Biomarkers in idiopathic pulmonary fibrosis

Therapeutic Strategies for Idiopathic Pulmonary Fibrosis - Thriving Present and Promising Tomorrow

Idiopathic pulmonary fibrosis (IPF) is a continuous, progressive, and lethal age-related respiratory disease. It is characterized by condensed and rigid lung tissue, which leads to a decline in the normal functioning of the lungs. The pathophysiology of IPF has still not been completely elucidated, so current strategies are lagging behind with respect to improving the condition of patients with IPF and increasing their survival rate. The desire for a better understanding of the pathobiology of IPF and its early detection has led to the identification of various biomarkers associated with IPF. The use of drugs such as pirfenidone and nintedanib as a safe and effective treatment alternative have marked a new chapter in the treatment of IPF. However, nonpharmacological therapies, involving long-term oxygen therapy, transplantation of the lungs, pulmonary rehabilitation, ventilation, and palliative care for cough and dyspnea, are still considered to be beneficial as supplementary methods for IPF therapy. A major risk factor for IPF is aging, with associated hallmarks such as telomere attrition, senescence, epigenetic drift, stem cell exhaustion, loss of proteostasis, and mitochondrial dysfunction. These are promising earmarks for the development of potential therapy for the disease. In this review, we have discussed current and emerging novel therapeutic strategies for IPF, especially for targets associated with age-related mechanisms.

Ziziphus spina-christi L. extract attenuates bleomycin-induced lung fibrosis in mice via regulating TGF-β1/SMAD pathway: LC-MS/MS Metabolic profiling, chemical composition, and histology studies

Ancient Egyptians (including Bedouins and Nubians) have long utilized Ziziphus spina-christi (L.), a traditional Arabian medicinal herb, to alleviate swellings and inflammatory disorders. It is also mentioned in Christian and Muslim traditions. Ziziphus spina-christi L. (Family: Rhamnaceae) is a plentiful source of polyphenols, revealing free radical scavenging, antioxidant, metal chelating, cytotoxic, and anti-inflammatory activities. Herein, different classes of the existing bioactive metabolites in Z. spina-christi L. were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the first time. The study also aimed to assess the anti-inflammatory and antifibrotic properties of Z. spina-christi L. extract against bleomycin-induced lung fibrosis in an experimental mouse model. 32 male Swiss Albino mice were assigned into 4 groups; the first and second were the normal control group and the bleomycin positive control (single 2.5 U/kg bleomycin intratracheal dose). The third and fourth groups received 100 and 200 mg/kg/day Z. spina-christi L. extract orally for 3 weeks, 2 weeks before bleomycin, and 1 week after. The bioactive metabolites in Z. spina-christi L. extract were identified as phenolic acids, catechins, flavonoids, chalcones, stilbenes, triterpenoid acids, saponins, and sterols. The contents of total phenolic compounds and flavonoids were found to be 196.62 mg GAE/gm and 33.29 mg QE/gm, respectively. In the experimental study, histopathological examination revealed that lung fibrosis was attenuated in both Z. spina-christi L.- treated groups. Z. spina-christi L. extract downregulated the expression of nuclear factor kappa B (NF-κB) p65 and decreased levels of the inflammatory markers tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and c-Jun N-terminal kinase (JNK) in lung tissue. Z. spina-christi L. also downregulated the expression of the fibrotic parameters collagen-1, alpha-smooth muscle actin (α-SMA), transforming growth factor-beta 1 (TGF-β1), matrix metalloproteinase-9 (MMP-9) and SMAD3, with upregulation of the antifibrotic SMAD7 in lung tissue. Overall, the present study suggests a potential protective effect of Z. spina-christi L. extract against bleomycin-induced lung fibrosis through regulation of the TGF-β1/SMAD pathway.

Cell selective BCL-2 inhibition enabled by lipid nanoparticles alleviates lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a high mortality rate due to limited treatment options. Current therapies cannot effectively reverse the damage caused by IPF. Research suggests that promoting programmed cell death (apoptosis) in myofibroblasts, the key cells driving fibrosis, could be a promising strategy. However, inducing apoptosis in healthy cells like epithelial and endothelial cells can cause unwanted side effects. This project addresses this challenge by developing a targeted approach to induce apoptosis specifically in myofibroblasts. We designed liposomes (LPS) decorated with peptides that recognize VCAM-1, a protein highly expressed on myofibroblasts in fibrotic lungs. These VCAM1-targeted LPS encapsulate Venetoclax (VNT), a small molecule drug that inhibits BCL-2, an anti-apoptotic protein. By delivering VNT directly to myofibroblasts, we hypothesize that VCAM1-VNT-LPS can selectively induce apoptosis in these cells, leading to reduced fibrosis and improved lung function. We successfully characterized VCAM1-VNT-LPS for size, surface charge, and drug loading efficiency. Additionally, we evaluated their stability over three months at different temperatures. In vitro and in vivo studies using a bleomycin-induced mouse model of lung fibrosis demonstrated the therapeutic potential of VCAM1-VNT-LPS. These studies showed a reduction in fibrosis-associated proteins (collagen, α-SMA, VCAM1) and BCL-2, while simultaneously increasing apoptosis in myofibroblasts. These findings suggest that VCAM1-targeted delivery of BCL-2 inhibitors using liposomes presents a promising and potentially selective therapeutic approach for IPF.

Biomarkers in idiopathic pulmonary fibrosis: Current insight and future direction

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease with a dismal prognosis. Early diagnosis, accurate prognosis, and personalized therapeutic interventions are essential for improving patient outcomes. Biomarkers, as measurable indicators of biological processes or disease states, hold significant promise in IPF management. In recent years, there has been a growing interest in identifying and validating biomarkers for IPF, encompassing various molecular, imaging, and clinical approaches. This review provides an in-depth examination of the current landscape of IPF biomarker research, highlighting their potential applications in disease diagnosis, prognosis, and treatment response. Additionally, the challenges and future perspectives of biomarker integration into clinical practice for precision medicine in IPF are discussed.

A novel model for predicting prognosis in patients with idiopathic pulmonary fibrosis based on endoplasmic reticulum stress-related genes

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic disease of unknown pathogenic origin. Endoplasmic reticulum (ER) stress refers to the process by which cells take measures to ER function when the morphology and function of the reticulum are changed. Recent studies have demonstrated that the ER was involved in the evolution and progression of IPF. In this study, we obtained transcriptome data and relevant clinical information from the Gene Expression Omnibus database and conducted bioinformatics analysis. Among the 544 ER stress-related genes (ERSRGs), 78 were identified as differentially expressed genes (DEGs). These DEGs were primarily enriched in response to ER stress, protein binding, and protein processing. Two genes (HTRA2 and KTN1) were included for constructing an accurate molecular signature. The overall survival of patients was remarkably worse in the high-risk group than in the low-risk group. We further analyzed the difference in immune cells between high-risk and low-risk groups. M0 and M2 macrophages were significantly increased in the high-risk group. Our results suggested that ERSRGs might play a critical role in the development of IPF by regulating the immune microenvironment in the lungs, which provide new insights on predicting the prognosis of patients with IPF.

Antifibrotic Drugs against Idiopathic Pulmonary Fibrosis and Pulmonary Fibrosis Induced by COVID-19: Therapeutic Approaches and Potential Diagnostic Biomarkers

The COVID-19 pandemic has had a significant impact on the health and economy of the global population. Even after recovery from the disease, post-COVID-19 symptoms, such as pulmonary fibrosis, continue to be a concern. This narrative review aims to address pulmonary fibrosis (PF) from various perspectives, including the fibrotic mechanisms involved in idiopathic and COVID-19-induced pulmonary fibrosis. On the other hand, we also discuss the current therapeutic drugs in use, as well as those undergoing clinical or preclinical evaluation. Additionally, this article will address various biomarkers with usefulness for PF prediction, diagnosis, treatment, prognosis, and severity assessment in order to provide better treatment strategies for patients with this disease.

LncRNA SNHG8 upregulates MUC5B to induce idiopathic pulmonary fibrosis progression by targeting miR-4701-5p

Long noncoding RNAs (lncRNAs) play a critical role in idiopathic pulmonary fibrosis (IPF); however, the underlying molecular mechanisms are unclear. Our study demonstrated that lncRNA small nucleolar RNA host gene 8 (SNHG8) was increased in bleomycin (BLM)-induced A549 cells. LncRNA SNHG8 overexpression further elevated fibrosis-related factors monocyte chemotactic protein 1 (MCP1), CC motif chemokine ligand 18 (CCL18), and α-smooth muscle actin (α-SMA), as well as increased collagen type I alpha-1 chain (COL1A1) and collagen type III alpha-1 chain (COL3A1). Meanwhile, lncRNA SNHG8 knockdown exhibited an opposite role in reducing BLM-induced pulmonary fibrosis. With regard to the mechanism, SNHG8 was then revealed to act as a competing endogenous RNA (ceRNA) for microRNA (miR)-4701-5p in regulating Mucin 5B (MUC5B) expression. Furthermore, the interactions between SNHG8 and miR-4701-5p, between miR-4701-5p and MUC5B, and between SNHG8 and MUC5B on the influence of fibrosis-related indicators were confirmed, respectively. In addition, SNHG8 overexpression enhanced the levels of transforming growth factor (TGF)-β1 and phosphorylation Smad2/3 (p-Smad2/3), which was suppressed by SNHG8 knockdown in BLM-induced A549 cells. Moreover, miR-4701-5p inhibitor-induced elevation of TGF-β1 and p-Smad2/3 was significantly suppressed by SNHG8 knockdown. In conclusion, SNHG8 knockdown attenuated pulmonary fibrosis progression by regulating miR-4701-5p/MUC5B axis, which might be associated with the modulation of TGF-β1/Smad2/3 signaling. These findings reveal that lncRNA SNHG8 may become a potential target for the treatment of IPF.

