Progressive Fibrosing Interstitial Lung Diseases: A Current Perspective

Nintedanib in chronic fibrosing interstitial lung diseases. A case series

Progressive pulmonary fibrosis (PPF) can be fatal in non-idiopathic interstitial lung diseases. We report a descriptive series of 13 patients with PPF who received treatment with nintedanib, a multitargeted tyrosine kinase inhibitor with antifibrotic effect. Although the reduced number of patients and the observational nature of a case series prevent us from providing strong evidence, our results suggest that nintedanib could be effective in PPF of various etiologies. Nintedanib could also be useful in specific populations such as patients awaiting lung transplant and elderly patients.

Correlation between high-resolution computed tomography appearance and histopathological features in the diagnosis of interstitial lung diseases. A real-life study

BACKGROUND

According to current guidelines, a surgical biopsy is rarely required when a high-confidence radiologic interstitial lung disease (ILD) diagnosis is made on thin-section high-resolution computed tomography (HRCT). Nevertheless, disowning HRCT scans diagnosed by biopsy are more common than presumed. Our study aimed to describe the concordance rate between HRCT scans and pathological diagnoses of ILDs obtained by surgical biopsy. The current guideline suggests the use of surgical lung biopsy (SLB) in patients with newly detected ILD of unknown cause.

METHODS

Patients who underwent mini-invasive surgical biopsies for interstitial lung diseases from January 2018 to August 2022 were analyzed. The HRCT scans were reviewed by an observer blinded to the patient's clinical information. The concordance between histological and HRCT-scan were assessed.

RESULTS

Data from 104 patients with uncertain low confidence diagnosis of interstitial lung diseases at HRCT were analyzed. Most of the patients are male (65; 62.5%). The more frequent HRCT pattern were: alternative diagnoses (46; 44.23%), UIP probable (42; 40.38%), UIP indeterminate (7; 6.73%), and non-specific interstitial pneumonia (NSIP) (9, 8.65%). The more common histological diagnosis was UIP definite (30; 28.84%), hypersensitivity pneumonia [HP](19; 18.44%), NSIP (15; 14.42%), sarcoidosis (10; 9.60%). In 7 (20%) cases, the final pathological finding denies HRCT-scans diagnoses; indeed, a moderate agreement was observed between HRCT-scan findings and the definitive histological diagnosis (kappa index: 0.428).

CONCLUSIONS

HRCT-scan has limitations if the objective is to define interstitial lung diseases accurately. Consequently, pathological assessment should be taken into account in order to provide more accurate tailored treatment strategies because the risk is to wait from 12 to 24 months to ascertain if the ILD will be treatable as progressive pulmonary fibrosis (PPF). Undeniably true, video-assisted surgical lung biopsy (VASLB) with endotracheal intubation and mechanical ventilation is associated with a risk of mortality and morbidity that is far from nil. Nevertheless, in recent years a VASLB approach performed in awake subjects under loco-regional anesthesia (awake-VASLB) has been suggested as an effective method to obtain a highly confident diagnosis in patients with diffuse pathologies of the lung parenchyma.

Targeting Progression in Pulmonary Fibrosis: An Overview of Underlying Mechanisms, Molecular Biomarkers, and Therapeutic Intervention

Interstitial lung diseases comprise a heterogenous range of diffuse lung disorders, potentially resulting in pulmonary fibrosis. While idiopathic pulmonary fibrosis has been recognized as the paradigm of a progressive fibrosing interstitial lung disease, other conditions with a progressive fibrosing phenotype characterized by a significant deterioration of the lung function may lead to a burden of significant symptoms, a reduced quality of life, and increased mortality, despite treatment. There is now evidence indicating that some common underlying biological mechanisms can be shared among different chronic fibrosing disorders; therefore, different biomarkers for disease-activity monitoring and prognostic assessment are under evaluation. Thus, understanding the common pathways that induce the progression of pulmonary fibrosis, comprehending the diversity of these diseases, and identifying new molecular markers and potential therapeutic targets remain highly crucial assignments. The purpose of this review is to examine the main pathological mechanisms regulating the progression of fibrosis in interstitial lung diseases and to provide an overview of potential biomarker and therapeutic options for patients with progressive pulmonary fibrosis.

An adjudication algorithm for respiratory-related hospitalisation in idiopathic pulmonary fibrosis

Background

There is no standard definition of respiratory-related hospitalisation, a common end-point in idiopathic pulmonary fibrosis (IPF) clinical trials. As diverse aetiologies and complicating comorbidities can present similarly, external adjudication is sometimes employed to achieve standardisation of these events.

