Diffuse parenchymal lung disease

Lower respiratory tract microbiome and lung cancer risk prediction in patients with diffuse lung parenchymal lesions

Objective

In clinical practice, imaging manifestations of diffuse lung parenchymal lesions are common and indicative of various diseases, making differential diagnosis difficult. Some of these lesions are eventually diagnosed as lung cancer.

Methods

Because respiratory microorganisms play an important role in lung cancer development, we searched for microbial markers that could predict the risk of lung cancer by retrospectively analyzing the lower respiratory tract (LRT) microbiome of 158 patients who were hospitalized in the First Affiliated Hospital of Guangzhou Medical University (March 2021-March 2023) with diffuse lung parenchymal lesions. The final diagnosis was lung cancer in 21 cases, lung infection in 93 cases, and other conditions (other than malignancy and infections) in 44 cases. The patient's clinical characteristics and the results of metagenomic next-generation sequencing of bronchoalveolar lavage fluid (BALF) were analyzed.

Results

Body mass index (BMI) and LRT microbial diversity (Shannon, Simpson, species richness, and Choa1 index) were significantly lower (P< 0.001, respectively) and Lactobacillus acidophilus relative abundance in the LRT was significantly higher (P< 0.001) in patients with lung cancer. The relative abundance of L. acidophilus in BALF combined with BMI was a good predictor of lung cancer risk (area under the curve = 0.985, accuracy = 98.46%, sensitivity = 95.24%, and specificity = 100.00%; P< 0.001).

Conclusion

Our study showed that an imbalance in the component ratio of the microbial community, diminished microbial diversity, and the presence of specific microbial markers in the LRT predicted lung cancer risk in patients with imaging manifestations of diffuse lung parenchymal lesions.

CTHRC1: An Emerging Hallmark of Pathogenic Fibroblasts in Lung Fibrosis

Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive accumulation of extracellular matrix (ECM) due to the aberrant activation of myofibroblasts in the alveolar environment. Transforming growth factor beta (TGF-β) signaling is a crucial driver of fibrogenesis because it promotes excessive ECM deposition, thereby leading to scar formation and lung damage. A primary target of TGF-β signaling in fibrosis is Collagen Triple Helix Repeat Containing 1 (CTHRC1), a secreted glycoprotein that plays a pivotal role in ECM deposition and wound repair. TGF-β transcriptionally regulates CTHRC1 in response to tissue injury and controls the wound healing response through functional activity. CTHRC1 may also play an essential role in re-establishing and maintaining tissue homeostasis after wound closure by modulating both the TGF-β and canonical Wnt signaling pathways. This dual function suggests that CTHRC1 regulates tissue remodeling and homeostasis. However, deregulated CTHRC1 expression in pathogenic fibroblasts has recently emerged as a hallmark of fibrosis in multiple organs and tissues. This review highlights recent studies suggesting that CTHRC1 can serve as a diagnostic and prognostic biomarker for fibrosis in idiopathic pulmonary fibrosis, systemic sclerosis, and post-COVID-19 lung fibrosis. Notably, CTHRC1 expression is responsive to antifibrotic drugs that target the TGF-β pathway, such as pirfenidone and bexotegrast, indicating its potential as a biomarker of treatment success. These findings suggest that CTHRC1 may present new opportunities for diagnosing and treating patients with lung fibrosis.

Enhancing Imagistic Interstitial Lung Disease Diagnosis by Using Complex Networks

Background and Objectives: Diffuse interstitial lung diseases (DILD) are a heterogeneous group of over 200 entities, some with dramatical evolution and poor prognostic. Because of their overlapping clinical, physiopathological and imagistic nature, successful management requires early detection and proper progression evaluation. This paper tests a complex networks (CN) algorithm for imagistic aided diagnosis fitness for the possibility of achieving relevant and novel DILD management data. Materials and Methods: 65 DILD and 31 normal high resolution computer tomography (HRCT) scans were selected and analyzed with the CN model. Results: The algorithm is showcased in two case reports and then statistical analysis on the entire lot shows that a CN algorithm quantifies progression evaluation with a very fine accuracy, surpassing functional parameters' variations. The CN algorithm can also be successfully used for early detection, mainly on the ground glass opacity Hounsfield Units band of the scan. Conclusions: A CN based computer aided diagnosis could provide the much-required data needed to successfully manage DILDs.

