Complications in Idiopathic Pulmonary Fibrosis: Focus on Their Clinical and Radiological Features

Characterisation of changes in global genes expression in the lung of ICR mice in response to the inflammation and fibrosis induced by polystyrene nanoplastics inhalation

This study characterised the changes in global gene expression in the lung of ICR mice in response to the inflammation and fibrosis induced by the inhalation of 0.5 μm polystyrene (PS)-nanoplastics (NPs) at various concentrations (4, 8, and 16 μg/mL) for 2 weeks. The total RNA extracted from the lung tissue of NPs-inhaled mice was hybridised into oligonucleotide microarrays. Significant upregulation was detected in several inflammatory responses, including the number of immune cells in bronchoalveolar lavage fluid (BALF), the expression level of inflammatory cytokines, mucin secretion, and histopathological changes, while they accumulated average of 13.38 ± 1.0 μg/g in the lungs of the inhaled ICR mice. Similar responses were observed regarding the levels of fibrosis-related factors in the NPs-inhaled lung of ICR mice, such as pulmonary parenchymal area, expression of pro-fibrotic marker genes, and TGF-β1 downstream signalling without any significant hepatotoxicity and nephrotoxicity. In microarray analyses, 60 genes were upregulated, and 55 genes were downregulated in the lung of ICR mice during inflammation and fibrosis induced by NPs inhalation compared to the Vehicle-inhaled mice. Among these genes, many were categorised into several ontology categories, including the anatomical structure, binding, membrane, and metabolic process. Furthermore, the major genes in the upregulated categories included Igkv14-126000, Egr1, Scel, Lamb3, and Upk3b. In contrast, the major genes in the down-regulated categories were Olfr417, Olfr519, Rps16, Rap2b, and Vmn1r193. These results suggest several gene functional groups and individual genes as specific biomarkers respond to inflammation and fibrosis induced by PS-NPs inhalation in ICR mice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00188-y.

Interstitial Lung Disease: A Focused Review for the Emergency Clinician

BACKGROUND

Interstitial lung disease (ILD) is a group of restrictive pulmonary diseases associated with diffuse interstitial and parenchymal inflammation. Patients can present to the emergency department with severe exacerbation.

OBJECTIVE

This narrative review provides emergency clinicians with the most recent evidence concerning acute exacerbation of ILD (AE-ILD).

DISCUSSION

AE-ILD can present as acute respiratory distress in a patient with a pre-existing ILD diagnosis or as a de novo presentation of ILD, and is associated with significant morbidity and mortality. A variety of underlying triggers may result in AE-ILD. Emergency clinicians must first assess for extraneous causes of respiratory decompensation prior to diagnosing AE-ILD. For a de novo presentation of ILD, emergency physicians should also assess for possible reversible causes. AE-ILD is managed with systemic steroids, immunosuppressants, intravenous antibiotics, supplemental oxygen, and extracorporeal membrane oxygenation in severe cases. Given the high mortality rates in the absence of lung transplantation, early referral to transplant centers is essential to increase chances of survival.

CONCLUSIONS

Emergency clinician knowledge of AE-ILD can improve the evaluation and management of these patients.

Genetics in Idiopathic Pulmonary Fibrosis: A Clinical Perspective

BACKGROUND

Unraveling the genetic background in a significant proportion of patients with both sporadic and familial IPF provided new insights into the pathogenic pathways of pulmonary fibrosis.

AIM

The aim of the present study is to overview the clinical significance of genetics in IPF.

PERSPECTIVE

It is fascinating to realize the so-far underestimated but dynamically increasing impact that genetics has on aspects related to the pathophysiology, accurate and early diagnosis, and treatment and prevention of this devastating disease. Genetics in IPF have contributed as no other in unchaining the disease from the dogma of a "a sporadic entity of the elderly, limited to the lungs" and allowed all scientists, but mostly clinicians, all over the world to consider its many aspects and "faces" in all age groups, including its co-existence with several extra pulmonary conditions from cutaneous albinism to bone-marrow and liver failure.

CONCLUSION

By providing additional evidence for unsuspected characteristics such as immunodeficiency, impaired mucus, and surfactant and telomere maintenance that very often co-exist through the interaction of common and rare genetic variants in the same patient, genetics have created a generous and pluralistic yet unifying platform that could lead to the understanding of the injurious and pro-fibrotic effects of many seemingly unrelated extrinsic and intrinsic offending factors. The same platform constantly instructs us about our limitations as well as about the heritability, the knowledge and the wisdom that is still missing.

