Report Standardization in Transbronchial Lung Cryobiopsy

The Diagnostic Efficiency and Safety of Transbronchial Lung Cryobiopsy Using 1.1-mm Cryoprobe in Diagnosing Interstitial Lung Disease

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) is increasingly used to diagnose interstitial lung disease (ILD). The 1.1-mm cryoprobe has recently been available in clinical practice. The diagnostic yield and safety of TBLC using a 1.1-mm cryoprobe need to be confirmed.

METHODS

A prospective, randomized controlled trial was conducted in patients with suspected ILD and randomly assigned to 1.1-mm and 1.9-mm cryoprobe groups. The primary outcome was the diagnostic yield of multidisciplinary discussion. Secondary outcomes were sample quality and incidence of complications. The tension and stress effects during TBLC onto the target lobe caused by 1.1-mm and 1.9-mm cryoprobes were also evaluated using finite element analysis.

RESULTS

A total of 224 patients were enrolled. No significant differences were observed in the diagnostic yield (80.4% vs. 79.5%, p = 0.845) and sample quality scores (5.73 ± 0.64 vs. 5.66 ± 0.77; p = 0.324) between the 1.9-mm cryoprobe group and 1.1-mm cryoprobe group. The average surface areas of samples in 1.1-mm cryoprobe group were smaller, while no difference in sample weights was observed. A decreased incidence of moderate bleeding was found in the 1.1-mm cryoprobe group (17.0% vs. 6.2%, p = 0.027), while there was no difference in the incidence of the pneumothorax, there was a trend to higher rate of pneumothorax in 1.1-mm group. In finite element analysis, the 1.1-mm cryoprobe required the largest tension and produced the largest stress.

CONCLUSION

Compared with a 1.9-mm cryoprobe, there was no difference in specimen quality or diagnostic rate but smaller sample size with a 1.1-mm cryoprobe. There was a decreased risk of moderate bleeding, but a trend towards increased risk for pneumothorax with 1.1-mm cryoprobe.

TRAIL REGISTRATION

Clinicaltrials.gov identifier NCT04047667; registered August 4, 2019.

Association between Parenchymal B-Cell Follicles and CT-Proven Enlarged Mediastinal Lymph Nodes in Patients with Pulmonary Fibrosis

BACKGROUND

Mediastinal lymph node enlargement (MLNE) is a finding described in a subset of patients with idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases (ILDs) and is associated with accelerated disease progression and increased mortality. The cause of MLNE is still not known. Our hypothesis is that there is an association between MLNE and B-cell follicles in lung tissue, another aspect detectable in the lung tissue of patients with IPF and other ILDs.

OBJECTIVES

The aim of this study was to assess if there is an association between MLNE and B-cell follicles in lung tissue in patients with IPF and other ILDs.

METHOD

Patients having transbronchial cryobiopsies performed as part of an investigation for ILD were included in this prospective observational study. MLNE (smallest diameter ≥10 mm) were assessed in station 7, 4R, and 4L on high-resolution computed tomography scans. B-cell follicles were assessed on haematoxylin-eosin-stained specimens. Lung function, 6-minute walk test, acute exacerbation, and mortality were registered after 2 years. In addition, we investigated if the finding of B-cell follicles was consistent in patients who underwent both surgical lung biopsies (SLBs) and cryobiopsies.

RESULTS

In total, 93 patients were included for analysis (46% diagnosed with IPF, 54% diagnosed with other ILDs). MLNE was found in 26 (60%) of the IPF patients and in 23 (46%) of the non-IPF patients (p = 0.164). Diffusing capacity for carbon monoxide was significantly lower (p = 0.03) in patients with MLNE compared to patients without MLNE. B-cell follicles were found in 11 (26%) of the IPF patients and in 22 (44%) of the non-IPF patients (p = 0.064). Germinal centres were not seen in any of the patients. There was no association between MLNE and B-cell follicles (p = 0.057). No significant difference in change of pulmonary function test was seen at 2-year follow-up when comparing the patients with and without MLNE or B-cell follicles. In 13 patients, both SLBs and cryobiopsies were performed. The presence of B-cell follicles was not consistent when comparing the two different methods.

CONCLUSION

MLNE is evident in a substantial part of patients with ILD and is associated with lower DLCO at inclusion. We could not demonstrate an association between histological B-cell follicles in biopsies and MLNE. A possible explanation for this is that the cryobiopsies might not have captured the changes we sought.

[Transbronchial lung cryobiopsy in interstitial lung diseases]

In some cases of interstitial lung disease (ILD), clinical and biological findings associated with CT scan pattern during multidisciplinary discussion (MDD) fail to yield a confident diagnosis. In these cases, histology may be necessary. Transbronchial lung cryobiopsy (TBLC) is a bronchoscopic procedure that has been developed in recent years and currently contributes to diagnostic work-up in patients with ILD. TBLC provides tissue samples for histological analysis with an acceptable risk of complications, consisting mainly in pneumothorax or bleeding. In addition to higher diagnostic yield than conventional forceps biopsies, the procedure shows a better safety profile than surgical biopsies. The indication to perform TBLC is decided during a 1st MDD and during a 2nd MDD, results can provide a diagnostic yield approximating 80%. TBLC appears to be an attractive, minimally invasive technique to be proposed as a first-line procedure in selected patients in experienced centers, while surgical lung biopsy may be considered as a second-line solution.

