Invasive diagnostic techniques in idiopathic interstitial pneumonias

Transbronchial cryobiopsy followed by as-needed surgical lung biopsy versus immediate surgical lung biopsy for diagnosing interstitial lung disease (the COLD study): a randomised controlled trial

BACKGROUND

An adequate diagnosis for interstitial lung disease (ILD) is important for clinical decision making and prognosis. In most patients with ILD, an accurate diagnosis can be made by clinical and radiological data assessment, but in a considerable proportion of patients, a lung biopsy is required. Surgical lung biopsy (SLB) is the most common method to obtain tissue, but it is associated with high morbidity and even mortality. More recently, transbronchial cryobiopsy has been introduced, with fewer adverse events but a lower diagnostic yield than SLB. The aim of this study is to compare two diagnostic strategies: a step-up strategy (transbronchial cryobiopsy, followed by SLB if the cryobiopsy is insufficiently informative) versus immediate SLB.

METHODS

The COLD study was a multicentre, randomised controlled trial in six hospitals across the Netherlands. We included patients with ILD with an indication for lung biopsy as assessed by a multidisciplinary team discussion. Patients were randomly assigned in a 1:1 ratio to the step-up or immediate SLB strategy, with follow-up for 12 weeks from the initial procedure. Patients, clinicians, and pathologists were not masked to the study treatment. The primary endpoint was unexpected chest tube drainage, defined as requiring any chest tube after transbronchial cryobiopsy, or prolonged (>24 h) chest tube drainage after SLB. Secondary endpoints were diagnostic yield, in-hospital stay, pain, and serious adverse events. A modified intention-to-treat analysis was performed. This trial is registered with the Dutch Trial Register, NL7634, and is now closed.

FINDINGS

Between April 8, 2019, and Oct 24, 2021, 122 patients with ILD were assessed for study participation; and 55 patients were randomly assigned to the step-up strategy (n=28) or immediate SLB (n=27); three patients from the immediate SLB group were excluded. Unexpected chest tube drainage occurred in three of 28 patients (11%; 95% CI 4-27%) in the step-up group, and the number of patients for whom the chest tube could not be removed within 24 h was 11 of 24 patients (46%; 95% CI 2-65%) in the SLB group, with an absolute risk reduction of 35% (11-56%; p=0·0058). In the step-up strategy, the multidisciplinary team diagnostic yield after transbronchial cryobiopsy alone was 82% (64-92%), which increased to 89% (73-96%) when subsequent SLB was performed after inconclusive transbronchial cryobiopsy. In the immediate surgery strategy, the multidisciplinary team diagnostic yield was 88% (69-97%). Total in-hospital stay was 1 day (IQR 1-1) in the step-up group versus 5 days (IQR 4-6) in the SLB group. One (4%) serious adverse event occurred in step-up strategy versus 12 (50%) in the immediate SLB strategy.

INTERPRETATION

In ILD diagnosis, if lung tissue assessment is required, a diagnostic strategy starting with transbronchial cryobiopsy, followed by SLB when transbronchial cryobiopsy is inconclusive, appears to result in a significant reduction of patient burden and in-hospital stay with a similar diagnostic yield versus immediate SLB.

FUNDING

Netherlands Organisation for Health Research and Development (ZonMW) and Amsterdam University Medical Centers.

Animal models of acute exacerbation of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive scarring interstitial lung disease with an unknown cause. Some patients may experience acute exacerbations (AE), which result in severe lung damage visible on imaging or through examination of tissue samples, often leading to high mortality rates. However, the etiology and pathogenesis of AE-IPF remain unclear. AE-IPF patients exhibit diffuse lung damage, apoptosis of type II alveolar epithelial cells, and an excessive inflammatory response. Establishing a reliable animal model of AE is critical for investigating the pathogenesis. Recent studies have reported a variety of animal models for AE-IPF, each with its own advantages and disadvantages. These models are usually established in mice with bleomycin-induced pulmonary fibrosis, using viruses, bacteria, small peptides, or specific drugs. In this review, we present an overview of different AE models, hoping to provide a useful resource for exploring the mechanisms and targeted therapies for AE-IPF.

