Bronchoalveolar lavage and lung biopsy in patients with cancer and hematopoietic stem-cell transplantation recipients: a systematic review and meta-analysis

Invasive fungal disease and antifungal prophylaxis in children with acute leukaemia: a multicentre retrospective Australian cohort study

Background

Invasive fungal disease (IFD) is a significant complication for children receiving treatment for leukaemia, contributing to morbidity and mortality. Recent regional paediatric epidemiological IFD data are lacking. Additionally uncertainty remains regarding the optimal prophylactic approach in this context.

Methods

In a multi-centre Australian cohort study of children diagnosed with de novo acute leukaemia between 1st January 2017 and 30th June 2020, we characterised antifungal prophylaxis prescribing and IFD prevalence. Impact of antifungal prophylaxis was assessed using Kaplan Meier curves and Cox-proportional hazards regression adjusting for known IFD risk factors.

Findings

A total of 434 children were included (47.2% female; median age 5.0 years, median follow-up 240 days). This cohort included 351 children with ALL (214 high-risk [HR-ALL]; 137 standard-risk [SR-ALL]), and 73 with AML. The prevalence of proven/probable IFD was 6.8% for AML, 14.0% for HR-ALL and 4.4% for SR-ALL. A mould was implicated as the causative pathogen in almost two thirds of cases. Antifungal prophylaxis was prescribed in 98.7% of chemotherapy cycles for AML, 56.7% for HR-ALL and 14.9% for SR-ALL. A mould-active agent was used in 77.4% of AML cycles and 21.2% of HR-ALL cycles. Mould-active prophylaxis was associated with a lower risk of IFD overall and increased IFD-free survival in AML.

Interpretation

These data demonstrate the persistent high regional burden of IFD in children with HR-ALL, and the potential for mould-active prophylaxis to ameliorate this. Strategies to increase uptake of appropriate prophylaxis are required in this cohort.

Funding

This study was supported by a Perth Children's Hospital Foundation grant (PCHF9973).

Cost-Effectiveness of Plasma Microbial Cell-Free DNA Sequencing When Added to Usual Care Diagnostic Testing for Immunocompromised Host Pneumonia

INTRODUCTION

Immunocompromised host pneumonia (ICHP) is an important cause of morbidity and mortality, yet usual care (UC) diagnostic tests often fail to identify an infectious etiology. A US-based, multicenter study (PICKUP) among ICHP patients with hematological malignancies, including hematological cell transplant recipients, showed that plasma microbial cell-free DNA (mcfDNA) sequencing provided significant additive diagnostic value.

AIM

The objective of this study was to perform a cost-effectiveness analysis (CEA) of adding mcfDNA sequencing to UC diagnostic testing for hospitalized ICHP patients.

METHODS

A semi-Markov model was utilized from the US third-party payer's perspective such that only direct costs were included, using a lifetime time horizon with discount rates of 3% for costs and benefits. Three comparators were considered: (1) All UC, which included non-invasive (NI) and invasive testing and early bronchoscopy; (2) All UC & mcfDNA; and (3) NI UC & mcfDNA & conditional UC Bronch (later bronchoscopy if the initial tests are negative). The model considered whether a probable causative infectious etiology was identified and if the patient received appropriate antimicrobial treatment through expert adjudication, and if the patient died in-hospital. The primary endpoints were total costs, life-years (LYs), equal value life-years (evLYs), quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio per QALY. Extensive scenario and probabilistic sensitivity analyses (PSA) were conducted.

RESULTS

At a price of $2000 (2023 USD) for the plasma mcfDNA, All UC & mcfDNA was more costly ($165,247 vs $153,642) but more effective (13.39 vs 12.47 LYs gained; 10.20 vs 9.42 evLYs gained; 10.11 vs 9.42 QALYs gained) compared to All UC alone, giving a cost/QALY of $16,761. NI UC & mcfDNA & conditional UC Bronch was also more costly ($162,655 vs $153,642) and more effective (13.19 vs 12.47 LYs gained; 9.96 vs 9.42 evLYs gained; 9.96 vs 9.42 QALYs gained) compared to All UC alone, with a cost/QALY of $16,729. The PSA showed that above a willingness-to-pay threshold of $50,000/QALY, All UC & mcfDNA was the preferred scenario on cost-effectiveness grounds (as it provides the most QALYs gained). Further scenario analyses found that All UC & mcfDNA always improved patient outcomes but was not cost saving, even when the price of mcfDNA was set to $0.

CONCLUSIONS

Based on the evidence available at the time of this analysis, this CEA suggests that mcfDNA may be cost-effective when added to All UC, as well as in a scenario using conditional bronchoscopy when NI testing fails to identify a probable infectious etiology for ICHP. Adding mcfDNA testing to UC diagnostic testing should allow more patients to receive appropriate therapy earlier and improve patient outcomes.

Detection of Bronchiolitis Obliterans Syndrome after Pediatric Hematopoietic Stem Cell Transplantation: An Official American Thoracic Society Clinical Practice Guideline

Background: Many children undergo allogeneic hematopoietic stem cell transplantation (HSCT) for the treatment of malignant and nonmalignant conditions. Unfortunately, pulmonary complications occur frequently post-HSCT, with bronchiolitis obliterans syndrome (BOS) being the most common noninfectious pulmonary complication. Current international guidelines contain conflicting recommendations regarding post-HSCT surveillance for BOS, and a recent NIH workshop highlighted the need for a standardized approach to post-HSCT monitoring. As such, this guideline provides an evidence-based approach to detection of post-HSCT BOS in children. Methods: A multinational, multidisciplinary panel of experts identified six questions regarding surveillance for, and evaluation of, post-HSCT BOS in children. A systematic review of the literature was undertaken to answer each question. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations addressing the role of screening pulmonary function testing and diagnostic tests in children with suspected post-HSCT BOS were made. Following a Delphi process, new diagnostic criteria for pediatric post-HSCT BOS were also proposed. Conclusions: This document provides an evidence-based approach to the detection of post-HSCT BOS in children while also highlighting considerations for the implementation of each recommendation. Further, the document describes important areas for future research.

Infectious complications in the paediatric immunocompromised host: a narrative review

BACKGROUND

Infections are a major cause of morbidity in children with primary or secondary immunodeficiency, and have a negative impact on overall outcome.

OBJECTIVES

This narrative review presents select paediatric-specific aspects regarding the clinical impact, diagnosis, management, and follow-up of infectious complications in patients with primary and secondary immunodeficiencies.

SOURCES

PubMed until January 2024 and searched references in identified articles including the search terms: infection, immunodeficiency or cancer, diagnostics, antimicrobial agents, bacteria or fungus or virus, and follow-up.

CONTENT

Major advances have been made in the early detection and management of patients with primary immunodeficiency, and multiple analyses report in children with cancer on risk groups and periods of risk for infectious complications. Although many diagnostic tools are comparable between children and adults, specific considerations have to be applied, such as minimizing the use of radiation. Antimicrobial drug development remains a major challenge in the paediatric setting, which includes the establishment of appropriate dosing and paediatric approval. Last, long-term follow-up and the impact of late effects are extremely important to be considered in the management of immunocompromised paediatric patients.

IMPLICATIONS

Although infectious disease supportive care of immunocompromised children and adolescents has considerably improved over the last three decades, close international collaboration is needed to target the specific challenges in this special population.

Plasma Microbial Cell-Free DNA Sequencing in Immunocompromised Patients With Pneumonia: A Prospective Observational Study

BACKGROUND

Pneumonia is a common cause of morbidity and mortality, yet a causative pathogen is identified in a minority of cases. Plasma microbial cell-free DNA sequencing may improve diagnostic yield in immunocompromised patients with pneumonia.

