The diagnosis of idiopathic pulmonary fibrosis: current and future approaches

A nitroreductase responsive probe for early diagnosis of pulmonary fibrosis disease

Idiopathic pulmonary fibrosis (IPF) is a serious interstitial lung disease. However, the definitive diagnosis of IPF is impeded by the limited capabilities of current diagnostic methods, which may fail to capture the optimal timing for treatment. The main goal of this study is to determine the feasibility of a nitroreductase (NTR) responsive probe, 18F-NCRP, for early detection and deterioration monitoring of IPF. 18F-NCRP was obtained with high radiochemical purity (>95 %). BLM-injured mice were established by intratracheal instillation with bleomycin (BLM) and characterized through histological analysis. Longitudinal PET/CT imaging, biodistribution study and in vitro autoradiography were performed. The correlations between the uptake of 18F-NCRP and mean lung density (tested by CT), as well as histopathological characteristics were analyzed. In PET imaging study, 18F-NCRP exhibited promising efficacy in monitoring the progression of IPF, which was earlier than CT. The ratio of uptake in BLM-injured lung to control lung increased from 1.4-fold on D15 to 2.2-fold on D22. Biodistribution data showed a significant lung uptake of 18F-NCRP in BLM-injured mice. There was a strong positive correlation between the 18F-NCRP uptake in the BLM-injured lungs and the histopathological characteristics. Given that, 18F-NCRP PET imaging of NTR, a promising biomarker for investigating the underlying pathogenic mechanism of IPF, is attainable as well as desirable, which might lay the foundation for establishing an NTR-targeted imaging evaluation system of IPF.

Leech extract alleviates idiopathic pulmonary fibrosis by TGF-β1/Smad3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Leech, as a traditional Chinese medicine for the treatment of blood circulation and blood stasis, was also widely used to cure pulmonary fibrosis in China. In clinical practice, some traditional Chinese medicine preparation such as Shui Zhi Xuan Bi Hua Xian Tang and Shui Zhi Tong Luo Capsule composed of leech, could improve the clinical symptoms and pulmonary function in patients with idiopathic pulmonary fibrosis (IPF). However, the material basis of the leech in the treatment of IPF were not yet clear.

AIM OF THE STUDY

Screen out the components of leech that have the anti-pulmonary fibrosis effects, and further explore the therapeutic mechanism of the active components.

MATERIALS AND METHODS

In this study, the different molecular weight components of leech extract samples were prepared using the semi-permeable membranes with different pore sizes. The therapeutic effects of the leech extract groups with molecular weight greater than 10 KDa (>10 KDa group), between 3 KDa and 10 KDa (3-10 KDa group), and less than 3 KDa (<3 KDa group) on pulmonary fibrosis were firstly investigated by cell proliferation and cytotoxicity assay (MTT), cell wound healing assay, immunofluorescence staining (IF) and Western blot (WB) assay through the TGF-β1-induced fibroblast cell model. Then bleomycin-induced pulmonary fibrosis (BML-induced PF) mouse model was constructed to investigate the pharmacological activities of the active component group of leech extract in vivo. Pathological changes of the mouse lung were observed by hematoxylin-eosin staining (H&E) and Masson's trichrome staining (Masson). The hydroxyproline (HYP) content of lung tissues was quantified by HYP detection kit. The levels of extracellular matrix-related fibronectin (FN) and collagen type Ⅰ (Collagen Ⅰ), pyruvate kinase M2 (PKM2) monomer and Smad7 protein were determined via WB method. PKM2 and Smad7 protein were further characterized by IF assays.

RESULTS

Using TGF-β1-induced HFL1 cell line as a PF cell model, the in vitro results demonstrated that the >10 KDa group could significantly inhibited the cell proliferation and migration, downregulated the expression level of cytoskeletal protein vimentin and α-smooth muscle actin (α-SMA), and reduced the deposition of FN and Collagen Ⅰ. In the BML-induced PF mouse model, the >10 KDa group significantly reduced the content of HYP, downregulated the expression levels of FN and Collagen Ⅰ in lung tissues, and delayed the pathological changes of lung tissue structure. The results of WB and IF assays further indicated that the >10 KDa group could up-regulate the expression level of PKM2 monomer and Smad7 protein in the cellular level, thereby delaying the progression of pulmonary fibrosis.

CONCLUSIONS

Our study revealed that the >10 KDa group was the main material basis of the leech extract that inhibited pulmonary fibrosis through TGF-β1/Smad3 signaling pathway.

Idiopathic pulmonary fibrosis (IPF): Diagnostic routes using novel biomarkers

Idiopathic pulmonary fibrosis (IPF) diagnosis is still the diagnosis of exclusion. Differentiating from other forms of interstitial lung diseases (ILDs) is essential, given the various therapeutic approaches. The IPF course is now unpredictable for individual patients, although some genetic factors and several biomarkers have already been associated with various IPF prognoses. Since its early stages, IPF may be asymptomatic, leading to a delayed diagnosis. The present review critically examines the recent literature on molecular biomarkers potentially useful in IPF diagnostics. The examined biomarkers are grouped into breath and sputum biomarkers, serologically assessed extracellular matrix neoepitope markers, and oxidative stress biomarkers in lung tissue. Fibroblasts and complete blood count have also gained recent interest in that respect. Although several biomarker candidates have been profiled, there has yet to be a single biomarker that proved specific to the IPF disease. Nevertheless, various IPF biomarkers have been used in preclinical and clinical trials to verify their predictive and monitoring potential.

Inhibition of bleomycin-induced pulmonary fibrosis in SD rats by sea cucumber peptides

BACKGROUND

Pulmonary fibrosis (PF) is the terminal manifestation of a type of pulmonary disease, which seriously affects the respiratory function of the body, and with no effective cure for treatment. This study evaluated the effect of sea cucumber peptides (SCP) on bleomycin-induced SD rat PF.

RESULTS

SCP can inhibit the PF induced by bleomycin. PF and SCP did not affect the food intake of rats, but PF reduced the body weight of rats, and SCP could improve the weight loss. SCP reduced lung index in PF rats in a dose-dependent manner. SCP significantly reduced IL-1β, IL-6, TNF-α, α-SMA and VIM expression levels in lung tissue (P < 0.05), significantly decreased TGF-β1 expression level in serum (P < 0.01) and the LSCP group and MSCP group had better inhibitory effects on PF than the HSCP group. Histomorphological results showed that SCP could ameliorate the structural damage of lung tissue, alveolar wall rupture, inflammatory cell infiltration, fibroblast proliferation and deposition of intercellular matrix and collagen fibers caused by PF. The improvement effect of the MSCP group was the most noteworthy in histomorphology. Metabolomics results showed that SCP significantly downregulated catechol, N-acetyl-l-histidine, acetylcarnitine, stearoylcarnitine, d-mannose, l-threonine, l-alanine, glycine, 3-guanidinopropionic acid, prostaglandin D2 and embelic acid d-(-)-β-hydroxybutyric acid expression levels in lung tissue.

CONCLUSION

SCP ameliorate bleomycin-induced SD rat PF. KEGG pathway analysis proved that SCP intervened in PF mainly via the lysosome pathway, with d-mannose as the key factor. © 2023 Society of Chemical Industry.

Early Diagnosis and Treatment of Idiopathic Pulmonary Fibrosis: A Narrative Review

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial lung disease of unknown aetiology. Patients typically present with symptoms of chronic dyspnoea and cough over a period of months to years. IPF has a poor prognosis, with an average life expectancy of 3-5 years from diagnosis if left untreated. Two anti-fibrotic medications (nintedanib and pirfenidone) have been approved for the treatment of IPF. These drugs slow disease progression by reducing decline in lung function. Early diagnosis is crucial to ensure timely treatment selection and improve outcomes. High-resolution computed tomography (HRCT) plays a major role in the diagnosis of IPF. In this narrative review, we discuss the importance of early diagnosis, awareness among primary care physicians, lung cancer screening programmes and early IPF detection, and barriers to accessing anti-fibrotic medications.

Observational findings of transbronchial lung biopsy in patients with interstitial lung disease: a retrospective study in Aleppo University Hospital

Clinicians face a significant obstacle when attempting to diagnose interstitial lung disease (ILD) patients. However, a thorough clinical examination together with the proper imaging and diagnostic techniques may provide a reliable diagnosis of a particular kind of ILD, and invasive tests such as rigid bronchoscopy or surgical lung biopsy may not be necessary. The aim of this study is to determine the histologic outcomes of an ILD transbronchial lung biopsy (TBLB) carried out at the university hospital in Aleppo.

