Obstacles to early treatment of idiopathic pulmonary fibrosis: current perspectives

Circadian clock molecule REV-ERBα regulates lung fibrotic progression through collagen stabilization

Molecular clock REV-ERBα is central to regulating lung injuries, and decreased REV-ERBα abundance mediates sensitivity to pro-fibrotic insults and exacerbates fibrotic progression. In this study, we determine the role of REV-ERBα in fibrogenesis induced by bleomycin and Influenza A virus (IAV). Bleomycin exposure decreases the abundance of REV-ERBα, and mice dosed with bleomycin at night display exacerbated lung fibrogenesis. Rev-erbα agonist (SR9009) treatment prevents bleomycin induced collagen overexpression in mice. Rev-erbα global heterozygous (Rev-erbα Het) mice infected with IAV showed augmented levels of collagens and lysyl oxidases compared with WT-infected mice. Furthermore, Rev-erbα agonist (GSK4112) prevents collagen and lysyl oxidase overexpression induced by TGFβ in human lung fibroblasts, whereas the Rev-erbα antagonist exacerbates it. Overall, these results indicate that loss of REV-ERBα exacerbates the fibrotic responses by promoting collagen and lysyl oxidase expression, whereas Rev-erbα agonist prevents it. This study provides the potential of Rev-erbα agonists in the treatment of pulmonary fibrosis.

Thy-1-Integrin Interactions in cis and Trans Mediate Distinctive Signaling

Thy-1 is a cell surface glycosylphosphatidylinositol (GPI)-anchored glycoprotein that bears a broad mosaic of biological roles across various cell types. Thy-1 displays strong physiological and pathological implications in development, cancer, immunity, and tissue fibrosis. Quite uniquely, Thy-1 is capable of mediating integrin-related signaling through direct trans- and cis-interaction with integrins. Both interaction types have shown distinctive roles, even when interacting with the same type of integrin, where binding in trans or in cis often yields divergent signaling events. In this review, we will revisit recent progress and discoveries of Thy-1–integrin interactions in trans and in cis, highlight their pathophysiological consequences and explore other potential binding partners of Thy-1 within the integrin regulation/signaling paradigm.

Evaluation for clinical benefit of metformin in patients with idiopathic pulmonary fibrosis and type 2 diabetes mellitus: a national claims-based cohort analysis

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with high morbidity and limited treatment options. Type 2 diabetes mellitus (T2DM) is a common comorbid illness among patients with IPF and is often treated with metformin, the first-line agent in the management of T2DM. There is growing evidence demonstrating metformin’s anti-fibrotic properties; however, there is little real-world clinical data regarding its potential effectiveness in IPF. This study aims to evaluate the clinical benefit of metformin in patients with IPF and T2DM.

Methods

This nationwide cohort study used de-identified administrative claims data from OptumLabs® Data Warehouse to identify 3599 adults with IPF and concomitant T2DM between January 1, 2014 and June 30, 2019. Two cohorts were created: a cohort treated with metformin (n = 1377) and a cohort not treated with metformin (n = 2222). A final 1:1 propensity score-matched cohort compared 1100 patients with IPF and T2DM receiving metformin to those with both diagnoses but not receiving metformin; matching accounted for age, sex, race/ethnicity, residence region, year, medications, oxygen use, smoking status, healthcare use, and comorbidities. Outcomes were all-cause mortality (primary) and hospitalizations (secondary).

Results

Among 2200 patients with IPF and T2DM included in this matched analysis, metformin therapy was associated with a reduction in all-cause mortality (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.36–0.58; p < 0.001) and hospitalizations (HR, 0.82; 95% CI, 0.72–0.93; p = 0.003) compared to patients not receiving metformin.

Conclusions

Among patients with IPF and T2DM, metformin therapy may be associated with improved clinical outcomes. However, further investigation with randomized clinical trials is necessary prior to metformin’s broad implementation in the clinical management of IPF.