Anti-Inflammatory and Anti-Fibrotic Effect of Immortalized Mesenchymal-Stem-Cell-Derived Conditioned Medium on Human Lung Myofibroblasts and Epithelial Cells

Idiopathic pulmonary fibrosis (IPF) is caused by progressive lung tissue impairment due to extended chronic fibrosis, and it has no known effective treatment. The use of conditioned media (CM) from an immortalized human adipose mesenchymal stem cell line could be a promising therapeutic strategy, as it can reduce both fibrotic and inflammatory responses. We aimed to investigate the anti-inflammatory and anti-fibrotic effect of CM on human pulmonary subepithelial myofibroblasts (hPSM) and on A549 pulmonary epithelial cells, treated with pro-inflammatory or pro-fibrotic mediators. CM inhibited the proinflammatory cytokine-induced mRNA and protein production of various chemokines in both hPSMs and A549 cells. It also downregulated the mRNA expression of IL-1α, but upregulated IL-1β and IL-6 mRNA production in both cell types. CM downregulated the pro-fibrotic-induced mRNA expression of collagen Type III and the migration rate of hPSMs, but upregulated fibronectin mRNA production and the total protein collagen secretion. CM's direct effect on the chemotaxis and cell recruitment of immune-associated cells, and its indirect effect on fibrosis through the significant decrease in the migration capacity of hPSMs, makes it a plausible candidate for further development towards a therapeutic treatment for IPF.

Utility of Computed Tomographic Angiography for Pulmonary Hypertension Assessment in a Cohort of West Highland White Terriers With or Without Canine Idiopathic Pulmonary Fibrosis

West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF) are at risk of developing precapillary pulmonary hypertension (PH). In humans, thoracic computed tomography angiography (CTA) is commonly used to diagnose and monitor patients with lower airway diseases. In such patients, CTA helps to identify comorbidities, such as PH, that could negatively impact prognosis. Diameter of the pulmonary trunk (PT), pulmonary trunk-to-aorta ratio (PT/Ao), and right ventricle-to-left ventricle ratio (RV/LV) are CTA parameters commonly used to assess the presence of PH. Pulmonary vein-to-right pulmonary artery ratio (PV/PA) is a new echocardiographic parameter that can be used in dogs to diagnose PH. The primary aim of this study was to evaluate the use of various CTA parameters to diagnose PH. An additional aim was to evaluate the correlation of RV/LV measurements between different CTA planes. CTA and echocardiography were prospectively performed on a total of 47 WHWTs; 22 affected with CIPF and 25 presumed healthy control dogs. Dogs were considered to have PH if pulmonary vein-to-right pulmonary artery ratio (PV/PA) measured on 2D-mode echocardiography was less than to 0.7. WHWTs affected with CIPF had higher PT/Ao compared with control patients. In WHWTs affected with CIPF, PT size was larger in dogs with PH (15.4 mm) compared with dogs without PH (13 mm, p = 0.003). A cutoff value of 13.8 mm predicted PH in WHWTs affected with CIPF with a sensitivity of 90% and a specificity of 87% (AUC = 0.93). High correlations were observed between the different CTA planes of RV/LV. Results suggest that diameter of the PT measured by CTA can be used to diagnose PH in WHWTs with CIPF.

Elucidation of prognostic factors and the effect of anti-fibrotic therapy on waitlist mortality in lung transplant candidates with idiopathic interstitial pneumonias

BACKGROUND

Lung transplantation (LTx) is the last resort for patients who fail to respond to drug therapy and progress to advanced idiopathic interstitial pneumonias (IIPs). However, more than one-third of patients registered for LTx face despair because of rapid disease progression and donor shortage. This study aimed to identify the risk factors of waitlist mortality in LTx candidates with IIPs and investigate the association of anti-fibrotic therapy with waitlist mortality.

METHODS

We retrospectively investigated 56 patients with IIPs, including 29 patients with idiopathic pulmonary fibrosis (51.7%) and 11 patients with idiopathic pleuroparenchymal fibroelastosis (19.6%), registered for LTx at Fukuoka University Hospital between January 2006 and June 2020. The risk factors affecting transplantation-censored survival were evaluated.

RESULTS

The waitlist mortality rate of patients with nonspecific interstitial pneumonia was significantly lower than that of others. Multivariate survival analysis using Cox's model identified a history of pneumothorax (P = 0.029) and short 6-min walk distance (6MWD) (P = 0.012) to be significant variables affecting waitlist mortality. Patients receiving anti-fibrotic therapy (n = 27, 48.2%) had a lower risk of pneumothorax (P = 0.017) and their 6MWD was longer than that of non-therapy patients (P < 0.001). The waitlist mortality rate of patients on anti-fibrotic therapy was significantly lower (P = 0.012).

CONCLUSIONS

History of pneumothorax and short 6MWD were independent predictors of waitlist mortality in LTx candidates with IIPs. The anti-fibrotic therapy may potentially reduce mortality in patients with IIPs on the waiting list for LTx.

Multidisciplinary Approach to Interstitial Lung Diseases: Nothing Is Better than All of Us Together

Interstitial Lung Diseases (ILDs) are a large family of disorders characterized by inflammation and/or fibrosis of areas of the lung dedicated to gas exchange. In this Special Issue entitled “Clinical and Radiological Features of Interstitial Lung Diseases”, we collected a series of contributions in which a multidisciplinary approach was crucial for the correct diagnostic assessment of ILD. Sharing knowledge between different specialties can significantly improve diagnostic approaches and the management of ILD patients.