Methods

This retrospective cohort research was done between 1 January 2020 and 18 April 2022 at the pulmonary department of Aleppo University Hospital, Syria, using patient records. In our study, 174 patients were examined. We included patients over the age of 18 who were referred or admitted to our department at Aleppo University Hospital after being diagnosed with diffuse parenchymal lung disease based on high-resolution computed tomography and clinical symptoms, while excluding other respiratory diseases such as tuberculosis and coronavirus disease 2019.

Results

Patients in the research were 53±7.1 years old on average. Cough and dyspnea were the most common clinical complaints among the patients, which accounted for 79.12 and 78.16%, respectively. A significant fraction of ground-glass opacity was detected on the high-resolution computed tomography, amounting to 102 (58.62%) and 74 (42.53%) for the reticular lesions, respectively. As a complication there were 40 patients with bleeding, of whom 24 had moderate bleeding, and 11 had major bleeding. We also had three patients with pneumothorax. The diagnostic yield of the TBLB in our ILD patients was 66.66%.

Conclusion

An adequate diagnostic accuracy (66.66%) was detected in the TBLB in confirming the diagnosis of ILD; in addition, the bleeding was the most prevalent complication of this procedure. More interventional studies are needed to compare the diagnostic accuracy of this procedure with other invasive and noninvasive diagnostic methodologies of ILD.

Saracatinib, a Selective Src Kinase Inhibitor, Blocks Fibrotic Responses in Preclinical Models of Pulmonary Fibrosis

Rationale: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal disorder. Two U.S. Food and Drug Administration-approved antifibrotic drugs, nintedanib and pirfenidone, slow the rate of decline in lung function, but responses are variable and side effects are common. Objectives: Using an in silico data-driven approach, we identified a robust connection between the transcriptomic perturbations in IPF disease and those induced by saracatinib, a selective Src kinase inhibitor originally developed for oncological indications. Based on these observations, we hypothesized that saracatinib would be effective at attenuating pulmonary fibrosis. Methods: We investigated the antifibrotic efficacy of saracatinib relative to nintedanib and pirfenidone in three preclinical models: 1) in vitro in normal human lung fibroblasts; 2) in vivo in bleomycin and recombinant Ad-TGF-β (adenovirus transforming growth factor-β) murine models of pulmonary fibrosis; and 3) ex vivo in mice and human precision-cut lung slices from these two murine models as well as patients with IPF and healthy donors. Measurements and Main Results: In each model, the effectiveness of saracatinib in blocking fibrogenic responses was equal or superior to nintedanib and pirfenidone. Transcriptomic analyses of TGF-β-stimulated normal human lung fibroblasts identified specific gene sets associated with fibrosis, including epithelial-mesenchymal transition, TGF-β, and WNT signaling that was uniquely altered by saracatinib. Transcriptomic analysis of whole-lung extracts from the two animal models of pulmonary fibrosis revealed that saracatinib reverted many fibrogenic pathways, including epithelial-mesenchymal transition, immune responses, and extracellular matrix organization. Amelioration of fibrosis and inflammatory cascades in human precision-cut lung slices confirmed the potential therapeutic efficacy of saracatinib in human lung fibrosis. Conclusions: These studies identify novel Src-dependent fibrogenic pathways and support the study of the therapeutic effectiveness of saracatinib in IPF treatment.

Raman spectroscopy combined with machine learning algorithms for rapid detection Primary Sjögren's syndrome associated with interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) is a major complication of Primary Sjögren's syndrome (pSS) patients.It is one of the main factors leading to death. The aim of this study is to evaluate the value of serum Raman spectroscopy combined with machine learning algorithms in the discriminatory diagnosis of patients with Primary Sjögren's syndrome associated with interstitial lung disease (pSS-ILD).

METHODS

Raman spectroscopy was performed on the serum of 30 patients with pSS, 28 patients with pSS-ILD and 30 healthy controls (HC). First, the data were pre-processed using baseline correction, smoothing, outlier removal and normalization operations. Then principal component analysis (PCA) is used to reduce the dimension of data. Finally, support vector machine(SVM), k nearest neighbor (KNN) and random forest (RF) models are established for classification.

RESULTS

In this study, SVM, KNN and RF were used as classification models, where SVM chooses polynomial kernel function (poly). The average accuracy, sensitivity, and precision of the three models were obtained after dimensionality reduction. The Accuracy of SVM (poly) was 5.71% higher than KNN and 6.67% higher than RF; Sensitivity was 5.79% higher than KNN and 8.56% higher than RF; Precision was 6.19% higher than KNN and 7.45% higher than RF. It can be seen that the SVM (poly) had better discriminative effect. In summary, SVM (poly) had a fine classification effect, and the average accuracy, sensitivity and precision of this model reached 89.52%, 91.27% and 89.52%, respectively, with an AUC value of 0.921.

CONCLUSIONS

This study demonstrates that serum RS combined with machine learning algorithms is a valuable tool for diagnosing patients with pSS-ILD. It has promising applications.

Anti-Fibrotic Effect of SDF-1β Overexpression in Bleomycin-Injured Rat Lung

Rational: Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease and is associated with high mortality due to a lack of effective treatment. Excessive deposition of the extracellular matrix by activated myofibroblasts in the alveolar space leads to scar formation that hinders gas exchange. Therefore, selectively removing activated myofibroblasts with the aim to repair and remodel fibrotic lungs is a promising approach. Stromal-derived growth factor (SDF-1) is known to stimulate cellular signals which attract stem cells to the site of injury for tissue repair and remodeling. Here, we investigate the effect of overexpression of SDF-1β on lung structure using the bleomycin-injured rat lung model. Methods: Intratracheal administration of bleomycin was performed in adult male rats (F344). Seven days later, in vivo electroporation-mediated gene transfer of either SDF-1β or the empty vector was performed. Animals were sacrificed seven days after gene transfer and histology, design-based stereology, flow cytometry, and collagen measurement were performed on the tissue collected. For in vitro experiments, lung fibroblasts obtained from IPF patients were used. Results: Seven days after SDF-1β gene transfer to bleomycin-injured rat lungs, reduced total collagen, reduced collagen fibrils, improved histology and induced apoptosis of myofibroblasts were observed. Furthermore, it was revealed that TNF-α mediates SDF-1β-induced apoptosis of myofibroblasts; moreover, SDF-1β overexpression increased alveolar epithelial cell numbers and proliferation in vivo and also induced their migration in vitro. Conclusions: Our study demonstrates a new antifibrotic mechanism of SDF-1β overexpression and suggests SDF-1β as a potential new approach for the treatment of lung fibrosis.

Functional Au nanoparticles for engineering and long-term CT imaging tracking of mesenchymal stem cells in idiopathic pulmonary fibrosis treatment

Idiopathic pulmonary fibrosis (IPF) therapy has always been a big and long-standing challenge in clinical practice due to the lack of miraculous medicine. Mesenchymal stem cells (MSCs)-based therapy has recently emerged as a promising candidate for redefining IPF therapy. Enhancing the therapeutic efficacy of MSCs and understanding of their growth, migration and differentiation in harsh lung microenviroments are two keys to improving the stem cell-based IPF treatment. Herein, a non-viral dual-functional nanocarrier is fabricated by a one-pot approach, using protamine sulfate stabilized Au nanoparticles (AuPS), to genetically engineer MSCs for simultaneous IPF treatment and monitoring the biological behavior of the MSCs. AuPS exhibits superior cellular uptake ability, which results in efficient genetic engineering of MSCs to overexpress hepatocyte growth factor for enhanced IPF therapy. In parallel, the intracellular accumulation of AuPS improves the CT imaging contrast of MSCs, allowing visual tracking of the therapeutic engineered MSCs up to 48 days. Overall, this work has described for the first time a novel strategy for enhanced therapeutic efficacy and long-term CT imaging tracking of transplanted MSCs in IPF therapy, providing great prospect for stem cell therapy of lung disease.

