Role of bronchoalveolar lavage in the management of immunocompromised patients with pulmonary infiltrates

Clinical Utility of Stepwise Bronchoalveolar Lavage Fluid Analysis in Diagnosing and Managing Lung Infiltrates in Leukemia/Lymphoma Patients With Febrile Neutropenia

PURPOSE

Febrile neutropenia (FN) is a serious complication in hematologic malignancies, and lung infiltrates (LIs) remain a significant concern. An accurate microbiological diagnosis is crucial but difficult to establish. To address this, we analyzed the utility of a standardized method for performing bronchoalveolar lavage (BAL) along with a two-step strategy for the analysis of BAL fluid.

PATIENTS AND METHODS

This prospective observational study was conducted at a tertiary cancer center from November 2018 to June 2020. Patients age 15 years and older with confirmed leukemia or lymphomas undergoing chemotherapy, with presence of FN, and LIs observed on imaging were enrolled.

RESULTS

Among the 122 enrolled patients, successful BAL was performed in 83.6% of cases. The study used a two-step analysis of BAL fluid, resulting in a diagnostic yield of 74.5%. Furthermore, antimicrobial therapy was modified in 63.9% of patients on the basis of BAL reports, and this population demonstrated a higher response rate (63% v 45%; P = .063).

CONCLUSION

Our study demonstrates that a two-step BAL fluid analysis is safe and clinically beneficial to establish an accurate microbiological diagnosis. Given the crucial impact of diagnostic delays on mortality in hematologic malignancy patients with FN, early BAL studies should be performed to enable prompt and specific diagnosis, allowing for appropriate treatment modifications.

Impact of bronchoalveolar lavage on the management of immunocompromised hosts

BACKGROUND

Respiratory infections are an important cause of morbidity and mortality in immunocompromised individuals. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is an important tool to detect infectious agents in immunocompromised patients with low respiratory tract infections (LRTI).

RESEARCH QUESTION

BAL changes the management of immunocompromised patients with suspected LRTI.

STUDY DESIGN AND METHODS

Immunocompromised patients with a suspicion of LRTI underwent diagnostic BAL. The primary composite outcome consisted of pre-defined modifications in the management of the immunocompromised patients following BAL. We quantified the impact of bronchoscopy up to 30 days after the procedure.

RESULTS

A total of 2666 visits from 1301 patients were included in the study and immunosuppression was classified as haematological (n = 1040; 544 patients), solid organ transplantation (n = 666; 107 patients) and other causes (n = 960; 650 patients). BAL led to a change in management in 52.36% (n = 1396) of all cases. This percentage, as well as the 30-day mortality differed significantly amongst the three groups. Age, C-reactive protein and aetiology of infection determined significantly the risk of 30-day mortality in all patients. In 1.89% (n = 50) of all cases, a combination of 2 respiratory viral agents was identified and 24.23% (n = 646) were diagnosed with a single respiratory viral agent.

INTERPRETATION

BAL leads to changes in management in the majority of immunosuppressed patients. There is a high prevalence of multimicrobial infections and respiratory viral infections in immunocompromised patients with respiratory symptoms. Individual virus infection is associated with diverse risk of a negative outcome.

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Ten Issues to Update in Nosocomial or Hospital-Acquired Pneumonia: An Expert Review

Nosocomial pneumonia, or hospital-acquired pneumonia (HAP), and ventilator-associated pneumonia (VAP) are important health problems worldwide, with both being associated with substantial morbidity and mortality. HAP is currently the main cause of death from nosocomial infection in critically ill patients. Although guidelines for the approach to this infection model are widely implemented in international health systems and clinical teams, information continually emerges that generates debate or requires updating in its management. This scientific manuscript, written by a multidisciplinary team of specialists, reviews the most important issues in the approach to this important infectious respiratory syndrome, and it updates various topics, such as a renewed etiological perspective for updating the use of new molecular platforms or imaging techniques, including the microbiological diagnostic stewardship in different clinical settings and using appropriate rapid techniques on invasive respiratory specimens. It also reviews both Intensive Care Unit admission criteria and those of clinical stability to discharge, as well as those of therapeutic failure and rescue treatment options. An update on antibiotic therapy in the context of bacterial multiresistance, in aerosol inhaled treatment options, oxygen therapy, or ventilatory support, is presented. It also analyzes the out-of-hospital management of nosocomial pneumonia requiring complete antibiotic therapy externally on an outpatient basis, as well as the main factors for readmission and an approach to management in the emergency department. Finally, the main strategies for prevention and prophylactic measures, many of them still controversial, on fragile and vulnerable hosts are reviewed.