Comprehensive analysis of an endoplasmic reticulum stress-related gene prediction model and immune infiltration in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease. This study aimed to investigate the involvement of endoplasmic reticulum stress (ERS) in IPF and explore its correlation with immune infiltration.

Methods

ERS-related differentially expressed genes (ERSRDEGs) were identified by intersecting differentially expressed genes (DEGs) from three Gene Expression Omnibus datasets with ERS-related gene sets. Gene Set Variation Analysis and Gene Ontology were used to explore the potential biological mechanisms underlying ERS. A nomogram was developed using the risk signature derived from the ERSRDEGs to perform risk assessment. The diagnostic value of the risk signature was evaluated using receiver operating characteristics, calibration, and decision curve analyses. The ERS score of patients with IPF was measured using a single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm. Subsequently, a prognostic model based on the ERS scores was established. The proportion of immune cell infiltration was assessed using the ssGSEA and CIBERSORT algorithms. Finally, the expression of ERSRDEGs was validated in vivo and in vitro via RT-qPCR.

Results

This study developed an 8-ERSRDEGs signature. Based on the expression of these genes, we constructed a diagnostic nomogram model in which agouti-related neuropeptide had a significantly greater impact on the model. The area under the curve values for the predictive value of the ERSRDEGs signature were 0.975 and 1.000 for GSE70866 and GSE110147, respectively. We developed a prognostic model based on the ERS scores of patients with IPF. Furthermore, we classified patients with IPF into two subtypes based on their signatures. The RT-qPCR validation results supported the reliability of most of our conclusions.

Conclusion

We developed and verified a risk model using eight ERSRDEGs. These eight genes can potentially affect the progression of IPF by regulating ERS and immune responses.

Development of a Novel Biomarker for the Progression of Idiopathic Pulmonary Fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is diverse and unpredictable. We identified and validated a new biomarker for IPF progression. To identify a candidate gene to predict progression, we assessed differentially expressed genes in patients with advanced IPF compared with early IPF and controls in three lung sample cohorts. Candidate gene expression was confirmed using immunohistochemistry and Western blotting of lung tissue samples from an independent IPF clinical cohort. Biomarker potential was assessed using an enzyme-linked immunosorbent assay of serum samples from the retrospective validation cohort. We verified that the final candidate gene reflected the progression of IPF in a prospective validation cohort. In the RNA-seq comparative analysis of lung tissues, CD276, COL7A1, CTSB, GLI2, PIK3R2, PRAF2, IGF2BP3, and NUPR1 were up-regulated, and ADAMTS8 was down-regulated in the samples of advanced IPF. Only CTSB showed significant differences in expression based on Western blotting (n = 12; p < 0.001) and immunohistochemistry between the three groups of the independent IPF cohort. In the retrospective validation cohort (n = 78), serum CTSB levels were higher in the progressive group (n = 25) than in the control (n = 29, mean 7.37 ng/mL vs. 2.70 ng/mL, p < 0.001) and nonprogressive groups (n = 24, mean 7.37 ng/mL vs. 2.56 ng/mL, p < 0.001). In the prospective validation cohort (n = 129), serum CTSB levels were higher in the progressive group than in the nonprogressive group (mean 8.30 ng/mL vs. 3.00 ng/mL, p < 0.001). After adjusting for baseline FVC, we found that CTSB was independently associated with IPF progression (adjusted OR = 2.61, p < 0.001). Serum CTSB levels significantly predicted IPF progression (AUC = 0.944, p < 0.001). Serum CTSB level significantly distinguished the progression of IPF from the non-progression of IPF or healthy control.

Exploring the Role of Biomarkers Associated with Alveolar Damage and Dysfunction in Idiopathic Pulmonary Fibrosis-A Systematic Review

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is one of the most aggressive forms of interstitial lung diseases (ILDs), marked by an ongoing, chronic fibrotic process within the lung tissue. IPF leads to an irreversible deterioration of lung function, ultimately resulting in an increased mortality rate. Therefore, the focus has shifted towards the biomarkers that might contribute to the early diagnosis, risk assessment, prognosis, and tracking of the treatment progress, including those associated with epithelial injury.

METHODS

We conducted this review through a systematic search of the relevant literature using established databases such as PubMed, Scopus, and Web of Science. Selected articles were assessed, with data extracted and synthesized to provide an overview of the current understanding of the existing biomarkers for IPF.

RESULTS

Signs of epithelial cell damage hold promise as relevant biomarkers for IPF, consequently offering valuable support in its clinical care. Their global and standardized utilization remains limited due to a lack of comprehensive information of their implications in IPF.

CONCLUSIONS

Recognizing the aggressive nature of IPF among interstitial lung diseases and its profound impact on lung function and mortality, the exploration of biomarkers becomes pivotal for early diagnosis, risk assessment, prognostic evaluation, and therapy monitoring.

Flavokawain A ameliorates pulmonary fibrosis by inhibiting the TGF-β signaling pathway and CXCL12/CXCR4 axis

Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease characterized by myofibroblast proliferation and extracellular matrix deposition that has a high mortality rate and limited therapeutic options. Flavokawain A(FKA) is the major component of chalcone in kava extract. FKA has been reported to inhibit TGF-β1-induced cardiomyocyte fibrosis by suppressing ROS production in A7r5 cells, but the role and mechanism of FKA in pulmonary fibrosis are unknown. In this study, we evaluated the effect of FKA on pulmonary fibrosis using an animal model of bleomycin-induced pulmonary fibrosis and showed that FKA alleviated the development of pulmonary fibrosis in a dose-dependent manner and improved lung function as well as collagen deposition and extracellular matrix accumulation in mice. In vitro studies showed that FKA inhibited myofibroblast activation and lung fibrosis progression by inhibiting TGF-β1/Smad signaling in a dose-dependent manner. In addition, we identified CXCL12 as a potential target of FKA through target prediction. Molecular docking, CETSA(cellular thermal displacement assay) and silver staining assays further demonstrated that FKA could interact with CXCL12 and that FKA could inhibit CXCL12 dimerization in vitro. Further analysis revealed that FKA could inhibit fibroblast activation and reduce extracellular matrix (ECM) production and collagen deposition by blocking CXCL12/CXCR4 signaling, and knocking down CXCR4 expression could weaken the inhibitory effect of FKA on CXCL12/CXCR4 signal transduction. In conclusion, our study showed that FKA inhibited CXCL12/CXCR4 signaling by inhibiting CXCL12 dimerization, blocked the CXCL12/CXCR4 signaling pathway and inhibited the TGF-β1-mediated signaling pathway to ameliorate pulmonary fibrosis, and FKA is a promising therapeutic agent for pulmonary fibrosis.

Voluntary wheel-running improved pulmonary fibrosis by reducing epithelial mesenchymal transformation

AIMS

Pulmonary fibrosis seriously affects the health and life quality of patients. Exercise has been shown to have anti-inflammatory and antioxidant effects, but its effect on pulmonary fibrosis is unclear. In this study, the effect and mechanism of exercise on pulmonary fibrosis induced by paraquat were detected.

MAIN METHODS

Three data sets were retrieved from GEO data. The biological significance of DEGs generation was determined by GO, KEGG, GSEA, and PPI. Thirty male BALB/C mice were randomly divided into control group, model group and exercise group. H&E staining, Masson staining, Immunohistochemistry and Western blot were used to explore the results. The levels of SOD, CAT, MDA, and GSH in lung tissue were analyzed with detection kits. The levels of inflammatory factors in serum and BALF were measured by ELISA.

KEY FINDINGS

Compared with the control group, the infiltration of inflammatory cells and fibrotic lesions were increased in the model group. Compared with the model group, voluntary wheel-running reducing the EMT of alveolar epithelial cells, the activation of the Wnt/β-catenin signaling pathway and the level of oxidative distress. Moreover, compared to model group, the serum IL-4, IL-10 and IFN-γ were increased, while the serum CXCL1 were decreased, while the levels of CXCL1, IL-6, IL-10, TNF-α and IFN-γ in the bronchoalveolar lavage fluid were decreased in exercise group.