METHODS

In this prospective, multicenter, observational study of immunocompromised adults undergoing bronchoscopy to establish a pneumonia etiology, plasma microbial cell-free DNA sequencing was compared to standardized usual care testing. Pneumonia etiology was adjudicated by a blinded independent committee. The primary outcome, additive diagnostic value, was assessed in the Per Protocol population (patients with complete testing results and no major protocol deviations) and defined as the percent of patients with an etiology of pneumonia exclusively identified by plasma microbial cell-free DNA sequencing. Clinical additive diagnostic value was assessed in the Per Protocol subgroup with negative usual care testing.

RESULTS

Of 257 patients, 173 met Per Protocol criteria. A pneumonia etiology was identified by usual care in 52/173 (30.1%), plasma microbial cell-free DNA sequencing in 49/173 (28.3%) and the combination of both in 73/173 (42.2%) patients. Plasma microbial cell-free DNA sequencing exclusively identified an etiology of pneumonia in 21/173 patients (additive diagnostic value 12.1%, 95% confidence interval [CI], 7.7% to 18.0%, P < .001). In the Per Protocol subgroup with negative usual care testing, plasma microbial cell-free DNA sequencing identified a pneumonia etiology in 21/121 patients (clinical additive diagnostic value 17.4%, 95% CI, 11.1% to 25.3%).

CONCLUSIONS

Non-invasive plasma microbial cell-free DNA sequencing significantly increased diagnostic yield in immunocompromised patients with pneumonia undergoing bronchoscopy and extensive microbiologic and molecular testing.

CLINICAL TRIALS REGISTRATION

NCT04047719.

Application of metagenomic next-generation sequencing in the clinical diagnosis of infectious diseases after allo-HSCT: a single-center analysis

BACKGROUND

We investigated the value of metagenomic next-generation sequencing (mNGS) in diagnosing infectious diseases in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

Fifty-four patients who had fever following allo-HSCT from October 2019 to February 2022 were enrolled. Conventional microbiological tests (CMTs) and mNGS, along with imaging and clinical manifestations, were used to diagnose infection following allo-HSCT. The clinical diagnostic value of mNGS was evaluated.

RESULTS

A total of 61 mNGS tests were performed, resulting in the diagnosis of 46 cases of infectious diseases. Among these cases, there were 22 cases of viral infection, 13 cases of fungal infection, and 11 cases of bacterial infection. Moreover, 27 cases (58.7%) were classified as bloodstream infections, 15 (32.6%) as respiratory infections, 2 (4.3%) as digestive system infections, and 2 (4.3%) as central nervous system infections. Additionally, there were 8 cases with non-infectious diseases (8/54, 14.81%), including 2 cases of interstitial pneumonia, 2 cases of bronchiolitis obliterans, 2 cases of engraftment syndrome, and 2 cases of acute graft-versus-host disease. The positive detection rates of mNGS and CMT were 88.9% and 33.3%, respectively, with significant differences (P < 0.001). The sensitivity of mNGS was 97.82%, the specificity was 25%, the positive predictive value was 93.75%, and the negative predictive value was 50%. Following treatment, 51 patients showed improvement, and 3 cases succumbed to multidrug-resistant bacterial infections.

CONCLUSIONS

mNGS plays an important role in the early clinical diagnosis of infectious diseases after allo-HSCT, which is not affected by immunosuppression status, empiric antibiotic therapy, and multi-microbial mixed infection.

A comprehensive assessment of the prolonged febrile neutropenia evaluation in pediatric oncology patients

BACKGROUND

Pediatric oncology patients with prolonged (≥96 hours) febrile neutropenia (absolute neutrophil count < 500/μL) often undergo an evaluation for invasive fungal disease (IFD) and other infections. Current literature suggests that beta-D-glucan (BDG), galactomannan, bronchoalveolar lavage (BAL), and computed tomography (CT) scans (sinus, chest, and abdomen/pelvis) may help determine a diagnosis in this population.

METHODS

In a retrospective cohort study of all cancer/stem cell transplant patients (diagnosed 2005-2019) from one pediatric hospital, all episodes with prolonged febrile neutropenia or IFD evaluations (defined as sending a fungal biomarker or performing a CT scan to assess for infection) were identified.

RESULTS

In total, 503 episodes met inclusion criteria and 64% underwent IFD evaluations. In total, 36.4% of episodes documented an infection after initiation of prolonged febrile evaluation, most commonly Clostridioides difficile colitis (6.4%) followed by a true bacterial bloodstream infection (BSI) (5.2%), proven/probable IFD (4.8%), and positive respiratory pathogen panel (3.6%). There was no difference in sinus CTs showing sinusitis (74% vs 63%, p = 0.46), whereas 32% of abdomen/pelvis CTs led to a non-IFD diagnosis, and 25% of chest CTs showed possible pneumonia. On chest CT, the positive predictive value (PPV) for IFD was 19% for nodules and 14% for tree and bud lesions. BDG had a PPV of 25% for IFD and GM 50%. BAL diagnosed IFD once and pneumocystis jirovecii pneumonia twice.

CONCLUSIONS

Chest CTs and abdomen/pelvis CTs provide clinically relevant information during the prolonged febrile neutropenia evaluation, whereas BDG, galactomannan, BAL, and sinus CTs have less certain utility.

HHV-6B detection and host gene expression implicate HHV-6B as pulmonary pathogen after hematopoietic cell transplant

Limited understanding of the immunopathogenesis of human herpesvirus 6B (HHV-6B) has prevented its acceptance as a pulmonary pathogen after hematopoietic cell transplant (HCT). In this prospective multicenter study of patients undergoing bronchoalveolar lavage (BAL) for pneumonia after allogeneic HCT, we test blood and BAL fluid (BALF) for HHV-6B DNA and mRNA transcripts associated with lytic infection and perform RNA-seq on paired blood. Among 116 participants, HHV-6B DNA is detected in 37% of BALs, 49% of which also have HHV-6B mRNA detection. We establish HHV-6B DNA viral load thresholds in BALF that are highly predictive of HHV-6B mRNA detection and associated with increased risk for overall mortality and death from respiratory failure. Participants with HHV-6B DNA in BALF exhibit distinct host gene expression signatures, notable for enriched interferon signaling pathways in participants clinically diagnosed with idiopathic pneumonia. These data implicate HHV-6B as a pulmonary pathogen after allogeneic HCT.

The Challenge of Diagnosing Invasive Pulmonary Aspergillosis in Children: A Review of Existing and Emerging Tools

Invasive pulmonary aspergillosis remains a major cause of morbidity and mortality for immunocompromised children, particularly for patients with acute leukaemia and those undergoing haematopoietic stem cell transplantation. Timely diagnosis, using a combination of computed tomography (CT) imaging and microbiological testing, is key to improve prognosis, yet there are inherent challenges in this process. For CT imaging, changes in children are generally less specific than those reported in adults and recent data are limited. Respiratory sampling by either bronchoalveolar lavage or lung biopsy is recommended but is not always feasible in children, and serum biomarkers, including galactomannan, have important limitations. In this review we summarise the current paediatric data on available diagnostic tests for IPA and highlight key emerging diagnostic modalities with potential for future use.

Changes in the epidemiology of invasive fungal disease in a Pediatric Hematology and Oncology Unit: the relevance of breakthrough infections

BACKGROUND

Invasive fungal disease (IFD) is a significant cause of morbimortality in children under chemotherapy or hematopoietic stem cell transplant (HSCT). The purpose of this study is to describe the changes in the IFD epidemiology that occurred in a Pediatric Hematology-Oncology Unit (PHOU) with an increasing activity over time.