Utility of multimodal sampling and testing during advanced bronchoscopy for diagnosing atypical respiratory infections in a Coccidioides-endemic region

Background

The role of advanced diagnostic bronchoscopy (ADB) for assessing atypical respiratory infections is unclear. The purpose of this study was to ascertain: (I) the diagnostic utility of ADB-tissue sampling in patients with focal thoracic lesions due to atypical respiratory infections; (II) how multimodal bronchoscopic sampling and testing enhance diagnosis in a Coccidioides-endemic region.

Methods

A retrospective observational cohort study analyzing all ADBs performed over a 10-year period in patients with focal thoracic lesions diagnosed with a non-malignant disorder. Only cases which procured lower respiratory tract secretion and tissue samples by ADB, and had both cytohistology and culture results available were included.

Results

Among 403 subjects with non-malignant disease, 136 (33.7%) were diagnosed with atypical respiratory infections, with ADB contributing a diagnosis in 119 (87.5%) of these. Coccidioidal disease was independently associated with a cytohistologic diagnosis [odds ratio =7.64, 95% confidence interval (CI): 2.51-23.26; P<0.001]. Mycobacteria were more effectively identified by culture (overall yield of 8.4%, vs. 2.7% by cytohistology; P<0.001). Among subjects for which both respiratory secretion and tissue sampling were dual-tested with culture and cytology/cytohistology, adding ADB-guided transbronchial needle aspiration and/or forceps biopsy (TBNA/TBFB) to bronchoalveolar lavage and/or bronchial washings (BAL/BW) more than doubled the yield for dimorphic fungi, from 7.1% to 15.1% (increase of 8.0%, 95% CI: 5.2-11.9%). For lung lesions, adding tissue culture to dual TBNA/TBFB cytohistology-tested lung samples doubled the proportion diagnosed with atypical infection over using TBNA-cytohistology alone (increase of 15.8%, 95% CI: 10.4-23.1%). Adding lymph node to lung sampling increased the proportion diagnosed with coccidioidomycosis by 8.8% (95% CI: 4.8-15%). Among subjects with atypical respiratory infections, major ADB-related complications occurred in 1.5%.

Conclusions

ADB is useful for diagnosing atypical respiratory infections manifesting as focal thoracic lesions. A multimodal approach to both sampling and testing enhances yield, while maintaining a favorable procedure safety profile. Cytohistology testing and nodal sampling are beneficial for pulmonary coccidioidomycosis, and culture for mycobacterial disease. The approach to ADB-sampling should be adjusted according to clinical context and regional infection patterns.

Beta-Lactam Antibiotics Can Be Measured in the Exhaled Breath Condensate in Mechanically Ventilated Patients: A Pilot Study

Different techniques have been proposed to measure antibiotic levels within the lung parenchyma; however, their use is limited because they are invasive and associated with adverse effects. We explore whether beta-lactam antibiotics could be measured in exhaled breath condensate collected from heat and moisture exchange filters (HMEFs) and correlated with the concentration of antibiotics measured from bronchoalveolar lavage (BAL). We designed an observational study in patients undergoing mechanical ventilation, which required a BAL to confirm or discard the diagnosis of pneumonia. We measured and correlated the concentration of beta-lactam antibiotics in plasma, epithelial lining fluid (ELF), and exhaled breath condensate collected from HMEFs. We studied 12 patients, and we detected the presence of antibiotics in plasma, ELF, and HMEFs from every patient studied. The concentrations of antibiotics were very heterogeneous over the population studied. The mean antibiotic concentration was 293.5 (715) ng/mL in plasma, 12.3 (31) ng/mL in ELF, and 0.5 (0.9) ng/mL in HMEF. We found no significant correlation between the concentration of antibiotics in plasma and ELF (R² = 0.02, p = 0.64), between plasma and HMEF (R² = 0.02, p = 0.63), or between ELF and HMEF (R² = 0.02, p = 0.66). We conclude that beta-lactam antibiotics can be detected and measured from the exhaled breath condensate accumulated in the HMEF from mechanically ventilated patients. However, no correlations were observed between the antibiotic concentrations in HMEF with either plasma or ELF.