SIGNIFICANCE

Voluntary wheel-running reduced inflammatory infiltration and upregulated the expression of antioxidative distress proteins, further to improve the degree of EMT, and ultimately alleviated paraquat induced pulmonary fibrosis.

Exosomal miR-17-5p from human embryonic stem cells prevents pulmonary fibrosis by targeting thrombospondin-2

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible lung disease characterized by pulmonary fibrosis and lung dysfunction, ultimately leading to respiratory failure. Many preclinical studies have investigated the therapeutic potential of stem cell-derived exosomes in this disease, particularly mesenchymal stem cell-derived exosomes. However, the effects of embryonic stem cell-derived exosomes in IPF remain unclear.

METHODS

We established a bleomycin (BLM)-induced pulmonary fibrosis mice model and administered human embryonic stem cell exosomes (hESC-exo) from the first day after BLM treatment. The effects of hESC-exo were assessed by pulmonary function tests, biochemical analysis, histochemistry, quantitative real-time polymerase chain reaction (qPCR), and western blot (WB). RNA-seq was used to screen for the potential therapeutic targets of hESC-exo in fibrotic lungs; the identified signaling axis was characterized using a luciferase assay, qPCR, and WB.

RESULTS

Results indicated hESC-exo administration notably alleviated inflammation, removed deposited collagen, and rescued alveolar architecture in the lungs of BLM-induced mice. In vivo and in vitro tests revealed that hESC-exo-derived miR-17-5p directly bound thrombospondin-2 (Thbs2) to regulate inflammation and fibrosis; thus, hESC-exo protected against BLM toxicity in the lungs via the miR-17-5p/Thbs2 axis.

CONCLUSION

These results suggest a promising new treatment for fibrosis-associated diseases.

Progress in understanding and treating idiopathic pulmonary fibrosis: recent insights and emerging therapies

Idiopathic pulmonary fibrosis (IPF) is a long-lasting, continuously advancing, and irrevocable interstitial lung disorder with an obscure origin and inadequately comprehended pathological mechanisms. Despite the intricate and uncharted causes and pathways of IPF, the scholarly consensus upholds that the transformation of fibroblasts into myofibroblasts-instigated by injury to the alveolar epithelial cells-and the disproportionate accumulation of extracellular matrix (ECM) components, such as collagen, are integral to IPF's progression. The introduction of two novel anti-fibrotic medications, pirfenidone and nintedanib, have exhibited efficacy in decelerating the ongoing degradation of lung function, lessening hospitalization risk, and postponing exacerbations among IPF patients. Nonetheless, these pharmacological interventions do not present a definitive solution to IPF, positioning lung transplantation as the solitary potential curative measure in contemporary medical practice. A host of innovative therapeutic strategies are presently under rigorous scrutiny. This comprehensive review encapsulates the recent advancements in IPF research, spanning from diagnosis and etiology to pathological mechanisms, and introduces a discussion on nascent therapeutic methodologies currently in the pipeline.

NFATc3 Promotes Pulmonary Inflammation and Fibrosis by Regulating Production of CCL2 and CXCL2 in Macrophages

Idiopathic pulmonary fibrosis (IPF) is a progressive and highly lethal inflammatory interstitial lung disease characterized by aberrant extracellular matrix deposition. Macrophage activation by cytokines released from repetitively injured alveolar epithelial cells regulates the inflammatory response, tissue remodeling, and fibrosis throughout various phases of IPF. Our previous studies demonstrate that nuclear factor of activated T cells cytoplasmic member 3 (NFATc3) regulates a wide array of macrophage genes during acute lung injury pathogenesis. However, the role of NFATc3 in IPF pathophysiology has not been previously reported. In the current study, we demonstrate that expression of NFATc3 is elevated in lung tissues and pulmonary macrophages in mice subjected to bleomycin (BLM)-induced pulmonary fibrosis and IPF patients. Remarkably, NFATc3 deficiency (NFATc3+/-) was protective in bleomycin (BLM)-induced lung injury and fibrosis. Adoptive transfer of NFATc3+/+ macrophages to NFATc3+/- mice restored susceptibility to BLM-induced pulmonary fibrosis. Furthermore, in vitro treatment with IL-33 or conditioned medium from BLM-treated epithelial cells increased production of CCL2 and CXCL2 in macrophages from NFATc3+/+ but not NFATc3+/- mice. CXCL2 promoter-pGL3 Luciferase reporter vector showed accentuated reporter activity when co-transfected with the NFATc3 expression vector. More importantly, exogenous administration of recombinant CXCL2 into NFATc3+/- mice increased fibrotic markers and exacerbated IPF phenotype in BLM treated mice. Collectively, our data demonstrate, for the first time, that NFATc3 regulates pulmonary fibrosis by regulating CCL2 and CXCL2 gene expression in macrophages.

Acute Exacerbations of Interstitial Lung Diseases: Focus on Biomarkers

Interstitial lung diseases (ILDs) are a large group of pulmonary disorders characterized histologically by the cardinal involvement of the pulmonary interstitium. The prototype of ILDs is idiopathic pulmonary fibrosis (IPF), an incurable disease characterized by progressive distortion and loss of normal lung architecture through unchecked collagen deposition. Acute exacerbations are dramatic events during the clinical course of ILDs, associated with high morbidity and mortality. Infections, microaspiration, and advanced lung disease might be involved in the pathogenesis of acute exacerbations. Despite clinical scores, the prediction of the onset and outcome of acute exacerbations is still inaccurate. Biomarkers are necessary to characterize acute exacerbations better. We review the evidence for alveolar epithelial cell, fibropoliferation, and immunity molecules as potential biomarkers for acute exacerbations of interstitial lung disease.

Machine learning-based prediction of candidate gene biomarkers correlated with immune infiltration in patients with idiopathic pulmonary fibrosis

Objective

This study aimed to identify candidate gene biomarkers associated with immune infiltration in idiopathic pulmonary fibrosis (IPF) based on machine learning algorithms.

Methods

Microarray datasets of IPF were extracted from the Gene Expression Omnibus (GEO) database to screen for differentially expressed genes (DEGs). The DEGs were subjected to enrichment analysis, and two machine learning algorithms were used to identify candidate genes associated with IPF. These genes were verified in a validation cohort from the GEO database. Receiver operating characteristic (ROC) curves were plotted to assess the predictive value of the IPF-associated genes. The cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm was used to evaluate the proportion of immune cells in IPF and normal tissues. Additionally, the correlation between the expression of IPF-associated genes and the infiltration levels of immune cells was examined.

Results

A total of 302 upregulated and 192 downregulated genes were identified. Functional annotation, pathway enrichment, Disease Ontology and gene set enrichment analyses revealed that the DEGs were related to the extracellular matrix and immune responses. COL3A1, CDH3, CEBPD, and GPIHBP1 were identified as candidate biomarkers using machine learning algorithms, and their predictive value was verified in a validation cohort. Additionally, ROC analysis revealed that the four genes had high predictive accuracy. The infiltration levels of plasma cells, M0 macrophages and resting dendritic cells were higher and those of resting natural killer (NK) cells, M1 macrophages and eosinophils were lower in the lung tissues of patients with IPF than in those of healthy individuals. The expression of the abovementioned genes was correlated with the infiltration levels of plasma cells, M0 macrophages and eosinophils.

Conclusion

COL3A1, CDH3, CEBPD, and GPIHBP1 are candidate biomarkers of IPF. Plasma cells, M0 macrophages and eosinophils may be involved in the development of IPF and may serve as immunotherapeutic targets in IPF.

Immune Mechanisms of Pulmonary Fibrosis with Bleomycin

Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial-mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.

Endothelin-1 as a Biomarker of Idiopathic Pulmonary Fibrosis and Interstitial Lung Disease Associated with Autoimmune Diseases

The aim of this study was to determine the role of endothelin-1 (ET-1), a molecule involved in multiple vascular and fibrosing abnormalities, as a biomarker of interstitial lung disease (ILD), as well as its use for the differential diagnosis between idiopathic pulmonary fibrosis (IPF) and ILD associated with autoimmune diseases (AD-ILD), using a large and well-defined cohort of patients with ILD. A total of 112 patients with IPF, 91 patients with AD-ILD (28 rheumatoid arthritis (RA), 26 systemic sclerosis, 20 idiopathic inflammatory myositis and 17 interstitial pneumonia with autoimmune features) and 44 healthy controls were included. ET-1 serum levels were determined by enzyme-linked immunosorbent assay. A significant increase in ET-1 levels was found in patients with IPF compared to controls. Likewise, AD-ILD patients also showed higher ET-1 levels than controls when the whole cohort was stratified by the type of AD. Similar ET-1 levels were found in IPF and AD-ILD patients, regardless of the underlying AD. Interestingly, increased ET-1 levels were correlated with worse lung function in IPF and RA-ILD patients. Our study supports that serum ET-1 may be useful as a biomarker of ILD, although it could not help in the differential diagnosis between IPF and AD-ILD. Moreover, ET-1 levels may be associated with ILD severity.