Transbronchial lung cryobiopsy for the diagnosis of interstitial lung diseases

PURPOSE OF REVIEW

Transbronchial lung cryobiopsy has shown promise in several studies in providing meaningful histological information in the multidisciplinary team diagnosis of fibrotic interstitial lung diseases. The purpose of this review is to describe recent literature providing support for the formal integration of cryobiopsy into the algorithm for interstitial lung disease diagnosis.

RECENT FINDINGS

Histopathological concordance between cryobiopsy and surgical biopsy and diagnostic agreement at multidisciplinary discussion have been reported good; furthermore, cryobiopsy may provide an increased diagnostic confidence to a level likely to influence management. Finally, although cryobiopsy is more likely to provide a probable usual interstitial pneumonia (UIP) pattern than a definite UIP pattern, given the limited sampling of sub-pleural lung parenchyma in most cases, finding of a probable UIP pattern at cryobiopsy samples is strongly predictive of a definite UIP pattern in the corresponding surgical biopsy and when a UIP pattern is found on cryobiopsy sample, this is associated with higher mortality compared with other histological patterns.

SUMMARY

Cryobiopsy is becoming a valid alternative to surgical lung biopsy for making histopathological diagnosis in patients with interstitial lung diseases of undetermined type in experienced centres, with standardized protocols, in order to have the best risks/diagnostic yields ratio.

PD-L1 Expression in Patients with Idiopathic Pulmonary Fibrosis

Background: Idiopathic pulmonary fibrosis (IPF) is the most common and severe form within the group of idiopathic interstitial pneumonias. It is characterized by repetitive alveolar injury in genetically susceptible individuals and abnormal wound healing, leading to dysregulated bronchiolar proliferation and excessive deposition of extracellular matrix, causing complete architectural distortion and fibrosis. Epithelial-to-mesenchymal transition is considered an important pathogenic event, a phenomenon also observed in various malignant neoplasms, in which tumor cells express programmed death-ligand one (PD-L1). The aim of this study was to assess the presence of PD-L1 in patients with IPF and other interstitial lung diseases (ILDs). Method: Patients with a clinically and radiologically suspected idiopathic interstitial pneumonia or other ILDs undergoing transbronchial cryobiopsy to confirm the diagnosis at the Department of Respiratory Diseases and Allergy, Aarhus University Hospital, were included in this prospective observational study. Cellular membrane PD-L1 expression in epithelial cells was determined using the DAKO PD-L1 IHC 22C3 PharmDx Kit. Results: Membrane-bound PD-L1 (mPD-L1) was found in twelve (28%) of the forty-three patients with IPF and in five (9%) of the fifty-five patients with other ILDs (p = 0.015). When adjusting for age, gender and smoking status, the odds ratio of having IPF when expressing mPD-L1 in alveolar and/or bronchiolar epithelial cells was 4.3 (CI: 1.3–14.3). Conclusion: Expression of mPD-L1 in epithelial cells in the lung parenchymal zones was detected in a consistent subgroup of patients with IPF compared to other interstitial pneumonias. Larger studies are needed to explore the role of mPD-L1 in patients with IPF.

Transbronchial Cryobiopsy in the Diagnosis of Fibrotic Interstitial Lung Disease

CONTEXT.—

Transbronchial cryobiopsy is an emerging procedure to obtain lung tissue for diagnosis of interstitial lung disease and has gained popularity because it is less invasive and has a lower rate of complications compared with nonselective surgical lung biopsy.

OBJECTIVE.—

To provide an overview of the status of the medical literature regarding transbronchial cryobiopsy.

DATA SOURCES.—

A literature search was performed using PubMed search engine. The terms "cryobiopsy" or "cryoprobe" and "interstitial lung disease" or "diffuse parenchymal lung disease" or "pulmonary fibrosis" were used, with the search concluding at the end of November 2019.

CONCLUSIONS.—

While the diagnostic yield of transbronchial cryobiopsy is slightly lower than surgical lung biopsy, a growing amount of literature suggests that with a multidisciplinary approach cryobiopsy provides diagnostic and prognostic information approaching that of surgical lung biopsy with lower morbidity and mortality.

Transbronchial Cryobiopsy in the Diagnosis of Diffuse Lung Disease

Transbronchial cryobiopsy, a new diagnostic procedure in patients with diffuse lung disease, provides larger and better-preserved lung specimens compared to forceps biopsy. The diagnostic yield of cryobiopsy is much better than that of forceps biopsy and slightly lower than that of surgical lung biopsy, but with a lower complication rate compared to the latter. Literature suggests that in the multidisciplinary approach to patients with diffuse lung disease cryobiopsy provides diagnostic and prognostic information similar to surgical lung biopsy. Cryobiopsy can also be performed in some patients unsuitable for surgical biopsy, yet in whom histologic input is needed.