A pilot study on the use of the super dimension navigation system for optimal cryobiopsy location in interstitial lung disease diagnostics

BACKGROUND

Transbronchial cryobiopsies has become increasingly important in the diagnostic workup for interstitial lung diseases. The rate of complications and mortality are low compared to surgical lung biopsies, but the diagnostic yield is not as high. The reason for the lower diagnostic yield could in some cases be explained by biopsies taken too centrally or in less affected areas. In this pilot study we examined the feasibility of using the electromagnetic navigation system, superDimension (SD), when performing cryobiopsies to increase the diagnostic yield.

METHODS

Electromagnetic navigation bronchoscopy and cryobiopsies were performed using SD. An electromagnetic board placed on the back of the patient and a position sensor at the tip of the navigational probe created a real-time 3D reconstruction of previously acquired computer tomography images. The procedure was performed with the patients in general anesthesia using a rigid bronchoscope when performed in Florence and with a flexible bronchoscope through an orotracheal tube when performed in Aarhus.

RESULTS

In total, 18 patients were included. Five patients were excluded, partly due to technical difficulties. Disposable 1.7 mm cryoprobes were used in Aarhus, and reusable 1.9 mm probes in Florence. Pneumothorax was detected in three (23%), mild hemorrhage was seen in one (8%) and moderate hemorrhage in six (46%). The biopsies contributed to the diagnosis in 11 of the patients (85%).

CONCLUSION

Using superDimension electromagnetic navigation system when performing cryobiopsies is feasible. A larger prospective trial is necessary to homogenize the technique between centres and to evaluate diagnostic advantage and complications.

The Impact of the Envisia Genomic Classifier in the Diagnosis and Management of Patients with Idiopathic Pulmonary Fibrosis

RATIONALE

The diagnosis of idiopathic pulmonary fibrosis (IPF) remains challenging and can result in delayed or misdiagnosis. IPF diagnosis is based upon the presence of either a radiographic or histologic usual interstitial pneumonia (UIP) pattern in the absence of an identifiable etiology. The Envisia Genomic Classifier is a clinically validated molecular diagnostic test that identifies UIP in transbronchial biopsies.

OBJECTIVE

To determine the impact of the Envisia Genomic Classifier on physician's clinical decision making in the diagnosis and management of IPF.

METHODS

This prospective randomized decision impact survey was designed to test the hypothesis that including an Envisia UIP positive (UIP+) result will increase IPF diagnoses, diagnostic confidence levels, and the recommendation for antifibrotic therapy. The survey included patients from the BRAVE study who had an HRCT scan without a typical UIP pattern, an Envisia UIP+ result, and a final diagnosis of IPF by multidisciplinary team discussion. Each case was presented in three different formats: a pre-post cohort where each case is presented initially without and then with Envisia, and two independent cohorts where each case is presented without and with Envisia, respectively.

RESULTS

U.S. based pulmonologists from community and academic centers in geographically diverse practices were approached for inclusion in this study. 103 (65%) US-based pulmonologists met the inclusion criteria and provided 605 case reviews of 11 patient cases. The number of IPF diagnoses increased with Envisia by an absolute difference of 39% from 47 (30%) pre-Envisia to 107 (69%) post-Envisia in the pre-post cohort and by 13% in the independent cohorts. High confidence (> 90%) of ILD diagnoses was more commonly seen with Envisia in both the pre-post cohort and in the independent cohorts. Recommendation for antifibrotic treatment increased with Envisia by an absolute difference of 36% from 15 (10%) pre-Envisia to 72 (46.4%) post-Envisia in the pre-post cohort and by 11% in the independent cohorts.

CONCLUSIONS

This decision impact survey suggests the clinical utility of the Envisia Classifier by demonstrating a significant increase in IPF diagnoses, diagnostic confidence, and recommendation for antifibrotic therapies to assist physicians to effectively manage patients to improve outcomes of patients with IPF.