Transforming growth factor-β signaling: From tissue fibrosis to therapeutic opportunities

Fibrosis refers to the excessive deposition of extracellular matrix components in the processes of wound repair or tissue regeneration after tissue damage. Fibrosis occurs in various organs such as lung, heart, liver, and kidney tissues, resulting in the failure of organ structural integrity and its functional impairment. It has long been thought to be relentlessly progressive and irreversible process, but both preclinical models and clinical trials in multiorgans have shown that fibrosis is a highly dynamic process. Transforming growth factor-beta (TGF-β) is a superfamily of related growth factors. Many studies have described that activation of profibrotic TGF-β signaling promotes infiltration and/or proliferation of preexisting fibroblasts, generation of myofibroblasts, extracellular matrix deposition, and inhibition of collagenolysis, which leads to fibrosis in the pathological milieu. This review describes the effect of TGF-β signaling in fibrotic-associate lung, heart, liver, and kidney tissues, followed by a detailed discussion of canonical and non-canonical TGF-β signaling pathway. In addition, this review also discusses therapeutic options by using natural products and chemical agents, for targeting tissue fibrosis via modulating TGF-β signaling to provide a more specific concept-driven therapy strategy for multiorgan fibrosis.

Theophylline Attenuates BLM-Induced Pulmonary Fibrosis by Inhibiting Th17 Differentiation

Idiopathic pulmonary fibrosis (IPF) is a chronic and refractory interstitial lung disease. Although there are two approved drugs for IPF, they were not able to completely cure the disease. Therefore, the development of new drugs is required for the effective treatment of IPF. In this study, we investigated the effect of theophylline, which has long been used for the treatment of asthma, on pulmonary fibrosis. The administration of theophylline attenuated the fibrotic changes of lung tissues and improved mechanical pulmonary functions in bleomycin (BLM)-induced pulmonary fibrosis. Theophylline treatment suppressed IL-17 production through inhibiting cytokines controlling Th17 differentiation; TGF-β, IL-6, IL-1β, and IL-23. The inhibition of IL-6 and IL-1β by theophylline is mediated by suppressing BLM-induced ROS production and NF-κB activation in epithelial cells. We further demonstrated that theophylline inhibited TGF-β-induced epithelial-to-mesenchymal transition in epithelial cells through suppressing the phosphorylation of Smad2/3 and AKT. The inhibitory effects of theophylline on the phosphorylation of Smad2/3 and AKT were recapitulated in BLM-treated lung tissues. Taken together, these results demonstrated that theophylline prevents pulmonary fibrosis by inhibiting Th17 differentiation and TGF-β signaling.

Genes related to N6-methyladenosine in the diagnosis and prognosis of idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis (IPF) is a chronic progressive pulmonary fibrotic disease with unknown etiology and poor outcomes. It severely affects the quality of life. In this study, we comprehensively analyzed the expression of N6-methyladenosine (m6A) RNA methylation regulators using gene expression data from various tissue sources in IPF patients and healthy volunteers. Methods: The gene expression matrix and clinical characteristics of IPF patients were retrieved from the Gene Expression Omnibus database. A random forest model was used to construct diagnosis signature m6A regulators. Regression analysis and correlation analysis were used to identify prognosis m6A regulators. Consensus cluster analysis was used to construct different m6A prognosis risk groups, then functional enrichment, immune infiltration and drug sensitivity analysis were performed. Result: Five candidate m6A genes from lung tissue were used to predict the incidence, and the incidence was validated using datasets from bronchoalveolar lavage fluid (BALF) and peripheral blood mononuclear cells. Subsequently, the BALF dataset containing outcomes data was used for the prognosis analysis of m6A regulators. METTL14, G3BP2, and ZC3H13 were independent protective factors. Using correlation analysis with lung function in the lung tissue-derived dataset, METTL14 was a protective factor in IPF. Based on METTL14 and G3BP2, a consensus cluster analysis was applied to distinguish the prognostic m6A regulation patterns. The low-risk group's prognosis was significantly better than the high-risk group. Biological processes regulated by various risk groups included fibrogenesis and cell adhesion. Analysis of immune cell infiltration showed upregulation of neutrophils in the m6A high-risk group. Subsequently, five m6A high-risk group sensitive drugs and one m6A low-risk group sensitive drug were identified. Discussion: These findings suggest that m6A regulators are involved in the diagnosis and prognosis of IPF, and m6A patterns are a method to identify IPF outcomes.

Identification of immune biomarkers associated with basement membranes in idiopathic pulmonary fibrosis and their pan-cancer analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease of unknown etiology, characterized by diffuse alveolitis and alveolar structural damage. Due to the short median survival time and poor prognosis of IPF, it is particularly urgent to find new IPF biomarkers. Previous studies have shown that basement membranes (BMs) are associated with the development of IPF and tumor metastasis. However, there is still a lack of research on BMs-related genes in IPF. Therefore, we investigated the expression level of BMs genes in IPF and control groups, and explored their potential as biomarkers for IPF diagnosis. In this study, the GSE32537 and GSE53845 datasets were used as training sets, while the GSE24206, GSE10667 and GSE101286 datasets were used as validation sets. In the training set, seven immune biomarkers related to BMs were selected by differential expression analysis, machine learning algorithm (LASSO, SVM-RFE, Randomforest) and ssGSEA analysis. Further ROC analysis confirmed that seven BMs-related genes played an important role in IPF. Finally, four immune-related Hub genes (COL14A1, COL17A1, ITGA10, MMP7) were screened out. Then we created a logistic regression model of immune-related hub genes (IHGs) and used a nomogram to predict IPF risk. The nomogram model was evaluated to have good reliability and validity, and ROC analysis showed that the AUC value of IHGs was 0.941 in the training set and 0.917 in the validation set. Pan-cancer analysis showed that IHGs were associated with prognosis, immune cell infiltration, TME, and drug sensitivity in 33 cancers, suggesting that IHGs may be potential targets for intervention in human diseases including IPF and cancer.

Hotspots and Frontiers of Host Immune Response in Idiopathic Pulmonary Fibrosis: A Bibliometric and Scientific Visual Research from 2000 to 2022

Background

Idiopathic pulmonary fibrosis (IPF) is a disease with significant morbidity, progressive deterioration of lung function till death, and lack of effective treatment options. This study aims to explore the global research trends in IPF and immune response to predict the research hotspot in the future. Materials and methods. All related publications on IPF and immune response since the establishment of diagnostic criteria for IPF were retrieved using the Web of Science (WOS) database. VOSviewer, GraphPad Prism 6, CiteSpace version 5.6. R5 64-bit, and a bibliometrics online platform were used to extract and analyze the trends in relevant fields.

Results

From March 1, 2000, to September 30, 2022, a total of 658 articles with 25,126 citations met the inclusion criteria. The United States ranked first in number of publications (n = 217), number of citations (n = 14,745), and H-index (62). China ranked second in publications (n = 124) and seventh and fifth for citation frequency and H-index, respectively. The American Journal of Respiratory and Critical Care Medicine (impact factor = 30.528) published the most articles in the field. The author Kaminski N. from the United States was the most influential author with 26 publications and an H-index of 24. Among the 52 keywords that co-occurred at least 20 times, the main keywords were concentrated in "Inflammation related" and "Biomarker related" clusters. "biomarker" (AAY 2018.64, 25 times) was a newly emerged keyword.

Conclusions

The United States has an unequivocal advantage in IPF and immunization, but China shows a faster developing trend. The American Journal of Respiratory and Critical Care Medicine should be prioritized for leading articles. This study indicates that exploration of ideal immune-related biomarkers to provide evidence for the clinical work of IPF might be a hotspot in the near future.

The Role of the Microbiome in Connective-Tissue-Associated Interstitial Lung Disease and Pulmonary Vasculitis

The microbiome can trigger and maintain immune-mediated diseases and is associated with the severity and prognosis of idiopathic pulmonary fibrosis, which is the prototype of interstitial lung diseases (ILDs). The latter can be a major cause of morbidity and mortality in patients with connective-tissue diseases (CTD). In the present review, we discuss the current evidence regarding microbiome in CTD-ILD and pulmonary vasculitis. In patients with rheumatoid arthritis (RA) the BAL microbiota is significantly less diverse and abundant, compared to healthy controls. These changes are associated with disease severity. In systemic sclerosis (SSc), gastrointestinal (GI)-dysbiosis is associated with ILD. Butyrate acid administration as a means of restoration of GI-microbiota has reduced the degree of lung fibrosis in animal models. Although related studies are scarce for SLE and Sjögren's syndrome, studies of the gut, oral and ocular microbiome provide insights into the pathogenesis of these diseases. In ANCA-associated vasculitis, disease severity and relapses have been associated with disturbed nasal mucosa microbiota, with immunosuppressive treatment restoring the microbiome changes. The results of these studies suggest however no causal relation. More studies of the lung microbiome in CTD-ILDs are urgently needed, to provide a better understanding of the pathogenesis of these diseases.