Diagnostic Utility of Bronchoalveolar Lavage in Immunocompromised Patients with Lung Infiltrates

Introduction

Lung infections are associated with a high mortality rate in immunocompromised patients. Achieving an accurate and rapid diagnosis is vital to help guide management, and thus improve survival.

Objective

To establish the diagnostic yield, clinical value, and safety of bronchoscopy with bronchoalveolar lavage (BAL) in immunocompromised adult patients with pulmonary infiltrates.

Methods

This retrospective study included all immunocompromised adult patients who underwent bronchoscopy with BAL for investigation of radiologically confirmed pulmonary infiltrates at a tertiary care hospital between January 01, 2014, and June 30, 2021. Clinically significant findings of BAL were defined as a positive microbiological result of a potential pathogen determined using routine culture, acid-fast bacilli smear, mycobacterial culture, tuberculosis PCR, fungal culture, Aspergillus antigen, and multiplex PCR panel and/or positive cytology.

Results

A total of 103 unique patients were included (mean ± SD age: 44.5 ± 14.1 years), of which the majority were male (60.2%). The BAL diagnostic yield was 52.4% (95% CI: 42.6-62.2%). In the multiple logistic regression model, positive BAL was predicted by symptom of sputum (aOR 4.01, 95% CI: 1.27-12.70, P = 0.018). Almost half of the procedures (43.7%, 95% CI: 33.9-53.4%) resulted in a change in the management plan, with positive BAL findings more than twice as likely to result in a change (OR 2.39, 95% CI: 1.07-5.33, P = 0.033). Only three (2.9%) procedures resulted in complications and required ventilator support and/or oxygen escalation.

Conclusions

BAL is a safe clinical tool that can be useful in impacting clinical management in a significant proportion of immunocompromised patients with pulmonary infiltrates.

Performance of galactomannan testing from endotracheal aspirate to guide bronchoalveolar lavage in the diagnosis of invasive aspergillosis

PURPOSE

Invasive aspergillosis is a major threat to immunocompromised individuals. Galactomannan (GM) is used as a biomarker for invasive aspergillosis. Investigations recommended in current guidelines include GM testing of bronchoalveolar lavage (BAL) fluids. GM testing of endotracheal aspirate, the sampling of which is less invasive, less resource-intensive and less aerosol-generating, is not validated. We compared the performance of endotracheal aspirate GM as a screening tool to predict BAL fluid GM-positivity in patients with suspected invasive aspergillosis.

METHODS

Of each patient, a pair of corresponding endotracheal aspirate and BAL fluid samples was tested and compared for GM results. Two sample sets were included. The first consisted of 140 consecutive BAL fluid/endotracheal aspirate pairs obtained from 133 patients. The pairs of the second sample set (n = 38) were selected based on the criterion that the BAL tested positive for GM. All specimens were obtained in a German 2,000 bed tertiary care center.

RESULTS

Among BAL fluid GM-positive samples, endotracheal aspirate GM demonstrated poor specificity (72%) but high sensitivity (92% in predicting BAL fluid GM of ≥ 0.50 and 91% for BAL fluid GM of ≥ 1.00) and an excellent negative predictive value (98%). The use of a marginally elevated cutoff of 0.63 resulted in an improved specificity (72-81%), without loss of sensitivity.

CONCLUSIONS

For screening purposes, one might consider testing endotracheal aspirate for GM, which could help avoid unnecessary BAL.

Clinical role of bronchoalveolar lavage in dermatomyositis-associated interstitial lung disease

OBJECTIVE

To investigate the role of bronchoalveolar lavage (BAL) in dermatomyositis (DM)-associated interstitial lung disease (ILD).

METHODS

We retrospectively reviewed the medical records of patients with DM-ILD who underwent bronchoscopy between October 2015 and September 2019. We then collated clinical features, laboratory data, and bronchoscopy findings. The follow-up study was terminated on the 1st May 2020.