Discrimination between NSIP- and IPF-Derived Fibroblasts Based on Multi-Parameter Characterization of Their Growth, Morphology and Physic-Chemical Properties

Background: The aim of the research presented here was to find a set of parameters enabling discrimination between three types of fibroblasts, i.e., healthy ones and those derived from two disorders mimicking each other: idiopathic pulmonary fibrosis (IPF), and nonspecific interstitial pneumonia (NSIP). Methods: The morphology and growth of cells were traced using fluorescence microscopy and analyzed quantitatively using cell proliferation and substrate cytotoxicity indices. The viability of cells was recorded using MTS assays, and their stiffness was examined using atomic force microscopy (AFM) working in force spectroscopy (FS) mode. To enhance any possible difference in the examined parameters, experiments were performed with cells cultured on substrates of different elasticities. Moreover, the chemical composition of cells was determined using time-of-flight secondary ion mass spectrometry (ToF-SIMS), combined with sophisticated analytical tools, i.e., Multivariate Curve Resolution (MCR) and Principal Component Analysis (PCA). Results: The obtained results demonstrate that discrimination between cell lines derived from healthy and diseased patients is possible based on the analysis of the growth of cells, as well as their physical and chemical properties. In turn, the comparative analysis of the cellular response to altered stiffness of the substrates enables the identification of each cell line, including distinguishing between IPF- and NSIP-derived fibroblasts.

Cost-effectiveness of the anti-fibrotics for the treatment of idiopathic pulmonary fibrosis in the United States

Background

The anti-fibrotic medications nintedanib and pirfenidone were approved in the United States for use in patients with idiopathic pulmonary fibrosis several years ago. While there is a growing body of evidence surrounding their clinical effectiveness, these medications are quite expensive and no prior cost-effectiveness analysis has been performed in the United States.

Methods

A previously published Markov model performed in the United Kingdom was replicated using United States data to project the lifetime costs and health benefits of treating idiopathic pulmonary fibrosis with: (1) symptom management; (2) pirfenidone; or (3) nintedanib. For the cost-effectiveness analysis, strategies were ranked by increasing costs and then checked for dominating treatment strategies. Then an incremental cost-effectiveness ratio was calculated for the dominant therapy.

Results

The anti-fibrotic medications were found to cost more than $110,000 per year compared to $12,291 annually for symptom management. While pirfenidone was slightly more expensive than nintedanib and provided the same amount of benefit, neither medication was found to be cost-effective in this U.S.-based analysis, with an average cost of $1.6 million to gain one additional quality-adjusted life year over symptom management.

Conclusions

Though the anti-fibrotics remain the only effective treatment option for patients with idiopathic pulmonary fibrosis and the data surrounding their clinical effectiveness continues to grow, they are not considered cost-effective treatment strategies in the United States due to their high price.

Combined Pulmonary Fibrosis Emphysema: Role of Cigarette Smoking and Pulmonary Hypertension in a Rural Cohort

Background

Disease heterogeneity in idiopathic pulmonary fibrosis (IPF) often complicates the systematic study of disease, management of patients and clinical investigations.

Objective

To describe combined pulmonary fibrosis emphysema (CPFE) phenotype in a rural Appalachian IPF cohort with the highest smoking rates in the United States.

Methods

CPFE patients (n = 60) in a developed IPF cohort (n = 153) were characterized. Groups (CPFE vs IPF without emphysema) were categorized based on the predominant HRCT patterns of UIP (n = 109). Demographics, clinical variables, and treatment details were recorded. Kaplan–Meier survival and multivariate logistic regression analysis were performed.