Stabil idiyopatik pulmoner fibrozde hastalik şiddeti ve prognostik belirteçler ile matriks metallaproteinaz düzeyleri arasindaki ilişki

Purpose: Blood-derived biomarkers have been extensively considered as possible prognostic indicators in idiopathic pulmonary fibrosis (IPF) recently. In order to assess the value of circulating biomarkers in common IPF clinical practice, the study intends to draw conclusions regarding the link between disease severity, prognostic indicators, and serum matrix metalloproteinase in patients with stable idiopathic pulmonary fibrosis. Materials and Methods: The study comprised 22 people with an IPF diagnosis that had been verified by a multidisciplinary approach. The sociodemographic details, clinical and radiologic symptoms, pulmonary function tests and the Gender-Age-Physiology (GAP) score were noted. ELISA has been used to research serum MMP concentrations. Results: There is no statistically significant correlation between the Matrix Metalloproteinase (MMP) 2, MMP 7, MMP 9, and MMP13 and the GAP index and, pulmonary function tests, or disease severity. GAP score was found to be higher in stage 3 in patients with severe disease, in stage 2 in patients with moderate disease, and in stage 1 in patients with mild disease. Conclusion: There are consistent findings in the literature, despite the fact that the association between MMP and IPF prognostic markers, pulmonary function tests, and disease severity could not be seen in this investigation. However, because they could open the door to a cutting-edge treatment strategy, these indicators should be investigated prospectively in larger series.

Prognostic Role of NLR, PLR and MHR in Patients With Idiopathic Pulmonary Fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease with low survival time. Since the pathophysiological progression of IPF is closely associated with immunological and inflammatory responses, immune biomarkers, including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-high density lipoprotein ratio (MHR), have the potential to predict overall survival in IPF patients.

Methods

A total of 278 patients with IPF were finally enrolled. The demographic and clinical characteristics of the patients at baseline were recorded. Multivariable Cox regression analysis was used to evaluate the association between the three biomarkers and overall survival in both the total cohort and acute exacerbation subgroup.

Results

The median follow-up was 5.84 months. After adjusting for confounders, we found that only elevated NLR was associated with worse overall survival (OR = 1.019, 95% CI 1.001-1.037, P =0.041) by using multivariable Cox regression analysis. In 116 acute exacerbation IPF patients, the results of the Cox multiple regression model also indicated that the NLR was a significant prognostic factor (OR= 1.022, 95% CI 1.001-1.044, P =0.036). The NLR before death was also significantly higher than that at admission in nonsurvival acute exacerbation IPF patients (P=0.014). No significant differences were found in PLR (P=0.739) or MHR changes (P=0.478).

Conclusions

Our results indicated that elevated NLR expression is associated with shorter overall survival in IPF patients, which is independent of other prognostic factors. The NLR may be regarded as a reliable prognostic biomarker for IPF patients.

Disturbance of serum lipid metabolites and potential biomarkers in the Bleomycin model of pulmonary fibrosis in young mice

Background

Altered metabolic pathways have recently been considered as potential drivers of idiopathic pulmonary fibrosis (IPF) for the study of drug therapeutic targets. However, our understanding of the metabolite profile during IPF formation is lacking.

Methods

To comprehensively characterize the metabolic disorders of IPF, a mouse IPF model was constructed by intratracheal injection of bleomycin into C57BL/6J male mice, and lung tissues from IPF mice at 7 days, 14 days, and controls were analyzed by pathology, immunohistochemistry, and Western Blots. Meanwhile, serum metabolite detections were conducted in IPF mice using LC–ESI–MS/MS, KEGG metabolic pathway analysis was applied to the differential metabolites, and biomarkers were screened using machine learning algorithms.

Results

We analyzed the levels of 1465 metabolites and found that more than one-third of the metabolites were altered during IPF formation. There were 504 and 565 metabolites that differed between M7 and M14 and controls, respectively, while 201 differential metabolites were found between M7 and M14. In IPF mouse sera, about 80% of differential metabolite expression was downregulated. Lipids accounted for more than 80% of the differential metabolite species with down-regulated expression. The KEGG pathway enrichment analysis of differential metabolites was mainly enriched to pathways such as the metabolism of glycerolipids and glycerophospholipids. Eight metabolites were screened by a machine learning random forest model, and receiver operating characteristic curves (ROC) assessed them as ideal diagnostic tools.

Conclusions

In conclusion, we have identified disturbances in serum lipid metabolism associated with the formation of pulmonary fibrosis, contributing to the understanding of the pathogenesis of pulmonary fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01972-6.

Asthma and Post-Asthmatic Fibrosis: A Search for New Promising Molecular Markers of Transition from Acute Inflammation to Pulmonary Fibrosis

Asthma is a heterogeneous pulmonary disorder, the progression and chronization of which leads to airway remodeling and fibrogenesis. To understand the molecular mechanisms of pulmonary fibrosis development, key genes forming the asthma-specific regulome and involved in lung fibrosis formation were revealed using a comprehensive bioinformatics analysis. The bioinformatics data were validated using a murine model of ovalbumin (OVA)-induced asthma and post-asthmatic fibrosis. The performed analysis revealed a range of well-known pro-fibrotic markers (Cat, Ccl2, Ccl4, Ccr2, Col1a1, Cxcl12, Igf1, Muc5ac/Muc5b, Spp1, Timp1) and a set of novel genes (C3, C3ar1, Col4a1, Col4a2, Cyp2e1, Fn1, Thbs1, Tyrobp) mediating fibrotic changes in lungs already at the stage of acute/subacute asthma-driven inflammation. The validation of genes related to non-allergic bleomycin-induced pulmonary fibrosis on asthmatic/fibrotic lungs allowed us to identify new universal genes (Col4a1 and Col4a2) associated with the development of lung fibrosis regardless of its etiology. The similarities revealed in the expression profiles of nodal fibrotic genes between asthma-driven fibrosis in mice and nascent idiopathic pulmonary fibrosis in humans suggest a tight association of identified genes with the early stages of airway remodeling and can be considered as promising predictors and early markers of pulmonary fibrosis.

The Prognostic Value of Integrated Analysis of Inflammation and Hypoxia-Related Genes in Idiopathic Pulmonary Fibrosis

Currently, the aetiology and pathogenesis of idiopathic pulmonary fibrosis (IPF) are still largely unclear. Moreover, patients with IPF exhibit a considerable difference in clinical presentation, treatment, and prognosis. Optimal biomarkers or models for IPF prognosis are lacking. Therefore, this study quantified the levels of various hallmarks using a single-sample gene set enrichment analysis algorithm. The hazard ration was calculated using Univariate Cox regression analysis based on the transcriptomic profile of bronchoalveolar lavage cells and clinical survival information. Afterwards, weighted Gene Co-expression Network Analysis was performed to construct a network between gene expression, inflammation response, and hypoxia. Subsequently, univariate Cox, random forest, and multivariate Cox regressions were applied to develop a robust inflammation and hypoxia-related gene signature for predicting clinical outcomes in patients with IPF. Furthermore, a nomogram was constructed to calculate risk assessment. The inflammation response and hypoxia were identified as latent risk factors for patients with IPF. Five genes, including HS3ST1, WFDC2, SPP1, TFPI, and CDC42EP2, were identified that formed the inflammation-hypoxia-related gene signature. Kaplan-Meier plotter showed that the patients with high-risk scores had a worse prognosis than those with low-risk scores in training and validation cohorts. The time-dependent concordance index and the receiver operating characteristic analysis revealed that the risk model could accurately predict the clinical outcome of patients with IPF. Therefore, this study contributes to elucidating the role of inflammation and hypoxia in IPF, which can aid in assessing individual prognosis and personalised treatment decisions.

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.

Cutting-edge Nanotechnological Approaches for Lung Cancer Therapy

Lung cancer is the second leading cancer with a high rate of mortality. It can be treated using different intervention techniques such as chemotherapy, radiation therapy, surgical removal, and photodynamic therapy. All of these interventions lack specificity, implying that it harms the normal cells adjacent to the infected ones. Nanotechnology provides a promising solution that increases the bioavailability of anticancer drugs at the tumor site with reduced toxicity and improved therapeutic efficacy. Nanotechnology also improves the way lung cancer is diagnosed and treated. Various nanocarriers like liposomes, polymeric nanoparticles, magnetic nanoparticles, and different theranostic approaches are already approved for medical use, while various are under clinical and preclinical stages. This review article covers the details about lung cancer, types of overexpressed receptors, and cutting-edge nanocarriers used for treating lung cancer at its specific target.

Urine-derived exosomes from individuals with IPF carry pro-fibrotic cargo

BACKGROUND

MicroRNAs (miRNA) and other components contained in extracellular vesicles may reflect the presence of a disease. Lung tissue, sputum, and sera of individuals with idiopathic pulmonary fibrosis (IPF) show alterations in miRNA expression. We designed this study to test whether urine and/or tissue derived exosomal miRNAs from individuals with IPF carry cargo that can promote fibrosis.

