Pneumonia in the neutropenic cancer patient

A real-world pharmacovigilance study of polatuzumab vedotin based on the FDA adverse event reporting system (FAERS)

Background

Polatuzumab vedotin, the first FDA-approved antibody-drug conjugate (ADC) targeting CD79b, is utilized in the treatment of previously untreated diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBL), as well as relapsed or refractory (R/R) DLBCL. Despite its approval, concerns persist regarding the long-term safety profile of polatuzumab vedotin. This study aims to evaluate the adverse events (AEs) associated with polatuzumab vedotin since its approval in 2019, utilizing data mining strategies applied to the FDA Adverse Event Reporting System (FAERS).

Methods

Signal detection employed four methodologies, including reporting odds ratio (ROR), proportional reporting ratio (PRR), bayesian confidence propagation neural network (BCPNN), and multi-item gamma poisson shrinker (MGPS), to evaluate and quantify the signals of polatuzumab vedotin-associated AEs. Additionally, subgroup analyses based on patients age, gender, and fatal cases were conducted to investigate AEs occurrences in specific subpopulations.

Results

A total of 1,521 reports listing polatuzumab vedotin as a "principal suspect (PS)" drug were collected from the FAERS database. Through concurrent compliance with four algorithms, 19 significant Standardized MedDRA Query (SMQ) AEs and 92 significant Preferred Term (PT) AEs were detected. Subgroup analyses revealed a higher incidence of PTs in male patients compared to female patients, increased likelihood of polatuzumab vedotin-associated AEs in elder patients (>65 years), and AEs with a high risk of fatal cases include: blood lactate dehydrogenase increased, cytopenia, and hydronephrosis. The median time to AEs occurrence following polatuzumab vedotin initiation was 18.5 (5∼57.75) days, with 95% of AEs occurred within 162 days.

Conclusion

This study identified various AEs associated with polatuzumab vedotin, offering critical insights for clinical monitoring and risk identification in patients receiving polatuzumab vedotin therapy.

Blocking HXA3-mediated neutrophil elastase release during S. pneumoniae lung infection limits pulmonary epithelial barrier disruption and bacteremia

Streptococcus pneumoniae (Sp), a leading cause of community-acquired pneumonia, can spread from the lung into the bloodstream to cause septicemia and meningitis, with a concomitant three-fold increase in mortality. Limitations in vaccine efficacy and a rise in antimicrobial resistance have spurred searches for host-directed therapies that target pathogenic immune processes. Polymorphonuclear leukocytes (PMNs) are essential for infection control but can also promote tissue damage and pathogen spread. The major Sp virulence factor, pneumolysin (PLY), triggers acute inflammation by stimulating the 12-lipoxygenase (12-LOX) eicosanoid synthesis pathway in epithelial cells. This pathway is required for systemic spread in a mouse pneumonia model and produces a number of bioactive lipids, including hepoxilin A3 (HXA3), a hydroxy epoxide PMN chemoattractant that has been hypothesized to facilitate breach of mucosal barriers. To understand how 12-LOX-dependent inflammation promotes dissemination during Sp lung infection and dissemination, we utilized bronchial stem cell-derived air-liquid interface (ALI) cultures that lack this enzyme to show that HXA3 methyl ester (HXA3-ME) is sufficient to promote basolateral-to-apical PMN transmigration, monolayer disruption, and concomitant Sp barrier breach. In contrast, PMN transmigration in response to the non-eicosanoid chemoattractant fMLP did not lead to epithelial disruption or bacterial translocation. Correspondingly, HXA3-ME but not fMLP increased release of neutrophil elastase (NE) from Sp-infected PMNs. Pharmacologic blockade of NE secretion or activity diminished epithelial barrier disruption and bacteremia after pulmonary challenge of mice. Thus, HXA3 promotes barrier disrupting PMN transmigration and NE release, pathological events that can be targeted to curtail systemic disease following pneumococcal pneumonia.

Lower Respiratory Infections in Children With Febrile Neutropenic Leukemia: A Case in a Jordanian Hospital

The study aimed to examine the prevalence of pneumonia in pediatric children diagnosed with leukemia at King Hussein Medical Center, Royal Medical Services, Amman, Jordan. The study was conducted from January 2019 to March 2020. A total of 100 hospitalized leukemia patients with febrile neutropenic episodes were evaluated for the presence of pneumonia. Samples were collected from all patients and tested for microbial growth. Univariate analysis revealed that age (P = .033) and packed cell volume (P = .006) were statistically significant risk factors, associated with the prevalence of pneumonia in leukemia patients with febrile neutropenia episodes. Similarly, as the absolute neutrophil count counts increased with an odds ratio and a 95% confidence interval of 2.386 (0.859-6.625), the odds of pneumonia in febrile neutropenic patients were more prevalent. The study reported the prevalence of pneumonia in immunocompromised febrile neutropenic patients with leukemia, which could lead to the development of evidence-based febrile neutropenic treatment protocol development. It will assure more responsive patient management and treatment.

The Spectrum of Infections in Patients with Lung Cancer

Although diagnostic and therapeutic advances in lung cancer (LC) have increased the survival of patients, infection and its complications are still among the most important causes of mortality. The disruption of tissue caused by tumor mass, management of cancer therapy and alteration in the humoral/cellular immune systems due to both cancer itself and therapy considerably increase susceptibility to infection in cancer patients. Particularly, opportunistic microorganisms should be considered, then applying rapid and sensitive diagnostic methods for them. Thus, cancer patients who are already exposed to difficult, long-term and expensive treatments can be prevented from dying from complications related to infections.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Adverse drug reactions associated with doxorubicin and epirubicin: A descriptive analysis from VigiBase

BACKGROUND

Cancer is one of the leading causes of death globally. Owing to high toxicity, patients using chemotherapy drugs have a higher risk for developing adverse drug reactions (ADRs). Pharmacovigilance studies are essential in oncology to evaluate ADRs caused by anticancer drugs and improve patient safety. This study aimed to analyze serious ADRs associated with the use of doxorubicin and epirubicin reported to VigiBase.

METHOD

All anonymized data on suspected ADRs for doxorubicin and epirubicin as 'serious' and 'suspected' or 'interacting' drugs between 1968 and 30 August 2021, were extracted from VigiBase. Descriptive statistics were conducted in Microsoft Excel, and data were summarized using frequencies and percentages.