Incidental discovery of interstitial lung disease: diagnostic approach, surveillance and perspectives

The incidental discovery of pre-clinical interstitial lung disease (ILD) has led to the designation of interstitial lung abnormalities (ILA), a radiological entity defined as the incidental finding of computed tomography (CT) abnormalities affecting more than 5% of any lung zone. Two recent documents have redefined the borders of this entity and made the recommendation to monitor patients with ILA at risk of progression. In this narrative review, we will focus on some of the limits of the current approach, underlying the potential for progression to full-blown ILD of some patients with ILA and the numerous links between subpleural fibrotic ILA and idiopathic pulmonary fibrosis (IPF). Considering the large prevalence of ILA in the general population (7%), restricting monitoring only to cases considered at risk of progression appears a reasonable approach. However, this suggestion should not prevent pulmonary physicians from pursuing an early diagnosis of ILD and timely treatment where appropriate. In cases of suspected ILD, whether found incidentally or not, the pulmonary physician is still required to make a correct ILD diagnosis according to current guidelines, and eventually treat the patient accordingly.

In patients with interstitial lung abnormalities (ILA), monitoring of those at risk of progression is currently recommended, and pulmonary physicians should pursue an early diagnosis when ILA become clinically significant to facilitate timely treatment https://bit.ly/3HKOQc8

Bronchoscopic Probe-Based Confocal Laser Endomicroscopy to Diagnose Diffuse Parenchymal Lung Diseases

BACKGROUND

Diagnosis of diffuse parenchymal lung disease (DPLD) is based on clinical evaluation, radiological imaging and histology. However, additional techniques are warranted to improve diagnosis.

AIMS AND OBJECTIVE

Probe based confocal laser endomicroscopy (pCLE) allows real time in vivo visualisation of the alveolar compartment during bronchoscopy based on autofluorescence of elastic fibres. We used pCLE (Cellvizio®, Mauna Kea Technology. Inc, Paris, France) to characterise alveolar patterns in patients with different types of DPLD.

METHODS

In this pilot study we included 42 therapy naive patients (13 female, age 72.6 +/- 2.3 years), who underwent bronchoscopy for workup of DPLD. pCLE images were obtained during rigid bronchoscopy in affected lung segments according to HR-CT scan, followed by cryobiopsies in the identical area. Diagnoses were made by a multidisciplinary panel. The description of pCLE patterns was based on the degree of distortion of the hexagonal alveolar pattern, the density of alveolar structures, the presence of consolidations or loaded alveolar macrophages (AM). The assessment was performed by 2 investigators blinded for the final diagnosis.

RESULTS

The normal lung showed a typical alveolar loop pattern. In amiodarone lung disease loaded AM were predominant. COP showed characteristic focal consolidations. IPF was characterized by significant distortion and destruction, NSIP showed significant increase in density, and chronic HP presented with consolidations, mild distortion and density.

CONCLUSION

pCLE shows potential as an adjunctive bronchoscopic imaging technique in the differential diagnosis of DPLD. Structured and quantitative analysis of the images is required.

Evaluation of Transbronchial Lung Cryobiopsy Freezing Time, Biopsy Size, Histological Quality, and Incidence of Complication: A Prospective Clinical Trial

BACKGROUND

Transbronchial cryobiopsy (TBCB), a novel way of obtaining a specimen of lung tissue using a flexible cryoprobe, can obtain large lung biopsies without crush artifacts. The freezing time of TBCB was empirically selected from 3 to 7 s in the previous studies. However, no consensus has yet been reached regarding the optimal freezing time used in TBCB.

OBJECTIVES

The primary endpoint was biopsy size in different freezing times. The secondary endpoints included sample histological quality, diagnostic confidence, and complications in different freezing times.

METHODS

Patients who were suspected of DPLD requiring histopathological examination for further evaluation were enrolled in this study. Distinct biopsies were obtained by using different freezing times increased from 3 to 6 s sequentially. Samples were reviewed by 2 external expert pathologists.