METHODS

Exosomes were isolated from urine (U-IPFexo), lung tissue myofibroblasts (MF-IPFexo), serum from individuals with IPF (n=16) and age/sex-matched controls without lung disease (n=10). We analyzed microRNA expression of isolated exosomes and their in vivo bio-distribution. We investigated the effect on ex vivo skin wound healing and in in vivo mouse lung models.

RESULTS

U-IPFexo or MF-IPFexo expressed miR-let-7d, miR-29a-5p, miR-181b-3p and miR-199a-3p consistent with previous reports of miRNA expression obtained from lung tissue/sera from patients with IPF. In vivo bio-distribution experiments detected bioluminescent exosomes in the lung of normal C57Bl6 mice within 5 min after intravenous infusion, followed by distribution to other organs irrespective of exosome source. Exosomes labeled with gold nanoparticles and imaged by transmission electron microscopy were visualized in alveolar epithelial type I and type II cells. Treatment of human and mouse lung punches obtained from control, non-fibrotic lungs with either U-IPFexo or MF-IPFexo produced a fibrotic phenotype. A fibrotic phenotype was also induced in a human ex vivo skin model and in in vivo lung models.

CONCLUSIONS

Our results provide evidence of a systemic feature of IPF whereby exosomes contain pro-fibrotic miRNAs when obtained from a fibrotic source and interfere with response to tissue injury as measured in skin and lung models.

FUNDING

This work was supported in part by Lester and Sue Smith Foundation and The Samrick Family Foundation and NIH grants R21 AG060338 (SE and MKG), U01 DK119085 (IP, RS, MTC).

A novel prognostic signature for idiopathic pulmonary fibrosis based on five-immune-related genes

Background

Idiopathic pulmonary fibrosis (IPF) is a highly fatal lung disease of unknown etiology with a median survival after diagnosis of only 2–3 years. Its poor prognosis is due to the limited therapy options available as well as the lack of effective prognostic indicators. This study aimed to construct a novel prognostic signature for IPF to assist in the personalized management of IPF patients during treatment.

Methods

Differentially-expressed genes (DEGs) in IPF patients versus healthy individuals were analyzed using the “limma” package of R software. Immune-related genes (IRGs) were obtained from the ImmPort database. Univariate Cox regression analysis was adopted to screen significantly prognostic IRGs for IPF patients. Multiple Cox regression analysis was used to identify optimal prognostic IRGs and construct a prognostic signature.

Results

Compared with healthy individuals, there were a total of 52 prognosis-related DEGs in the bronchoalveolar lavage (BAL) samples of IPF patients, of which 37 genes were identified as IRGs. Of these, five genes (CXCL14, SLC40A1, RNASE3, CCR3, and RORA) were significantly associated with overall survival (OS) in IPF patients, and were utilized for establishment of the prognostic signature. IPF patients were divided into high- and low-risk groups based on the prognostic signature. Marked differences in the OS probability were observed between high- and low-risk IPF patients. The area under curves (AUCs) of the receiver operating characteristic (ROC) curve for the prognostic signature in the training and validation cohorts were 0.858 and 0.837, respectively. The expression levels between RNASE3 and SLC40A1 (P<0.01, r=0.394), between RORA and CXCL14 (P<0.01, r=−0.355), between CCR3 and CXCL14 (P<0.01, r=0.258), as well as between RNASE3 and CCR3 (P<0.01, r=0.293) were significantly correlated.

Conclusions

We developed a validated and reproducible IRG-based prognostic signature that should be helpful in the personalized management of patients with IPF, providing new insights into the relationship between the immune system and IPF.

The Impact of Inflammatory Immune Reactions of the Vascular Niche on Organ Fibrosis

Inflammation is a type of defense response against tissue damage, and can be mediated by lymphocytes and macrophages. Fibrosis is induced by tissue injury and inflammation, which leads to an increase in fibrous connective tissue in organs and a decrease in organ parenchyma cells, finally leading to organ dysfunction or even failure. The vascular niche is composed of endothelial cells, pericytes, macrophages, and hematopoietic stem cells. It forms a guiding microenvironment for the behavior of adjacent cells, and mainly exists in the microcirculation, including capillaries. When an organ is damaged, the vascular niche regulates inflammation and affects the repair of organ damage in a variety of ways, such as via its angiocrine function and transformation of myofibroblasts. In this paper, the main roles of vascular niche in the process of organ fibrosis and its mechanism of promoting the progress of fibrosis through inflammatory immunoregulation are summarized. It was proposed that the vascular niche should be regarded as a new therapeutic target for organ fibrosis, suggesting that antifibrotic effects could be achieved by regulating macrophages, inhibiting endothelial-mesenchymal transition, interfering with the angiocrine function of endothelial cells, and inhibiting the transformation of pericytes into myofibroblasts, thus providing new ideas for antifibrosis drug research.

The Role of Interaction between Mitochondria and the Extracellular Matrix in the Development of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a condition which affects mainly older adults, that suggests mitochondrial dysfunction and oxidative stress, which follow cells senescence, and might contribute to the disease onset. We have assumed pathogenesis associated with crosstalk between the extracellular matrix (ECM) and mitochondria, mainly based on mitochondrial equilibrium impairment consisting of (1) tyrosine kinases and serine-threonine kinase (TKs and ST-Ks) activation via cytokines, (2) mitochondrial electron transport chain dysfunction and in consequence electrons leak with lower ATP synthesis, (3) the activation of latent TGF-β via αVβ6 integrin, (4) tensions transduction via α2β1 integrin, (5) inefficient mitophagy, and (6) stress inhibited biogenesis. Mitochondria dysfunction influences ECM composition and vice versa. Damaged mitochondria release mitochondrial reactive oxygen species (mtROS) and the mitochondrial DNA (mtDNA) to the microenvironment. Therefore, airway epithelial cells (AECs) undergo transition and secrete cytokines. Described factors initiate an inflammatory process with immunological enhancement. In consequence, local fibroblasts exposed to harmful conditions transform into myofibroblasts, produce ECM, and induce progression of fibrosis. In our review, we summarize numerous aspects of mitochondrial pathobiology, which seem to be involved in the pathogenesis of lung fibrosis. In addition, an increasing body of evidence suggests considering crosstalk between the ECM and mitochondria in this context. Moreover, mitochondria and ECM seem to be important players in the antifibrotic treatment of IPF.

Screening of Biomarkers Involved in Idiopathic Pulmonary Fibrosis and Regulation of Upstream miRNAs

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is the most common type of fatal interstitial lung disease and IPF patients usually have a poor prognosis. Biomarkers that can predict the occurrence, process and prognosis of IPF will be useful for its diagnosis and treatment. This study aimed to identify the potential biomarkers of IPF and analyze the regulation of upstream miRNAs.

METHODS

The miRNA and gene expression profiles were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and miRNAs (DEMs) between IPF and normal groups were identified. After co-expression gene pair analysis, functional enrichment analysis was performed. Then, the potential biomarkers of IPF were screened and validated. Finally, the upstream regulatory miRNA of biomarkers was predicted.

RESULTS

A total of 343 DEGs and 21 DEMs were identified between IPF and normal samples. CLDN18, COL6A3, MYRF, PRSS8, RRAS, and SBNO1 were identified as potential IPF biomarkers. In addition, 17 miRNA-target relationship pairs were obtained. The up-regulation of hsa-miR-657, hsa-miR-671-5p, hsa-miR-198, and hsa-miR-940 could regulate the down-regulation of MYRF and the up-regulation of hsa-miR-198 and hsa-miR-373-3p could regulate the down-regulation of RRAS and CLDN18, respectively. Our data indicated that PRSS8, hsa-miR-614, and hsa-miR-503-5p might be involved in the migration and invasion of IPF related cells.

CONCLUSIONS

CLDN18, COL6A3, MYRF, PRSS8, RRAS, and SBNO1 might be potential IPF biomarkers. However, the specific role of these genes and miRNA in IPF needs further experimental research.

Maiwei Yangfei decoction prevents bleomycin-induced pulmonary fibrosis in mice

Maiwei Yangfei (MWYF) is a compound Chinese herb that is safe and effective in the clinical setting in patients with pulmonary fibrosis (PF). The aim of the present study was to assess the role of a (MWYF) decoction in a bleomycin (BLM)-induced PF mouse model and to investigate the underlying functional mechanism. Chemical components within the MWYF decoction were analysed using liquid chromatography-mass spectrometry. A total of 50 C57BL/6 mice were randomly assigned to one of the following five groups with 10 mice per group: Control, model, low dose MWYF (20 g/kg), medium dose MWYF (40 g/kg) and high dose MWYF (60 g/kg). A mouse PF model was established by the tracheal instillation of BLM (5 mg/kg) prior to MWYF treatment, except for mice in the control group. After 21 days of treatment with MWYF, the mice were sacrificed and the body weights were recorded. In addition, pulmonary tissues and bronchial alveolar lavage fluid were collected. TNF-α, IL-6, IL-17, hydroxyproline, pyridinoline and collagen I levels were determined using ELISA. Vimentin, α-smooth muscle actin (α-SMA), fibronectin, TGF-β1, Smad3, TNF-α, IL-6, IL-17, collagen I and collagen III were determined using western blotting. Vimentin and α-SMA levels were also determined using immunofluorescence analysis. Collagens I and III were detected using immunohistochemical analysis and TGF-β1 and Smad3 levels were determined using reverse transcription-quantitative PCR. Following treatment with MWYF decoction, the body weight of the mice in the PF group increased, the degree of pulmonary alveolitis and PF was reduced, collagen levels were reduced and the expression levels of α-SMA, vimentin and fibronectin were decreased. Although both protein and mRNA expression levels of TGF-β1 and Smad3 were reduced, they remained higher than those observed in the control group. To conclude, MWYF decoction delayed the development of BLM-induced PF in mice, where the functional mechanism was likely associated with the TGF-β1/Smad3 signalling pathway.

