Forced Vital Capacity (FVC) decline, mortality and healthcare resource utilization in idiopathic pulmonary fibrosis

Computed tomography machine learning classifier correlates with mortality in interstitial lung disease

BACKGROUND

A machine learning classifier system, Fibresolve, was designed and validated as an adjunct to non-invasive diagnosis in idiopathic pulmonary fibrosis (IPF). The system uses a deep learning algorithm to analyze chest computed tomography (CT) imaging. We hypothesized that Fibresolve is a useful predictor of mortality in interstitial lung diseases (ILD).

METHODS

Fibresolve was previously validated in a multi-site >500-patient dataset. In this analysis, we assessed the usefulness of Fibresolve to predict mortality in a subset of 228 patients with IPF and other ILDs in whom follow up data was available. We applied Cox regression analysis adjusting for the Gender, Age, and Physiology (GAP) score and for other known predictors of mortality in IPF. We also analyzed the role of Fibresolve as tertiles adjusting for GAP stages.

RESULTS

During a median follow-up of 2.8 years (range 5 to 3434 days), 89 patients died. After adjusting for GAP score and other mortality risk factors, the Fibresolve score significantly predicted the risk of death (HR: 7.14; 95% CI: 1.31-38.85; p = 0.02) during the follow-up period, as did forced vital capacity and history of lung cancer. After adjusting for GAP stages and other variables, Fibresolve score split into tertiles significantly predicted the risk of death (p = 0.027 for the model; HR 1.37 for 2nd tertile; 95% CI: 0.77-2.42. HR 2.19 for 3rd tertile; 95% CI: 1.22-3.93).

CONCLUSIONS

The machine learning classifier Fibresolve demonstrated to be an independent predictor of mortality in ILDs, with prognostic performance equivalent to GAP based solely on CT images.

Hospitalisation patterns in interstitial lung diseases: data from the EXCITING-ILD registry

BACKGROUND

Interstitial lung diseases (ILD) comprise a heterogeneous group of mainly chronic lung diseases with more than 200 entities and relevant differences in disease course and prognosis. Little data is available on hospitalisation patterns in ILD.

METHODS

The EXCITING-ILD (Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases) registry was analysed for hospitalisations. Reasons for hospitalisation were classified as all cause, ILD-related and respiratory hospitalisations, and patients were analysed for frequency of hospitalisations, time to first non-elective hospitalisation, mortality and progression-free survival. Additionally, the risk for hospitalisation according to GAP index and ILD subtype was calculated by Cox proportional-hazard models as well as influencing factors on prediction of hospitalisation by logistic regression with forward selection.

RESULTS

In total, 601 patients were included. 1210 hospitalisations were recorded during the 6 months prior to registry inclusion until the last study visit. 800 (66.1%) were ILD-related, 59.3% of admissions were registered in the first year after inclusion. Mortality was associated with all cause, ILD-related and respiratory-related hospitalisation. Risk factors for hospitalisation were advanced disease (GAP Index stages II and III) and CTD (connective tissue disease)-ILDs. All cause hospitalisations were associated with pulmonary hypertension (OR 2.53, p = 0.005). ILD-related hospitalisations were associated with unclassifiable ILD and concomitant emphysema (OR = 2.133, p = 0.001) as well as with other granulomatous ILDs and a positive smoking status (OR = 3.082, p = 0.005).

CONCLUSION

Our results represent a crucial contribution in understanding predisposing factors for hospitalisation in ILD and its major impact on mortality. Further studies to characterize the most vulnerable patient group as well as approaches to prevent hospitalisations are warranted.

Clinical implications of frailty assessed in hospitalized patients with acute-exacerbation of interstitial lung disease

BACKGROUND

Approximately 50% of patients with interstitial lung disease (ILD) experience frailty, which remains unexplored in acute exacerbations of ILD (AE-ILD). A better understanding may help with prognostication and resource planning. We evaluated the association of frailty with clinical characteristics, physical function, hospital outcomes, and post-AE-ILD recovery.

METHODS

Retrospective cohort study of AE-ILD patients (01/2015-10/2019) with frailty (proportion ≥0.25) on a 30-item cumulative-deficits index. Frail and non-frail patients were compared for pre- and post-hospitalization clinical characteristics, adjusted for age, sex, and ILD diagnosis. One-year mortality, considering transplantation as a competing risk, was analysed adjusting for age, frailty, and Charlson Comorbidity Index (CCI).