RESULTS

A total of 35,620 serious individual case safety reports was analyzed. The majority of reports were from females (Dox = 61.41%; Epi = 86.56%), while the predominant age group was 45-64 years (Dox = 42.06%; Epi = 57.39%). Physicians were the more likely group to report serious ADRs (Dox = 50.03%; Epi = 34.11%). In general, Europe reported the highest for doxorubicin (38.08%), while Asia recorded the highest reports for epirubicin (53.28%). Oceania reported the least for both drugs (Dox = 0.45%; Epi = 0.04%), followed by Africa (Dox = 0.72%; Epi = 0.29%). Blood and lymphatic system disorders were the most reported serious category (Dox = 11053 [44.47%]; Epi = 6659 [61.84%]). The most common manifestations were febrile neutropenia (Dox = 10.52%) and bone marrow failure (Epi = 23.89%).

CONCLUSION

This study provides relevant global insights into serious ADRs for doxorubicin and epirubicin. This knowledge may assist in minimizing and proactively managing ADRs. It can also inform policies to improve patients' quality of life.

Incidence and Predictors of Community-Acquired Pneumonia in Patients With Hematological Cancers Between 2016 and 2019

Background

Patients with hematological cancers (HC) are at high risk of infections, in particular community-acquired pneumonia (CAP). Recent data on incidence and predictors of CAP among patients with HC are scarce.

Methods

We performed a cohort study (2016–2019) in 2 hospitals in the Netherlands among adults with HC to calculate incidence rates (IRs) of CAP. In addition, we performed a nested case-control study to identify predictors of CAP.

Results

We identified 275 CAP cases during 6264 patient-years of follow-up. The IR of CAP was 4390/100 000 patient-years of follow-up. Compared with the general population, IR ratios ranged from 5.4 to 55.3 for the different HCs. The case fatality and intensive care unit (ICU) admission rates were 5.5% and 9.8%, respectively. Predictors for CAP in patients with HC were male sex, anemia, lymphocytopenia, chronic kidney disease, cardiovascular disease, autologous and allogeneic stem cell transplantation, treatment with immunosuppressive medication for graft-vs-host disease, treatment with rituximab in the past year, and treatment with immunomodulators (lenalidomide, thalidomide, pomalidomide and/or methotrexate) in the past month. Independent predictors of a severe disease course (death or ICU admission) included neutropenia (odds ratio, 4.14 [95% confidence interval, 1.63–10.2]), pneumococcal pneumonia (10.24 [3.48–30.1]), chronic obstructive pulmonary disease (6.90 [2.07–23.0]), and the use of antibacterial prophylaxis (2.53 [1.05–6.08]).

Conclusions

The burden of CAP in patients with HC is high, with significant morbidity and mortality rates. Therefore, vaccination against respiratory pathogens early in the disease course is recommended, in particular before starting certain immunosuppressive therapies.

Infectious diseases as a cause of death among cancer patients: a trend analysis and population-based study of outcome in the United States based on the Surveillance, Epidemiology, and End Results database

Background

Infectious diseases are a major cause of morbidity and mortality among cancer patients. We aimed to determine the incidence of infectious diseases as a cause of death among cancer patients and analyze the trends and risk factors associated with mortality.

Methods

In total, 151,440 cancer patients who died from infectious diseases in the US diagnosed between 1973 and 2014 from the Surveillance, Epidemiology, and End Results program were enrolled. A trend analysis of annual cancer deaths caused by infectious diseases was conducted. Cox proportional hazards model and survival decision tree model were performed.

Result

The most common infectious diseases were pneumonia and influenza (n = 72,133), parasitic and other infectious (n = 47,310) diseases, and septicemia (n = 31,119). The patients’ mean age was 66.33 years; majority of them were male (62%). The overall incidence from 1973 to 2014 showed an insignificant decrease (annual percentage change =  − 0.3, 95% confidence interval [CI] =  − 2.2–1.7, P = 0.8). Parasitic and other infectious diseases, including HIV (standardized incidence ratio [SIR] = 1.77, 95% CI = 1.69–1.84), had the highest incidence, followed by septicemia (SIR = 0.84, 95% CI = 0.81–0.88), tuberculosis (SIR = 0.72, 95% CI = 0.51–0.99), and pneumonia (SIR = 0.63, 95% CI = 0.61–0.64). Based on the Cox regression analysis, old black male patients with intrahepatic tumor or acute leukemia of different grades, except the well-differentiated grade, had the highest risk of dying from infectious diseases.

Conclusion

Infectious diseases remain the major cause of morbidity and mortality among cancer patients. Early recognition of risk factors and timely intervention may help mitigate the negative consequences on patients’ quality of life and prognosis, improving the prognosis and preventing early death from infection, which is preventable in most cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-021-00413-z.

Deep learning computer-aided detection system for pneumonia in febrile neutropenia patients: a diagnostic cohort study

Background

Diagnosis of pneumonia is critical in managing patients with febrile neutropenia (FN), however, chest X-ray (CXR) has limited performance in the detection of pneumonia. We aimed to evaluate the performance of a deep learning-based computer-aided detection (CAD) system in pneumonia detection in the CXRs of consecutive FN patients and investigated whether CAD could improve radiologists’ diagnostic performance when used as a second reader.

Methods

CXRs of patients with FN (a body temperature ≥ 38.3 °C, or a sustained body temperature ≥ 38.0 °C for an hour; absolute neutrophil count < 500/mm³) obtained between January and December 2017 were consecutively included, from a single tertiary referral hospital. Reference standards for the diagnosis of pneumonia were defined by consensus of two thoracic radiologists after reviewing medical records and CXRs. A commercialized, deep learning-based CAD system was retrospectively applied to detect pulmonary infiltrates on CXRs. For comparing performance, five radiologists independently interpreted CXRs initially without the CAD results (radiologist-alone interpretation), followed by the interpretation with CAD. The sensitivities and specificities for detection of pneumonia were compared between radiologist-alone interpretation and interpretation with CAD. The standalone performance of the CAD was also evaluated, using area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Moreover, sensitivity and specificity of standalone CAD were compared with those of radiologist-alone interpretation.