A systematic review of blood biomarkers with individual participant data meta-analysis of matrix-metalloproteinase-7 in IPF

Background

Blood-derived biomarkers have been described extensively as potential prognostic markers in idiopathic pulmonary fibrosis (IPF), but studies have been limited by analyses using data-dependent thresholds, inconsistent adjustment for confounders and an array of end-points, thus often yielding ungeneralisable results. Meta-analysis of individual participant data (IPD) is a powerful tool to overcome these limitations. Through systematic review of blood-derived biomarkers, sufficient studies with measurements of matrix metalloproteinase (MMP)-7 were identified to facilitate standardised analyses of the prognostic potential of this biomarker in IPF.

Methods

Electronic databases were searched on 12 November 2020 to identify prospective studies reporting outcomes in patients with untreated IPF, stratified according to at least one pre-specified biomarker, measured at either baseline, or change over 3 months. IPD were sought for studies investigating MMP-7 as a prognostic factor. The primary outcome was overall mortality according to standardised MMP-7 z-scores, with a secondary outcome of disease progression in 12 months, all adjusted for age, gender, smoking and baseline forced vital capacity.

Results

IPD was available for nine studies out of 12 identified, reporting outcomes from 1664 participants. Baseline MMP-7 levels were associated with increased mortality risk (adjusted hazard ratio 1.23, 95% CI 1.03–1.48; I²=64.3%) and disease progression (adjusted OR 1.27, 95% CI 1.11–1.46; I²=5.9%). In limited studies, 3-month change in MMP-7 was not associated with outcomes.

Conclusion

IPD meta-analysis demonstrated that greater baseline MMP-7 levels were independently associated with an increased risk of poor outcomes in patients with untreated IPF, while short-term changes did not reflect disease progression.

Robust methodology using individual participant data meta-analysis demonstrates that baseline MMP-7 levels predict overall mortality and disease progression in patients with untreated IPF independent of age, gender, smoking status and lung functionhttps://bit.ly/2WlPudQ

Serial Measurements of Circulating KL-6, SP-D, MMP-7, CA19-9, CA-125, CCL18, and Periostin in Patients with Idiopathic Pulmonary Fibrosis Receiving Antifibrotic Therapy: An Exploratory Study

Idiopathic pulmonary fibrosis (IPF) is a progressive and inevitably fatal disease with a heterogeneous clinical course. This study aimed to evaluate the usefulness of circulating biomarkers in routine IPF clinical practice. We conducted an exploratory study in a cohort of 28 IPF subjects qualified for anti-fibrotic therapy with up to 24 months serial measurements of seven IPF biomarkers, including those that are well-established, Krebs von den Lungen-6 (KL-6), surfactant protein D (SP-D), matrix metalloproteinase 7 (MMP-7), and more recently introduced ones, cancer antigen 19-9 (CA19-9), cancer antigen 125 (CA-125), chemokine (C-C motif) ligand 18 (CCL18), and periostin. Among studied biomarkers, SP-D had the highest diagnostic accuracy to differentiate IPF subjects from controls, followed by MMP-7 and KL-6. At each study timepoint, KL-6 levels correlated inversely with forced vital capacity % predicted (FVC% pred.), and transfer factor of the lung for carbon monoxide % predicted (T_L,CO% pred.), while SP-D levels correlated inversely with FVC% pred. and T_L,CO% pred. at 24 months of anti-fibrotic therapy. Baseline KL-6 and CA19-9 concentrations were significantly elevated in patients with progressive disease in comparison to patients with stable disease. In addition, in the progressors subgroup CA19-9 concentrations significantly increased over the second year of study follow-up. In patients with progressive disease, we observed a significant inverse correlation between a change in SP-D levels and a change in FVC% pred. in the first year of treatment, whereas in the second year a significant inverse correlation between a change in KL-6 levels and a change in FVC% pred. was noted. Our study findings support the view that both well-established IPF biomarkers, including KL-6, SP-D, and MMP-7, and more recently introduced ones, like CA19-9, have the potential to support clinical practice in IPF.

Matrix metalloproteinases inhibitors in idiopathic pulmonary fibrosis: Medicinal chemistry perspectives

Idiopathic pulmonary fibrosis (IPF) is a lethal disease with limited therapeutic options and a particularly poor prognosis. Matrix metalloproteinases (MMPs), promising targets for the treatment of IPF, have been identified as playing a pivotal role in IPF. Although the pathological processes of MMPs and IPF have been verified, there are no MMP inhibitors for the treatment of IPF in the clinic. In this review, we will present the latest developments in MMP inhibitors, including pharmacophores, binding modes, selectivity and optimization strategies. In addition, we will also discuss the future development direction of MMP inhibitors based on emerging tools and techniques.

Identification and Validation of Potential Biomarkers and Pathways for Idiopathic Pulmonary Fibrosis by Comprehensive Bioinformatics Analysis

Objective

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible, high-mortality lung disease, but its pathogenesis is still unclear. Our purpose was to explore potential genes and molecular mechanisms underlying IPF.

Methods

IPF-related data were obtained from the GSE99621 dataset. Differentially expressed genes (DEGs) were identified between IPF and controls. Their biological functions were analyzed. The relationships between DEGs and microRNAs (miRNAs) were predicted. DEGs and pathways were validated in a microarray dataset. A protein-protein interaction (PPI) network was constructed based on these common DEGs. Western blot was used to validate hub genes in IPF cell models by western blot.

Results

DEGs were identified for IPF than controls in the RNA-seq dataset. Functional enrichment analysis showed that these DEGs were mainly enriched in immune and inflammatory response, chemokine-mediated signaling pathway, cell adhesion, and other biological processes. In the miRNA-target network based on RNA-seq dataset, we found several miRNA targets among all DEGs, like RAB11FIP1, TGFBR3, and SPP1. We identified 304 upregulated genes and 282 downregulated genes in IPF compared to controls both in the microarray and RNA-seq datasets. These common DEGs were mainly involved in cell adhesion, extracellular matrix organization, oxidation-reduction process, and lung vasculature development. In the PPI network, 3 upregulated and 4 downregulated genes could be considered hub genes, which were confirmed in the IPF cell models.

Conclusion

Our study identified several IPF-related DEGs that could become potential biomarkers for IPF. Large-scale multicentric studies are eagerly needed to confirm the utility of these biomarkers.

IL-18 binding protein can be a prognostic biomarker for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic, fibrosing interstitial pneumonia that presents with various clinical courses and progression ranging from rapid to slow. To identify novel biomarkers that can support the diagnosis and/or prognostic prediction of idiopathic pulmonary fibrosis, we performed gene expression analysis, and the mRNA of interleukin-18 binding protein was increasingly expressed in patients with idiopathic pulmonary fibrosis compared with healthy controls. Therefore, we hypothesized that the interleukin-18 binding protein can serve as a diagnostic and/or prognostic biomarker for idiopathic pulmonary fibrosis. We investigated the expression of interleukin-18 binding protein in lung tissue, bronchoalveolar lavage fluid, and serum. Additionally, the correlation between interleukin-18 binding protein expression levels and the extent of fibrosis was investigated using mouse models of lung fibrosis induced by subcutaneous bleomycin injections. Serum interleukin-18 binding protein levels were significantly higher in idiopathic pulmonary fibrosis patients (5.06 ng/mL, interquartile range [IQR]: 4.20–6.35) than in healthy volunteers (3.31 ng/mL, IQR: 2.84–3.99) (p < 0.001). Multivariate logistic regression models revealed that the correlation between serum interleukin-18 binding protein levels and idiopathic pulmonary fibrosis was statistically independent after adjustment for age, sex, and smoking status. Multivariate Cox proportional hazard models revealed that serum interleukin-18 binding protein levels were predictive of idiopathic pulmonary fibrosis disease prognosis independent of other covariate factors (hazard ratio: 1.655, 95% confidence interval: 1.224–2.237, p = 0.001). We also demonstrated a significant positive correlation between lung hydroxyproline expression levels and interleukin-18 binding protein levels in bronchoalveolar lavage fluid from bleomycin-treated mice (Spearman r = 0.509, p = 0.004). These results indicate the utility of interleukin-18 binding protein as a novel prognostic biomarker for idiopathic pulmonary fibrosis.