Nintedanib Inhibits Endothelial Mesenchymal Transition in Bleomycin-Induced Pulmonary Fibrosis via Focal Adhesion Kinase Activity Reduction

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease (ILD). Pulmonary fibroblasts play an important role in the development of IPF. Emerging evidence indicates that pulmonary endothelial cells could be the source of pulmonary fibroblasts through endothelial mesenchymal transition (EndoMT), which contributes to pulmonary fibrosis. EndoMT is a complex process in which endothelial cells lose their expression of endothelial markers and give rise to the characteristics of mesenchymal cells, including morphological fibroblast-like change and the expression of mesenchymal markers, which result in cardiac, renal, and dermal fibroses. Furthermore, EndoMT inhibition attenuates pulmonary fibrosis. Herein, we demonstrate that nintedanib, a tyrosine kinase receptor inhibitor, ameliorated murine bleomycin (BLM)-induced pulmonary fibrosis and suppressed the in vivo and in vitro models of EndoMT. We demonstrated that the activity of focal adhesion kinase (FAK), a key EndoMT regulator, increased in murine lung tissues and human pulmonary microvascular endothelial cells after BLM stimulation. Nintedanib treatment inhibited BLM-induced FAK activation and thus suppressed both in vivo and in vitro BLM-induced EndoMT. Importantly, we found that the VEGF/FAK signaling pathway was involved in nintedanib regulating EndoMT. These novel findings help us understand the mechanism and signaling pathway of EndoMT to further develop more efficacious drugs for IPF treatment.

Diagnostic delay in IPF impacts progression-free survival, quality of life and hospitalisation rates

BACKGROUND

The diagnosis of idiopathic pulmonary fibrosis (IPF) is often delayed up to several years. The objective of this study was to assess the impact of the diagnostic delay on progression-free survival, quality of life and hospitalisation rates.

METHODS

A total of 264 incident patients with IPF were included immediately after their diagnosis and followed for up to 5 years, with regular collection of clinical data, quality-of-life questionnaires and assessment of disease progression. Hospitalisation data were extracted from electronic patient records. Analyses were performed on the entire cohort and strata according to forced vital capacity (FVC) at diagnosis.

RESULTS

A long diagnostic delay (>1 year) was associated with worse progression-free survival compared with a short diagnostic delay (<1 year) (HR: 1.70, 95% CI: 1.18 to 2.46, p=0.004) especially in patients with mild disease at the time of diagnosis (FVC>80% predicted). Mean total scores of the St. George's respiratory questionnaire (SGRQ), a derived IPF-specific version of the SGRQ and the chronic obstructive pulmonary disease assessment test (CAT) were consistently higher in patients with long diagnostic delays, indicating worse quality of life. Mean hospitalisation rates were higher during the first year after diagnosis (Incidence rate ratio [IRR]: 3.28, 95% CI: 1.35 to 8.55, p=0.01) and during the entire follow-up (IRR: 1.74, 95% CI: 1.01 to 3.02, p=0.04).

CONCLUSION

A diagnostic delay of more than 1 year negatively impacts progression-free survival, quality of life and hospitalisation rates in patients with IPF. These findings highlight the importance of an early diagnosis for proper management of IPF.

TRIAL REGISTRATION NUMBER

NCT02755441.

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.

Idiopathic pulmonary fibrosis: Current and future treatment

Objectives

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease characterized by dry cough, fatigue, and progressive exertional dyspnea. Lung parenchyma and architecture is destroyed, compliance is lost, and gas exchange is compromised in this debilitating condition that leads inexorably to respiratory failure and death within 3–5 years of diagnosis. This review discusses treatment approaches to IPF in current use and those that appear promising for future development.

Data Source

The data were obtained from the Randomized Controlled Trials and scientific studies published in English literature. We used search terms related to IPF, antifibrotic treatment, lung transplant, and management.

Results

Etiopathogenesis of IPF is not fully understood, and treatment options are limited. Pathological features of IPF include extracellular matrix remodeling, fibroblast activation and proliferation, immune dysregulation, cell senescence, and presence of aberrant basaloid cells. The mainstay therapies are the oral antifibrotic drugs pirfenidone and nintedanib, which can improve quality of life, attenuate symptoms, and slow disease progression. Unilateral or bilateral lung transplantation is the only treatment for IPF shown to increase life expectancy.

Conclusion

Clearly, there is an unmet need for accelerated research into IPF mechanisms so that progress can be made in therapeutics toward the goals of increasing life expectancy, alleviating symptoms, and improving well‐being.

The histone methyltransferase DOT1L is a new epigenetic regulator of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with increasing occurrence, high death rates, and unfavorable treatment regimens. The pathogenesis underlying IPF is complex and the epigenetic contributions to IPF are largely unknown. Recent studies have shown that DOT1L (Disruptor of telomeric silencing-1 like), a histone H3K79 methyltransferase, contributes to fibrosis response, but its role in IPF remains unclear. DOT1L, H3K79me3, and the profibrotic proteins levels were upregulated in the pulmonary fibrosis models both in vivo and in vitro. Lentivirus-mediated DOT1L knockdown or DOT1L-specific inhibitor EPZ5676 alleviated the pathogenesis of bleomycin-induced mouse pulmonary fibrosis. Furthermore, heterozygous DOT1L-deficient mice (Dot1l^+/−) showed less sensitive to pulmonary fibrosis, as shown by decreased lung fibrosis phenotypes in vivo. Mechanically, DOT1L regulated TGF-β1-induced fibroblasts fibrosis by increasing enrichments of H3K79me3 on the promoter of Jag1 gene (encoding the Notch ligand Jagged1), enhancing the expression of Jagged1, which in turn stimulated exuberant Notch signaling and actuated the fibrosis response. In conclusion, our study confirmed DOT1L to be an epigenetic modifier in the pathogenesis of lung fibrosis, revealed a counterbalancing mechanism governing Jag1 transcription by modulating H3K79 trimethylation at the Jag1 promoter, activating the Notch signaling, and affecting the expression of profibrotic proteins to accelerate the lung fibrosis.

Icariin attenuates bleomycin-induced pulmonary fibrosis by targeting Hippo/YAP pathway

Pulmonary fibrosis is a manifestation of the progression of interstitial pulmonary disease. Icariin (ICA) has been found to exhibit protective effects on multiple chronic diseases like diabetes, liver, heart, and renal fibrosis. Here, a systemic pharmacological study was designed to investigate whether ICA treatment alleviates bleomycin (BLM)-induced pulmonary fibrosis. The rat pulmonary fibrosis model was constructed by non-invasive endotracheal intubation instillation of BLM to observe the intervention effects of ICA on pulmonary fibrosis in the whole process of inflammation and fibrosis. ICA reduced the collagen deposition and inflammation induced by BLM in rat. The comparative RNA-sequencing was conducted to analyze the lung gene expression profiles in rat. KEGG analysis indicated that most of the genes were enriched in Hippo pathway, NF-κB pathway, and B-cell receptor signaling pathway, etc. Immunohistochemistry staining showed that the expression of YAP was significantly elevated in the model group and decreased in the ICA treatment group. Taken together, the anti-fibrotic effect of ICA appears to be mediated by its inhibitory of YAP, which is the core transcriptional regulator of Hippo pathway.

The role of osteoprotegerin (OPG) in fibrosis: its potential as a biomarker and/or biological target for the treatment of fibrotic diseases

Fibrosis is defined by excessive formation and accumulation of extracellular matrix proteins, produced by myofibroblasts, that supersedes normal wound healing responses to injury and results in progressive architectural remodelling. Fibrosis is often detected in advanced disease stages when an organ is already severely damaged and can no longer function properly. Therefore, there is an urgent need for reliable and easily detectable markers to identify and monitor fibrosis onset and progression as early as possible; this will greatly facilitate the development of novel therapeutic strategies. Osteoprotegerin (OPG), a well-known regulator of bone extracellular matrix and most studied for its role in regulating bone mass, is expressed in various organs and functions as a decoy for receptor activator of nuclear factor kappa-B ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Recently, OPG has been linked to fibrosis and fibrogenesis, and has been included in a panel of markers to diagnose liver fibrosis. Multiple studies now suggest that OPG may be a general biomarker suitable for detection of fibrosis and/or monitoring the impact of fibrosis treatment. This review summarizes our current understanding of the role of OPG in fibrosis and will discuss its potential as a biomarker and/or novel therapeutic target for fibrosis.