RESULTS

A total of 113 DM-ILD patients were included in this study, including 27 patients with acute/subacute interstitial pneumonia (A/SIP) and 86 patients with chronic interstitial pneumonia (CIP). The A/SIP group had significantly lower proportions of lymphocytes and eosinophils in the bronchoalveolar lavage fluid (BALF) than the CIP group, but had a significantly higher proportion of neutrophils. Pathogens were discovered in BALF from 28 (24.8%) patients. Twenty-five (22.1%) patients commenced or changed antibiotic therapy on the basis of their bronchoscopy results. Lymphopenia and ICU care were significantly associated with pathogen-positive BALF findings. Complications of bronchoscopy occurred in 9 (8.0%) patients; fever (5.3%) was the most common complication. Twenty-five deaths (25/106, 23.6%) were observed during a mean follow-up of 22 months. Age, A/SIP, and anti-MDA5 antibody, were identified as independent predictors of a poor outcome, while mechanic's hands was an independent protective factor. However, cellular and pathogen findings in BALF had no significant influence on 30-day or overall mortality.

CONCLUSION

Bronchoscopy is a relatively useful instrument to evaluate ILD in patients with DM and BAL can improve the diagnosis of infection. However, cellular and pathogen findings from BALF had no significant influence on prognosis.

Pulmonary infiltration as the initial manifestation of chronic lymphoproliferative disorder of natural killer cells: a case report and literature review

BACKGROUND

Chronic lymphoproliferative disorder of natural killer cells (CLPD-NK) is an extremely rare haematological disease. To the best of our knowledge, pulmonary infiltration in CLPD-NK has not been reported before. Our case study aimed to present the clinical characteristics, chest computed tomography (CT) findings, and flow cytometry immunophenotyping (FCI) results of an unusual case of migratory pulmonary infiltration in a patient with CLPD-NK.

CASE PRESENTATION

A 51-year-old female patient was admitted to our hospital on October 8, 2019. Eight months before this visit, she had been diagnosed with pneumonia in a community hospital with 1 month of low-grade fever and had recovered after oral antibiotic administration. During follow-up, the patient presented with persistent peripheral blood (PB) lymphocytosis and ground-glass opacities on lung CT scans without any symptoms and signs or any evidence of infectious, allergic or autoimmunity pulmonary diseases. Abnormal NK cells were identified in the PB, bone marrow and bronchoalveolar lavage fluid (BALF) using FCI in our hospital. Eventually, the patient was diagnosed with pulmonary infiltration of CLPD-NK. The patient had an indolent clinical course without symptoms, hepatosplenomegaly or palpable lymphadenopathy and did not receive any therapy. The patient has remained in a good performance status 13 months after the diagnosis.

CONCLUSIONS

Our study described a unique case of pulmonary infiltration in a patient with CLPD-NK. The present case highlights the importance of FCI of the BALF in patients with lymphocytosis and pulmonary shadows to avoid misdiagnosis.

Diagnostic Yield of Bronchoalveolar Lavage in Immunocompromised Children

Results from early studies in the diagnostic yield of bronchoalveolar lavage (BAL) in immunocompromised adults and children were variable. This prospective study aimed to determine the diagnostic yield of BALs in immunocompromised children over the first 18 months of service at a newly established children's hospital. Relationship between BAL results and changes in antimicrobial management was also studied. Twenty-one bronchoscopic BALs were performed on 18 children; 14 BALs (66.7%) yielded at least 1 pathogen and 7 (33.3%) yielded no pathogen. Two pathogens were found in 2 samples, and 1 pathogen was identified in 12 samples. Bacteria (n = 7 patients), viruses (n = 8 patients) and fungus (Pneumocycstis jirovecii in one patient) were yielded. Of the 21 BALs, 8 (38.1%) were associated with changes in antimicrobial management (Fisher's exact test, p = 0.018). No significant side effects such as pneumothorax or pulmonary hemorrhages were observed in this series. In conclusion, BAL in immunocompromised children is rewarding and has potential to impact on antimicrobial management.