METHODS

Retrospective revision of the medical records of children (from 6 months to 18 years old) diagnosed with IFD in the PHOU of a tertiary hospital in Madrid (Spain), between 2006 and 2019. IFD definitions were performed according to the EORTC revised criteria. Prevalence, epidemiological, diagnostic and therapeutic parameters were described. Comparative analyses were conducted using Chi-square, Mann-Whitney and Kruskal-Wallis tests, according to three time periods, the type of infection (yeast vs mold infections) and the outcome.

RESULTS

Twenty-eight episodes of IFD occurred in 27 out of 471 children at risk (50% males; median age of 9.8 years old, [IQR 4.9-15.1]), resulting in an overall global prevalence of 5.9%. Five episodes of candidemia and 23 bronchopulmonary mold diseases were registered. Six (21.4%), eight (28.6%) and 14 (50%) episodes met criteria for proven, probable and possible IFD, respectively. 71.4% of patients had a breakthrough infection, 28.6% required intensive care and 21.4% died during treatment. Over time, bronchopulmonary mold infections and breakthrough IFD increased (p=0.002 and p=0.012, respectively), occurring in children with more IFD host factors (p=0.028) and high-risk underlying disorders (p=0.012). A 64% increase in the number of admissions in the PHOU (p<0.001) and a 277% increase in the number of HSCT (p=0.008) were not followed by rising rates of mortality or IFD/1000 admissions (p=0.674).

CONCLUSIONS

In this study, we found that yeast infections decreased, while mold infections increased over time, being most of them breakthrough infections. These changes are probably related to the rising activity in our PHOU and an increase in the complexity of the baseline pathologies of patients. Fortunately, these facts were not followed by an increase in IFD prevalence or mortality rates.

Prospective Evaluation of the Fungitell® (1→3) Beta-D-Glucan Assay as a Diagnostic Tool for Invasive Fungal Disease in Pediatric Allogeneic Hematopoietic Cell Transplantation: A Report from the Children's Oncology Group

BACKGROUND

Invasive fungal disease (IFD) is a major source of morbidity and mortality for hematopoietic cell transplant (HCT) recipients. Non-invasive biomarkers, such as the beta-D-glucan assay, may improve the diagnosis of IFD. The objective was to define the utility of surveillance testing using Fungitell® beta-D-glucan (BDG) assay in children receiving antifungal prophylaxis in the immediate post-HCT period.

METHODS

Weekly surveillance blood testing with the Fungitell® BDG assay was performed during the early post-HCT period in the context of a randomized trial of children, adolescents, and young adults undergoing allogeneic HCT allocated to triazole or caspofungin prophylaxis. Positivity was defined at the manufacturer cutoff of 80 pg/ml. IFD was adjudicated using blinded central reviewers. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the Fungitell® BDG assay for the outcome of proven or probable IFD.

RESULTS

A total of 51 patients (out of 290 patients in the parent trial) contributed blood specimens. In total, 278 specimens were evaluated. Specificity was 80.8% (95% confidence interval [CI]: 75.6%-85.3%), and NPV was over 99% (95% CI: 86.8%-99.9%). However, there were no true positive results, resulting in sensitivity of 0% (95% CI: 0.0%-84.2%) and PPV of 0% (95% CI: 0.0%-6.7%).

CONCLUSIONS

Fungitell® BDG screening is of limited utility in diagnosing IFD in the post-HCT period, mainly due to high false-positive rates. Fungitell® BDG surveillance testing should not be performed in children during the early post-HCT period while receiving antifungal prophylaxis as the pretest probability for IFD is low.

Double Infection in a Patient with Chronic GVHD Post Allogeneic Transplant: “Hickam's Dictum” Trumps “Occam's Razor”!—A Case Report with Review of Literature

Double pneumonia with Pneumocystis jirovecii (PCP) and Mycobacterium tuberculosis (MTB) has been reported in patients with acquired immune deficiency syndrome. A similar immune-suppressed state exists in allogeneic transplant survivors treated for graft-versus-host disease (GVHD). The clinical features and imaging findings could be quite similar in both the etiologies. Reaching a timely diagnosis and initiation of appropriate therapy is essential to prevent complications. We report a patient who had concurrent PCP and MTB pneumonia while on treatment for chronic GVHD. We describe the diagnostic challenge, the treatment, and outcome of this patient. We intend to sensitize physicians to consider more than one etiology in this subset of patients.

Metagenomic Next-Generation Sequencing Successfully Detects Pulmonary Infectious Pathogens in Children With Hematologic Malignancy

Background

Pulmonary infection is a leading cause of mortality in pediatric patients with hematologic malignancy (HM). In clinical settings, pulmonary pathogens are frequently undetectable, and empiric therapies may be costly, ineffective and lead to poor outcomes in this vulnerable population. Metagenomic next-generation sequencing (mNGS) enhances pathogen detection, but data on its application in pediatric patients with HM and pulmonary infections are scarce.

Methods

We retrospectively reviewed 55 pediatric patients with HM and pulmonary infection who were performed mNGS on bronchoalveolar lavage fluid from January 2020 to October 2021. The performances of mNGS methods and conventional microbiological methods in pathogenic diagnosis and subsequently antibiotic adjustment were investigated.

Results

A definite or probable microbial etiology of pulmonary infection was established for 50 of the 55 patients (90.9%) when mNGS was combined with conventional microbiological tests. The positive rate was 87.3% (48 of 55 patients) for mNGS versus 34.5% (19 of 55 patients) with conventional microbiological methods (P < 0.001). Bacteria, viruses and fungi were detected in 17/55 (30.9%), 25/55 (45.5%) and 19/55 (34.5%) cases using mNGS, respectively. Furthermore, 17 patients (30.9%) were identified as pulmonary mixed infections. Among the 50 pathogen-positive cases, 38% (19/50) were not completely pathogen-covered by empirical antibiotics and all of them were accordingly made an antibiotic adjustment. In the present study, the 30-day mortality rate was 7.3%.

Conclusion

mNGS is a valuable diagnostic tool to determine the etiology and appropriate treatment in pediatric patients with HM and pulmonary infection. In these vulnerable children with HM, pulmonary infections are life-threatening, so we recommend that mNGS should be considered as a front-line diagnostic test.

A Systematic Review on Pulmonary Complications Secondary to Hematopoietic Stem Cell Transplantation

The main purpose of this systematic review was to identify and synthesize evidence about pulmonary complications following stem cell transplantation to raise awareness among physicians since it is a lesser-known topic. Studies that included targeted pulmonary complications that occurred after stem cell transplantation; in humans; and were randomized controlled trials, cohort studies, and case studies between January 2011 and 2021. Fifteen intervention features were identified and analyzed in terms of their association with successful or unsuccessful interventions. Fifteen of 15 studies that met inclusion criteria had positive results. Features that appeared to have the most consistent positive effects included relevant information consisting of clinical presentations and management of complications. 

Hematopoietic stem cell transplantation is a therapeutic method that has been introduced for various hematological diseases. Its main objective is to restore the hematopoietic function that has been eradicated or affected. The stem cell transplantation requires a period of administration of chemotherapeutic agents that may lead to infectious and/or non-infectious pulmonary complications that require follow-up.

Noninfectious pulmonary complications include bronchiolitis obliterans, alveolar hemorrhage, fibroelastosis, pulmonary hypertension, and infections. Bronchiolitis obliterans syndrome is an obstructive lung disease that affects the small airways, reducing lung function, and it’s the most frequent late-onset complication. Furthermore, diffuse pulmonary hemorrhage is a fatal adverse effect and the most common noninfectious pulmonary complication of acute leukemia, observed within the first weeks after the procedure. Pulmonary hypertension has multiple etiologies, mainly related to the pulmonary veno-occlusive disease. It carries a poor prognosis, with a 55% mortality rate. The area of hematology is very wide and prone to new development of treatments and procedures that could be available for new emerging diseases and improving survival rates. 