Micellar Hyaluronidase and Spiperone as a Potential Treatment for Pulmonary Fibrosis

Concentration of hyaluronic acid (HA) in the lungs increases in idiopathic pulmonary fibrosis (IPF). HA is involved in the organization of fibrin, fibronectin, and collagen. HA has been proposed to be a biomarker of fibrosis and a potential target for antifibrotic therapy. Hyaluronidase (HD) breaks down HA into fragments, but is a subject of rapid hydrolysis. A conjugate of poloxamer hyaluronidase (pHD) was prepared using protein immobilization with ionizing radiation. In a model of bleomycin-induced pulmonary fibrosis, pHD decreased the level of tissue IL-1β and TGF-β, prevented the infiltration of the lung parenchyma by CD16⁺ cells, and reduced perivascular and peribronchial inflammation. Simultaneously, a decrease in the concentrations of HA, hydroxyproline, collagen 1, total soluble collagen, and the area of connective tissue in the lungs was observed. The effects of pHD were significantly stronger compared to native HD which can be attributed to the higher stability of pHD. Additional spiperone administration increased the anti-inflammatory and antifibrotic effects of pHD and accelerated the regeneration of the damaged lung. The potentiating effects of spiperone can be explained by the disruption of the dopamine-induced mobilization and migration of fibroblast progenitor cells into the lungs and differentiation of lung mesenchymal stem cells (MSC) into cells of stromal lines. Thus, a combination of pHD and spiperone may represent a promising approach for the treatment of IPF and lung regeneration.

Development and Validation of a Clinical Diagnostic Scoring System for the Diagnosis of IPF

RATIONALE

Interpreting the radiological data in conjunction with an objective clinical score could help to harmonize IPF diagnostic and improve accuracy.

OBJECTIVES

We sought to establish and validate a multivariable objective scoring model based on clinical parameters, by stratifying the risk for patients to be diagnosed as IPF versus other forms of interstitial lung disease (ILD).

METHODS

A clinical score was derived from review of patients evaluated at the Inova Fairfax ILD program and validated in three distinct cohorts. Based on known IPF clinical characteristics, a multivariable model was created and assessed by receiver operator curve (ROC) characteristics.

RESULTS

There were 844 ILD patients diagnosed as either IPF (n=347, 41%) or non-IPF ILD (n=497, 59%). Based on calculated odds ratios, a score was assigned to each of the following clinical parameters: age, sex, smoking history, ethnicity, ILD family history, exposures, presence of CTD signs or symptoms, and Velcro crackles. The final Fairfax IPF clinical score (FICS) ranged from 1 to 25. The clinical diagnostic score system was accurate in predicting IPF, as measured by the area under the curve (AUC 0.88) in the derivation cohort with similar AUCs of 0.91, 0.81 and 0.71 in the respective validation cohorts.

CONCLUSION

The FICS appears to be an accurate tool for estimating the pretest probability of IPF in patients with ILD. How the FICS performs in conjunction with the various HRCT patterns remains to be determined. This model could ultimately be useful for increasing the degree of confidence in the final diagnosis and help to obviate the need for lung biopsy in cases of non-UIP patterns on HRCT.

Baseline characteristics and survival of patients of idiopathic pulmonary fibrosis: a longitudinal analysis of the Swedish IPF Registry

Background

Observational data under real-life conditions in idiopathic pulmonary fibrosis (IPF) is scarce. We explored anti-fibrotic treatment, disease severity and phenotypes in patients with IPF from the Swedish IPF Registry (SIPFR).

Methods

Patients enrolled between September 2014 and April 2020 and followed ≥ 6 months were investigated. Demographics, comorbidities, lung function, composite variables, six-minute walking test (6MWT), quality of life, and anti-fibrotic therapy were evaluated. Agreements between classification of mild physiological impairment (defined as gender-age-physiology (GAP) stage 1) with physiological and composite measures of severity was assessed using kappa values and their impact on mortality with hazard ratios. The factor analysis and the two-step cluster analysis were used to identify phenotypes. Univariate and multivariable survival analyses were performed between variables or groups.

Results

Among 662 patients with baseline data (median age 72.7 years, 74.0% males), 480 had a follow up ≥ 6 months with a 5 year survival rate of 48%. Lung function, 6MWT, age, and BMI were predictors of survival. Patients who received anti-fibrotic treatment ≥ 6 months had better survival compared to untreated patients [p = 0.007, HR (95% CI): 1.797 (1.173–2.753)] after adjustment of age, gender, BMI, smoking status, forced vital capacity (FVC) and diffusion capacity of carbon monoxide (DLCO). Patients with mild physiological impairment (GAP stage 1, composite physiological index (CPI) ≤ 45, DLCO ≥ 55%, FVC ≥ 75%, and total lung capacity (TLC) ≥ 65%, respectively) had better survival, after adjustment for age, gender, BMI and smoking status and treatment. Patients in cluster 1 had the worst survival and consisted mainly of male patients with moderate-severe disease and an increased prevalence of heart diseases at baseline; Cluster 2 was characterized by mild disease with more than 50% females and few comorbidities, and had the best survival; Cluster 3 were younger, with moderate-severe disease and had few comorbidities.

Conclusion

Disease severity, phenotypes, and anti-fibrotic treatment are closely associated with the outcome in IPF, with treated patients surviving longer. Phenotypes may contribute to predicting outcomes of patients with IPF and suggest the patients’ need for special management, whereas single or composite variables have some limitations as disease predictors.

Pathological Insight into 5-HT2B Receptor Activation in Fibrosing Interstitial Lung Diseases

Interstitial lung disease (ILD) encompasses a heterogeneous group of more than 200 conditions, of which primarily idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia, hypersensitivity pneumonitis, ILD associated with autoimmune diseases and sarcoidosis may present a progressive fibrosing (PF) phenotype. Despite different aetiology and histopathological patterns, the PF-ILDs have similarities regarding disease mechanisms with self-sustaining fibrosis, which suggests that the diseases may share common pathogenetic pathways. Previous studies show an enhanced activation of serotonergic signaling in pulmonary fibrosis, and the serotonin (5-HT)₂ receptors have been implicated to have important roles in observed profibrotic actions. Our research findings in support by others, demonstrate antifibrotic effects with 5-HT_2B receptor antagonists, alleviating several key events common for the fibrotic diseases such as myofibroblast differentiation and connective tissue deposition. In this review, we will address the potential role of 5-HT and in particular the 5-HT_2B receptors in three PF-ILDs: ILD associated with systemic sclerosis (SSc-ILD), ILD associated with rheumatoid arthritis (RA-ILD) and IPF. Highlighting the converging pathways in these diseases discloses the 5-HT_2B receptor as a potential disease target for PF-ILDs, which today have an urgent unmet need for therapeutic strategies.

An efficient electrochemical assay for miR-3675-3p in human serum based on the nanohybrid of functionalized fullerene and metal-organic framework

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with unclear pathogenesis, for which diagnosis has been a great challenge. Recent researches have revealed that miR-3675-3p is a promising biomarker for IPF diagnosis. Herein, the present work describes a novel electrochemical microRNA biosensor for rapid and sensitive detection of miR-3675-3p based on multiple signal amplification strategies. First of all, fullerene (C₆₀) is doped with poly(amidoamine) (PAMAM)-functionalized metal-organic framework (MOF) to form a new nanohybrid of C₆₀@PAMAM-MOF, which exhibits more remarkable redox activity compared with the other two synthesized C₆₀-based nanohybrids when triggered by tetraoctylammonium bromide (TOAB). C₆₀@PAMAM-MOF also possesses a large specific surface area and abundant amino groups to anchor Au nanoparticles (AuNPs) for the immobilization of signal probe (SP) to form tracer label and enhance the electrochemical response signal. In addition, core@shell Au-Pt nanoparticles (Au@PtNPs) are absorbed on chitosan-acetylene black (CS-AB) to act as sensing platform, which can promote electron transfer and increase the loading of capture probe (CP). Under optimum conditions, the proposed biosensor displays a wide linear range for miR-3675-3p from 10 fM to 10 nM, with a limit of detection (LOD) as low as 2.99 fM. More significantly, this biosensor shows a lower LOD and wider linear range than that of qRT-PCR, and its trial application in human serum shows favorable results, which exhibits a promising prospect for IPF diagnosis.

Potent and Selective Human Prostaglandin F (FP) Receptor Antagonist (BAY-6672) for the Treatment of Idiopathic Pulmonary Fibrosis (IPF)

Idiopathic pulmonary fibrosis (IPF) is a rare and devastating chronic lung disease of unknown etiology. Despite the approved treatment options nintedanib and pirfenidone, the medical need for a safe and well-tolerated antifibrotic treatment of IPF remains high. The human prostaglandin F receptor (hFP-R) is widely expressed in the lung tissue and constitutes an attractive target for the treatment of fibrotic lung diseases. Herein, we present our research toward novel quinoline-based hFP-R antagonists, including synthesis and detailed structure-activity relationship (SAR). Starting from a high-throughput screening (HTS) hit of our corporate compound library, multiple parameter improvements-including increase of the relative oral bioavailability F_rel from 3 to ≥100%-led to a highly potent and selective hFP-R antagonist with complete oral absorption from suspension. BAY-6672 (46) represents-to the best of our knowledge-the first reported FP-R antagonist to demonstrate in vivo efficacy in a preclinical animal model of lung fibrosis, thus paving the way for a new treatment option in IPF.