Results

The prevalence of CPFE in our IPF cohort was 45% (n = 49). The CPFE group was younger (73.9 vs 78.2), had a more extensive smoking history (93.9% vs 53.3%) with greater mean smoking pack years (49.09 vs 15.39) and had lower percentage predicted DL_CO on presentation (38.35 vs 51.09) compared to IPF without emphysema group. Both groups shared equivalent higher burden of comorbidities, including pulmonary hypertension (PH) (46.9% vs 33.3%). One-fifth of patients were prescribed antifibrotics and only a subset (5%) of patients underwent lung transplantation. There was a non-significant trend towards reduced survival in CPFE (p = 0.076). Smoking status and DL_CO predicted CPFE in our cohort. Body mass index (BMI), PH, and pirfenidone use were significant predictors of mortality.

Conclusion

CPFE was highly prevalent in our rural IPF cohort. In contrast to previous studies, CPFE group was older and had higher female (approx. 30%) occurrence. A greater exposure to cigarette smoke and reduced DL_CO at diagnosis predicted CPFE. Lower BMI and PH predicted higher mortality whereas use of pirfenidone improved survival in our cohort. This study highlights a complex interaction of cigarette smoking, advanced fibrosis of UIP, PH and potential utility of antifibrotic agents in CPFE phenotype. Substantial burden of comorbidities, older age, and the limited utilization of advanced therapeutics in the cohort emphasize the challenges faced by rural Appalachian patients.

Different Faces of Idiopathic Pulmonary Fibrosis With Preserved Forced Vital Capacity

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is progressive and irreversible. Some discrepancies about IPF staging exists, especially in mild phases. Forced vital capacity (FVC) higher than 80% has been considered early or mild IPF even for the design of clinical trials.

METHODS

Spanish multicentre, observational, retrospective study of IPF patients diagnosed between 2012 and 2016, based on the ATS/ERS criteria, which presented FVC greater or equal 80% at diagnosis. Clinical and demographic characteristics, lung function, radiological pattern, treatment, and follow-up were analyzed.

RESULTS

225 IPF patients were included, 72.9% were men. The mean age was 69.5 years. The predominant high-resolution computed tomography (HRCT) pattern was consistent usual interstitial pneumonia (UIP) (51.6%). 84.7% of patients presented respiratory symptoms (exertional dyspnea and/or cough) and 33.33% showed oxygen desaturation below 90% in the 6min walking test (6MWT). Anti-fibrotic treatment was initiated at diagnosis in 55.11% of patients. Median FVC was 89.6% (IQR 17) and 58.7% of patients had a decrease of diffusion lung capacity for carbon monoxide (DLCO) below 60% of theoretical value; most of them presented functional progression (61.4%) and higher mortality at 3 years (20.45%). A statistically significant correlation with the 3-years mortality was observed between DLCO <60% and consistent UIP radiological pattern.

CONCLUSIONS

Patients with preserved FVC but presenting UIP radiological pattern and moderate-severe DLCO decrease at diagnosis associate an increased risk of progression, death or lung transplantation. Therefore, in these cases, preserved FVC would not be representative of early or mild IPF.

Effect of tuned elasticity and chemical modification of substrate on fibrotic and healthy lung fibroblasts

Response to substrate elasticity, dependent on mechanical properties of cells, differs for lung fibroblast derived from idiopathic pulmonary fibrosis (IPF) and the healthy ones. These altered interactions might potentially act as a 'biomarker' for easy and reliable IPF diagnosis. In this work, systematic studies on the effect of polydimethylsiloxane (PDMS) substrate elasticity, tuned stepwise from 600 kPa to 1.5 MPa on the growth of IPF-derived (LL97A) and healthy (LL24) lung fibroblasts were reported. Additionally, impact of substrate chemistry on both cell lines was studied for fibroblasts cultured on glass substrates modified with three organosilanes - 3-aminopropyltriethoxysilane (APTES), 3-mercaptopropyltriethoxysilane (MPTES) and 3-glycidyloxypropyl trimethoxysilane (GOPS), with different end groups. Finally, the effect of the simultaneous modification of mechanical and chemical properties on the cellular behavior was studied for fibroblast cultured on PDMS substrates covered with silanes. The growth of cells was traced using fluorescence microscopy and analyzed quantitatively by nucleus-cytoplasm ratio, indicating strong, cell-dependent impact of substrate elasticity dominating over effect of chemical modification.