Consolidative opacity in a patient with acute leukemia

27 year old man with newly diagnosed acute myeloid leukemia presents with new parenchymal consolidation. Although biopsy was precluded, diagnostic studies support myeloid sarcoma. Resolution of consolidation occurred with hematopoietic stem cell transplantation.

The place of the bronchoalveolar lavage in the diagnosis of interstitial lung disease: a descriptive and qualitative study

BACKGROUND

Interstitial lung disease represents a challenge and consists in more than 200 entities. Their diagnoses are assessed through a multidisciplinary approach including pulmonologists, radiologists, pathologists and biologists. BAL analysis is useful mainly when clinical and radiological findings aren't suggestive of an etiology. Even if, the indication of BAL is consensual, its real place as a diagnostic mean remains non consensual.

AIM

To describe the BAL findings and to analyse the perceptions of the pulmonologists, anaesthesiologists and pathologists implicated in the interpretation of the BAL data, that are related to the presentation and the validity of the results.

METHODS

the authors performed a descriptive study about BAL results during an 8-year-period (2010-2018) and a qualitative study assessing the pulmonologists, anaesthesiologists and pathologists' opinions concerning the different results performed in the same institution. Two questionnaires were conceived with participation of different experts and satisfaction scores were calculated.

RESULTS

2508 BAL were recorded including 1320 women (53%) and 1188 men (47%) with a sex-ratio (H/F) of 0,9. The mean age of the patients was 51 years. The mean response delay was 3.25 days. An accurate diagnosis was retained in 24.3%. It consisted in infection evoked in 13.89% cases. Eosinophilic pneumonia was evoked in 0.35% cases. 15.01% cases presented erythrophagocytosis with a golde score>100 favouring active alveolar haemorrhage with occult alveolar haemorrhage. Lipoproteinosis was diagnosed in 2 cases. Adenocarcinoma was retained in 1.04% cases and lymphoma in 0.16% cases. Langerhans cell histiocytosis was confirmed in 1.51% cases. In the other cases, cellular profile was not specific evoking tuberculosis or sarcoidosis in 316 cases with a CD4/CD8 ratio superior to 1,6 and the diagnoses of tuberculosis or hypersensitivity pneumonia in 202 cases with a CD4/CD8 ratio inferior to 1,2. Concerning the questionnaire-based study, 50 pulmonologists and anaesthesiologists attributed a mean score of 7.96/10 (DS=0.55) concerning the presentation of the results and 9.28/15 (DS=0.77) concerning the quality and validity of the results. On the other hand, the mean satisfaction score rated by pathologists reached 24/40.

CONCLUSION

BAL results could be helpful for the management of interstitial lung disease depending on the experience of pathologists and a good communication between pulmonologists, anaesthesiologists and pathologists.

Risk factors and prognosis of non-infectious pulmonary complications after allogeneic hematopoietic stem cell transplantation

Non-infectious pulmonary complications (NIPCs) following allogeneic hematopoietic stem cell transplantation (HSCT) are relatively rare, but frequently fatal. This study investigated the pre-transplant risk factors for developing NIPCs using Japanese transplant registry database entries from 2001 to 2009. Among 13,573 eligible patients, 535 experienced NIPCs (3.9%). Multivariate analysis identified high recipient age (60 + years: HR 1.85, P = 0.003), HLA mismatch (HR 1.61, P < 0.001), female to male HSCT (HR 1.54, P < 0.001), and unrelated bone marrow transplantation (UR-BMT) (HR 3.88, P < 0.001) as significantly associated with an increased risk of NIPCs. In contrast, a non-total body irradiation (TBI) regimen with reduced intensity conditioning (RIC) were associated with a decreased risk of NIPCs compared with a cyclophosphamide (CY) + TBI regimen (busulfan + CY: HR 0.67, P = 0.009, other non-TBI: HR 0.46, P < 0.001), fludarabine-based RIC (HR 0.52, P < 0.001), and other RIC (HR 0.42, P = 0.003). The mortality rate was significantly worse for patients with NIPCs than those without (HR 1.54, 71 P < 0.001). This large-scale retrospective study suggests that both allo-reactions to donor cells and conditioning regimen toxicity contributed to NIPCs following HSCT.

Noninfectious complications of hematopoietic cell transplantation

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.

Pulmonary Complications in Children Following Hematopoietic Cell Transplantation: A Case Report and Review of the Diagnostic Approach

Pulmonary complications are common in children following hematopoietic cell transplantation (HCT) and contribute to their morbidity and mortality. Early diagnosis is essential for management and prevention of progression of lung injury and damage. In many cases, diagnosis can be challenging and may require diagnostic imaging and more invasive testing such as bronchoscopy and lung biopsy. We report the case of a 12-year-old girl who developed recurrent episodes of acute respiratory failure requiring intensive care unit admission in the post-HCT phase and describe the diagnostic and multidisciplinary approach for her management. In addition, we review the diagnostic approach of pulmonary complications post-HCT and highlight the utility and risks of bronchoscopy and lung biopsy in these children.

Pulmonary Complications After Pediatric Stem Cell Transplant

The number of disorders that benefit from hematopoietic stem cell transplantation (HSCT) has increased, causing the overall number of HSCT to increase accordingly. Disorders treated by HSCT include malignancy, benign hematologic disorders, bone marrow failure syndromes, and certain genetic diagnoses. Thus, understanding the complications, diagnostic workup of complications, and subsequent treatments has become increasingly important. One such category of complications includes the pulmonary system. While the overall incidence of pulmonary complications has decreased, the morbidity and mortality of these complications remain high. Therefore, having a clear differential diagnosis and diagnostic workup is imperative. Pulmonary complications can be subdivided by time of onset and whether the complication is infectious or non-infectious. While most infectious complications have clear diagnostic criteria and treatment courses, the non-infectious complications are more varied and not always well understood. This review article discusses pulmonary complications of HSCT recipients and outlines current knowledge, gaps in knowledge, and current treatment of each complication. This article includes some adult studies, as there is a significant paucity of pediatric data.

Invasive fungal disease in children with acute myeloid leukaemia: An Australian multicentre 10-year review

BACKGROUND

Invasive fungal disease (IFD) is a common and important complication in children with acute myeloid leukaemia (AML). We describe the epidemiology of IFD in a large multicentre cohort of children with AML.

METHODS

As part of the retrospective multicentre cohort TERIFIC (The Epidemiology and Risk factors for Invasive Fungal Infections in immunocompromised Children) study, proven/probable/possible IFD episodes occurring in children with primary or relapsed/refractory AML from 2003 to 2014 were analysed. Crude IFD prevalence, clinical characteristics, microbiology and treatment were assessed. Kaplan-Meier survival analysis was used to estimate 6-month survival.

RESULTS

There were 66 IFD episodes diagnosed in 63 children with AML. The majority (75.8%) of episodes occurred in the context of primary AML therapy. During primary AML therapy, the overall prevalence was 20.7% (95% CI 15.7%-26.5%) for proven/probable/possible IFD and 10.3% (95% CI 6.7%-15.0%) for proven/probable IFD. Of primary AML patients, 8.2% had IFD diagnosed during the first cycle of chemotherapy. Amongst pathogens implicated in proven/probable IFD episodes, 74.4% were moulds, over a third (37.9%) of which were non-Aspergillus spp. Antifungal prophylaxis preceded 89.4% of IFD episodes, most commonly using fluconazole (50% of IFD episodes). All-cause mortality at 6 months from IFD diagnosis was 16.7% with IFD-related mortality of 7.6% (all in cases of proven IFD).