Results

Among 525 CXRs from 413 patients (52.3% men; median age 59 years), pneumonia was diagnosed in 128 (24.4%) CXRs. In the interpretation with CAD, average sensitivity of radiologists was significantly improved (75.4% to 79.4%, P = 0.003) while their specificity remained similar (75.4% to 76.8%, P = 0.101), compared to radiologist-alone interpretation. The CAD exhibited AUC, sensitivity, and specificity of 0.895, 88.3%, and 68.3%, respectively. The standalone CAD exhibited higher sensitivity (86.6% vs. 75.2%, P < 0.001) and lower specificity (64.8% vs. 75.4%, P < 0.001) compared to radiologist-alone interpretation.

Conclusions

In patients with FN, the deep learning-based CAD system exhibited radiologist-level performance in detecting pneumonia on CXRs and enhanced radiologists’ performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01768-0.

Side Effects of Oncologic Treatment in the Chest: Manifestations at FDG PET/CT

Fluorodeoxyglucose (FDG) PET/CT is a vital imaging technique used for staging, assessing treatment response, and restaging following completion of therapy in patients who are undergoing or have completed oncologic treatment. A variety of adverse effects from chemotherapy, targeted therapy, immunotherapy, and radiation therapy are commonly encountered in oncologic patients. It is important to be aware of the manifestations of these adverse effects seen on FDG PET/CT images to avoid misinterpreting these findings as disease progression. Furthermore, early identification of these complications is important, as it may significantly affect patient management and even lead to a change in treatment strategy. The authors focus on the FDG PET/CT manifestations of a broad spectrum of oncologic therapy-related adverse effects in the thorax, as well as some treatment-related changes that may potentially mimic malignancy. Online supplemental material is available for this article. ^©RSNA, 2021.

Early Radiologic Diagnosis of Pulmonary Infection in Febrile Neutropenic Patients: A Comparison of Serial Chest Radiography and Single CT Chest

Objective

The purpose of this study is to compare the early radiologic diagnosis of pulmonary infection between serial chest radiography (chest film) and single chest computed tomography (CT chest) in the first seven days of febrile neutropenia.

Methods

This study included 78 patients with hematologic malignancies who developed 107 episodes of febrile neutropenia from January 2012 to October 2017 and had a chest film performed within the first seven days. Demographic and radiographic data were retrospectively reviewed. Three radiologists independently and blindly evaluated chest films and CT chests. The sensitivity, specificity, and correlation of chest film with absolute neutrophil count were carried out.

Results

A total of 222 chest films were performed during this period and found thirty-nine episodes (36.4%) of radiographic active pulmonary infection. The diagnosis of clinical positive for pulmonary infection is 44.8% (48/107). Sensitivity, specificity, positive predictive value, and negative predictive value of serial chest film in the early radiologic diagnosis of pulmonary infection are 50%, 74%, 61%, and 64%, respectively. The false-positive rate was 14%, and the false-negative rate was 22%. For single CT chest examinations, twenty-six studies were assessed, and 42.3% was indicative of radiographic active pulmonary infection. Sensitivity, specificity, positive predictive value, and negative predictive value of CT chest in the early radiologic diagnosis of pulmonary infection are 91%, 40%, 53%, and 86%, respectively. The false-positive rate was 60%. The absolute neutrophil count was not useful for predicting radiographic active pulmonary infection.

Conclusion

Serial chest film for early radiologic diagnosis of pulmonary infection within the first seven days of febrile neutropenia has lower sensitivity with higher specificity as compared to a single CT chest. Conversely, CT chest may not only have a higher sensitivity in determining early pulmonary infection but also has a higher rate of false-positives.

Clinical significance of microbial colonization identified by initial bronchoscopy in patients with lung cancer requiring chemotherapy

Background

There are limited data on the association between bronchial colonization and respiratory infections in people with lung cancer requiring cytotoxic chemotherapy. We investigated whether bronchial colonization in initial bronchoscopy specimens can predict the development of pneumonia after chemotherapy in patients with lung cancer.

Methods

Four hundred thirteen patients with lung cancer included in the Catholic Medical Center lung cancer registry were enrolled from March 2015 to August 2018. Demographic data, microbiology results, development of pneumonia after chemotherapy, and clinical information about lung cancer were analyzed retrospectively.

Results

A total of 206 lung cancer patients treated with chemotherapy were included in the analysis. Forty patients (19.4%) had positive results for the bronchial washing culture during the initial evaluation of lung cancer. The most common organisms were Klebsiella pneumoniae (n=14) and Streptococcus pneumoniae (n=6) in the surveillance culture, and Pneumocystis jirovecii (n=12) and Staphylococcus aureus (n=8) at the time of pneumonia development. Eighty-nine patients (43.2%) had pneumonia after chemotherapy, but the occurrence of pneumonia did not differ according to the colonization. There were no patients for whom the initial isolated organism was a causative microbe for the development of pneumonia after or during chemotherapy. The pneumonia group had poorer prognosis than the non-pneumonia group (378 vs. 705 days, P=0.0004).

Conclusions

Microbial colonization in bronchoscopy specimens was not associated with pneumonia development or mortality after chemotherapy for lung cancer. This finding suggests that testing surveillance culture may not be helpful for predicting pneumonia or improving survival in lung cancer patients with chemotherapy.

Infectious Disease Complications in Patients with Cancer

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

Macrophage LC3-associated phagocytosis is an immune defense against Streptococcus pneumoniae that diminishes with host aging

Streptococcus pneumoniae is a leading cause of pneumonia and invasive disease, particularly, in the elderly. S. pneumoniae lung infection of aged mice is associated with high bacterial burdens and detrimental inflammatory responses. Macrophages can clear microorganisms and modulate inflammation through two distinct lysosomal trafficking pathways that involve 1A/1B-light chain 3 (LC3)-marked organelles, canonical autophagy, and LC3-associated phagocytosis (LAP). The S. pneumoniae pore-forming toxin pneumolysin (PLY) triggers an autophagic response in nonphagocytic cells, but the role of LAP in macrophage defense against S. pneumoniae or in age-related susceptibility to infection is unexplored. We found that infection of murine bone-marrow-derived macrophages (BMDMs) by PLY-producing S. pneumoniae triggered Atg5- and Atg7-dependent recruitment of LC3 to S. pneumoniae-containing vesicles. The association of LC3 with S. pneumoniae-containing phagosomes required components specific for LAP, such as Rubicon and the NADPH oxidase, but not factors, such as Ulk1, FIP200, or Atg14, required specifically for canonical autophagy. In addition, S. pneumoniae was sequestered within single-membrane compartments indicative of LAP. Importantly, compared to BMDMs from young (2-mo-old) mice, BMDMs from aged (20- to 22-mo-old) mice infected with S. pneumoniae were not only deficient in LAP and bacterial killing, but also produced higher levels of proinflammatory cytokines. Inhibition of LAP enhanced S. pneumoniae survival and cytokine responses in BMDMs from young but not aged mice. Thus, LAP is an important innate immune defense employed by BMDMs to control S. pneumoniae infection and concomitant inflammation, one that diminishes with age and may contribute to age-related susceptibility to this important pathogen.