RESULTS

A total of 33 patients were enrolled, and 143 transbronchial cryobiopsies were taken in this trial. An average of 4.33 samples were taken from each patient. The mean biopsy size of different freezing times from 3 to 6 s was 9.10 ± 4.37, 13.23 ± 5.83, 16.26 ± 5.67, and 18.83 ± 7.50 mm2, respectively. A strong correlation between freezing time and biopsy size was observed (r = 0.99, p < 0.01). Statistically significant difference of biopsy size was detected in the freezing time of 3 s versus 4 s (p < 0.01) and 4 s versus 5 s (p = 0.02), but not in the freezing time of 5 s versus 6 s (p = 0.10). Overall bleeding in different freezing times from 3 to 6 s was 53.33%, 67.50%, 89.47%, and 77.14%, respectively. A significantly higher overall bleeding was observed when the freezing time exceeded 4 s (RR = 1.67, p < 0.01). Pneumothorax occurred in 4 cases (12.12%). One lethal case (3.03%) was noted 25 days after TBCB. Lung parenchyma was preserved well in all cryobiopsy samples. Thirty-one (93.94%) patients' histopathological findings were identified as sufficient to establish a CRP diagnosis. There was no statistical difference in diagnostic confidence between different freezing times.

CONCLUSION

A longer freezing time was associated with a larger size of the biopsy sample but a higher risk of bleeding. The optimal transbronchial cryobiopsy freezing time is 3-4 s, which is easily achievable and provides an adequate biopsy size whilst creating a safety threshold from complications.

Outcomes of Video-Assisted Thoracic Surgical Lung Biopsy for Interstitial Lung Diseases

Purpose: Surgical lung biopsy (SLB) is an important diagnostic tool for interstitial lung disease (ILD), yet the risk factors for SLB are still debatable and long-term outcomes remain unknown.

Methods: We retrospectively reviewed the records of 85 consecutive patients with ILD who underwent SLB by video-assisted thoracic surgery (VATS) from 2008 to 2019. Risk factors for complications and differences of outcomes between idiopathic pulmonary fibrosis (IPF) and other ILDs were examined.

Results: All patients who underwent VATS had no mortality or acute exacerbation of ILD within 90 days of SLB. The rate of complication was 9.4%, and there were no statistically significant risk factors for complications. While the IPF group was not significantly different from the non-IPF group with regard to surgical parameters or complications, patients with IPF had significantly higher rates of mortality (50% vs. 9% in 5 years; p <0.001) and readmission due to acute exacerbation (75% vs. 8% in 5 years; p <0.001).

Conclusion: VATS lung biopsy for ILD can be a safe approach regardless of underlying phenotypes. An accurate diagnosis of IPF via SLB may be beneficial for correct patient management.

Ultrasound B-lines in the evaluation of interstitial lung disease in patients with systemic sclerosis: Cut-off point definition for the presence of significant pulmonary fibrosis

The aim of this study was to establish the cut-off point of ultrasound (US) B-lines number for detecting the presence of significant interstitial lung disease (ILD) in patients with systemic sclerosis (SSc) (SSc-ILD) in relation to high-resolution computed tomography (HRCT) findings.Consecutive SSc-ILD patients underwent chest HRCT, lung US (LUS), pulmonary function test, and clinical assessment. Exclusion criteria were represented by the presence of a coexisting congestive heart failure and a clinical history suggestive of lung or pleural diseases. HRCT images were scored for the presence of ILD by 2 readers, in accordance with the Warrick scoring system. US assessment was performed by a US skilled rheumatologist, blinded to HRCT results and clinical data, and included the bilateral evaluation of 14 lung intercostal spaces (LIS). In each LIS, the number of B-lines was recorded and summed. To test discriminant validity, we used the receiver operating characteristic (ROC) curve analysis applying a Warrick score of 7 as external criterion for the presence of SSc-ILD.Forty patients completed the study. The US B-lines number and the Warrick score confirmed excellent correlation (Spearman rho: 0.958, P = .0001). The ROC curve analysis revealed that the presence of 10 US B-lines is the cut-off point with the greatest positive likelihood ratio (12.52) for the presence of significant SSc-ILD.The detection of 10 B-lines is highly predictive for the HRCT presence of significant SSc-ILD. In SSc patients, the LUS assessment as first imaging tool may represent an effective model to improve the correct timing of chest HRCT.