CONCLUSIONS

IFD is a common and serious complication during paediatric AML therapy. Mould infections, including non-Aspergillus spp. predominated in this cohort. A systematic approach to the identification of patients at risk, and a targeted prevention strategy for IFD is needed.

Metagenomic next-generation sequencing to identify pathogens and cancer in lung biopsy tissue

BACKGROUND

Lung biopsy tissue samples can be used for infection detection and cancer diagnosis. Metagenomic next-generation sequencing (mNGS) has the potential to further improve diagnosis.

METHODS

From July 2018 to May 2020, lung biopsy samples of 133 patients with suspected pulmonary infection or abnormal imaging findings were collected and subjected to clinical microbiological testing, Illumina and Nanopore sequencing to identify pathogens. The neural networks were pretrained by extracting features of human reads from 2,095 metagenomic next-generation sequencing results, and the human reads of lung biopsy samples were entered into the validated pipeline to predict the risk of cancer.

FINDINGS

Based on the pathogen-cancer detection pipeline, the Illumina platform showed 77·6% sensitivity and 97·6% specificity compared to the composite reference standard for infection diagnosis. However, the Nanopore platform showed 34·7% sensitivity and 98·7% specificity. mNGS identified more fungi, which was confirmed by subsequent pathological examination. M. tuberculosis complex was weakly detected. For cancer detection, compared with histology, the Illumina platform showed 83·7% sensitivity and 97·6% specificity, diagnosing an additional 36 cancer patients, of whom half had abnormal imaging findings (pulmonary shadow, space-occupying lesions, or nodules).

INTERPRETATION

For the first time, we have established a pipeline to simultaneously detect pathogens and cancer based on Illumina sequencing of lung biopsy tissue. This pipeline efficiently diagnosed cancer in patients with abnormal imaging findings.

FUNDING

This work was supported by the National Key Research and Development Program of China and National Natural Science Foundation of China.

Prospective Evaluation of Galactomannan and (1→3) β-d-Glucan Assays as Diagnostic Tools for Invasive Fungal Disease in Children, Adolescents, and Young Adults With Acute Myeloid Leukemia Receiving Fungal Prophylaxis

BACKGROUND

Patients receiving chemotherapy for acute myeloid leukemia (AML) are at high risk for invasive fungal disease (IFD). Diagnosis of IFD is challenging, leading to interest in fungal biomarkers. The objective was to define the utility of surveillance testing with Platelia Aspergillus galactomannan (GM) enzyme immunoassay (EIA) and Fungitell β-d-glucan (BDG) assay in children with AML receiving antifungal prophylaxis.

METHODS

Twice-weekly surveillance blood testing with GM EIA and BDG assay was performed during periods of neutropenia in the context of a randomized trial of children, adolescents, and young adults with AML allocated to fluconazole or caspofungin prophylaxis. Proven or probable IFD was adjudicated using blinded central reviewers. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for Platelia and Fungitell assays alone and in combination for the outcomes of proven and probable invasive aspergillosis (IA) or invasive candidiasis (IC).

RESULTS

Among 471 patients enrolled, 425 participants (209 fluconazole and 216 caspofungin) contributed ≥1 blood specimen. In total, 6103 specimens were evaluated, with a median of 15 specimens per patient (range 1-43). The NPV was >99% for GM EIA and BDG assay alone and in combination. However, there were no true positive results, resulting in sensitivity and PPV for each assay of 0%.

CONCLUSIONS

The GM EIA and the BDG assay alone or in combination were not successful at detecting IA or IC during periods of neutropenia in children, adolescents, and young adults with AML receiving antifungal prophylaxis. Utilization of these assays for surveillance in this clinical setting should be discouraged.

Safety and harms of bronchoalveolar lavage for acute respiratory failure: A systematic review and meta-analysis

BACKGROUND

This review aimed to investigate whether bronchoalveolar lavage (BAL) is safe in patients with severe acute respiratory failure (ARF).

METHODS

We searched the MEDLINE, CENTRAL, and other databases up to June 2, 2021 for studies that examined BAL for severe ARF. We included all cohort studies and randomized or non-randomized trials, while we excluded case-control studies, case reports, and case series. We evaluated the quality of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

We included 17 studies (1085 patients) in the meta-analysis. The integrated frequency of death was 0.000% (95% confidence interval [CI]: 0.000-0.045%, I² = 0.0%). The pooled risk of severe complications of respiratory system, cardiovascular system, and major bleeding was 1.32% (95% CI: 0.000-4.41%, I² = 84.8%), 0.040% (95% CI: 0.000-0.71%, I² = 9.3%), and 0.000% (95% CI: 0.000-0.27%, I² = 0.0%), respectively. In the subgroup analysis with mechanical ventilation during BAL, there were few severe complications of the respiratory system (3/717 patients in 13 studies) and almost no heterogeneity (I² = 0.0%).

CONCLUSIONS

Our study suggests that severe complications of BAL for severe ARF are probably rare, particularly in patients receiving mechanical ventilation. After considering the risks and benefits, it would be worthwhile to consider performing BAL in patients with severe ARF of unknown etiology to pursue its cause.

TRIAL REGISTRATION

The protocol was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000040600).

Pulmonary Complications of Pediatric Hematopoietic Cell Transplantation. A National Institutes of Health Workshop Summary

Approximately 2,500 pediatric hematopoietic cell transplants (HCTs), most of which are allogeneic, are performed annually in the United States for life-threatening malignant and nonmalignant conditions. Although HCT is undertaken with curative intent, post-HCT complications limit successful outcomes, with pulmonary dysfunction representing the leading cause of nonrelapse mortality. To better understand, predict, prevent, and/or treat pulmonary complications after HCT, a multidisciplinary group of 33 experts met in a 2-day National Institutes of Health Workshop to identify knowledge gaps and research strategies most likely to improve outcomes. This summary of Workshop deliberations outlines the consensus focus areas for future research.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

Imaging features of fungal pneumonia in haematopoietic stem cell transplant patients

Patients who have received haematopoietic stem cell transplantation (HSCT) have a high rate of pulmonary complications, and in this immunosuppressed population, fungal pneumonia is of great concern. Fungal pneumonia can have a similar appearance to non-infectious pulmonary processes in HSCT patients, and radiologists should be familiar with the subtle features that may help to differentiate these disease entities. The focus of this article is on the diagnosis of fungal pneumonia in HSCT patients with an emphasis on radiologists’ roles in establishing the diagnosis of fungal pneumonia and the guidance of clinical management.

Pediatric Airway Endoscopy: Recommendations of the Society for Pediatric Pneumology

For many decades, pediatric bronchoscopy has been an integral part of the diagnosis and treatment of acute and chronic pulmonary diseases in children. Rapid technical advances have continuously influenced the performance of the procedure. Over the years, the application of pediatric bronchoscopy has considerably expanded to a broad range of indications. In this comprehensive and up-to-date guideline, the Special Interest Group of the Society for Pediatric Pneumology reviewed the most recent literature on pediatric bronchoscopy and reached a consensus on a safe technical performance of the procedure.

Utility of Transbronchial Biopsy in the Immunocompromised Host With New Pulmonary Radiographic Abnormalities

OBJECTIVE

To assess how often transbronchial biopsy (TBBx) added unique positive findings apart from other synchronous bronchoscopic sampling techniques including the bronchoalveolar lavage-immunocompromised host (BAL-ICH) panel that justified changes in management in an array of immunocompromised patients with new pulmonary radiographic abnormalities.