Added Diagnostic Utility of Clinical Metagenomics for the Diagnosis of Pneumonia in Immunocompromised Adults

BACKGROUND

In the evaluation of community-acquired pneumonia, 30% to 60% of cases remain undiagnosed, despite extensive conventional microbiologic testing (CMT). Clinical metagenomics (CM) is an unbiased pathogen detection method that can increase diagnostic yield.

RESEARCH QUESTION

Does adding clinical metagenomics to conventional microbiologic testing improve the diagnostic yield for pneumonia in immunocompromised adults?

STUDY DESIGN AND METHODS

We performed a noninterventional prospective study of immunocompromised adults with pneumonia who underwent bronchoscopy and BAL over 2 years. CMT was performed per standard of care. A commercial CM test was performed on residual BAL fluid. Final microbiologic diagnoses were based on CMT vs CMT + CM. Final clinical diagnoses for CMT and CMT + CM were made based on laboratory results in conjunction with clinical and radiologic findings. Hypothetical impact of CMT + CM on management and antimicrobial stewardship was also assessed.

RESULTS

A total of 30 immunocompromised adult patients (31 episodes of pneumonia) were included. Final microbiologic diagnoses were made in 11 cases (35%) with the use of CMT and in 18 cases (58%) with the use of CMT + CM. Bacterial pneumonia was diagnosed in five cases (16%) by CMT and in 13 cases (42%) by CMT + CM; fungal pneumonia was diagnosed in six cases (19%) by CMT and in seven cases (23%) by CMT + CM, and viral pneumonia was diagnosed in two cases (6%) by CMT and in five cases (16%) by CMT + CM. The hypothetical impact of CMT + CM on management was deemed probable in one case, possible in eight cases, and unlikely in two cases, whereas the impact on antimicrobial stewardship was possible in 13 cases and unlikely in seven cases. Final clinical diagnoses were made in 20 of 31 cases (65%) based on CMT and in 23 of 31 cases (74%) based on CMT + CM.

INTERPRETATION

CMT + CM increased diagnostic yield in immunocompromised adults with pneumonia from 35% to 58%, mostly by the detection of additional bacterial causes but was less useful for fungal pneumonia.

The Diagnostic Utility and Clinical Implications of Bronchoalveolar Lavage in Cancer Patients With Febrile Neutropenia and Lung Infiltrates

Introduction Febrile neutropenia (FN) is a dreaded complication of cancer chemotherapy and frequently associated with respiratory infections. Flexible bronchoscopy (FB) serves as a useful diagnostic tool in this regard. Objective To determine the diagnostic yield, safety and clinical implications of bronchoalveolar lavage (BAL) in cancer patients with FN, having lung infiltrates on radiographic chest imaging. Methods We reviewed medical records of FN patients who underwent FB at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, from July 2015 till July 2018. The culture yield of BAL, resultant change of management and outcome over the subsequent 30 days were retrospectively analysed. Statistical Package for Social Sciences (SPSS) version 20 (IBM Corp., Armonk, NY) was used for data analysis. Results Ninety FN patients, with mean age 26 ± 18 years and predominantly males (65.6%, n = 59) were included in the study. Seventy-seven (85.6%) had hematological and 13 (14.4%) solid organ malignancy. The mean absolute neutrophil count was 0.20 +/- 0.36/ µL. BAL cultures were diagnostic in 40 (44%) patients; the etiology was bacterial, fungal and mixed in 25 (62.5%), 14 (35%) and one (2.5%) patient, respectively. All patients were on empirical antibiotics prior to bronchoscopy: 32 (35.6%) on antibacterial alone and 58 (64.4%) on antibacterial plus antifungal therapy. Change of management occurred in 51 (56.7%) patients after BAL results, including de-escalation from dual antibiotics in 28 (55%) and initiation of new culture sensitive antibiotic in 23 (45%). FB-associated complications developed in three (5.6%) non-intensive care patients (ICU), including transient hypoxia in two and minor hemoptysis in one patient, while five (14.8%) mechanically ventilated patients in ICU experienced worsening of oxygenation parameters within 48 hours. Overall, 24 (26.7%) patients died. Mortality was 3.7% in non-ICU and 69% in ICU setting and significantly higher in patients with fungal pneumonias (p-value 0.01) and with prolonged neutropenia (p-value 0.001). Conclusions BAL is a safe diagnostic tool for FN patients with lung infiltrates, with minimal complications and sufficient diagnostic yield to improve diagnosis and management of such patients.

Indications and clinical outcomes of indwelling pleural catheter placement in patients with malignant pleural effusion in a cancer setting hospital

BACKGROUND

The placement of indwelling pleural catheters (IPC) is an effective outpatient approach for the management of malignant pleural effusions (MPE).

AIMS

The indications and outcome of IPC in patients with MPE. Risk stratifications, prevention and management of IPC-related complications.

METHODS

We retrospectively reviewed the clinical data of patients with MPE who underwent IPC insertion from July 2011 to July 2019. The multivariable logistic regression model was used to identify the independent risk factors associated with IPC infection and the Kaplan-Meier method to determine the overall survival.