RESULTS

89 AE-ILD patients were admitted (median: 67 years, 63% idiopathic pulmonary fibrosis). 31 were frail, which was associated with older age, greater CCI, lower 6-min walk distance, and decreased independence pre-hospitalization. Frail patients had more major complications (32% vs 10%, p = .01) and required more multidisciplinary support during hospitalization. Frailty was not associated with 1-year mortality (HR: 0.97, 95%CI: [0.45-2.10]) factoring transplantation as a competing risk.

CONCLUSIONS

Frailty was associated with reduced exercise capacity, increased comorbidities and hospital complications. Identifying frailty may highlight those requiring additional multidisciplinary support, but further study is needed to explore whether frailty is modifiable with AE-ILD.

Historical eye on IPF: a cohort study redefining the mortality scenario

Rationale

Therapies that slow idiopathic pulmonary fibrosis (IPF) progression are now available and recent studies suggest that the use of antifibrotic therapy may reduce IPF mortality.

Objectives

The aim of the study was to evaluate whether, to what extent, and for which factors the survival of IPF in a real-life setting has changed in the last 15 years.

Methods

Historical eye is an observational study of a large cohort of consecutive IPF patients diagnosed and treated in a referral center for ILDs with prospective intention. We recruited all consecutive IPF patients seen at GB Morgagni Hospital, Forlì, Italy between January 2002 and December 2016 (15 years). We used survival analysis methods to describe and model the time to death or lung transplant and Cox regression to model prevalent and incident patient characteristics (time-dependent Cox models were fitted).

Measurements and main results

The study comprised 634 patients. The year 2012 identifies the time point of mortality shift (HR 0.58, CI 0.46-0.63, p < 0.001). In the more recent cohort, more patients had better preserved lung function, underwent cryobiopsy instead of surgery, and were treated with antifibrotics. Highly significant negative prognostic factors were lung cancer (HR 4.46, 95% CI 3.3-6, p < 0.001), hospitalizations (HR 8.37, 95% CI 6.5-10.7, p < 0.001), and acute exacerbations (HR 8.37, 95% CI 6.52-10.7, p < 0.001). The average antifibrotic treatment effect estimated using propensity score matching showed a significant effect in the reduction of all-cause mortality (ATE coeff -0.23, SE 0.04, p < 0.001), acute exacerbations (ATE coeff -0.15, SE 0.04, p < 0.001), and hospitalizations (ATE coeff -0.15, SE 0.04, p < 0.001) but no effect on lung cancer risk (ATE coeff -0.03, SE 0.03, p = 0.4).

Conclusion

Antifibrotic drugs significantly impact hospitalizations, acute exacerbations, and IPF survival. After the introduction of cryobiopsy and antifibrotic drugs, the prognosis of IPF patients has significantly improved together with our ability to detect IPF at an earlier stage.

Economic Burden of Idiopathic Pulmonary Fibrosis in Spain: A Prospective Real-World Data Study (OASIS Study)

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease associated with dyspnoea, cough and impaired quality of life affecting around 7500 patients in Spain.

OBJECTIVE

Our aim was to estimate the economic impact of IPF according to forced vital capacity (FVC) % predicted level in adult patients.

METHODS

We conducted a prospective, observational, multicentric study of patients with confirmed IPF in Spain. Total annual IPF-related costs were estimated per patient, and categorised according to the FVC% predicted value (FVC < 50%, FVC 50-80%, FVC > 80%) and total sample. Incurred direct health- and non-health-related costs and indirect costs were calculated considering the IPF-related healthcare resource use and the corresponding unitarian costs. Results were updated to 2023 euros.

RESULTS

Two hundred and four consecutive patients with IPF were included: 77% male, average age (standard deviation) 70.8 (7.6) years. At baseline, FVC% was < 50%, 50-80% and > 80% of predicted value in 10.8%, 74.5% and 14.7% of patients, respectively. The final cost-evaluable population included 180 subjects. The mean (standard deviation) total annual IPF-related cost was €26,997 (17,555), with statistically significant differences (p = 0.0002) between groups: €44,412 (33,389) for the FVC < 50%, €25,803 (14,688) for the FVC 50-80% and €23,242 (13,642) for the FVC > 80%. Annual direct health costs had the greatest weight and included pharmacological treatments [€22,324 (13,773)] and hospitalisation days [€1659 (7362)]. 14 patients had ≥ 1 acute exacerbation of IPF during the study; mean total cost of an acute exacerbation of IPF was €10,372. According to the multivariate analysis, an impaired lung function (FVC < 50%) and use of antifibrotic treatment were determinants of cost (p < 0.0001 both).

