin resistance warranted the use of vancomycin extensively. Surveillance cultures were found to be useful in selected patients. Although slime factor is an important virulence factor, there was no difference between slime factor positive and negative coagulase-negative staphylococci isolated during infections. In conclusion, febrile episodes are the most frequent complication of PBSCT and Gram-positive microorganisms remain the main pathogen in these patients because of catheter use, mucositis and ciprofloxacin prophylaxis. Methicillin resistance is increasing and glycopeptides remain the only choice for treating such infections. Although the infection rate is high, measures taken to prevent and treat infections result in very low rates of mortality from infection in PBSCT patients.