RESULTS

A total of 102 patients underwent IPC insertion during the stipulated period and the mean age was 50.49 ± 14.36 years. Seventy-one (69.6%) were females. The indications were Trap Lung in 38 (37.3%), failed talc pleurodesis in 28 (27.5%) and as a primary intervention in 36 (35.3%). The infection rate was 25.5%, of which 65.4% patients had nosocomial infections. Post-IPC overall median survival time was 9.0 ± 2.50 weeks with highest in patients with trap lung (18 ± 1.50 weeks). In multivariable analysis, following variables were identified as a significant independent risk factor for IPC infection: Multiloculated MPE (AOR 2.80; 95%CI (1.00-9.93), 0.04), trap lung (AOR 7.57; 95%CI (1.39-41.25), 0.01), febrile neutropenia (FN) (AOR 28.55; 95%CI (4.23-19.74), 0.001), IPC domiciliary education (AOR 0.18; 95%CI (0.05-0.66), 0.001) and length of hospital stay (AOR 1.16; 95%CI (1.01-1.33), 0.03).

CONCLUSION

IPC insertion is an effective management for MPE with reasonable survival benefits. Infection is the most common complication, of which mostly are nosocomial infections with higher incidence in multiloculated effusions, trap lung, FN and with lack of domiciliary IPC care education.

Cancer patients with neutropenic septic shock: etiology and antimicrobial resistance

BACKGROUND/AIMS

Among patients with febrile neutropenia that developed after chemotherapy, high-risk patients, such as those having clinical instability or Multinational Association of Supportive Care in Cancer score of < 21, require hospitalization for intravenous empiric antibiotic therapy. Monotherapy with an anti-pseudomonal ß-lactam agent is recommended. Although many studies reported the microbial etiology of infections and resistant patterns of febrile neutropenia, the patients were not well characterized as having neutropenic septic shock. Therefore, this study aimed to determine the microbial spectrum of infections and resistance patterns of their isolates in patients with chemotherapy-induced neutropenic septic shock.

METHODS

Data of adult patients diagnosed with neutropenic septic shock in the emergency department between June 2012 and December 2016 were extracted from a prospectively compiled septic shock registry at a single academic medical center. Thereafter, microbiological studies and antimicrobial susceptibility tests were conducted.

RESULTS

In total, 109 bacteria were found in patients with neutropenic septic shock. Gram-negative bacteria were the predominant causative organisms (84, 77.1%). Moreover, 33 microorganisms (30.3%) were multidrug-resistant (MDR) bacteria with extended-spectrum ß-lactamase-producing Escherichia coli (17, 50%) being the commonest. The most commonly affected sites in patients with MDR bacterial infections were the gastrointestinal tract (45%) and unknown (43.5%). Approximately 48.5% of MDR bacteria were resistant to cefepime but not to piperacillin-tazobactam or carbapenem.

CONCLUSION

MDR bacteria were prevalent in patients with chemotherapy-induced neutropenic septic shock. Therefore, piperacillin-tazobactam or carbapenem may be considered as empiric antibiotics if MDR bacteria are suspected to be causative agents.

In Vitro Evaluation of Radiolabeled Amphotericin B for Molecular Imaging of Mold Infections

Invasive pulmonary aspergillosis and mucormycosis are life-threatening complications in immunocompromised patients. A rapid diagnosis followed by early antifungal treatment is essential for patient survival. Given the limited spectrum of biomarkers for invasive mold infections, recent studies have proposed the use of radiolabeled siderophores or antibodies as molecular probes to increase the specificity of radiological findings by nuclear imaging modalities. While holding enormous diagnostic potential, most of the currently available molecular probes are tailored to the detection of Aspergillus species, and their cost-intensive and sophisticated implementation restricts their accessibility at less specialized centers. In order to develop cost-efficient and broadly applicable tracers for pulmonary mold infections, this study established streamlined and high-yielding protocols to radiolabel amphotericin B (AMB) with the gamma emitter technetium-99m (^99mTc-AMB) and the positron emitter gallium-68 (⁶⁸Ga-AMB). The radiochemical purity of the resulting tracers consistently exceeded 99%, and both probes displayed excellent stability in human serum (>98% after 60 to 240 min at 37°C). The uptake kinetics by representative mold pathogens were assessed in an in vitro Transwell assay using infected endothelial cell layers. Both tracers accumulated intensively and specifically in Transwell inserts infected with Aspergillus fumigatus, Rhizopus arrhizus, and other clinically relevant mold pathogens compared with their accumulation in uninfected inserts and inserts infected with bacterial controls. Inoculum-dependent enrichment was confirmed by gamma counting and autoradiographic imaging. Taken together, this pilot in vitro study proposes ^99mTc-AMB and ⁶⁸Ga-AMB to be facile, stable, and specific probes, meriting further preclinical in vivo evaluation of radiolabeled amphotericin B for molecular imaging in invasive mycoses.

Non-ventilator health care associated pneumonia (NV-HAP): Oncology

Literature suggests that cancer patients can become colonized or infected with a variety of opportunistic and health care-associated pathogens, putting them at higher risk for nonventilator health care-associated pneumonia. This section will review the epidemiology of nonventilator health care-associated pneumonia and the importance of prevention strategies in this vulnerable population. Prevention strategies for cancer patients across the continuum of care are highlighted.

Smoking is associated with pneumonia development in lung cancer patients

Background

Various host factors can promote pneumonia susceptibility of lung cancer patients. However, data about risk factors for pneumonia in lung cancer patients receiving active treatments such as chemotherapy, radiotherapy, and surgical intervention are limited. Thus, the purpose of this study was to identify risk factors for pneumonia development in lung cancer patients.

Methods

The present study used a lung cancer cohort of the Catholic Medical Center at the Catholic University of Korea from January 2015 to December 2018. Pneumonia was defined by the presence of a new or progressive infiltration on chest imaging together with any of the following: new onset purulent sputum, change in character of chronic sputum, and fever. We ruled out noninfectious infiltration such as drug or radiation toxicity and hydrostatic pulmonary edema. We especially excluded those if computed tomography revealed sharp demarcation consolidation or ground glass opacity limited radiation field.