CONCLUSIONS

We observed a significantly higher annual IPF-related cost at a lower level of predicted FVC%, the direct cost having the greatest weight to the total costs. Maintaining patients at early disease stages by slowing IPF progression is relevant to reduce the economic impact of IPF.

CLINICAL TRIAL REGISTRATION

EU PAS register number EUPAS19387 (1 June, 2017).

Clinical Characteristics and Disease Course of Fibrosing Interstitial Lung Disease Patients in a Real-World Setting

Background and Objectives: This single-center retrospective study was conducted to describe clinical characteristics and the disease course of patients with interstitial lung diseases (ILD). Materials and Methods: The study included adult patients with fibrosing ILD (IPF, non-IPF fibrosing ILD (F-ILD), and non-IPF progressive pulmonary fibrosis (PPF)) treated between 2014 and 2017. Patients were followed annually from the first visit until the end of the study period in 2019. Data were collected from the Turku University Hospital data lake and analyzed using descriptive statistics. Results: 591 patients formed the patient cohort: 110 had IPF, 194 F-ILD, 142 PPF, and the remaining 145 patients were uncertain, F-ILD-U, whose disease progression nature could not be confirmed by FVC measurements. There were more males in each patient group and median age of the groups was similar, although there were younger patients in the PPF, F-ILD, and F-ILD-U groups. PPF patients had more UIP pattern than F-ILD patients. Exposure-related ILDs were clearly the most found ILD diagnoses for both PPF and F-ILD, followed by unclassifiable IIP. Baseline FVC % predicted reduction in every group was moderate. Half of the patients in each group had comorbidities, and the most common were cardiovascular diseases, diabetes, sleep apnea, and chronic lower respiratory diseases; F-ILD-U patients had malignant diseases as well. IPF patients had less medications than the other groups. Glucocorticoids were the most used medication in all patient groups. More PPF and F-ILD patients remained in the follow-up than IPF and F-ILD-U patients. Similarly, mortality of F-ILD-U was the highest, followed by IPF. Evolvement of lung function, oxygen use, and number of acute hospitalizations were similar for IPF and PPF patients whereas the corresponding results were always better for F-ILD patients. Conclusions: The disease course of IPF and PPF was similar, and PPF patient amount exceeded the amount of IPF patients.

Idiopathic pulmonary fibrosis therapy development: a clinical pharmacology perspective

Drug development for idiopathic pulmonary fibrosis (IPF) has been challenging due to poorly understood disease etiology, unpredictable disease progression, highly heterogeneous patient populations, and a lack of robust pharmacodynamic biomarkers. Moreover, because lung biopsy is invasive and dangerous, making the extent of fibrosis as a direct longitudinal measurement of IPF disease progression unfeasible, most clinical trials studying IPF can only assess progression of fibrosis indirectly through surrogate measures. This review discusses current state-of-art practices, identifies knowledge gaps, and brainstorms development opportunities for preclinical to clinical translation, clinical populations, pharmacodynamic endpoints, and dose optimization strategies. This article highlights clinical pharmacology perspectives in leveraging real-world data as well as modeling and simulation, special population considerations, and patient-centric approaches for designing future studies.

Quality of Life and Healthcare Resource Use in a Real-world Patient Population with Idiopathic Pulmonary Fibrosis: The PROOF Registry

Introduction

The PROOF registry is a prospective, observational study that aimed to monitor disease progression in a real-world cohort of patients with idiopathic pulmonary fibrosis (IPF). Here, longitudinal quality-of-life (QoL) outcomes, healthcare resource use (HCRU), and the association between QoL and mortality in patients enrolled in the PROOF registry are presented.

Methods

QoL outcomes (St. George’s Respiratory Questionnaire [SGRQ], EuroQoL-5 dimensions-5 levels Health Questionnaire [EQ-5D-5L], EuroQoL-5 dimensions Health Questionnaire [EQ-5D] visual analogue scale [VAS] and cough VAS) and HCRU were collected for all patients. Associations between baseline QoL and mortality were assessed using univariate and multivariate analyses. During multivariate analyses, individual QoL measures were adjusted for the following covariates: age, sex, percent predicted forced vital capacity, percent predicted diffusing capacity of the lungs for carbon monoxide, smoking status, and supplementary oxygen use at registry inclusion.