Fibrotic progression and radiologic correlation in matched lung samples from COVID-19 post-mortems

Data on the pathology of COVID-19 are scarce; available studies show diffuse alveolar damage; however, there is scarce information on the chronologic evolution of COVID-19 lung lesions. The primary aim of the study is to describe the chronology of lung pathologic changes in COVID-19 by using a post-mortem transbronchial lung cryobiopsy approach. Our secondary aim is to correlate the histologic findings with computed tomography patterns. SARS-CoV-2-positive patients, who died while intubated and mechanically ventilated, were enrolled. The procedure was performed 30 min after death, and all lung lobes sampled. Histopathologic analysis was performed on thirty-nine adequate samples from eight patients: two patients (illness duration < 14 days) showed early/exudative phase diffuse alveolar damage, while the remaining 6 patients (median illness duration—32 days) showed progressive histologic patterns (3 with mid/proliferative phase; 3 with late/fibrotic phase diffuse alveolar damage, one of which with honeycombing). Immunohistochemistry for SARS-CoV-2 nucleocapsid protein was positive predominantly in early-phase lesions. Histologic patterns and tomography categories were correlated: early/exudative phase was associated with ground-glass opacity, mid/proliferative lesions with crazy paving, while late/fibrous phase correlated with the consolidation pattern, more frequently seen in the lower/middle lobes. This study uses an innovative cryobiopsy approach for the post-mortem sampling of lung tissues from COVID-19 patients demonstrating the progression of fibrosis in time and correlation with computed tomography features. These findings may prove to be useful in the correct staging of disease, and this could have implications for treatment and patient follow-up.

Lung Cryobiopsy for the Diagnosis of Interstitial Lung Diseases: A Series Contribution to a Debated Procedure

Introduction: Transbronchial cryobiopsy is an alternative to surgical biopsy for the diagnosis of fibrosing interstitial lung diseases, although the role of this relatively new method is rather controversial. Aim of this study is to evaluate the diagnostic performance and the safety of transbronchial cryobiopsy in patients with fibrosing interstitial lung disease. Materials and methods: The population in this study included patients with interstitial lung diseases who underwent cryobiopsy from May 2015 to May 2018 at the Division of Pneumology of San Giuseppe Hospital in Milan and who were retrospectively studied. All cryobiopsy procedures were performed under fluoroscopic guidance using a flexible video bronchoscope and an endobronchial blocking system in the operating room with patients under general anaesthesia. The diagnostic performance and safety of the procedure were assessed. The main complications evaluated were endobronchial bleeding and pneumothorax. All cases were studied with a multidisciplinary approach, before and after cryobiopsy. Results: Seventy-three patients were admitted to this study. A specific diagnosis was reached in 64 cases, with a diagnostic sensitivity of 88%; 5 cases (7%) were considered inadequate, 4 cases (5%) were found to be non-diagnostic. Only one major bleeding event occurred (1.4%), while 14 patients (19%) experienced mild/moderate bleeding events while undergoing bronchoscopy; 8 cases of pneumothorax (10.9%) were reported, of which 2 (2.7%) required surgical drainage. Conclusions: When performed under safe conditions and in an experienced center, cryobiopsy is a procedure with limited complications having a high diagnostic yield in fibrotic interstitial lung disease.

Critical reappraisal of underlying histological patterns in patients with suspected idiopathic pulmonary fibrosis

PURPOSE OF REVIEW

Usual interstitial pneumonia (UIP) pattern is the histologic marker of idiopathic pulmonary fibrosis (IPF), but usefulness of ancillary histologic findings may discriminate idiopathic from secondary UIP.

RECENT FINDINGS

Alternative less invasive procedures may identify UIP pattern preventing conventional surgical lung biopsy, whereas genomic analysis may recognize UIP pattern from otherwise poorly diagnostic samples.

SUMMARY

High-resolution computed tomography identifies a 'definite' UIP pattern in about half of cases, failing to recognize UIP in the absence of honeycombing or in limited disease. Although radiologic criteria for UIP need redefinition to improve their diagnostic yield, histologic features of UIP did not significantly change from the 1960s but continue to represent a major diagnostic tool, particularly in challenging interstitial lung diseases. A careful recognition of some histologic ancillary findings in UIP (e.g., cellular/follicular bronchiolitis with germinal centers, chronic pleuritis, interstitial granulomas/giant cells, bridging fibrosis) may be helpful in supporting secondary forms (e.g., connective tissue disease, chronic hypersensitivity pneumonia) from IPF. Cryobiopsy and awake-biopsy are promising approaches to obtain representative lung tissue preventing conventional surgical lung biopsy. Genomic techniques have recently demonstrated good-to-high sensitivity and specificity to disclose UIP pattern starting from RNA obtained in transbronchial biopsy, possibly replacing and/or flanking soon traditional histology.