The Role of Surgical Lung Biopsy in the Diagnosis of Fibrotic Interstitial Lung Disease: Perspective from the Pulmonary Fibrosis Foundation

Diagnosis of interstitial lung disease (ILD) requires a multidisciplinary diagnosis (MDD) approach that includes clinicians, radiologists, and pathologists. Surgical lung biopsy (SLB) is currently the recommended standard in obtaining pathological specimens for patients with ILD requiring a tissue diagnosis. The increased diagnostic confidence and accuracy provided by microscopic pathology assessment of SLB specimens must be balanced with the associated risks in ILD patients. This document was developed by the Surgical Lung Biopsy Working Group of the Pulmonary Fibrosis Foundation, composed of a multidisciplinary group of ILD physicians including pulmonologists, radiologists, pathologists, and thoracic surgeons. In this document, we present an up-to-date literature review of the indications, contraindications, risks, and alternatives to SLB in the diagnosis of fibrotic ILD, outline an integrated approach to the decision-making around SLB in the diagnosis of fibrotic ILD, and provide practical information to maximize the yield and safety of SLB.

Transbronchial cryobiopsy for diagnosing parenchymal lung diseases: real-life experience from a tertiary referral center

Background and Objectives:

Transbronchial cryobiopsy (cryo-TBB) is increasingly being used in the diagnosis of diffuse parenchymal lung diseases (DPLD). Varying diagnostic success and complication rates have been reported. Herein we report our experience with cryo-TBB, focusing on diagnostic yield, factors affecting diagnosis, and safety.

Methods:

This retrospective study was conducted in a tertiary referral chest diseases hospital. Data regarding the patients, procedures, complication rates, diagnostic yield, and the final diagnosis made by a multidisciplinary committee at all diagnosis stages were evaluated.

Results:

We recruited 147 patients with suspected DPLD. The definitive diagnosis was made pathologically in 98 of 147 patients (66.6%) and using a multidisciplinary approach in 109 of 147 (74.1%) cases. The number of samples had a significant effect on diagnostic success. Histopathologic diagnostic yield and diagnostic yield with a multidisciplinary committee after a single biopsy were 50%, and histopathological diagnostic yield and diagnostic yield with multidisciplinary committee increased to 71.4% and 85.7%, respectively, with a second biopsy (p = 0.034). The incidence of mild-to-moderate hemorrhage was 31.9%; no severe hemorrhage occurred. Pneumothorax rate was 15.6%, and the mortality rate was 0.68%.

Conclusions:

Cryo-TBB has sufficient diagnostic yield in the context of a multidisciplinary diagnosis with acceptable complication rates. Performing at least 2 biopsies and from at least 2 segments increases diagnostic success.

Transbronchial lung cryobiopsy in smoking-related interstitial lung diseases

BACKGROUND

Transbronchial lung cryobiopsy (TBLC) is an emerging technique in the diagnostic approach to diffuse parenchymal lung diseases. However, the role of TBLC in smoking-related Interstitial Lung Diseases (ILDs) is still under discussion.

OBJECTIVES

The aim of the present study was to describe our experience with TBLC in diagnostic work-up of patients with smoking-related ILDs.

METHOD

We retrospectively reviewed data of patients evaluated in a tertiary hospital ILDs outpatient clinic, who underwent TBLC, from September 2014 to December 2019. TBLC was performed in accordance with the 2018 expert statement from the Cryobiopsy Working Group.

RESULTS

Forty-five patients (25 men [55.6%]) with a mean age of 53.9 years [SD, 9.1] were included. The most frequent radiological pattern was ground glass opacity (42 patients). TBLC was performed in different segments of the same lobe in 38 patients and in two lobes in 7 patients. The mean maximal diameter of the samples was 5.2 mm (range, 3-16 mm [SD 2.0]). Pneumothorax occurred in seven patients (15%) and moderate bleeding occurred in one patient. A specific pathological diagnosis was achieved in 43 of 45 patients. The most frequent histopathologic pattern found was desquamative interstitial pneumonia (33 patients), followed by smoking-related interstitial fibrosis (7 patients), respiratory bronchiolitis - ILD (1 patient) and pulmonary Langerhans cell histiocytosis (1 patient). Two patients had alternative diagnosis (Pneumoconiosis and Interstitial Pneumonia with unspecific features) and one patient had normal lung parenchyma. A definitive multidisciplinary team (MDT) diagnosis was reached in 95.5% (43 of 45 cases). Two patients were submitted to additional diagnostic techniques.