Results

In total, 277 patients were enrolled in the PROOF registry. During the follow-up period, worsening in cough VAS score, SGRQ symptom score, and SGRQ activity score was observed, while EQ-5D VAS, SGRQ total score, and SGRQ impact score remained stable. During univariate analyses, EQ-5D VAS and all SGRQ sub-scores and total score at baseline were associated with mortality; however, during multivariate analyses, only the SGRQ total score, SGRQ impact score, and SGRQ symptom score at baseline were associated with mortality. During the follow-up period, 261 (94.2%) patients required an outpatient consultation (IPF- or non-IPF-related) and there were 182 hospitalizations in total, most of which were respiratory related (66.5%).

Conclusions

The PROOF registry provided valuable, real-world data on the association between baseline QoL and mortality, and longitudinal HCRU and QoL outcomes in patients with IPF over 24 months and identified that SGRQ may be an independent prognostic factor in IPF.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-022-00187-8.

The role of eCIRP in bleomycin-induced pulmonary fibrosis in mice

OBJECTIVE AND DESIGN

We examined the role of eCIRP in the pathogenesis of bleomycin-induced pulmonary fibrosis (PF).

MATERIAL AND METHODS

Publicly available gene expression omnibus datasets were analyzed for the expression of CIRP in lung samples from patients with PF. Wild type (WT) or CIRP-/- mice received daily injections of 10 μg/g bleomycin for 10 days. A subset of bleomycin-injected WT mice was treated with the eCIRP antagonist C23 (8 μg/g/day) from day 10 to day 19. At three weeks, transthoracic echocardiography was performed to measure the degree of pulmonary hypertension, and lung tissues were collected and analyzed for markers of fibrosis.

RESULTS

Analysis of the mRNA data of human lung samples showed a significant positive correlation between CIRP and α-smooth muscle actin (α-SMA), an important marker of fibrosis. Moreover, the expression of CIRP was higher in patients with acute exacerbation of PF than in patients with stable PF. CIRP-/- mice showed attenuated induction of α-SMA and collagens (Col1a1, Col3a1), reduced hydroxyproline content, decreased histological fibrosis scores, and improved pulmonary hypertension as compared to WT mice. WT mice treated with C23 also had significant attenuation of the above endpoint measure.

CONCLUSIONS

Our study demonstrates that eCIRP plays a key role in promoting the development of PF, and blocking eCIRP with C23 can significantly attenuate this process.

FVC-NET: An Automated Diagnosis of Pulmonary Fibrosis Progression Prediction Using Honeycombing and Deep Learning

Pulmonary fibrosis is a severe chronic lung disease that causes irreversible scarring in the tissues of the lungs, which results in the loss of lung capacity. The Forced Vital Capacity (FVC) of the patient is an interesting measure to investigate this disease to have the prognosis of the disease. This paper proposes a deep learning-based FVC-Net architecture to predict the progression of the disease from the patient's computed tomography (CT) scan and the patient's metadata. The input to the model combines the image score generated based on the degree of honeycombing for a patient identified based on segmented lung images and the metadata. This input is then fed to a 3-layer net to obtain the final output. The performance of the proposed FVC-Net model is compared with various contemporary state-of-the-art deep learning-based models, which are available on a cohort from the pulmonary fibrosis progression dataset. The model showcased significant improvement in the performance over other models for modified Laplace Log-Likelihood (-6.64). Finally, the paper concludes with some prospects to be explored in the proposed study.

Impact of lung function decline on time to hospitalisation events in systemic sclerosis-associated interstitial lung disease (SSc-ILD): a joint model analysis

BACKGROUND

Interstitial lung disease (ILD) is a common organ manifestation in systemic sclerosis (SSc) and is the leading cause of death in patients with SSc. A decline in forced vital capacity (FVC) is an indicator of ILD progression and is associated with mortality in patients with SSc-associated ILD (SSc-ILD). However, the relationship between FVC decline and hospitalisation events in patients with SSc-ILD is largely unknown. The objective of this post hoc analysis was to investigate the relationship between FVC decline and clinically important hospitalisation endpoints.

METHODS

We used data from SENSCIS®, a phase III trial investigating the efficacy and safety of nintedanib in patients with SSc-ILD. Joint models for longitudinal and time-to-event data were used to assess the association between rate of decline in FVC% predicted and hospitalisation-related endpoints (including time to first all-cause hospitalisation or death; time to first SSc-related hospitalisation or death; and time to first admission to an emergency room [ER] or admission to hospital followed by admission to intensive care unit [ICU] or death) during the treatment period, over 52 weeks in patients with SSc-ILD.