Results

A total of 413 patients were enrolled in this study. Pneumonia occurred in 118 (28.6%) patients. The pneumonia group had significantly worse overall survival (OS) than the non-pneumonia group (456.7 ± 35.0 days vs. 813.4 ± 36.1 days, log rank p < 0.001). In patients with pneumonia, OS was shorter in ex-smokers and current smokers than in never smokers (592.0 ± 101.0 days vs. 737.0 ± 102.8 days vs. 1357.0 days, log rank p < 0.001). Age (hazard ratio [HR]: 1.046; 95% confidence interval [CI]: 1.019–1.074; p = 0.001), clinical stage IV (HR: 1.759; 95% CI: 1.004–3.083; p = 0.048), neutropenia (HR: 2.620; 95% CI: 1.562–4.396; p < 0.001], and smoking (HR: 2.040; 95% CI: 1.100–3.784; p = 0.024) were independent risk factors of pneumonia development in lung cancer patients in multivariate analysis. In subgroup analysis for patients treated with chemotherapy, age (HR: 1.043; 95% CI: 1.012–1.074; p = 0.006), neutropenia (HR: 3.199; 95% CI: 1.826–5.605; p < 0.001), and smoking (HR: 2.125; 95% CI: 1.071–4.216; p = 0.031) were independent risk factors of pneumonia development.

Conclusions

Smoking and neutropenia were risk factors affecting pneumonia development in the total group and subgroup of patients with lung cancer.

Comprehensive evaluation of complex polymicrobial specimens using next generation sequencing and standard microbiological culture

Optimal clinical decision-making depends on identification of clinically relevant organisms present in a sample. Standard microbiological culture may fail to identify unusual or fastidious organisms and can misrepresent relative abundance of sample constituents. Culture-independent methods have improved our ability to deconvolute polymicrobial patient samples. We used next-generation 16S rRNA gene sequencing (NGS16S) to determine how often cultivatable organisms in complex polymicrobial samples are not reported by standard culture. Twenty consecutive bronchoalveolar lavage (BAL) samples were plated to standard and additional media; bacteria were identified by NGS16S analysis of DNA extracted directly from samples or from washed culture plates. 96% of organisms identified were cultivable, but only 21% were reported by standard culture, indicating that standard work-up provides an incomplete assessment of microbial constituents. Direct NGS16S correlated well with standard culture, identifying the same predominant organism in 50% of samples. When predominant organisms differed, NGS16S most often detected anaerobes, whose growth is unsupported by standard culture conditions for this specimen. NGS16S identified more organisms per sample and allowed identification of fastidious organisms, while culture was better at capturing organisms when bacterial load was low, and allowed incidental recovery of non-bacterial pathogens. Molecular and culture-based methods together detect more organisms than either method alone.

Dysphagia Screening for Pneumonia Prevention in a Cancer Hospital: Results of a Quality/Safety Initiative

OBJECTIVE

Hospital-acquired aspiration pneumonia remains a rare but potentially devastating problem. The best means by which to prevent aspiration in a cancer hospital population has not been evaluated. The aim of this study was to evaluate the impact of dysphagia screening on aspiration pneumonia rates in an acute care oncology hospital.

METHODS

A prospective single-institution quality improvement dysphagia screening protocol at a comprehensive cancer center. Effect of dysphagia screening implemented in 2016 on hospital-acquired aspiration pneumonia rates coded "aspiration pneumonitis due to food/vomitus" was compared with rates from 2014 to 2015 prior to implementation. Screening compliance, screening outcomes, patient demographics, and medical data were reviewed as part of a post hoc analysis.

RESULTS

Of 12,392 admissions in 2014 to 2016, 97 patients developed aspiration pneumonia during their hospitalization. No significant change in aspiration pneumonia rate was seen during the dysphagia screening year when compared to prior years (baseline, 7.36; screening year, 8.78 per 1000 discharges; P = .33). Sixty-eight of the cases (66%) were associated with emesis/gastrointestinal obstruction or perioperative aspiration and only 15 (15%) with oropharyngeal dysphagia. Multivariate analysis found that patients admitted to gastrointestinal surgery had an aspiration risk equivalent to patients admitted to head and neck, thoracic, and pulmonary services (odds ratio, 0.65; P = .2).

DISCUSSION

Nursing-initiated dysphagia screening did not decrease aspiration pneumonia rates. The causes of aspiration-associated pneumonia were heterogeneous. Aspiration of intestinal contents is a more common source of hospital-acquired pneumonia than oropharyngeal dysphagia.

A clinical approach to respiratory disease in patients with hematological malignancy, with a focus on respiratory infection

Respiratory complications, in particular infections, are common in the setting of hematological malignancy and after hematopoetic stem cell transplant. The symptoms can be nonspecific; therefore, it can be difficult to identify and treat the cause. However, an understanding of the specific immune defect, clinical parameters such as speed of onset, and radiological findings, allows the logical diagnostic and treatment plan to be made. Radiological findings can include consolidation, nodules, and diffuse changes such as ground glass and tree-in-bud changes. Common infections that induce these symptoms include bacterial pneumonia, invasive fungal disease, Pneumocystis jirovecii and respiratory viruses. These infections must be differentiated from inflammatory complications that often require immune suppressive treatment. The diagnosis can be refined with the aid of investigations such as bronchoscopy, computed tomography (CT) guided lung biopsy, culture, and serological tests. This article gives a schema to approach patients with respiratory symptoms in this patient group; however, in the common scenario of a rapidly deteriorating patient, treatment often has to begin empirically, with the aim to de-escalate treatment subsequently after targeted investigations.

Significance of the Reverse Halo Sign in Immunocompromised Patients

OBJECTIVE. The purpose of this study is to assess the most common causes of the reverse halo sign (RHS) in immunocompromised patients and to identify clinicoradiologic features that help in achieving a specific diagnosis. MATERIALS AND METHODS. This retrospective study included 70 patients with hematologic malignancy, neutropenia, or history of solid organ transplant or stem cell transplant who had the RHS at chest CT. Absolute neutrophil count, imaging features of the RHS, and presence of pleural effusions were noted and correlated with the specific diagnosis. A decision tree was constructed from predictive imaging features and compared with radiologist assessment for infectious versus noninfectious cause. RESULTS. Infection, including fungal and bacterial pneumonia, was the most common cause of the RHS (66%), followed by organizing pneumonia (26%). Noninfectious causes such as organizing pneumonia were more likely in the solid organ transplant group, whereas infections were more likely in patients with hematologic malignancy and stem cell transplant. Among fungal pneumonias, aspergillosis (20%) was as common as mucormycosis (19%). In univariate analysis, neutropenia, rim thickness, central ground-glass attenuation, and lesion diameter correlated with infectious cause. A decision tree using neutropenia, rim thickness, central ground-glass attenuation, and pleural effusion could differentiate infectious from noninfectious cause with accuracy of 78%, compared with radiologist accuracy of 81%. CONCLUSION. Infections are more likely to cause RHS than noninfectious processes in immunocompromised patients, and aspergillosis may be as likely overall as mucormycosis because of its higher frequency in these patients. A decision tree using clinical and imaging features can help differentiate infectious from noninfectious causes of RHS.