CONCLUSIONS

The results from this series support TBLC as a safe procedure with a meaningful diagnostic value in the context of a MDT approach of smoking-related ILDs. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (4): e2020013).

Diagnostic approach in parenchymal lung diseases: transbronchial lung biopsy or cryobiopsy?

Background/aim

Diagnosis of interstitial lung diseases requires a multidisciplinary approach, and a gold standard for histological diagnosis is open lung biopsy. Transbronchial lung biopsy (TBLB) and in recent years an alternative method, cryobiopsy (TBLC), are used for the diagnosis of parenchymal lung lesions. The aim of this study is to compare the efficacy of concomitant conventional TBLB and TBLC.

Materials and methods

A total of 82 patients who underwent TBLC for diagnosis of diffuse parenchymal lung diseases at Dr. Suat Seren Chest Diseases and Surgery Training and Research Hospital between 2015 and 2018 were screened retrospectively and included in the study. Of the patients, 53.7% (n: 44) were male, and 46.4% (n:38) of them were female. The mean age was 58.37 (±9.33) years. First TBLB and then TBLC were performed to all patients in the same session and their diagnostic performances were compared.

Results

Although both procedures were done in the same session, 45 patients (54.9%) were diagnosed with TBLB and 75 patients (91.5%) were diagnosed with TBLC (P ˂ 0.001). Hemorrhage was observed in 39 patients (47.6%), but only one had a massive hemorrhage. Pneumothorax was observed in 6 patients (7.3%) and none of them required tube drainage.

Conclusion

Transbronchial lung cryobiopsy is a promising technique for the diagnosis of parenchymal lung diseases compared to transbronchial lung biopsy. 

The significance of multidisciplinary classifications based on transbronchial pathology in possible idiopathic interstitial pneumonias

Surgical lung biopsy is regarded as the golden standard for the diagnosis of idiopathic interstitial pneumonias (IIPs). Here, we attempted to show the diagnostic accuracy of multidisciplinary classifications based on transbronchial pathology including transbronchial lung cryobiopsy (TBLC) , bronchoalveolar lavage fluid (BALF) and endobronchial ultrasound-guided transbronchial needle aspiration biopsy (EBUS-TBNA).Patients with suspected interstitial lung diseases admitted from June 1, 2016 to December 31, 2018 were involved. Patients with known causes of interstitial lung diseases and typical idiopathic pulmonary fibrosis diagnosed through clinical, radiological information were excluded. Patients with atypical idiopathic pulmonary fibrosis and possible IIPs accepted transbronchial pathological evaluation. Initial multidisciplinary diagnosis (MDD) classifications were made depending on clinical, radiological and transbronchial pathological information by a multidisciplinary team (MDT). The final MDD classifications were confirmed by subsequent therapeutic effects. All patients were followed up for at least 6 months.A total of 70 patients were finally involved. The samples of lung parenchyma extracted through TBLC were enough for confirmation of pathological diagnoses in 68.6% (48/70) cases. Samples of 6 cases were extracted by EBUS-TBNA. Bacteriological diagnoses were positive in 1 case by BALF. Pathological diagnoses of 77.1% (54/70) cases were achieved through TBLC, EBUS-TBNA and BALF. During the follow up study, the pulmonary lesions of 60% patients were improved, 11.43% were relapsed when glucocorticoid was reduced to small dose or withdrawal, 14.29% were leveled off and 8.57% were progressed. The diagnoses of 4 patients with progressed clinical feature were revised. As a result, 94.3% initial MDD classifications based on transbronchial pathology were consistent with the final MDD, and the difference of diagnostic yield wasn't significant between initial and final MDD (Z = -1.414, P = .157).Classifications of IIPs based on transbronchial pathology were useful and quite agreed with final MDD.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 1. Introduction