Interstitial Lung Fibrosis Imaging Reporting and Data System: What Radiologist Wants to Know?

The aim of this work is to review interstitial lung fibrosis Imaging Reporting and Data System (ILF-RADS) that was designed for reporting of interstitial lung fibrosis (ILF). Findings include pulmonary and extrapulmonary findings and is subsequently designed into 4 categories. Pulmonary findings included lung volume, reticulations, traction bronchiectasis, honeycomb, nodules, cysts, ground glass, consolidation, mosaic attenuation and emphysema, and distribution of pulmonary lesions; axial (central, peripheral and diffuse), and zonal distribution (upper, middle, and lower zones). Complications in the form of acute infection, acute exacerbation, and malignancy were also assessed. Extrapulmonary findings included mediastinal, pleural, tracheal, and bone or soft tissue lesions. The lexicon of usual interstitial pneumonia (UIP) was classified into 4 categories designated as belonging in 1 of 4 categories. Lexicon of ILF-RADS-1 (typical UIP), ILF-RADS-2 (possible UIP), ILF-RADS-3 (indeterminate for UIP), and ILF-RADS-4 (inconsistent with UIP).

miR-205 Suppresses Pulmonary Fibrosis by Targeting GATA3 Through Inhibition of Endoplasmic Reticulum Stress

OBJECTIVE

To investigate the role of miR-205 and GATA3 in Pulmonary Fibrosis (PF).

METHODS

Bleomycin (BLM) was used to induce PF in SD rats and in vitro PF model was established by using TGFβ1-induced RLE-6TN cells. miR-205 mimics were used for the overexpression of miR- 205. The expression of miR-205, GATA3, α-SMA, Collagen I, CHOP and GRP78 were measured using RT-qPCR or western blotting. Dual-luciferase reporter assay was used to confirm binding between GATA3 3'-UTR and miR-205.

RESULTS

The expression of miR-205 was significantly down-regulated, while the expression of GATA3 was remarkably up-regulated in the model rats. GATA3 levels were remarkably decreased when miR-205 was overexpressed. When miR-205 was overexpressed, the lung injury by BLM-induced fibrosis was improved. The expression of α-SMA, Collagen I, as well as GRP78 and CHOP, was significantly up-regulated in both in vivo and in vitro PF models, and overexpression of miR-205 remarkably reversed the effects. Dual-luciferase reporter assay showed that miR-205 directly targeted and negatively regulated GATA3.

CONCLUSION

miR-205 improved pulmonary fibrosis through inhibiting ER-stress by targeting GATA3.

Idiopathic pulmonary fibrosis: Educational needs of health-care providers, patients, and caregivers

Idiopathic pulmonary fibrosis (IPF) is a progressive disease associated with poor quality of life. Debilitating symptoms and the reality of shortened survival impact patients’ physical and emotional well-being and constrain the lives of patients’ caregivers. This study assessed the informational needs of medical providers who care for patients with IPF, IPF patients themselves, and their caregivers. Tailored surveys were sent electronically to providers, patients with IPF, and caregivers of patients with IPF collected on a rolling basis in March of 2017. Providers answered questions regarding their own informational needs and what information they believed patients needed. Patients and caregivers identified their own informational needs and the perceived needs for each other. About 2636 surveys were sent to providers, including 2041 to physicians, of whom 156 completed it. One hundred sixty patients and 29 caregivers responded to the survey via a link on a website. Eighty-six percent of providers described themselves as physicians who diagnose and treat IPF patients themselves. Providers ranked information on “making the diagnosis of IPF” as their top informational need. Patients and caregivers chose “disease progression/what to expect” as the most important informational need for themselves and for each other. Providers want to make a correct diagnosis when IPF is in the differential diagnosis. Patients and caregivers desire clarity around how IPF will behave over time and what their futures with IPF will look like. Resources for patients and their caregivers should include information on disease natural history in empathically worded, clear, and easily accessible formats.

Galangin ameliorated pulmonary fibrosis in vivo and in vitro by regulating epithelial-mesenchymal transition

Pulmonary fibrosis (PF) is a disease that is characterized by abnormal epithelial-mesenchymal transition (EMT) and persistent inflammatory injury, with high mortality and poor prognosis, but the current therapies are accompanied by certain adverse side effects. In this study, we investigated the role of galangin (GA), an anti-inflammatory and anti-tumoral phytochemical extracted from galangal, in preventing and curing bleomycin (BLM)-induced pulmonary fibrosis and the underlying mechanism. Histopathological staining confirmed that GA dramatically moderated bleomycin-induced pulmonary fibrosis in mice. Compared with the vehicle treatment, GA treatment inhibited the expression of vimentin and increased the expression of E-cadherin. The expression of α-Smooth muscle actin (α-SMA), which is a myofibroblast marker, was also suppressed. In addition, GA diminished the increase in the numbers of CD4⁺CD69⁺ and CD8⁺CD69⁺ T cells and dendritic cells induced by bleomycin, and reduced the residence of inflammatory cells in the lung tissues. Notably, GA inhibited the TGF-β1-induced EMT and fibroblast differentiation in vitro, which further confirmed the potential protective effect of GA on pulmonary fibrosis. Taken together, our results suggest that GA exerts a beneficial effect on bleomycin-induced pulmonary fibrosis by attenuating EMT and inflammatory damage and may have prevent potential of pulmonary fibrosis.

Prevalence and risk factors of interstitial lung disease in patients with primary Sjögren's syndrome: A systematic review and meta-analysis

OBJECTIVE

To systematically review the prevalence and risk factors for interstitial lung disease (ILD) in patients with primary Sjögren's syndrome (pSS).

METHODS

We searched PubMed, Embase, and Cochrane Library from inception to December 2019. Two investigators reviewed records according to predefined criteria. We calculated the pooled prevalence, weighted mean differences (WMDs), odds ratio (OR) and 95% confidence intervals (CIs) using a random effects model, and performed subgroup analysis, sensitivity analysis, and Egger's test.

RESULTS

In 23 studies with 6157 pSS patients, the pooled prevalence of ILD in pSS patients was 13% (95% CI: 9-19). The pSS-ILD prevalence was higher in Asia (20%) than that in Europe (10%). Male gender (OR = 1.92, 95% CI: 1.26-2.95), elder age (WMD = 9.25 years, 95% CI: 2.78-15.72) and higher C-reactive protein (CRP) (WMD = 3.92 mg/L, 95% CI: 0.27-1.61) was associated with ILD in pSS patients.

CONCLUSION

Interstitial lung disease was prevalent in pSS patients. Elder age, male gender and higher CRP were risk factors for pSS-ILD. Our data highlighted the importance of screening for ILD in high-risk pSS patients.

Automated evaluation of probe-based confocal laser endomicroscopy in the lung

RATIONALE

Probe-based confocal endomicroscopy provides real time videos of autoflourescent elastin structures within the alveoli. With it, multiple changes in the elastin structure due to different diffuse parenchymal lung diseases have previously been described. However, these evaluations have mainly relied on qualitative evaluation by the examiner and manually selected parts post-examination.

OBJECTIVES

To develop a fully automatic method for quantifying structural properties of the imaged alveoli elastin and to perform a preliminary assessment of their diagnostic potential.

METHODS

46 patients underwent probe-based confocal endomicroscopy, of which 38 were divided into 4 groups categorizing different diffuse parenchymal lung diseases. 8 patients were imaged in representative healthy lung areas and used as control group. Alveolar elastin structures were automatically segmented with a trained machine learning algorithm and subsequently evaluated with two methods developed for quantifying the local thickness and structural connectivity.

MEASUREMENTS AND MAIN RESULTS

The automatic segmentation algorithm performed generally well and all 4 patient groups showed statistically significant differences with median elastin thickness, standard deviation of thickness and connectivity compared to the control group.

CONCLUSION

Alveoli elastin structures can be quantified based on their structural connectivity and thickness statistics with a fully-automated algorithm and initial results highlight its potential for distinguishing parenchymal lung diseases from normal alveoli.