METHODS

We retrospectively reviewed all bronchoscopies performed at Mayo Clinic Rochester between January 2012 and December 2017; on the basis of the physician's selection of a BAL-ICH panel, we identified 192 immunocompromised patients who underwent bronchoscopy with both a BAL-ICH panel and TBBx. The results of the BAL-ICH panel and TBBx were compared and subsequent management decisions analyzed from clinical notes. We identified changes in immunosuppressive agents, antibiotics, chemotherapy, goals of care, and decisions on further evaluation and procedures. We assessed whether the TBBx findings added information not identified on the BAL-ICH panel and other bronchoscopic sampling methods performed during the same procedure that justified subsequent management changes.

RESULTS

Of 192 bronchoscopic procedures performed on immunocompromised patients with acute and subacute pulmonary radiographic abnormalities, management changes justified by the unique positive results of the TBBx occurred 28% (51/192) of the time. Those immunocompromised by solid malignant neoplasms and receiving active immunosuppressive therapy had management changes justified 62.1% (18/29) of the time by the TBBx results. No additional fungal organisms were identified on TBBx that were accounted for on the BAL-ICH panel.

CONCLUSION

Transbronchial biopsy may add information to other bronchoscopic findings in immunocompromised patients, especially those with solid malignant neoplasms receiving active immunosuppressive treatment. These potential benefits must be weighed against the risks inherent to the procedure.

Comparing cytomegalovirus diagnostics by cell culture and quantitative nucleic acid testing in broncho-alveolar lavage fluids

Many clinical laboratories have replaced virus isolation in cell-culture (VIC) for cytomegalovirus (CMV) by quantitative-nucleic-acid testing (QNAT), rendering clinically relevant CMV-replication difficult to distinguish from CMV-shedding or latent infection. We compared direct VIC in 1109 consecutive bronchoalveolar lavage fluids (BALFs) and a well-validated CMV-QNAT (Basel-CMV-UL111a-77bp). In the retrospective Group 1 (N = 694) and Group 2 (N = 303), CMV-QNAT was performed within 48 h from 2-fold and 10-fold concentrated total nucleic acid (TNA) eluates, respectively. In Group 3 (N = 112), 2-fold and 10-fold concentrated TNA eluates were prospectively analyzed in parallel to VIC. CMV was detected by VIC in 79 of 694 (11%) and 26 of 303 (9%) of Groups 1 and 2, but in 114 of 694 (16%) and 57 of 303 (17%) by CMV-QNAT, respectively. Median CMV loads were significantly higher in VIC-positive than in VIC-negative BALF. The likelihood for CMV detection by VIC was 85% for BALF CMV- loads >4 log10 copies/ml. In the prospective Group 3, CMV was detected by VIC in 10 of 112 (9%), and in 14 of 112 (13%) and 20 of 112 (18%) by CMV-QNAT, when using 2-fold and 10-fold concentrated TNA eluates, respectively. Notably, CMV was undetectable by CMV-QNAT in 10 VIC-positive cases of Groups 1 and 2, but in none of Group 3. We conclude that CMV-QNAT can be adopted to BALF diagnostics but requires several careful steps in validation. CMV-QNAT loads >10 000 copies/ml in BALF may indicate significant CMV replication as defined by VIC, if short shipment and processing procedures can be guaranteed. Discordance of detecting CMV in time-matched plasma samples emphasises the role of local pulmonary CMV replication, for which histopathology remains the gold standard of proven CMV pneumonia.

The use of transbronchial cryobiopsy for diffuse parenchymal lung disease in critically ill patients with acute hypoxemic respiratory failure-A case series

OBJECTIVES

Accurate diagnosis and management of undifferentiated diffuse parenchymal lung disease (DPLD) in critically ill patients is challenging. Transbronchial forceps biopsies have limited utility and surgical lung biopsies can be detrimental for critically ill patients. Transbronchial cryobiopsy (TBC) has shown increased diagnostic yield compared to conventional forceps biopsy in DPLD. However, TBC has not been studied in intensive care unit (ICU) patients. In this case series, we describe our experience with TBC for diagnosis of DPLD in ICU patients with acute hypoxemic respiratory failure.

METHODS

This case series includes critically ill patients who underwent TBC at two different tertiary care hospitals. Procedures were performed by the same interventional pulmonologist using the two therapeutic bronchoscopes with a 2.8-mm working channel, and a 1.9- or 2.4-mm cryoprobe.

RESULTS

We performed TBC in 17 patients of which 12 (70.1%) were performed at bedside in ICU without fluoroscopic guidance. Pathological diagnosis was made in 15 (88%) patients which resulted in changes in management in most of these patients. Six patients (35.3%) developed pneumothorax post-procedure with 5 (29.4%) requiring a chest tube. Moderate bleeding was noted in one (6%) patient and no severe or fatal bleeding occurred. Our 30-day ICU mortality was 47% (n = 8); however, no deaths were directly attributable to the procedure.

CONCLUSIONS

TBC is a feasible technique with an acceptable complication rate and a fairly high histopathological yield in ICU patients with DPLD and acute hypoxemic respiratory failure. Appropriate diagnosis can be crucial in making management decisions for these patients.

Inflammatory Lesions Mimicking Chest Malignancy: CT, Bronchoscopy, EBUS, and PET Evaluation From an Oncology Referral Center

Infective and inflammatory diseases can mimic malignancy of the lung. Granulomatous inflammations are common causes of pulmonary nodule, mass, or nodal disease. Systemic infection or inflammation also commonly involves the lung that may raise suspicion of a malignant process. Even in patients with a known malignancy, inflammatory diseases can simulate new metastasis or disease progression. Knowledge of the imaging features of these diseases is essential to prevent missed or overdiagnosis of malignancy. Radiologists also need to be familiar with the scope and limitations of bronchoscopy, endobronchial ultrasound, PET-CT, and biopsy to guide clinical management. In this review, we discuss the imaging features and diagnostic approach of common mimickers of chest malignancy that involve the chest wall, pleura, lung parenchyma, and mediastinal nodes.

How We Treat Fever and Hypotension in Pediatric Hematopoietic Cell Transplant Patients

Pediatric allogeneic hematopoietic cell transplant (HCT) survival is limited by the development of post-transplant infections. In this overview, we discuss a clinical approach to the prompt recognition and treatment of fever and hypotension in pediatric HCT patients. Special attention is paid to individualized hemodynamic resuscitation, thorough diagnostic testing, novel anti-pathogen therapies, and the multimodal support required for recovery. We present three case vignettes that illustrate the complexities of post-HCT sepsis and highlight best practices that contribute to optimal transplant survival in children.

[The place of bronchoalveolar lavage in the diagnosis of pneumonia in the immunocompromised patient]

INTRODUCTION

Bronchoalveolar lavage (BAL) was previously considered as the standard diagnostic procedure to investigate pneumonia occurring in immunocompromised patients, and it is probably still widely used. However, the development of new microbiological diagnostic tools, applicable to samples obtained non-invasively, leads to questioning of the predominant place of BAL in this situation.

BACKGROUND

The available studies agree on the acceptable tolerance of BAL performed in immunocompromised patients. Although imperfect, the diagnostic yield of BAL in immunocompromised patients is well established, but it may vary between studies depending on the underlying disease. However, it must also be compared to the yield of non-invasive microbiological tools, now widely available and effective. The position of BAL remains important both for the diagnosis of fungal infections (invasive aspergillosis, pneumocystis pneumonia) and non-infectious lung diseases both of which occur frequently in immunocompromised patients.