Pulmonary infections in patients with and without hematological malignancies: diagnostic yield and safety of flexible bronchoscopy-a retrospective analysis

Background

Fiberoptic bronchoscopy (FOB) with broncho-alveolar lavage (BAL) is frequently performed in patients with hematological malignancies and pulmonary opacities. While the safety of the procedure in this patient population has been shown, data about the diagnostic yield widely differ between studies. Furthermore, data comparing diagnostic yield and safety of flexible bronchoscopy to narrow sources of pulmonary infections in patients with and without underlying hematological malignancy are lacking.

Methods

We carried out a retrospective analysis of bronchoscopies done for the diagnostic work-up of pulmonary infections. Diagnostic yield and the occurrence of complications in patients with and without hematological disease were compared.

Results

In total n=268 bronchoscopies were done in patients suffering from a hematological malignancy (HM) compared to n=408 bronchoscopies in patients without hematological malignancy (NHM). The overall diagnostic yield was similar and did not differ between the groups (HM: 67.2% vs. NHM: 64.7%; P=0.5622). However, when cultures positive for Candida were not considered as clinically relevant diagnostic yield was higher in the HM group (HM: 62.7% vs. NHM: 53.9%; P=0.0261) due to a higher detection rate of fungi and viruses (both P<0.001). Interestingly, the diagnostic yield for bacteria was not decreased by pre-treatment with antibiotics in either group (both P>0.05). There was no difference in the complication rate between the groups and most complications were considered as minor.

Conclusions

In summary, our data demonstrate similar diagnostic yield and safety of flexible bronchoscopy for diagnosing pulmonary infection in patients with and without underlying hematological malignancy.

Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study

In patients presenting with anti-glomerular basement membrane (GBM) disease with advanced isolated kidney involvement, the benefit of intensive therapy remains controversial due to adverse events, particularly infection. We aim to describe the burden of severe infections (SI) (requiring hospitalization or intravenous antibiotics) and identify predictive factors of SI in a large cohort of patients with anti-GBM disease. Among the 201 patients (median [IQR] age, 53 [30–71] years) included, 74 had pulmonary involvement and 127 isolated glomerulonephritis. A total of 161 SI occurred in 116 patients during the first year after diagnosis. These infections occurred during the early stage of care (median [IQR] time, 13 [8–19] days after diagnosis) with mainly pulmonary (45%), catheter-associated bacteremia (22%) and urinary tract (21%) infections. In multivariable analysis, positive ANCA (HR [95% CI] 1.62 [1.07−2.44]; p = 0.02) and age at diagnosis (HR [95% CI] 1.10 [1.00–1.21]; p = 0.047) remained independently associated with SI. Age-adjusted severe infection during the first three months was associated with an increased three-year mortality rate (HR [95% CI] 3.13 [1.24–7.88]; p = 0.01). Thus, SI is a common early complication in anti-GBM disease, particularly in the elderly and those with positive anti-neutrophil cytoplasmic antibodies (ANCA). No significant association was observed between immunosuppressive strategy and occurrence of SI.

Interferon signature in immunosuppressed patients with lower respiratory tract infections: dosage on bronchoalveolar lavage

BACKGROUND

Interferon signature (IS) is the measure of transcripts belonging to pathways of interferon activation. Viral infections can interfere with the interferon pathway, in particular herpesvirus present in immunocompromised hosts. The aim of our study was to evaluate if herpesvirus infections in immunocompromised patients with lower respiratory tract infections (LRTI) could lead to IS alterations.

METHODS

We measured IS transcription of six genes on bronchoalveolar lavage of immunocompromised patients with LRTI (IFI27, IFI44, IFIT1, ISG15, RSAD2, SIGLEC1). Patients were divided in three groups based on Epstein-Barr virus (EBV) and other herpesviruses coinfections.

RESULTS

We included 56 patients, 10 without and 17 with only EBV reactivation (respectively N and E groups) and 29 with EBV and other herpesviruses (group C). IS was higher in group C (P=0.01) compared to other ones, but single gene expressions were different among groups: IFI27 was higher whereas IFIT1 and ISG15 were lower in group C (P<0.05).

CONCLUSIONS

The continuous stimulation of interferon cascade by herpesviruses enhances IS. The analysis of IS in immunocompromised population is possible by limiting the use of IFI27, IFIT1, ISG15 genes. Our preliminary results seem to indicate that IS is a useful biomarker of cellular response to herpesvirus infection in immunocompromised patients.