Effects of tetrandrine combined with acetylcysteine on exercise tolerance, pulmonary function and serum TNF-β1 and MMP-7 in silicosis patients

The aim of the study was to investigate the effects of tetrandrine combined with acetylcysteine on exercise tolerance, pulmonary function, transforming growth factor-β1 (TGF-β1) and matrix metalloproteinase 7 (MMP-7) in silicosis patients. A retrospective analysis was performed on 149 silicosis patients admitted to the Maternal and Child Health Care Hospital of Zhangqiu District between August, 2015 and September, 2017. Of the 149 patients, 70 patients treated with acetylcysteine comprised the control group, and 79 treated with tetrandrine combined with acetylcysteine constituted the study group. The concentrations of serum TGF-β1 and MMP-7 before and after treatment were detected by enzyme-linked immunosorbent assay (ELISA), and the exercise tolerance and pulmonary function were compared. Chest distress, chest pain, cough, expectoration and dyspnea in the two groups were relieved after treatment, and the improvement rates of chest distress, chest pain and dyspnea in the study group were significantly higher than those in the control group (P<0.05). Before treatment, there was no significant difference in the results of the 6-minute walk test (6MWT) between the two groups (P>0.05). After treatment, the 6MWT in the two groups was significantly increased (P<0.05), and the improvement effect in the study group was more marked than that in the control group (P<0.05). There was no significant difference in the pulmonary function indexes between the two groups before treatment (P>0.05). Before treatment, there was no significant difference in serum TGF-β1 and MMP-7 expression levels between the two groups (P>0.05). By contrast, after treatment, the levels in the two groups were significantly decreased, with the levels in the study group being significantly lower than that the control group (P<0.05). In conclusion, tetrandrine combined with acetylcysteine can improve pulmonary function and exercise tolerance of patients with silicosis by inhibiting the expressions of TGF-β1 and MMP-7, thus improving clinical efficacy.

Possible Role of Chest Ultrasonography for the Evaluation of Peripheral Fibrotic Pulmonary Changes in Patients Affected by Idiopathic Pulmonary Fibrosis—Pilot Case Series

Lung ultrasonography (LUS) provides an estimation of peripheral airspace (PAS) geometry of the lung. Altered PAS produces sonographic interstitial syndrome (SIS). Idiopathic pulmonary fibrosis (IPF) involves peripheral lung with altered PAS. The aim of the study is to correlate echographic patterns with peripheral fibrotic changes on high-resolution Chest CT scan (HRCT). Patients underwent LUS and HRCT on the same date. Four LUS patterns were described: (1) near normal; (2) SIS with predominance of reverberant artifacts; (3) SIS with vertical predominance; (4) white lung. Four HRCT grades of peripheral fibrotic infiltrates were reported: grade 1 mild; grade 2 moderate; grade 3 severe; grade 4 massive or honeycomb. LUS pattern 1 was indicative of mild to moderate fibrotic alterations in 100% of cases. LUS pattern 2 matched with HRCT grade 2 in 24 out of 30 cases (77%). Huge discordance in four cases because of large honeycomb cysts. LUS pattern 3 was indicative of severe to massive alterations in 100% of cases. LUS pattern 4 showed a heterogeneous distribution of HRCT grades, severe changes, and ground glass opacities (GGO). This preliminary work demonstrates some level of agreement between LUS patterns and HRCT grades. Limitations and methodological issues have been shown to support subsequent studies of agreement.

[Artificial intelligence in lung imaging]

CLINICAL/METHODICAL ISSUE

Artificial intelligence (AI) has the potential to improve diagnostic accuracy and management in patients with lung disease through automated detection, quantification, classification, and prediction of disease progression.

STANDARD RADIOLOGICAL METHODS

Owing to unspecific symptoms, few well-defined CT disease patterns, and varying prognosis, interstitial lungs disease represents a focus of AI-based research.

METHODICAL INNOVATIONS

Supervised and unsupervised machine learning can identify CT disease patterns using features which may allow the analysis of associations with specific diseases and outcomes.

PERFORMANCE

Machine learning on the one hand improves computer-aided detection of pulmonary nodules. On the other hand it enables further characterization of pulmonary nodules, which may improve resource effectiveness regarding lung cancer screening programs.

ACHIEVEMENTS

There are several challenges regarding AI-based CT data analysis. Besides the need for powerful algorithms, expert annotations and extensive training data sets that reflect physiologic and pathologic variability are required for effective machine learning. Comparability and reproducibility of AI research deserve consideration due to a lack of standardization in this emerging field.

PRACTICAL RECOMMENDATIONS

This review article presents the state of the art and the challenges concerning AI in lung imaging with special consideration of interstitial lung disease, and detection and consideration of pulmonary nodules.

Idiopathic pulmonary fibrosis and occupational risk factors

Idiopathic pulmonary fibrosis (IPF) is a rare lung disease of unknown origin that rapidly leads to death. However, the rate of disease progression varies from one individual to another and is still difficult to predict. The prognosis of IPF is poor, with a median survival of three to five years after diagnosis, without curative therapies other than lung transplantation. The factors leading to disease onset and progression are not yet completely known. The current disease paradigm is that sustained alveolar epithelial micro-injury caused by environmental triggers (e.g., cigarette smoke, microaspiration of gastric content, particulate dust, viral infections or lung microbial composition) leads to alveolar damage resulting in fibrosis in genetically susceptible individuals. Numerous epidemiological studies and case reports have shown that occupational factors contribute to the risk of developing IPF. In this perspective, we briefly review the current understanding of the pathophysiology of IPF and the importance of occupational factors in the pathogenesis and prognosis of the disease. Prompt identification and elimination of occult exposure may represent a novel treatment approach in patients with IPF.

Idiopathic pulmonary fibrosis in patients with early-stage non-small-cell lung cancer after surgical resection

Background The outcomes of patients with both lung cancer and idiopathic pulmonary fibrosis (IPF) are unfavorable. Therapeutic interventions for lung cancer such as surgery can cause acute exacerbation of IPF (aeIPF). This study aimed to assess the frequency of IPF in a group of patients with early-stage non-small-cell lung cancer (NSCLC) and to report clinical characteristics and outcomes of this cohort of patients. Patients and methods This observational cohort retrospective study analyzed 641 pathological records of patients after surgical resection of early-stage non-small-cell lung cancer (NSCLC) at University Clinic Golnik from May 2010 to April 2017. Pathological records of NSCLC with coexisting IPF were reviewed. CT scans and biopsy specimens for this group of patients were analyzed by a thoracic radiologist and pathologist, independently. We searched radiological and pathological features of usual interstitial pneumonia (UIP) pattern in this group of patients. We report the clinical characteristics and outcome of this cohort of patients. Results Out of 641 patients with early-stage NSCLC, only 13 (2.0%) had histologically and radiologically proven coexisting UIP/IPF. Squamous cell carcinoma was the most common type of lung cancer (7/13 patients). The majority of tumors were small size (all being pT1 or pT2), stage I-II (11/13 patients), located in the lower lung lobes (11/13 patients). Almost all patients were current or ex-smokers (11/13 patients). There were two pathologically confirmed fatal cases (15.4%) due to aeIPF in the first two months after radical treatment, one after adjuvant radiotherapy and the other after surgery. Out of 13 patients, one patient had a lung cancer relapse. Conclusions Frequency of UIP/IPF in surgically treated early stage NSCLC is rather low. Our observational study shows that radical treatment of lung cancer can cause aeIPF with dismal outcome in this group of patients. The standard of care in these mostly elderly patients still remains unresolved.

Autoantibodies in interstitial lung diseases

The role of autoantibody testing for patients with interstitial lung disease is an evolving area. Recent guidelines recommend routine anti-nuclear antibodies, rheumatoid factor, and anti-citrullinated cyclic peptide antibody testing for patients undergoing diagnostic evaluation for interstitial lung disease, with further autoantibody testing reserved for selected cases guided by rheumatological features. Even this approach may miss patients with clinically significant autoantibodies when interstitial lung disease is the dominant or first manifestation of autoimmune disease. We retrospectively performed autoimmune serology in a clinically well characterised cohort of interstitial lung disease patients. Using stored serum, additional testing was performed to ensure all patients had complete autoantibody profiles including anti-nuclear antibodies, extractable nuclear antigen antibodies, double-stranded DNA antibodies, rheumatoid factor, anti-citrullinated cyclic peptide antibodies, anti-neutrophil cytoplasmic antibodies, and myositis antibodies. Eighty patients with interstitial lung disease, and available stored serum, were assessed. Mean age at interstitial lung disease diagnosis was 65.2 years and 42 patients were male. Positive autoimmune serology was found in 56 of 80 (70.0%) patients; the most common positive result was anti-nuclear antibodies (n=34; 42.5%). Myositis antibodies were detected in 13 of 80 (16.2%) patients. Four (5%) patients had elevated anti-citrullinated cyclic peptide antibodies, and two (2.5%) patients had detectable myeloperoxidase antibodies. Eleven (13.7%) patients with negative anti-nuclear antibodies had other significant disease associated autoantibodies. An extended panel of autoantibody testing may detect cases of connective tissue disease associated interstitial lung disease, regardless of clinical or radiological subtype, and prior to extra-pulmonary manifestations of systemic autoimmunity.