Idiopathic interstitial pneumonia (IIP) is a histologically identifiable pulmonary disease without a known cause that usually infiltrates the lung interstitium. IIP is largely classified into idiopathic pulmonary fibrosis, idiopathic non-specific interstitial pneumonia, respiratory bronchiolitis-interstitial lung disease (ILD), cryptogenic organizing pneumonia, desquamative interstitial pneumonia, and acute interstitial pneumonia. Each of these diseases has a different prognosis and requires specific treatment, and a multidisciplinary approach that combines chest high-resolution computed tomography (HRCT), histological findings, and clinical findings is necessary for their diagnosis. Diagnosis of IIP is made based on clinical presentation, chest HRCT findings, results of pulmonary function tests, and histological findings. For histological diagnosis, video-assisted thoracoscopic biopsy and transbronchial lung biopsy are used. In order to identify ILD associated with connective tissue disease, autoimmune antibody tests may also be necessary. Many biomarkers associated with disease prognosis have been recently discovered, and future research on their clinical significance is necessary. The diagnosis of ILD is difficult because patterns of ILD are both complicated and variable. Therefore, as with other diseases, accurate history taking and meticulous physical examination are crucial.

Transbronchial Cryobiopsies for Diagnosing Interstitial Lung Disease: Real-Life Experience from a Tertiary Referral Center for Interstitial Lung Disease

BACKGROUND

Transbronchial cryobiopsy (cTBB) may offer an alternative to surgical lung biopsy (SLB) for histopathological diagnosis of interstitial lung diseases (ILDs). However, real-life experience is limited, although case series are increasingly reported.

OBJECTIVES

We aimed to evaluate the value of cTBB performed under real-life conditions in a tertiary care center for ILDs.

METHODS

Data on all patients undergoing a cTBB for evaluation of suspected ILD between October 2015 and January 2017 were included in this retrospective case series. Procedure details, complication rates, histopathological results, and diagnostic consensus reached by a multidisciplinary team (MDT) discussion were collated and evaluated.

RESULTS

A total of 109 patients (mean age 64 years, range 19-85; 66% male, 38% never smokers) referred to our center with features suggestive of ILD underwent cTBB. The mean FVC% predicted was 77% (range 41-131), with a mean DLCO of 51% (range 20-86), and a 6-min walking test (6MWT) of 402 m (range 100-642). On average, 4 samples were taken from each patient (range 1-8), with a mean biopsy diameter of 5 mm (range 2-12). Complications included pneumothorax (11.9%), all treated with chest drain. Moderate bleeding occurred in 28.4% (all resolved without active measures). No acute disease exacerbations and no deaths occurred. A histopathological pattern diagnosis was possible in 80 cases (73.4%), and 26.6% of cases were considered nonspecific. An MDT consensus diagnosis was reached in 83.5% of cases. Subsequent SLB was proposed in 13 cases and performed in 8 cases.

CONCLUSIONS

In the real-world setting, cTBB has a meaningful diagnostic value in the context of a MDT approach and may enable histopathological assessment even in patients with more advanced disease unsuitable for SLB.

Cryobiopsies are diagnostic in Pleuroparenchymal and Airway-centered Fibroelastosis

BACKGROUND

Idiopathic pulmonary fibroelastosis (iPPFE) is a rare lung lesion characterized by pleural and subpleural parenchymal thickening due to accumulation of fibroelastotic tissue. Only recently, a few cases with a peribronchiolar distribution of fibroelastotic tissue have been reported. These lesions are more prominent in the upper lobes. Even though high resolution computed tomography (HRCT) scan features are considered characteristic, a histological confirmation is suggested, mainly when the clinical setting is not clearly defined. However, due to non-negligible complications, a surgical lung biopsy is not often recommended. The prognosis is usually poor and currently, the only effective treatment is lung transplantation.

METHOD

Patients with a multidisciplinary diagnosis of iPPFE or airway-centered fibroelastosis (airway-centered FE), with histological confirmation by transbronchial cryobiopsy, were identified from an ongoing interstitial lung disease registry. Data on patient demographics, HRCT patterns, size and number of biopsies, histology patterns and complications were registered.