RESULTS

There was a statistically significant association between FVC decline and the risk of all-cause (n = 78) and SSc-related (n = 42) hospitalisations or death (both P < 0.0001). A decrease of 3% in FVC corresponded to a 1.43-fold increase in risk of all-cause hospitalisation or death (95% confidence interval [CI] 1.24, 1.65) and a 1.48-fold increase in risk of SSc-related hospitalisation or death (95% CI 1.23, 1.77). No statistically significant association was observed between FVC decline and admission to ER or to hospital followed by admission to ICU or death (n = 75; P = 0.15). The estimated slope difference for nintedanib versus placebo in the longitudinal sub-model was consistent with the primary analysis in SENSCIS®.

CONCLUSIONS

The association of lung function decline with an increased risk of hospitalisation suggests that slowing FVC decline in patients with SSc-ILD may prevent hospitalisations. Our findings also provide evidence that FVC decline may serve as a surrogate endpoint for clinically relevant hospitalisation-associated endpoints.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02597933 . Registered on 8 October 2015.

Clinical significance of pectoralis muscle strength in elderly patients with idiopathic pulmonary fibrosis

Introduction

Investigations of muscle dysfunction in patients with idiopathic pulmonary fibrosis (IPF) are limited to peripheral muscles. However, decreased thoracic muscle mass is known and deterioration of chest wall muscle strength is not clear.

Objective

The aims of the present study were to evaluate pectoralis muscle strength located on the chest wall and to investigate the relationship of spirometric measurements and respiratory muscle strength with pectoralis muscle strength.

Methods

Elderly patient with IPF (mean disease duration 7.47±7.04 years) and the age-and sex-matched healthy volunteers were recruited in this cross-sectional study. The pulmonary function test was performed by a portable spirometer for spirometric variables and a gas analyzer for diffusing capacity for carbon monoxide (DL_CO). Maximal inspiratory (MIP) and expiratory pressure (MEP) were measured with mouth pressure device. Modified Medical Research Council Dyspnea Scale (MMRC) was used to determined dyspnea severity. The pectoralis muscle strength was assessed isometrically during shoulder joint horizontal adduction movement with a handheld dynamometer.

Results

A total of 17 patients with IPF (9 males, mean age 69.06±3.94 years) and 19 healthy controls (10 males, mean age 70.95 ±4.99 years) were included. Patients with IPF had lower pectoralis muscle strength than healthy controls (p<0.001). Significant relationships were found between pectoralis muscle strength and MIP (r=0.79, p<0.001), MEP (r=0.81, p<0.001), FEV₁% (r=0.54, p=0.02), FVC% (r=0.68, p<0.003) and DL_CO (r=0.61, p=0.009). With multiple linear regression analysis, pectoralis muscle strength was the only independent predictor of FVC% (adjusted R²=0.37, p<0.05).

Conclusion

In patients with IPF, pectoralis muscle strength decreases and is associated with pulmonary function. In particular pectoralis muscle strength is likely to have an important impact on FVC%. Therefore, we consider that this test should be included routinely in chest diseases and rehabilitation clinics. The trial was registered U.S. National Library of Medicine clinical trial registry (https://clinicaltrials.gov, Trial ID: NCT04803617).

Mortality and survival in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

There are substantial advances in diagnosis and treatment for idiopathic pulmonary fibrosis (IPF), but without much evidence available on recent mortality and survival trends.

Methods

A narrative synthesis approach was used to investigate the mortality trends, then meta-analyses for survival trends were carried out based on various time periods.

Results

Six studies reported the mortality data for IPF in 22 countries, and 62 studies (covering 63 307 patients from 20 countries) reported survival data for IPF. Age-standardised mortality for IPF varied from ∼0.5 to ∼12 per 100 000 population per year after year 2000. There were increased mortality trends for IPF in Australia, Brazil, Belgium, Canada, Czech Republic, Finland, France, Germany, Hungary, Italy, Lithuania, the Netherlands, Poland, Portugal, Spain, Sweden and UK, while Austria, Croatia, Denmark, Romania and the USA showed decreased mortality trends. The overall 3-year and 5-year cumulative survival rates (CSRs) were 61.8% (95% CI 58.7-64.9; I2=97.1%) and 45.6% (95% CI 41.5-49.7; I2=97.7%), respectively. Prior to 2010, the pooled 3-year CSR was 59.9% (95% CI 55.8-64.1; I2=95.8%), then not significantly (p=0.067) increased to 66.2% (95% CI 62.9-69.5; I2=92.6%) in the 2010s decade. After excluding three studies in which no patients received antifibrotics after year 2010, the pooled 3-year CSRs significantly (p=0.039) increased to 67.4% (95% CI 63.9-70.9; I2=93.1%) in the 2010s decade.