Methods

An algorithm for respiratory-related hospitalisation was developed through a literature review of IPF clinical trials with respiratory-related hospitalisation as an end-point. Experts reviewed the algorithm until a consensus was reached. The algorithm was validated using data from the phase 3 ISABELA trials (clinicaltrials.gov identifiers NCT03711162 and NCT03733444), by assessing concordance between nonadjudicated, investigator-defined, respiratory-related hospitalisations and those defined by the adjudication committee using the algorithm.

Results

The algorithm classifies respiratory-related hospitalisation according to cause: extraparenchymal (worsening respiratory symptoms due to left heart failure, volume overload, pulmonary embolism, pneumothorax or trauma); other (respiratory tract infection, right heart failure or exacerbation of COPD); "definite" acute exacerbation of IPF (AEIPF) (worsening respiratory symptoms within 1 month, with radiological or histological evidence of diffuse alveolar damage); or "suspected" AEIPF (as for "definite" AEIPF, but with no radiological or histological evidence of diffuse alveolar damage). Exacerbations ("definite" or "suspected") with identified triggers (infective, post-procedural or traumatic, drug toxicity- or aspiration-related) are classed as "known AEIPF"; "idiopathic AEIPF" refers to exacerbations with no identified trigger. In the ISABELA programme, there was 94% concordance between investigator- and adjudication committee-determined causes of respiratory-related hospitalisation.

Conclusion

The algorithm could help to ensure consistency in the reporting of respiratory-related hospitalisation in IPF trials, optimising its utility as an end-point.

Role of Ferroptosis in Fibrosis Diseases

Ferroptosis is a pervasive non-apoptotic mode of cell death that is different from autophagy or necrosis. It is mainly caused by an imbalance between the production and degradation of lipid reactive oxygen species in cells. Several metabolic pathways and biochemical processes, such as amino acid and lipid metabolism, iron handling, and mitochondrial respiration, affect and regulate cell sensitivity to peroxidation and ferroptosis. Organ fibrosis, a pathological manifestation of several etiological conditions, leads to chronic tissue injury and is characterized by excessive deposition of extracellular matrix components. Excessive tissue fibrosis can have diverse pathophysiological effects on several organ systems, eventually causing organ dysfunction and failure. The current manuscript provides a review that illustrates the link between ferroptosis and organ fibrosis and to better understand the underlying mechanisms. It provides novel potential therapeutic approaches and targets for fibrosis diseases.

Single-cell sequencing analysis fibrosis provides insights into the pathobiological cell types and cytokines of radiation-induced pulmonary fibrosis

BACKGROUND

Radiotherapy is an essential treatment for chest cancer. Radiation-induced pulmonary fibrosis (RIPF) is an almost irreversible interstitial lung disease; however, its pathogenesis remains unclear.

METHODS

We analyzed specific changes in cell populations and potential markers by using single-cell sequencing datasets from the Sequence Read Archive database, PERFORMED from control (0 Gy) and thoracic irradiated (20 Gy) mouse lungs at day 150 post-radiation. We performed IHC and ELISA on lung tissue and cells to validate the potential marker cytokines identified by the analysis on rat thoracic irradiated molds (30 Gy).

RESULTS

Single-cell sequencing analysis showed changes in abundance across cell types and at the single-cell level, with B and T cells showing the most significant changes in abundance. And four cytokines, CCL5, ICAM1, PF4, and TNF, were significantly upregulated in lung tissues of RIPF rats and cell supernatants after ionizing radiation.

CONCLUSION

Cytokines CCL5, ICAM1, PF4, and TNF may play essential roles in radiation pulmonary fibrosis. They are potential targets for the treatment of radiation pulmonary fibrosis.

High-Resolution Computed Tomography and Lung Ultrasound in Patients with Systemic Sclerosis: Which One to Choose?

Imaging plays a pivotal role in systemic sclerosis for both diagnosis management of pulmonary complications, and high-resolution computed tomography (HRCT) is the most sensitive technique for the evaluation of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Indeed, several studies have demonstrated that HRCT helps radiologists and clinicians to make a correct diagnosis on the basis of recognised typical patterns for SSc-ILD. Most SSc patients affected by ILD have a non-specific interstitial pneumonia pattern (NISP) on HRCT scan, whilst a minority of cases fulfil the criteria for usual interstitial pneumonia (UIP). Moreover, several recent studies have demonstrated that lung ultrasound (LUS) is an emergent tool in SSc diagnosis and follow-up, although its role is still to be confirmed. Therefore, this article aims at evaluating the role of LUS in SSc screening, aimed at limiting the use of CT to selected cases.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.