Early gut microbiota signature of aGvHD in children given allogeneic hematopoietic cell transplantation for hematological disorders

BACKGROUND

The onset of acute Graft-versus-Host Disease (aGvHD) has been correlated with the gut microbiota (GM) composition, but experimental observations are still few, mainly involving cohorts of adult patients. In the current scenario where fecal microbiota transplantation has been used as a pioneer therapeutic approach to treat steroid-refractory aGvHD, there is an urgent need to expand existing observational studies of the GM dynamics in Hematopoietic Stem Cell Transplantation (HSCT). Aim of the present study is to explore the GM trajectory in 36 pediatric HSCT recipients in relation to aGvHD onset.

METHODS

Thirty-six pediatric patients, from four transplantation centers, undergoing HSCT were enrolled in the study. Stools were collected at three time points: before HSCT, at time of engraftment and > 30 days following HSCT. Changes in the GM phylogenetic structure were studied by 16S rRNA gene Illumina sequencing and phylogenetic assignation.

RESULTS

Children developing gut aGvHD had a dysbiotic GM layout before HSCT occurred. This putative aGvHD-predisposing ecosystem state was characterized by (i) reduced diversity, (ii) lower Blautia content, (iii) increase in Fusobacterium abundance. At time of engraftment, the GM structure underwent a deep rearrangement in all patients but, regardless of the occurrence of aGvHD and its treatment, it reacquired a eubiotic configuration from day 30.

CONCLUSIONS

We found a specific GM signature before HSCT predictive of subsequent gut aGvHD occurrence. Our data may open the way to a GM-based stratification of the risk of developing aGvHD in children undergoing HSCT, potentially useful also to identify patients benefiting from prophylactic fecal transplantation.

[A multicenter, retrospective study of pathogenic bacteria distribution and drug resistance in febrile neutropenic patients with hematological diseases in Shanghai]

目的

了解上海地区中性粒细胞缺乏（粒缺）伴发热血液病患者致病细菌的分布及耐药情况。

方法

回顾性分析2012年1月至2014年12月上海市12家医院血液科粒缺伴发热住院患者的临床分离菌株，用纸片扩散法进行药敏试验，WHONET 5.6软件分析病原菌分布及药敏数据。

结果

从上海地区粒缺伴发热患者中共分离出1 260株细菌，其中革兰阳性菌420株（33.3%），革兰阴性菌840株（66.7%）。排在前七位的分别是肺炎克雷伯菌158株（12.5%）、嗜麦芽窄食单胞菌120株（9.5%）、大肠埃希菌115株（9.1%）、铜绿假单胞菌109株（8.7%）、鲍曼不动杆菌83株（6.6%）、金黄色葡萄球菌70株（5.6%）和屎肠球菌63株（5.0%）。呼吸道分泌物标本中，非发酵菌占56.2%（350/623）。其中嗜麦芽窄食单胞菌占15.3%（95/623）。血液标本中，肠杆菌科细菌占42.3%（104/246），凝固酶阴性葡萄球菌占34.6%（85/246）。脓液标本中肠杆菌科细菌占39.4%（76/193），肠球菌属细菌占28.5%（55/193）。耐甲氧西林金黄色葡萄球菌葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）的检出率分别为54.3%和82.5%，未发现耐利奈唑胺、万古霉素、替考拉宁葡萄球菌属菌株，耐万古霉素屎肠球菌的检出率为8.9%，肠球菌属未检出耐利奈唑胺的菌株。肠杆菌科细菌对碳青霉烯类药物高度敏感。铜绿假单胞菌对亚胺培南和美罗培南的耐药率已分别达34.1%和15.8%。嗜麦芽窄食单胞菌对米诺环素、左氧氟沙星、复方磺胺甲恶唑等药物敏感。鲍曼不动杆菌仅对头孢哌酮/舒巴坦的耐药率低于10.0%。肺炎克雷伯菌、嗜麦芽窄食单胞菌、铜绿假单胞菌、鲍曼不动杆菌等革兰阴性菌对大多常用抗菌药物的耐药率低于CHINET监测的数据。

结论

粒缺伴感染患者常见感染部位致病菌株分布有其特点，细菌耐药率整体低于CHINET全国医院大样本监测。

Respiratory Infections

Pneumonia is defined as the presence of a new pulmonary infiltrate on radiologic imaging in the patient with appropriate clinical symptoms such as fever, cough, production of purulent sputum, shortness of breath and/or hypoxia, in the absence of pulmonary edema [1, 2].

Patients immunodéprimés, quel pathogène pour quel déficit immunitaire ? (en dehors de l’infection à VIH)

Le nombre de patients immunodéprimés ne cesse d’augmenter en raison de l’amélioration du pronostic global du cancer et de l’utilisation croissante d’immunosuppresseurs tant en transplantation qu’au cours des maladies auto-immunes. Les infections sévères restent la première cause d’admission en réanimation dans cette population et sont dominées par les atteintes respiratoires. On distingue les déficits primitifs, volontiers révélés dans l’enfance, des déficits secondaires (médicamenteux ou non), les plus fréquents. Dans tous les cas, les sujets sont exposés à des infections inhabituelles de par leur fréquence, leur type et leur sévérité. À côté des pyogènes habituels, les infections opportunistes et la réactivation d’infections latentes font toute la complexité de la démarche diagnostique. Celle-ci doit être rigoureuse, orientée par le type de déficit, les antécédents, les prophylaxies éventuelles et la présentation clinicoradiologique. Elle permettra seule de guider le traitement probabiliste et les examens étiologiques, l’absence de diagnostic étant associée à une mortalité élevée.

Diagnostic Evaluation of Pulmonary Abnormalities in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation

Pulmonary complications (PC) of hematologic malignancies and their treatments are common causes of morbidity and mortality. Early diagnosis is challenging due to host risk factors, clinical instability, and provider preference. Delayed diagnosis impairs targeted treatment and may contribute to poor outcomes. An integrated understanding of clinical risk and radiographic patterns informs a timely approach to diagnosis and treatment. There is little prospective evidence guiding optimal modality and timing of minimally invasive lung sampling; however, a low threshold for diagnostic bronchoscopy during the first 24 to 72 hours after presentation should be a guiding principle in high-risk patients.