Single-Cell Transcriptomic Analysis of Human Lung Provides Insights into the Pathobiology of Pulmonary Fibrosis

Rationale: The contributions of diverse cell populations in the human lung to pulmonary fibrosis pathogenesis are poorly understood. Single-cell RNA sequencing can reveal changes within individual cell populations during pulmonary fibrosis that are important for disease pathogenesis. Objectives: To determine whether single-cell RNA sequencing can reveal disease-related heterogeneity within alveolar macrophages, epithelial cells, or other cell types in lung tissue from subjects with pulmonary fibrosis compared with control subjects. Methods: We performed single-cell RNA sequencing on lung tissue obtained from eight transplant donors and eight recipients with pulmonary fibrosis and on one bronchoscopic cryobiospy sample from a patient with idiopathic pulmonary fibrosis. We validated these data using in situ RNA hybridization, immunohistochemistry, and bulk RNA-sequencing on flow-sorted cells from 22 additional subjects. Measurements and Main Results: We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to nonoverlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. We developed a web-based tool to explore these data. Conclusions: We generated a single-cell atlas of pulmonary fibrosis. Using this atlas, we demonstrated heterogeneity within alveolar macrophages and epithelial cells from subjects with pulmonary fibrosis. These results support the feasibility of discovery-based approaches using next-generation sequencing technologies to identify signaling pathways for targeting in the development of personalized therapies for patients with pulmonary fibrosis.

Risk factors for diagnostic delay in idiopathic pulmonary fibrosis

Background

Surveys and retrospective studies of patients with idiopathic pulmonary fibrosis (IPF) have shown a significant diagnostic delay. However, the causes and risk factors for this delay are not known.

Methods

Dates at six time points before the IPF diagnosis (onset of symptoms, first contact to a general practitioner, first hospital contact, referral to an interstitial lung disease (ILD) centre, first visit at an ILD centre, and final diagnosis) were recorded in a multicentre cohort of 204 incident IPF patients. Based on these dates, the delay was divided into specific patient-related and healthcare-related delays. Demographic and clinical data were used to determine risk factors for a prolonged delay, using multivariate negative binomial regression analysis.

Results

The median diagnostic delay was 2.1 years (IQR: 0.9–5.0), mainly attributable to the patients, general practitioners and community hospitals. Male sex was a risk factor for patient delay (IRR: 3.84, 95% CI: 1.17–11.36, p = 0.006) and old age was a risk factor for healthcare delay (IRR: 1.03, 95% CI: 1.01–1.06, p = 0.004). The total delay was prolonged in previous users of inhalation therapy (IRR: 1.99, 95% CI: 1.40–2.88, p <  0.0001) but not in patients with airway obstruction. Misdiagnosis of respiratory symptoms was reported by 41% of all patients.

Conclusion

Despite increased awareness of IPF, the diagnostic delay is still 2.1 years. Male sex, older age and treatment attempts for alternative diagnoses are risk factors for a delayed diagnosis of IPF. Efforts to reduce the diagnostic delay should focus on these risk factors.

Trial registration

This study was registered at http://clinicaltrials.gov (NCT02772549) on May 10, 2016.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1076-0) contains supplementary material, which is available to authorized users.

Nationwide cloud-based integrated database of idiopathic interstitial pneumonias for multidisciplinary discussion

Multidisciplinary discussion (MDD) requiring close communication between specialists (clinicians, radiologists and pathologists) is the gold standard for the diagnosis of idiopathic interstitial pneumonias (IIPs). However, MDD by specialists is not always feasible because they are often separated by time and location. An online database would facilitate data sharing and MDD. Our aims were to develop a nationwide cloud-based integrated database containing clinical, radiological and pathological data of patients with IIPs along with a web-based MDD system, and to validate the diagnostic utility of web-based MDD in IIPs.

Clinical data, high-resolution computed tomography images and lung biopsy slides from patients with IIPs were digitised and uploaded to separate servers to develop a cloud-based integrated database. Web-based MDD was performed using the database and video-conferencing to reach a diagnosis.

Clinical, radiological and pathological data of 524 patients in 39 institutions were collected, uploaded and incorporated into the cloud-based integrated database. Subsequently, web-based MDDs with a pulmonologist, radiologist and pathologist using the database and video-conferencing were successfully performed for the 465 cases with adequate data. Overall, the web-based MDD changed the institutional diagnosis in 219 cases (47%). Notably, the MDD diagnosis yielded better prognostic separation among the IIPs than did the institutional diagnosis.

This is the first study of developing a nationwide cloud-based integrated database containing clinical, radiological and pathological data for web-based MDD in patients with IIPs. The database and the web-based MDD system that we built made MDD more feasible in practice, potentially increasing accurate diagnosis of IIPs.

Acloud-based integrated database of idiopathic interstitial pneumonias containing clinical, radiological and pathological data along with a web-based multidisciplinary discussion system can make discussions more feasible and improve disease managementhttp://ow.ly/NqqD30nYenb

The Role of Follow-up Evaluation in the Diagnostic Algorithm of Idiopathic Interstitial Pneumonia: A Retrospective Study

We aimed to evaluate the alteration of diagnosis of individual expert and multidisciplinary discussion (MDD) team in the longitudinal diagnostic assessment of idiopathic interstitial pneumonia (IIP). The retrospective analysis included 56 patients diagnosed as IIP by The First Affiliated Hospital of Guangzhou Medical University with follow-up visits during Jan 1^st to Aug 31^st 2014. Each expert was provided information in a sequential manner and was asked to assign an individual diagnosis and an MDD diagnosis after group discussion. The level of agreement among individual experts and between different visits was calculated by kappa and the agreement between individual specialist and MDD team with different consensus levels was measured by weighted-kappa coefficients. Follow-up data changed the original clinical diagnosis and MDD diagnosis in 24.1% and 10.7% of all cases, respectively, and clinician and MDD consensus level in 55.4% and 25.0%, respectively. The diagnostic performance of individual clinicians or radiologist was closer to that of the MDD compared with the pathologist, and follow-up further increased the agreement. The longitudinal evaluation of patients with IIP improved the inter-observer agreement in a multidisciplinary team. The performance of individual clinicians or radiologist was approaching the accuracy of multidisciplinary team when provided with follow-up data.

Artificial intelligence outperforms pulmonologists in the interpretation of pulmonary function tests

The interpretation of pulmonary function tests (PFTs) to diagnose respiratory diseases is built on expert opinion that relies on the recognition of patterns and the clinical context for detection of specific diseases. In this study, we aimed to explore the accuracy and interrater variability of pulmonologists when interpreting PFTs compared with artificial intelligence (AI)-based software that was developed and validated in more than 1500 historical patient cases.120 pulmonologists from 16 European hospitals evaluated 50 cases with PFT and clinical information, resulting in 6000 independent interpretations. The AI software examined the same data. American Thoracic Society/European Respiratory Society guidelines were used as the gold standard for PFT pattern interpretation. The gold standard for diagnosis was derived from clinical history, PFT and all additional tests.The pattern recognition of PFTs by pulmonologists (senior 73%, junior 27%) matched the guidelines in 74.4±5.9% of the cases (range 56-88%). The interrater variability of κ=0.67 pointed to a common agreement. Pulmonologists made correct diagnoses in 44.6±8.7% of the cases (range 24-62%) with a large interrater variability (κ=0.35). The AI-based software perfectly matched the PFT pattern interpretations (100%) and assigned a correct diagnosis in 82% of all cases (p<0.0001 for both measures).The interpretation of PFTs by pulmonologists leads to marked variations and errors. AI-based software provides more accurate interpretations and may serve as a powerful decision support tool to improve clinical practice.