Discussion

IPF is a diagnosis associated with high mortality. There was no observed increasing survival trend for patients with IPF before year 2010, with then a switch to an improvement, which is probably multifactorial.

Efficacy of antifibrotic drugs, nintedanib and pirfenidone, in treatment of progressive pulmonary fibrosis in both idiopathic pulmonary fibrosis (IPF) and non-IPF: a systematic review and meta-analysis

Background

Research questions To compare the efficacy of nintedanib and pirfenidone in the treatment of progressive pulmonary fibrosis; and to compare the efficacy of anti-fibrotic therapy (grouping nintedanib and pirfenidone together) in patients with IPF versus patients with progressive lung fibrosis not classified as IPF.

Study design and methods

A search of databases including MEDLINE, EMBASE, PubMed, and clinicaltrials.gov was conducted. Studies were included if they were randomised controlled trials of pirfenidone or nintedanib in adult patients with IPF or non-IPF patients, and with extractable data on mortality or decline in forced vital capacity (FVC). Random effects meta-analyses were performed on changes in FVC and where possible on mortality in the selected studies.

Results

13 trials of antifibrotic therapy were pooled in a meta-analysis (with pirfenidone and nintedanib considered together as anti-fibrotic therapy). The change in FVC was expressed as a standardised difference to allow pooling of percentage and absolute changes. The mean effect size in the IPF studies was − 0.305 (SE 0.043) (p < 0.001) and in the non-IPF studies the figures were − 0.307 (SE 0.063) (p < 0.001). There was no evidence of any difference between the two groups for standardised rate of FVC decline (p = 0.979). Pooling IPF and non-IPF showed a significant reduction in mortality, with mean risk ratio of 07.01 in favour of antifibrotic therapy (p = 0.008). A separate analysis restricted to non-IPF did not show a significant reduction in mortality (risk ratio 0.908 (0.547 to 1.508), p = 0.71.

Interpretation

Anti-fibrotic therapy offers protection against the rate of decline in FVC in progressive lung fibrosis, with similar efficacy shown between the two anti-fibrotic agents currently in clinical use. There was no significant difference in efficacy of antifibrotic therapy whether the underlying condition was IPF or non-IPF with progressive fibrosis, supporting the hypothesis of a common pathogenesis. The data in this analysis was insufficient to be confident about a reduction in mortality in non-IPF with anti-fibrotic therapy.

Trial Registration PROSPERO, registration number CRD42021266046.

MicroRNA and protein-coding gene expression analysis in idiopathic pulmonary fibrosis yields novel biomarker signatures associated to survival

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of unknown etiology that poses significant challenges in early diagnosis and prediction of progression. Analyses of microRNA and gene expression in IPF have yielded potentially predictive information. However, the relationship between microRNA/gene expression and quantitative phenotypic value in IPF remains controversial, as is the added value of this approach to current molecular signatures in IPF. To identify biomarkers predictive of survival in IPF via a microRNA-driven strategy. We profiled microRNA and protein-coding gene expression in peripheral blood mononuclear cells from 70 IPF subjects in a discovery cohort. We linked the microRNA/gene expression level with the quantitative phenotypic variation in IPF, including diffusing capacity of the lung for carbon monoxide and the forced vital capacity percent predicted. In silico analyses of expression profiles and quantitative phenotypic data allowed the generation of 2 sets of IPF molecular signatures (unique for microRNAs and protein-coding genes) that predict IPF survival. Each signature performed well in a validation cohort comprised of IPF patients aggregated from distinct patient populations recruited from different sites. Resampling test suggests that the protein-coding gene based signature is comparable and potentially superior to published IPF prognostic gene signatures. In conclusion, these results highlight the utility of microRNA-driven peripheral blood molecular signatures as valuable and novel biomarkers associated to individuals at high survival risk and for potentially facilitating individualized therapies in this enigmatic disorder.

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.