CONCLUSION

The place of BAL in the diagnostic work-up of pneumonia occurring in immunocompromised patients must be considered in the framework of a structured consideration, taking into account the diagnostic performance of non invasive microbiological tests and the broad spectrum of lung diseases occurring in this context.

Pulmonary Infectious Complications in Children with Hematologic Malignancies and Chemotherapy-Induced Neutropenia

Infections frequently complicate the treatment course in children with hematologic malignancies undergoing chemotherapy. Febrile neutropenia (FN) remains a major cause of hospital admissions in this population, and respiratory tract is often proven to be the site of infection even without respiratory signs and symptoms. Clinical presentation may be subtle due to impaired inflammatory response. Common respiratory viruses and bacteria are widely identified in these patients, while fungi and, less commonly, bacteria are the causative agents in more severe cases. A detailed history, thorough clinical and basic laboratory examination along with a chest radiograph are the first steps in the evaluation of a child presenting signs of a pulmonary infection. After stratifying patient’s risk, prompt initiation of the appropriate empirical antimicrobial treatment is crucial and efficient for the majority of the patients. High-risk children should be treated with an intravenous antipseudomonal beta lactam agent, unless there is suspicion of multi-drug resistance when an antibiotic combination should be used. In unresponsive cases, more invasive procedures, including bronchoalveolar lavage (BAL), computed tomography (CT)-guided fine-needle aspiration or open lung biopsy (OLB), are recommended. Overall mortality rate can reach 20% with higher rates seen in cases unresponsive to initial therapy and those under mechanical ventilation.

Noninfectious pulmonary complications of haematopoietic stem cell transplantation

Haematopoietic stem cell transplantation (HSCT) is an established treatment for a variety of malignant and nonmalignant conditions. Pulmonary complications, both infectious and noninfectious, are a major cause of morbidity and mortality in patients who undergo HSCT. Recent advances in prophylaxis and treatment of infectious complications has increased the significance of noninfectious pulmonary conditions. Acute lung injury associated with idiopathic pneumonia syndrome remains a major acute complication with high morbidity and mortality. On the other hand, bronchiolitis obliterans syndrome is the most challenging chronic pulmonary complication facing clinicians who are taking care of allogeneic HSCT recipients. Other noninfectious pulmonary complications following HSCT are less frequent. This review provides a clinical update of the incidence, risk factors, pathogenesis, clinical characteristics and management of the main noninfectious pulmonary complications following HSCT.

Clinical Usefulness of Bronchoalveolar Lavage in the Management of Pulmonary Infiltrates in Adults with Hematological Malignancies and Stem Cell Transplantation

Introduction

Pulmonary complications are frequent in patients with hematologic malignancies and stem cell transplantation. Regardless of the microbiological usefulness of bronchoalveolar lavage (BAL), little information exists on both its benefits as a guide for therapeutic decisions and its impact on patients’ clinical outcome.

Methods

A prospective observational single-center study was performed between July 2011 and July 2016. Consecutive episodes of pulmonary infiltrates were analyzed in subjects over 18 years of age who presented hematologic malignancies and underwent chemotherapy or stem cell transplantation.

Results

Ninety-six episodes of pulmonary infiltrates were analyzed. Acute leukemia was the most frequent underlying condition. Thirty-seven patients (38.5%) received a stem cell transplant. Sixty-one (62.9%) were neutropenic at the moment of inclusion in the study. A definitive etiologic diagnosis was obtained in 41 cases (42.7%), where infection accounted for the vast majority of cases (33 cases, 80.5%). Definitive diagnosis was reached by non-invasive methods in 13 cases (13.5%). BAL was performed in 47 cases and led to a diagnosis in 40.4% of the cases. BAL results led to therapeutic changes in 27 cases (57.4%), including the addition of new antimicrobials to empiric treatments in 10. Regarding BAL’s safety, two patients experienced minor adverse events and one a severe adverse event; no procedure-related deaths were observed.

Conclusions

Infection was the leading cause of pulmonary infiltrates in patients with hematologic malignancies and stem cell transplantation. BAL was a useful decision-making diagnostic tool, with minor adverse events.

Utility of bronchoscopy in immunocompromised paediatric patients: Systematic review

PURPOSE

The objective of this study was to describe the diagnostic yield and safety of bronchoalveolar lavage (BAL) in the evaluation of pulmonary lesions in immunocompromised children.

METHODS

We conducted a systematic review of literature published during the past 20 years, searching Medline, Medline EPub, EMBASE, and Scopus. Studies included involved paediatric patients (<18 years) on treatment for an oncological diagnosis or other immune compromise who underwent BAL for evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 272 studies were screened and 19 included. All were observational studies with moderate (11/19) or serious (8/19) risk of bias. BAL yielded a potential pathogen in 43% of cases (496/1156). Two papers reported improved diagnostic yield with early BAL (less than 3 days of presentation). A change in patient management after BAL was reported in 53% of cases (275/519). Adverse events were reported in 19% of cases following BAL (193/993) but were generally mild with no procedure-related mortality reported.

CONCLUSION

BAL appears to be useful for evaluation of pulmonary lesions in immunocompromised children with generally acceptable safety, though included studies had at least moderate risk of bias. Future prospective studies may provide more definitive estimates of benefit, timing and risk of BAL in this population.

Using Bronchoalveolar Lavage to Evaluate Changes in Pulmonary Diseases

Bronchoalveolar lavage (BAL) is a procedure that can be used to collect samples from human and animal lungs to efficiently evaluate the immune response and the potentially pathological changes by examining both the compositions of cells and fluid from lavage. There are observable changes including inflammatory response in human and animal lungs exposed to environmental exposures such as toxic chemicals and microorganisms, or under pathophysiological conditions in respiratory system. The profile of inflammatory cells in BAL provides a qualitative description of inflammatory response, and the secretion in BAL fluid contains secreted proteins of inflammatory mediators and albumin as a quantitative measurement of inflammation and tissue injury in the lungs. Mouse is the most common model system being used for pulmonary disease-related research. A consistent experimental approach on how to lavage mouse lungs and collect samples from mouse lungs is important for a reproducible evaluation of pathological and physiological changes in mouse lung especially for the analysis of inflammation.

Video-Assisted Thoracoscopic Lung Biopsy in Critically Ill Patients With Hematologic Malignancy and Acute Respiratory Distress Syndrome: A Case Series Report

Pulmonary complications are prevalent among patients with hematologic malignancies, who are at high risk of developing acute respiratory distress syndrome (ARDS). Although diffuse alveolar damage is considered the diagnostic hallmark of ARDS, there are plenty of other non-diffuse alveolar damage etiologies that can mimic ARDS and benefit from a specific therapy, therefore correcting the underlying cause. When the etiology remains unclarified despite noninvasive procedures, a surgical lung biopsy (either open via thoracotomy or video-assisted thoracoscopic surgery [VATS]) may be warranted. However, the role of surgical lung biopsy has not been extensively studied in patients with hematologic malignancy and ARDS and so doubt exists about the risk-benefit relationship of such procedures. In this article, we report a series of 8 critically ill patients with hematologic malignancies and ARDS, who underwent VATS lung biopsy, in a specialized institution in Cali, Colombia, from 2015 to 2019, with special emphasis on its diagnostic yield, modifications in treatment protocol, and safety. VATS lung biopsy is a minimally invasive procedure that appears to be a relatively safe with few postoperative complications and minimal perioperative mortality. It has a high diagnostic yield, resulting in a modification of treatment in a nondepreciable percentage of patients. However, this subset of patients was critically ill, with a high risk of mortality, and the lung biopsy did not appear to affect in this aspect. Future randomized controlled trials are needed to further clarify this topic.