RESULTS

Seven patients were diagnosed with iPPFE and one patient was diagnosed with airway-centered FE. Pneumothorax was documented in three cases, but none of them required a chest tube. No other complications during or after the procedure were observed.

CONCLUSION

This study suggests that using cryobiopsies in the diagnostics of PPFE and airway-centered FE is safe and effective.

Usual Interstitial Pneumonia Can Be Detected in Transbronchial Biopsies Using Machine Learning

RATIONALE

Usual interstitial pneumonia (UIP) is the histopathologic hallmark of idiopathic pulmonary fibrosis. Although UIP can be detected by high-resolution computed tomography of the chest, the results are frequently inconclusive, and pathology from transbronchial biopsy (TBB) has poor sensitivity. Surgical lung biopsy may be necessary for a definitive diagnosis.

OBJECTIVES

To develop a genomic classifier in tissue obtained by TBB that distinguishes UIP from non-UIP, trained against central pathology as the reference standard.

METHODS

Exome enriched RNA sequencing was performed on 283 TBBs from 84 subjects. Machine learning was used to train an algorithm with high rule-in (specificity) performance using specimens from 53 subjects. Performance was evaluated by cross-validation and on an independent test set of specimens from 31 subjects. We explored the feasibility of a single molecular test per subject by combining multiple TBBs from upper and lower lobes. To address whether classifier accuracy depends upon adequate alveolar sampling, we tested for correlation between classifier accuracy and expression of alveolar-specific genes.

RESULTS

The top-performing algorithm distinguishes UIP from non-UIP conditions in single TBB samples with an area under the receiver operator characteristic curve (AUC) of 0.86, with specificity of 86% (confidence interval = 71-95%) and sensitivity of 63% (confidence interval = 51-74%) (31 test subjects). Performance improves to an AUC of 0.92 when three to five TBB samples per subject are combined at the RNA level for testing. Although we observed a wide range of type I and II alveolar-specific gene expression in TBBs, expression of these transcripts did not correlate with classifier accuracy.

CONCLUSIONS

We demonstrate proof of principle that genomic analysis and machine learning improves the utility of TBB for the diagnosis of UIP, with greater sensitivity and specificity than pathology in TBB alone. Combining multiple individual subject samples results in increased test accuracy over single sample testing. This approach requires validation in an independent cohort of subjects before application in the clinic.

Recent advances in managing idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a rare pulmonary disease with a poor prognosis and severe impact on quality of life. Early diagnosis is still challenging and important delays are registered before final diagnosis can be reached. Available tools fail to predict the variable course of the disease and to evaluate response to antifibrotic drugs. Despite the recent approval of pirfenidone and nintedanib, significant challenges remain to improve prognosis and quality of life. It is hoped that the new insights gained in pathobiology in the last few years will lead to further advances in the diagnosis and management of IPF. Currently, early diagnosis and prompt initiation of treatments reducing lung function loss offer the best hope for improved outcomes. This article aims at providing an overview of recent advances in managing patients with IPF and has a particular focus on how to reach a diagnosis, manage comorbidities and lung transplantation, care for the non-pharmacological needs of patients, and address palliative care.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease characterized by progressive lung scarring and the histological picture of usual interstitial pneumonia (UIP). It is associated with increasing cough and dyspnoea and impaired quality of life. IPF affects ∼3 million people worldwide, with incidence increasing dramatically with age. The diagnostic approach includes the exclusion of other interstitial lung diseases or overlapping conditions and depends on the identification of the UIP pattern, usually with high-resolution CT; lung biopsy might be required in some patients. The UIP pattern is predominantly bilateral, peripheral and with a basal distribution of reticular changes associated with traction bronchiectasis and clusters of subpleural cystic airspaces. The biological processes underlying IPF are thought to reflect an aberrant reparative response to repetitive alveolar epithelial injury in a genetically susceptible ageing individual, although many questions remain on how to define susceptibility. Substantial progress has been made in the understanding of the clinical management of IPF, with the availability of two pharmacotherapeutic agents, pirfenidone and nintedanib, that decrease physiological progression and likely improve progression-free survival. Current efforts are directed at identifying IPF early, potentially relying on combinations of biomarkers that include circulating factors, demographics and imaging data.