Comorbidity in idiopathic pulmonary fibrosis - what can biomarkers tell us?

Idiopathic pulmonary fibrosis (IPF) is characterized by progressive parenchymal scarring, leading to dyspnoea, respiratory failure and premature death. Although IPF is confined to the lungs, the importance of IPF comorbidities such as pulmonary hypertension and ischaemic heart disease, lung cancer, emphysema/chronic obstructive pulmonary disease, gastroesophageal reflux, sleep apnoea and depression has been increasingly recognized. These comorbidities may be associated with increased mortality and significant loss of quality of life, so their identification and management are vital. The development of good-quality biomarkers could lead to numerous gains in the management of these patients. Biomarkers can be used for the identification of predisposed individuals, early diagnosis, assessment of prognosis, selection of best treatment and assessment of response to treatment. However, the role of biomarkers for IPF comorbidities is still quite limited, and mostly based on evidence coming from populations without IPF. The future development of new biomarker studies could be informed by those that have been studied independently for each of these conditions. For now, clinicians should be mostly attentive to clinical manifestations of IPF comorbidities, and use validated diagnostic methods for diagnosis. As research on biomarkers of most common diseases continues, it is expected that useful biomarkers are developed for these diseases and then validated for IPF populations. The reviews of this paper are available via the supplemental material section.

Machine Learning-Assisted Array-Based Detection of Proteins in Serum Using Functionalized MoS2 Nanosheets and Green Fluorescent Protein Conjugates

Abnormal concentrations of a specific protein or the presence of some biomarker proteins may indicate life-threatening diseases. Pattern-based detection of specific analytes using affinity-regulated receptors is one of the potential alternatives to specific antigen-antibody-based detection. In this report, we have schemed a sensor array by using various functionalized two-dimensional (2D)-MoS2 nanosheets and green fluorescent protein (GFP) as the receptor and the signal transducer, respectively. Two-dimensional MoS2 has been used as a promising candidate for recognition of the bioanalytes because of its high surface-to-volume ratio compared to those of other nanomaterials. Easy surface tunability of this material provides additional advantages to analyze the target of interest. The optimized 2D-MoS2-GFP conjugates are able to discriminate 15 different proteins at 50 nM concentration with a detection limit of 1 nM. Moreover, proteins in the binary mixture and in the presence of serum were discriminated successfully. Ten different proteins in serum media at relevant concentrations were classified successfully with 100% jackknifed classification accuracy, which proves the potentiality of the above system. We have also implemented and discussed the implication of using different machine learning models on the pattern recognition problem associated with array-based sensing.

Role of VEGF Polymorphisms in the Susceptibility and Severity of Interstitial Lung Disease

The search for biomarkers that can help to establish an early diagnosis and prognosis of interstitial lung disease (ILD) is of potential interest. VEGF polymorphisms have been implicated in the development of several lung disorders. Consequently, we assessed, for the first time, the role of VEGF polymorphisms in the susceptibility and severity of ILD. A total of 436 Caucasian ILD patients (244 with idiopathic interstitial pneumonias (IIPs) and 192 with non-IIP) and 536 ethnically-matched healthy controls were genotyped for VEGF rs833061, rs1570360, rs2010963, rs3025020, and rs3025039 polymorphisms by TaqMan assays. Pulmonary function tests were collected from all the patients. VEGF serum levels were determined by ELISA in a subgroup of patients. No VEGF genotype, allele, carrier, or haplotype differences were found between ILD patients and controls as well as between IIP and non-IIP patients. However, an association of rs1570360 with IIP in women and also with lung function in IIP patients was found. None of the VEGF polymorphisms were associated with VEGF levels. In conclusion, our results suggest that VEGF does not seem to play a relevant role in ILD, although rs1570360 may influence the severity of ILD in women and a worse outcome in IIP patients.

Inhibitory effects of alkaline extract from the pericarp of Citrus reticulata Blanco on collagen behavior in bleomycin-induced pulmonary fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Peel of Citrus reticulata, a Chinese herbal drug with functions of regulating Qi and expelling phlegm, has been used for the treatment of lung related diseases in Chinese medicine for a long time. Its detailed effects on collagen in anti-idiopathic pulmonary fibrosis (IPF) is still unclear.

AIM OF THE STUDY

To explore the effects of citrus alkaline extract (CAE) on collagen synthesis, crosslinking and deposition in pulmonary fibrosis and understand the possible signal pathways involved in the activity.

MATERIALS AND METHODS

CAE was prepared from C. reticulata. Bleomycin-induced pulmonary fibrosis mouse model was applied. Pulmonary fibrosis of lung was estimated with histopathology analysis, and collagen deposition was evaluated with immunohistochemistry. Collagen crosslinking related biomarkers and enzymes were analyzed with chemical methods, immunohistochemical and western blot analyses.

RESULTS

CAE oral administration lowered hydroxyproline content, inhibited the collagen deposition including expressions of collagen I and III, and relieved bleomycin-induced pulmonary fibrosis in mice model. The productions of a collagen crosslink pyridinoline and crosslinking related enzymes including lysyl oxidase (LOX), lysyl oxidase-like protein 1 (LOXL1) in lung were suppressed by CAE treatment. Furthermore, the protein expressions of TGF-β1 and Smad3 levels in lungs were also downregulated by CAE.

CONCLUSIONS

This study demonstrated that CAE inhibited collagen synthesis, crosslinking and deposition, and ameliorated bleomycin-induced pulmonary fibrosis. Preliminary mechanism study revealed that CAE exerted its bioactivity at least via downregulation of TGF-β1/Smad3 pathway. Our findings provided a great potential in fighting IPF based on CAE.

Nosocomial Pneumonia in the Era of Multidrug-Resistance: Updates in Diagnosis and Management

Nosocomial pneumonia (NP), including hospital-acquired pneumonia in non-intubated patients and ventilator-associated pneumonia, is one of the most frequent hospital-acquired infections, especially in the intensive care unit. NP has a significant impact on morbidity, mortality and health care costs, especially when the implicated pathogens are multidrug-resistant ones. This narrative review aims to critically review what is new in the field of NP, specifically, diagnosis and antibiotic treatment. Regarding novel imaging modalities, the current role of lung ultrasound and low radiation computed tomography are discussed, while regarding etiological diagnosis, recent developments in rapid microbiological confirmation, such as syndromic rapid multiplex Polymerase Chain Reaction panels are presented and compared with conventional cultures. Additionally, the volatile compounds/electronic nose, a promising diagnostic tool for the future is briefly presented. With respect to NP management, antibiotics approved for the indication of NP during the last decade are discussed, namely, ceftobiprole medocaril, telavancin, ceftolozane/tazobactam, ceftazidime/avibactam, and meropenem/vaborbactam.

Serum Concentrations of KL-6 in Patients with IPF and Lung Cancer and Serial Measurements of KL-6 in IPF Patients Treated with Antifibrotic Therapy

Simple Summary

Evaluation of the prognostic significance of serial measurements of serum concentrations of Krebs von den Lungen-6 (KL-6) showed that an annual increment in KL-6 exceeding a threshold amount was an independent risk factor for progressive disease and poor prognosis. No literature data are available on long-term KL-6 measurements in the follow-up of IPF patients treated with Nintedanib. The aim of this study is to serially analyze KL-6 in idiopathic pulmonary fibrosis (IPF) patients after 24 months of Nintedanib and to investigate its biomarker potential in patients with IPF and lung cancer with respect to fibrotic hypersensitivity pneumonitis patients, pulmonary fibrosis associated with autoimmune diseases group and healthy controls.

Abstract

Background: Krebs von den Lungen-6 (KL-6) was suggested as ILD biomarker including idiopathic pulmonary fibrosis (IPF). Lung cancer is one of the most severe comorbidity of IPF patients. This study aims to serially analyze KL-6 in IPF patients after 24 months of Nintedanib and to first investigate the biomarker behavior in IPF associated with adenocarcinoma. Materials and methods: One hundred and forty-two ILD patients (median (IQR), 69 (63–75) years; 86 males) were retrospectively enrolled. Serial serum samples were collected from IPF patients before starting antifibrotic therapy and after 12 months. Serum KL-6 levels were measured by KL-6 reagent assay (Fujirebio Europe, UK). Results: Increased KL-6 concentrations were identified in IPF-LC patients than IPF, fibrotic hypersensitivity pneumonitis, and pulmonary fibrosis associated with autoimmune disease groups. A cut-off value was calculated to distinguish IPF and IPF-LC patients. IPF patients monitored for 24 months with Nintedanib showed persisted increased levels of KL-6 with a progressive decline of FVC percentages. Conclusion: This preliminary study offers a first demonstration that very high serum concentrations of KL-6 in IPF-LC patients are associated with poor prognosis. Moreover, serial evaluation of serum KL-6 in IPF patients over 24 months of Nintedanib treatment revealed that most patients experienced a stabilization of lung function parameters and of serum concentrations of KL-6.