Diagnosis of invasive fungal disease in children: a narrative review

Introduction: Invasive fungal diseases (IFD) represent important causes of morbidity and mortality in pediatrics. Early diagnosis and treatment of IFD is associated with better outcome and this entails the need to use fast and highly sensitive and specific methods that can support clinicians in the management of IFD.Areas covered: A narrative review was performed on conventional diagnostic methods such as culture, microscopy and histopathology are still gold standard but are burdened by a lack of sensitivity and specificity; on the other hand, imaging and noninvasive antigen-based such as beta-D-glucan, galactomannan and molecular biomarkers are the most convenient nonculture methods for diagnosis and monitoring effects of therapy. Aim of the present review is to summarize what is available in these fields at end of the second decade of the third millennium and look for future perspectives.Expert opinion: Promising and useful diagnostic methods have been applied in infectious disease diagnosis in clinical practice or in designing platforms. Unfortunately, most of them are not standardized or validated in pediatric population. However, clinicians should be aware of all innovative diagnostic tools to use in combination with conventional diagnostic methods for a better management of pathology and patient.

Diagnosis of Invasive Fungal Infection Among Pediatric Oncology Patients

INTRODUCTION

The diagnosis of pulmonary invasive fungal infection (IFI) in the pediatric oncology patient is challenging. Consensus criteria developed in 2008 state that bronchioalveolar lavage (BAL) results cannot confirm this diagnosis. A video-assisted thoracoscopic biopsy (VATS-biopsy) of lungs has been increasingly used to assist in evaluating these children for IFI. Our goal was to evaluate the impact of BAL and VATS-biopsy results on the management of IFI among pediatric oncology patients.

METHODS

A retrospective review of all oncology patients evaluated for IFI with VATS-biopsy and/or BAL over 9 years was carried out at a single free-standing children's hospital. The primary outcome was management changes in the use of antifungal therapy on the basis of diagnostic procedure, fungal culture results, lung imaging, and serological markers.

RESULTS

A total of 102 patients underwent 122 diagnostic evaluations for IFI. Ninety-one workups included only BAL, 17 evaluations involved only VATS-biopsy, and 14 cases involved both BAL and VATS-biopsy. The diagnostic yield of VATS-biopsy (38.7%) was superior to that of BAL (27.6%). There was poor concordance between VATS-biopsy and BAL results in the 14 cases where both were performed. Upon workup completion, IFI was proven in 12 children, probable in 29, and possible in 52. The odds of continuing antifungals increased 3-fold for patients with probable IFI and 12.7 times for those with the proven disease.

DISCUSSION

On the basis of the inferior diagnostic yield of BAL, we believe that VATS-biopsy may be a more useful diagnostic adjuvant in the diagnosis of IFI in the immunocompromised pediatric oncologic patient population.

Unusual trifecta of infections, aspiration, and metastatic prostatic adenocarcinoma in a bronchoalveolar lavage specimen

Bronchoalveolar lavage (BAL) is a useful procedure to evaluate lung infiltrates in order to identify infection, foreign body aspiration, and neoplasms. However, it is indeed unusual to find all three in the same sample. We report such a case in a 68-year-old male with a history of metastatic prostate adenocarcinoma and longstanding chronic obstructive pulmonary disease who presented with features of pneumonia. BAL revealed Aspergillus and parainfluenza infections, food particle aspiration pneumonia, as well as metastatic prostatic adenocarcinoma. The food particles were initially confused for yeast infection, but we finally identified them as nut products. This may be the first documented case of nut product aspiration diagnosed on BAL. The potential pitfalls that may complicate the evaluation are also discussed.

Sequence-Specific Detection of Unlabeled Nucleic Acid Biomarkers Using a "One-Pot" 3D Molecular Sensor

DNA and RNA biomarkers have not progressed beyond the automated specialized clinic due to failure in the reproducibility necessary to standardize robust and rapid nucleic acid detection at the point of care, where health outcomes can be most improved by early-stage diagnosis and precise monitoring of therapy and disease prognosis. We demonstrate here a new analytical platform to meet this challenge using functional 3D hydrogels engineered from peptide and oligonucleotide building blocks to provide sequence-specific, PCR-free fluorescent detection of unlabeled nucleic acid sequences. We discriminated at picomolar detection limits (<7 pM) "perfect-match" from mismatched sequences, down to a single nucleotide mutation, buried within longer lengths of the target. Detailed characterization by NMR, TEM, mass spectrometry, and rheology provided the structural understanding to design these hybrid peptide-oligonucleotide biomaterials with the desired sequence sensitivity and detection limit. We discuss the generic design, which is based on a highly predictable secondary structure of the oligonucleotide components, as a platform to detect genetic abnormalities and to screen for pathogenic conditions at the level of both DNA (e.g., SNPs) and RNA (messenger, micro, and viral genomic RNA).

Therapeutic Impact and Complications Associated with Surgical Lung Biopsy after Allogeneic Hematopoietic Stem Cell Transplantation in Children

Hematopoietic stem cell transplantation (HSCT) in the pediatric population is associated with pulmonary complications in 25% of recipients. The role of surgical lung biopsy (SLB) remains unclear because of concerns about both the therapeutic impact and morbidity associated with the procedure. A retrospective review of consecutive allogeneic HSCT recipients at Dana-Farber and Boston Children's Hospital Cancer and Blood Disorders Center between 2006 and 2016 was performed. All recipients who underwent SLB during the study period were identified and charts reviewed for perioperative complications, histopathologic findings, and changes in therapy delivered. Pearson's chi-square test and Student's t-test (or appropriate nonparametric test) were used to evaluate the associations between perioperative complication and categorical and continuous variables, respectively. Five hundred fifty-five HSCTs were included, among which 48 SLBs (8.6%) were identified. Median follow-up time was 24 months (range, 0 to 139). Thirty-day postoperative morbidity was 16.7% and 30-day postoperative mortality 10.4% (n = 5). The overall 30-day postoperative complication rate (including mortality) was 20.8% (n = 10). No mortalities were directly attributable to SLB. Definitive diagnoses were identified in 70.8% of SLBs (n = 34), and therapeutic changes occurred in 79.2% (n = 38). Overall, 83.3% of SLBs (n = 40) either provided a diagnosis or led to a change in therapy. SLB has an acceptable risk of perioperative complications in this medically complicated and often severely ill population. In most HSCT patients, SLB aids in defining the etiology of pulmonary infiltrates and can inform therapeutic decisions in patients where noninvasive diagnostic modalities have failed to provide a definitive diagnosis.

Diagnostic work up to assess early response indicators in invasive pulmonary aspergillosis in adult patients with haematologic malignancies

In immunocompromised patients with acute leukaemia as well as in allogeneic hematopoietic stem cell transplant patients, pulmonary lesions are commonly seen. Existing guidelines provide useful algorithms for diagnostic procedures and treatment options, but they do not give recommendations on how to evaluate early success or failure and if or when it is best to change therapy. Here, we review the diagnostic techniques currently used in association with clinical findings and propose an approach using a combination of computer tomography, clinical and all available biomarkers and inflammation parameters, especially those positive at baseline, to assess early response in invasive pulmonary aspergillosis. Computed tomography scans should be carried out at regular intervals during early and long-term follow-up. Imaging on day seven, or even earlier in clinically unstable patients, combined with an additional testing of biomarkers and inflammatory markers in between, is needed for a reliable assessment at day 14. If no improvement is seen after 2 weeks of therapy or the clinical condition is deteriorating, a change of antifungal therapy should be considered. Alleged breakthrough infections or treatment failure should undergo early diagnostic workup, including tissue biopsies when possible, to retrieve fungal cultures for resistance testing.