Interstitial lung disease: the diagnostic role of bronchoscopy

Interstitial lung diseases (ILDs) form one of the most fascinating fields in pulmonary medicine. They also pose one of the greatest challenges for accurate diagnosis and proper treatment. Even within the recommended and warranted multidisciplinary approach, differentiating between one disease and another may lead to frustration, especially when proper lung tissue is not available for adequate pathological review. A surgical lung biopsy (SLB) might render enough tissue for histopathology, but this could come at the expense of high morbidity and even mortality, as in the case of usual interstitial pneumonia (UIP). Could bronchoscopy and its various techniques offer a safer and higher yield alternative? Since the very late 19th century, efforts have been made to better examine the airways, obtain tissue and treat various conditions. This resulted in the successive emergence of bronchoalveolar lavage (BAL), endobronchial and transbronchial forceps biopsies, until recently when transbronchial cryobiopsy surfaced as a nascent technique with much promise. The use of endobronchial ultrasound revolutionized the diagnosis and staging of lung cancer, while adding to the yield of other conditions such as sarcoidosis. Ongoing research, efforts and studies have continuously scrutinized the roles of various techniques in the approach to ILDs. For example, BAL seems to serve mostly to eliminate infection as an etiology or a complicating factor in the acute worsening of a fibrotic lung disease, while a predominant cellular component might be diagnostic, such as eosinophilia in eosinophilic lung disease, or lymphocytosis in hypersensitivity pneumonitis (HP). On the other hand, endobronchial biopsy's (EBB) role appears limited to sarcoidosis. As for transbronchial biopsy by forceps, the small sample size and related artifact appear to be limiting factors in making an accurate diagnosis. Recently, however, the use of cryotherapy via employing a cryoprobe in obtaining transbronchial lung biopsies is unfolding into a refined interventional method which might transform indefinitely our approach to the pathological diagnosis of the various ILDs.

The role of macrophages in interstitial lung diseases

The finding of collections of macrophages/histiocytes in lung biopsy and bronchoalveolar lavage is relatively common in routine practice. This morphological feature in itself is pathological, but the exact clinical significance and underlying disease should be evaluated together with clinical data, functional respiratory and laboratory tests and imaging studies.

Morphological characteristics of macrophages and their distribution along the different pulmonary structures should be examined carefully by pathologists. Indeed, haemosiderin-laden macrophages are associated with smoking-related diseases when pigment is fine and distribution is bronchiolocentric, while alveolar haemorrhage or pneumoconiosis are the main concerns when pigment is chunky or coarse and the macrophages show an intra-alveolar or perilymphatic location, respectively. In the same way, pulmonary accumulation of macrophages with foamy cytoplasm is generally associated with pathologies leading to broncho-bronchiolar obstruction (e.g.diffuse panbronchiolitis, hypersensitivity pneumonia or cryptogenic organising pneumonia) or alternatively to exogenous lipoid pneumonia, some drug toxicity (e.g.amiodarone exposure or toxicity) and metabolic disorders (e.g.type B Niemann–Pick disease).

This pathology-based perspectives article is aimed at concisely describing the diagnostic possibilities when faced with collection of macrophages in lung biopsy and cytology.

Connective tissue disease associated interstitial pneumonia: a challenge for both rheumatologists and pulmonologists

Interstitial lung disease (ILD) can be either idiopathic, the result of exposure or may be associated with extrapulmonary diseases. Among the latter, connective tissue diseases (CTDs) make up the largest part. The identification, follow-up and treatment of CTD-associated ILD (CTD-ILD) are a challenge for every physician as ILD can occur before, during and after the diagnosis of CTD. Early detection of pulmonary involvement is an essential task for the treating rheumatologist and recognition of the underlying CTD can pose a challenge for the treating pulmonologist. Multidisciplinary engagement towards the patient is therefore indispensable for optimal clinical care. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 326-335).