Drug discovery and development in idiopathic pulmonary fibrosis: challenges and opportunities

The pharmacological and adverse effect profiles of the two approved therapies for IPF make the development of new therapies challenging. Considering the similarity of the characteristics of drug candidates to Standard of Care is important in defining positioning and development strategies for this disease.

Clinical Effectiveness of Antifibrotic Medications for Idiopathic Pulmonary Fibrosis

Rationale: Since their approval, there has been no real-world or randomized trial evidence evaluating the effect of the antifibrotic medications pirfenidone and nintedanib on clinically important outcomes such as mortality and hospitalizations. Objectives: To evaluate the clinical effectiveness of the antifibrotic medications pirfenidone and nintedanib in patients with idiopathic pulmonary fibrosis. Methods: Using a large U.S. insurance database, we identified 8,098 patients with idiopathic pulmonary fibrosis between October 1, 2014 and March 1, 2018. A one-to-one propensity score-matched cohort was created to compare patients treated with antifibrotic medications (n = 1,255) with those not on treatment (n = 1,255). The primary outcome was all-cause mortality. The secondary outcome was acute hospitalizations. Subgroup analyses were performed to evaluate mortality differences by drug. Measurements and Main Results: The use of antifibrotic medications was associated with a decreased risk of all-cause mortality (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.62-0.98; P value = 0.034). However, this association was present only through the first 2 years of treatment. There was also a decrease in acute hospitalizations in the treated cohort (HR, 0.70; 95% CI, 0.61-0.80; P value <0.001). There was no significant difference in all-cause mortality between patients receiving pirfenidone and those on nintedanib (HR, 1.14; 95% CI, 0.79-1.65; P = 0.471). Conclusions: Among patients with idiopathic pulmonary fibrosis, antifibrotic agents may be associated with a lower risk of all-cause mortality and hospitalization compared with no treatment. Future research should test the hypothesis that these treatments reduce early, but not long-term, mortality as demonstrated in our study.

Protective effect of bicyclol against pulmonary fibrosis via regulation of microRNA-455-3p in rats

Idiopathic pulmonary fibrosis (IPF), a chronic, progressive and irreversible disease, needs long-term treatment. Bicyclol was found to play a great role in pulmonary fibrosis, and the present study is to explore how bicyclol affects IPF with the involvement of microRNA-455-3p (miR-455-3p) and Bax. Bleomycin (BLM) was used to induce the IPF model in Sprague-Dawley rats to detect the expression of miR-455-3p, Bax, and B-cell lymphoma factor 2 (Bcl-2). Moreover, to further investigate the mechanisms of bicyclol, the BLM-induced fibrotic cell model was used after the lung epithelial cells HPAEpiC received miR-455-3p knockout treatment. The rats were then treated with vehicle and bicyclol, respectively. The apoptosis of fibrotic cells and Bax/Bcl-2 were identified. Inhibition function of bicyclol was optimal at a dose of 150 mg/kg. Bicyclol inhibited cell apoptosis and reduced Bax/Bcl-2 expression in rats. miR-455-3p could potentially bind to Bax gene. Bicyclol reduced the levels of methylenedioxyamphetamine, superoxide dismutase, and glutathione in rat lung tissue, inhibited the apoptosis of rats with IPF and upregulated miR-455-3p expression. In vitro studies showed that bicyclol significantly promoted miR-455-3p expression in HPAEpiC fibrosis. Bicyclol inhibited fibrosis-induced apoptosis of HPAEpiC in alveolar epithelial cells through promoting miR-455-3p, which inhibited Bax expression in IPF. Bicyclol may suppress the apoptosis of alveolar epithelial cells by upregulating miR-455-3p. This study laid a theoretical foundation for further understanding of IPF and searching for new molecular therapeutic targets.