Tetraspanin 1 as a mediator of fibrosis inhibits EMT process and Smad2/3 and beta-catenin pathway in human pulmonary fibrosis

Tetraspanin 1(TSPAN1) as a clinically relevant gene target in cancer has been studied, but there is no direct in vivo or vitro evidence for pulmonary fibrosis (PF). Using reanalysing Gene Expression Omnibus data, here, we show for the first time that TSPAN1 was markedly down-regulated in lung tissue of patient with idiopathic PF (IPF) and verified the reduced protein expression of TSPAN1 in lung tissue samples of patient with IPF and bleomycin-induced PF mice. The expression of TSPAN1 was decreased and associated with transforming growth factor-β1 (TGF-β₁ )-induced molecular characteristics of epithelial-to-mesenchymal transition (EMT) in alveolar epithelial cells (AECs). Silencing TSPAN1 promoted cell migration, and the expression of alpha-smooth muscle actin, vimentin and E-cadherin in AECs with TGF-β₁ treatment, while exogenous TSPAN1 has the converse effects. Moreover, silencing TSPAN1 promotes the phosphorylation of Smad2/3 and stabilizes beta-catenin protein, however, overexpressed TSPAN1 impeded TGF-β₁ -induced activation of Smad2/3 and beta-catenin pathway in AECs. Together, our study implicates TSPAN1 as a key regulator in the process of EMT in AECs of IPF.

Apoptotic PET Imaging of Rat Pulmonary Fibrosis With [18F]ML-8

Objective:

To investigate the value of 2-(3-[¹⁸F]fluoropropyl)-2-methyl-malonic acid ([¹⁸F]ML-8) positron emission tomography (PET) imaging of rat pulmonary fibrosis.

Methods:

Male Sprague-Dawley rats were divided into 2 groups, including pulmonary fibrosis model group and control group. The rat model was established by an intratracheal instillation of bleomycin (BLM). Control rats were treated with saline. Positron emission tomography/computed tomography (CT) with [¹⁸F]ML-8 or ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) was performed on 2 groups. After PET/CT imaging, lung tissues were collected for histologic examination. Data were analyzed and comparisons between 2 groups were performed using Student t test.

Results:

Bleomycin-treated rats showed a higher lung uptake of [¹⁸F]ML-8 than control rats (P < .05). In BLM-treated rats, the lung to muscle relative uptake ratio of [¹⁸F]ML-8 was also higher than that of [¹⁸F]FDG (P < .05). Pathological examination showed overproliferation of fibroblasts and deposition of collagen in lungs from BLM-treated rats. Compared to control rats, BLM-treated rats had higher lung hydroxyproline content (P < .05). Immunofluorescence staining indicated more apoptotic cells in BLM-treated rats than those in control rats. Moreover, the apoptosis rate of lung tissues obtained from BLM-treated rats was higher than that from control rats (P < .05).

Conclusions:

2-(3-[¹⁸F]fluoropropyl)-2-methyl-malonic acid PET/CT could be used for noninvasive diagnosis of pulmonary fibrosis in a rat model.

Mortality from idiopathic pulmonary fibrosis: a temporal trend analysis in Brazil, 1979-2014

Objective:

To analyze mortality from idiopathic pulmonary fibrosis (IPF) in Brazil over the period 1979-2014.

Methods:

Microdata were extracted from the Brazilian National Ministry of Health Mortality Database. Only deaths for which the underlying cause was coded as International Classification of Diseases version 9 (ICD-9) 515 or 516.3 (until 1995) or as ICD version 10 (ICD-10) J84.1 (from 1996 onward) were included in our analysis. Standardized mortality rates were calculated for the 2010 Brazilian population. The annual trend in mortality rates was analyzed by joinpoint regression. We calculated risk ratios (RRs) by age group, time period of death, and gender, using a person-years denominator.

Results:

A total of 32,092 deaths were recorded in the study period. Standardized mortality rates trended upward, rising from 0.24/100,000 population in 1979 to 1.10/100,000 population in 2014. The annual upward trend in mortality rates had two inflection points, in 1992 and 2008, separating three distinct time segments with an annual growth of 2.2%, 6.8%, and 2.4%, respectively. The comparison of RRs for the age groups, using the 50- to 54-year age group as a reference, and for the study period, using 1979-1984 as a reference, were 16.14 (14.44-16.36) and 6.71 (6.34-7.12), respectively. Men compared with women had higher standardized mortality rates (per 100,000 person-years) in all age groups.

Conclusion:

Brazilian IPF mortality rates are lower than those of other countries, suggesting underdiagnosis or underreporting. The temporal trend is similar to those reported in the literature and is not explained solely by population aging.

Imaging in idiopathic pulmonary fibrosis: diagnosis and mimics

Idiopathic pulmonary fibrosis is a chronic disease of unknown etiology that usually has a progressive course and is commonly associated with a poor prognosis. The main symptoms of idiopathic pulmonary fibrosis, including progressive dyspnea and dry cough, are often nonspecific. Chest high-resolution computed tomography is the primary modality used in the initial assessment of patients with suspected idiopathic pulmonary fibrosis and may have considerable influence on subsequent management decisions. The main role of computed tomography is to distinguish chronic fibrosing lung diseases with a usual interstitial pneumonia pattern from those presenting with a non-usual interstitial pneumonia pattern, suggesting an alternative diagnosis when possible. A usual interstitial pneumonia pattern on chest tomography is characterized by the presence subpleural and basal predominance, reticular abnormality honeycombing with or without traction bronchiectasis, and the absence of features suggestive of an alternative diagnosis. Idiopathic pulmonary fibrosis can be diagnosed according to clinical and radiological criteria in approximately 66.6% of cases. Confirmation of an idiopathic pulmonary fibrosis diagnosis is challenging, requiring the exclusion of pulmonary fibroses with known causes, such as asbestosis, connective tissue diseases, drug exposure, chronic hypersensitivity pneumonitis, and other forms of idiopathic interstitial pneumonitis. The histopathological hallmark of usual interstitial pneumonia is a heterogeneous appearance, characterized by areas of fibrosis with scarring and honeycombing alternating with areas of less affected or normal parenchyma. The aim of this article was to review the clinical, radiological, and pathological features of idiopathic pulmonary fibrosis and of diseases that might mimic idiopathic pulmonary fibrosis presentation.

Breath biomarkers in idiopathic pulmonary fibrosis: a systematic review

BACKGROUND

Exhaled biomarkers may be related to disease processes in idiopathic pulmonary fibrosis (IPF) however their clinical role remains unclear. We performed a systematic review to investigate whether breath biomarkers discriminate between patients with IPF and healthy controls. We also assessed correlation with lung function, ability to distinguish diagnostic subgroups and change in response to treatment.

METHODS

MEDLINE, EMBASE and Web of Science databases were searched. Study selection was limited to adults with a diagnosis of IPF as per international guidelines.

RESULTS

Of 1014 studies screened, fourteen fulfilled selection criteria and included 257 IPF patients. Twenty individual biomarkers discriminated between IPF and controls and four showed correlation with lung function. Meta-analysis of three studies indicated mean (± SD) alveolar nitric oxide (CalvNO) levels were significantly higher in IPF (8.5 ± 5.5 ppb) than controls (4.4 ± 2.2 ppb). Markers of oxidative stress in exhaled breath condensate, such as hydrogen peroxide and 8-isoprostane, were also discriminatory. Two breathomic studies have isolated discriminative compounds using mass spectrometry. There was a lack of studies assessing relevant treatment and none assessed differences in diagnostic subgroups.

CONCLUSIONS

Evidence suggests CalvNO is higher in IPF, although studies were limited by small sample size. Further breathomic work may identify biomarkers with diagnostic and prognostic potential.

Role of imaging in progressive-fibrosing interstitial lung diseases

Imaging techniques are an essential component of the diagnostic process for interstitial lung diseases (ILDs). Chest radiography is frequently the initial indicator of an ILD, and comparison of radiographs taken at different time points can show the rate of disease progression. However, radiography provides only limited specificity and sensitivity and is primarily used to rule out other diseases, such as left heart failure. High-resolution computed tomography (HRCT) is a more sensitive method and is considered central in the diagnosis of ILDs. Abnormalities observed on HRCT can help identify specific ILDs. HRCT also can be used to evaluate the patient's prognosis, while disease progression can be assessed through serial imaging. Other imaging techniques such as positron emission tomography-computed tomography and magnetic resonance imaging have been investigated, but they are not commonly used to assess patients with ILDs. Disease severity may potentially be estimated using quantitative methods, as well as visual analysis of images. For example, comprehensive assessment of disease staging and progression in patients with ILDs requires visual analysis of pulmonary features that can be performed in parallel with quantitative analysis of the extent of fibrosis. New approaches to image analysis, including the application of machine learning, are being developed.

Imaging techniques, particularly HRCT, are the cornerstone for ILD diagnosis and new approaches to analysing HRCT images, including machine-learning technology, are being developedhttp://ow.ly/1R1e30mOqhn