Introduction of cryobiopsies in the diagnostics of interstitial lung diseases - experiences in a referral center

Introduction: Transbronchial cryobiopsies (cTBB) has emerged as a new method for obtaining lung tissue biopsies in the diagnosis of interstitial lung diseases (ILDs). Until now, it has been used in a few highly specialized interventional centers and has shown promising results in obtaining a definite diagnosis of ILDs. Method: All patients undergoing a cTBB between November 2015 and June 2016 were included in this case series study. Data on patient demographics, high-resolution computed tomography patterns, size and number of biopsies, histology patterns, the contribution to a confident diagnosis and complications were registered. Results: Thirty-eight patients underwent cTBB in the period. cTBB contributed to the diagnosis in 28 (74%) of the 38 patients. Only few complications were observed; pneumothorax was the most frequent complication (10 patients, 26%). In six patients, local bleeding occurred during the procedure and was easily controlled by a Fogarty catheter balloon and in some cases tranexamic acid. Conclusion: Performing cTBB in the diagnostics of ILDs is a safe and feasible procedure. cTBB resulted in a confident diagnosis in 74% of cases.

Transbronchial Cryobiopsy in Diffuse Lung Disease: Update for the Pathologist

CONTEXT

- Transbronchial cryobiopsy has recently been proposed as an alternative to surgical biopsy in the diagnosis of diffuse lung disease.

OBJECTIVE

- To familiarize pathologists with transbronchial cryobiopsy, including what it is, how it is performed, how it compares to other techniques of lung biopsy in diffuse lung disease, what are the technical issues relating to it, what the complications are, how cryobiopsies should be interpreted, and the clinical usefulness of cryobiopsy.

DATA SOURCES

- All the available literature on cryobiopsy in diffuse lung disease through May 2016, primarily in the last 5 years, was reviewed, and some unpublished data known to the authors were included.

CONCLUSIONS

- Cryobiopsies are considerably larger than forceps biopsies and allow pattern recognition approaching that of a surgical lung biopsy in many cases. Artifacts associated with cryobiopsy are minimal. In comparison with surgical lung biopsies, the diagnosis rate with cryobiopsies is lower, in the neighborhood of 80%, versus higher than 90% for surgical lung biopsies. Cryobiopsy is proposed as an alternative to surgical lung biopsy and a technique that may appreciably decrease the number of patients who require surgical lung biopsy for diagnosis. This is important because the mortality from cryobiopsy is very small (0.1% to date) compared with surgical lung biopsy (1.7% for elective procedures and considerably higher for nonelective procedures).

The standard of care of patients with ARDS: ventilatory settings and rescue therapies for refractory hypoxemia

Purpose

Severe ARDS is often associated with refractory hypoxemia, and early identification and treatment of hypoxemia is mandatory. For the management of severe ARDS ventilator settings, positioning therapy, infection control, and supportive measures are essential to improve survival.

Methods and results

A precise definition of life-threating hypoxemia is not identified. Typical clinical determinations are: arterial partial pressure of oxygen < 60 mmHg and/or arterial oxygenation < 88 % and/or the ratio of PaO₂/FIO₂ < 100. For mechanical ventilation specific settings are recommended: limitation of tidal volume (6 ml/kg predicted body weight), adequate high PEEP (>12 cmH₂O), a recruitment manoeuvre in special situations, and a ‘balanced’ respiratory rate (20-30/min). Individual bedside methods to guide PEEP/recruitment (e.g., transpulmonary pressure) are not (yet) available. Prone positioning [early (≤ 48 hrs after onset of severe ARDS) and prolonged (repetition of 16-hr-sessions)] improves survival. An advanced infection management/control includes early diagnosis of bacterial, atypical, viral and fungal specimen (blood culture, bronchoalveolar lavage), and of infection sources by CT scan, followed by administration of broad-spectrum anti-infectives. Neuromuscular blockage (Cisatracurium ≤ 48 hrs after onset of ARDS), as well as an adequate sedation strategy (score guided) is an important supportive therapy. A negative fluid balance is associated with improved lung function and the use of hemofiltration might be indicated for specific indications.

Conclusions

A specific standard of care is required for the management of severe ARDS with refractory hypoxemia.