Acute myeloid leukemia and the infectious diseases consultant

Infectious complications following treatment of acute myeloid leukemia (AML) are important causes of morbidity and mortality. The spectrum and complexity of these infections is reflected by the severe net state of immunosuppression of AML patients, that is dynamic and continuously changing, the polypharmacy, including the widespread use of anti-infectives and the complex epidemiology of severe and frequently resistant pathogens afflicting these patients. Infectious diseases (ID) consultants having a critical mass of expertise and intimate knowledge of the intricacies of leukemia care, add considerable value in improving outcomes of patients with AML who develop infections. Furthermore, pharmaco-economic considerations such as length of stay, choice of cost-effective anti-infective program, infection control and antibiotic stewardship strategies create a delicate interplay of the ID consultant and the ecosystem of care of AML patients. This is an increasingly recognized area of cross collaboration and a productive direction for future collaborative practice models and research.

Impact of the Microbiota on Bacterial Infections during Cancer Treatment

Patients being treated for cancer are at high risk for infectious complications, generally due to colonizing organisms that gain access to sterile sites via disrupted epithelial barriers. There is an emerging understanding that the ability of bacterial pathogens, including multidrug-resistant organisms, to colonize and subsequently infect humans is largely dependent on protective bacterial species present in the microbiome. Thus, herein we review recent studies demonstrating strong correlations between the microbiome of the oncology patient and infections occurring during chemotherapy. An increased knowledge of the interplay between potential pathogens, protective commensals, and the host immune system may facilitate the development of novel biomarkers or therapeutics that could help ameliorate the toll that infections take during the treatment of cancer.

Bacterial Pneumonia in Patients with Cancer: Novel Risk Factors and Management

Bacterial pneumonias exact unacceptable morbidity on patients with cancer. Although the risk is often most pronounced among patients with treatment-induced cytopenias, the numerous contributors to life-threatening pneumonias in cancer populations range from derangements of lung architecture and swallow function to complex immune defects associated with cytotoxic therapies and graft-versus-host disease. These structural and immunologic abnormalities often make the diagnosis of pneumonia challenging in patients with cancer and impact the composition and duration of therapy. This article addresses host factors that contribute to pneumonia susceptibility, summarizes diagnostic recommendations, and reviews current guidelines for management of bacterial pneumonia in patients with cancer.

Lower Respiratory Tract Infections

This review will focus on the infectious etiologies and more common noninfectious causes of lower respiratory tract syndromes among major immunosuppressed populations. The changing epidemiology of infections in the era of highly active antiretroviral therapy (HAART) in the case of HIV-positive patients and the impacts of both newer immune-suppressant therapies and anti-infective prophylaxis for other immunocompromised hosts will be discussed, with emphasis on diagnostic approaches and practice algorithms.

Clinical features, aetiology and outcome of bacteraemic pneumonia in neutropenic cancer patients

BACKGROUND AND OBJECTIVE

We aimed to assess the clinical features, aetiology and outcomes of bacteraemic pneumonia in neutropenic cancer patients (NCP) in the current era of increasing antimicrobial resistance.

METHODS

All episodes of bacteraemia occurring in hospitalized patients with cancer, including haematopoietic stem cell transplant recipients, from January 2006 to April 2015 were included.

RESULTS

We identified 1723 episodes of bacteraemia, of which 795 occurred in neutropenic patients with cancer, and among them, 55 episodes were identified as bacteraemic pneumonia. The most frequent causative agents were Pseudomonas aeruginosa (39.6%), Streptococcus pneumoniae (20.6%) and Escherichia coli (8.6%). Among the Gram-negative organisms, 12.8% were multidrug resistant (MDR). Eleven patients (20%) required admission to intensive care, and eight (14.8%) underwent invasive mechanical ventilation. Nine patients (16.3%) received inadequate empirical antibiotic therapy, of whom six (66.6%) died; eight of these nine patients had pneumonia caused by resistant microorganisms. The early (48 h) case-fatality rate was 24% and the overall (30 day) case-fatality rate was 46.2%.

CONCLUSION

Bacteraemic pneumonia is a frequent complication among NCP and is mainly caused by P. aeruginosa and S. pneumoniae. The emergence of MDR organisms is of special concern. Despite the improvement in the management of cancer patients, case-fatality rates of NCP with bacteraemic pneumonia remain high. Urgent assessment is needed to identify a better approach for the management and support of these patients.

Inducible epithelial resistance protects mice against leukemia-associated pneumonia

Despite widespread infection prevention efforts, pneumonia remains the leading cause of death among patients with acute leukemia, due to complex disease- and treatment-dependent immune defects. We have reported that a single inhaled treatment with a synergistic combination of Toll-like receptor 2/6 (TLR 2/6) and TLR9 agonists (Pam2-ODN) induces protective mucosal defenses in mice against a broad range of pathogens. As Pam2-ODN-induced protection persists despite depletion of several leukocyte populations, we tested whether it could prevent pneumonia in a mouse model of acute myeloid leukemia (AML) remission induction therapy. Pam2-ODN prevented death due to pneumonia caused by Pseudomonas aeruginosa, Streptococcus pneumoniae, and Aspergillus fumigatus when mice were heavily engrafted with leukemia cells, had severe chemotherapy-induced neutropenia or both. Pam2-ODN also extended survival of pneumonia in NSG mice engrafted with primary human AML cells. Protection was associated with rapid pathogen killing in the lungs at the time of infection and with reduced pathogen burdens at distant sites at the end of observation. Pathogen killing was inducible directly from isolated lung epithelial cells and was not abrogated by the presence of leukemia cells or cytotoxic agents. Pam2-ODN had no discernible effect on replication rate, total tumor population, or killing by chemotherapy of mouse or human leukemia cells, either in vitro or in vivo. Taken together, we report that therapeutic stimulation of lung epithelial defenses robustly protects against otherwise lethal pneumonias despite the profound immune dysfunction associated with acute leukemia and its treatment. These findings may suggest an opportunity to protect this population during periods of peak vulnerability.