Early Idiopathic Pulmonary Fibrosis Research Articles

Tertiary lymphoid structures and B-cell infiltration are IPF features with functional consequences.

Recent literature has shown the presence of B cells and autoantibodies in idiopathic pulmonary fibrosis (IPF) which would imply the presence of tertiary lymphoid structures (TLS, sites where the immune response is triggered), yet TLS are not considered features of the histological characteristics of IPF. This study aims to quantify the presence, size, and degree of activation of TLS in biopsied and explanted lungs from patients with early- and late-IPF, never treated with antifibrotics, and relate their presence and activity to the clinical course, disease progression, and lung inflammation. Immunohistochestry for B cells and CD4, CD8, and CD45 cells was performed in lung tissue from IPF patients: 18 at diagnosis (early), 39 explanted (end-stage), and 12 smoking controls. TLS activation was assessed by CD40 expression. Spirometry along 31 (12-72) months of follow-up was used to characterize end-stage IPF as slow progressors or rapid progressors. B cells, along with other inflammatory cells, were higher in early- and end-stage IPF than in controls (p < 0.001). In rapid progressors, all inflammatory cells were higher than in slow progressors (p < 0.05). TLS were present in 100% of early- and end-stage IPF and in 50% of controls. In end-stage IPF, the TLS area and activation score were higher than in early IPF (p < 0.0001; p = 0.005) and controls (p < 0.04; p < 0.002). TLS activation score correlated with FVC decline during follow-up in rapid progressors (r = 0.73; p = 0.007) but not in slow progressors. A prominent B-cell infiltration, along with the presence of TLS, the activity of which correlates with FVC decline, is an important component of IPF from the beginning of the disease, likely playing an important role on its mechanism and progression.

Early pirfenidone treatment enhances lung function in idiopathic pulmonary fibrosis patients.

This editorial comments on the study by Lei et al investigating the efficacy of early treatment with pirfenidone on the lung function of patients with idiopathic pulmonary fibrosis (IPF) published. This study evaluates the efficacy of early treatment with pirfenidone on lung function in patients with IPF. The early and advanced stages of IPF are defined, highlighting the drug's benefits. While prior research indicates pirfenidone's effectiveness in advanced IPF, this study focuses on its advantages in early stages. The study emphasizes the importance of computed tomography imaging alongside biochemical data and lung function tests for a comprehensive analysis of symptom relief. Results show that early intervention with pirfenidone significantly reduces disease progression and preserves lung function, underscoring its potential as a critical treatment strategy in early IPF.

Regenerative capacity of alveolar type 2 cells is proportionally reduced following disease progression in idiopathic pulmonary fibrosis-derived organoid cultures.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that leads to respiratory failure and death due to irreversible scarring of the distal lung. While historically considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now recognized to play a central role in IPF pathophysiology. This study aimed to investigate the regenerative capacity of AT2 cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Lung tissues from 3 pneumothorax patients and 6 IPF patients (early and advanced stages) were obtained by VATS and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-EpCAM+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immuno-staining was used to confirm the presence of AT2 cells. FACS sorting yielded approximately 1% AT2 cells of the total cells in early IPF tissue, and the number decreased as the disease progressed, compared with 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller in size and fewer in number compared to those from pneumothorax patients. The colony-forming efficiency decreased as the disease progressed. In immuno-staining results, the IPF organoids showed lower expression of SFTPC compared to the pneumothorax group and contained KRT5+ cells. This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, and IPF AT2 cells inherently exhibit functional abnormalities and altered differentiation plasticity.

Microscopic Small Airway Abnormalities Identified in Early Idiopathic Pulmonary Fibrosis InVivo Using Endobronchial Optical Coherence Tomography.

Rationale: Idiopathic pulmonary fibrosis (IPF) affects the subpleural lung but is considered to spare small airways. Micro-computed tomography (micro-CT) studies demonstrated small airway reduction in end-stage IPF explanted lungs, raising questions about small airway involvement in early-stage disease. Endobronchial optical coherence tomography (EB-OCT) is a volumetric imaging modality that detects microscopic features from subpleural to proximal airways. Objectives: In this study, EB-OCT was used to evaluate small airways in early IPF and control subjects invivo. Methods: EB-OCT was performed in 12 subjects with IPF and 5 control subjects (matched by age, sex, smoking history, height, and body mass index). Subjects with IPF had early disease with mild restriction (FVC: 83.5% predicted), which was diagnosed per current guidelines and confirmed by surgical biopsy. EB-OCT volumetric imaging was acquired bronchoscopically in multiple, distinct, bilateral lung locations (total: 97 sites). IPF imaging sites were classified by severity into affected (all criteria for usual interstitial pneumonia present) and less affected (some but not all criteria for usual interstitial pneumonia present). Bronchiole count and small airway stereology metrics were measured for each EB-OCT imaging site. Measurements and Main Results: Compared with the number of bronchioles in control subjects (mean = 11.2/cm3; SD = 6.2), there was significant bronchiole reduction in subjects with IPF (42% loss; mean = 6.5/cm3; SD = 3.4; P = 0.0039), including in IPF affected (48% loss; mean: 5.8/cm3; SD: 2.8; P < 0.00001) and IPF less affected (33% loss; mean: 7.5/cm3; SD: 4.1; P = 0.024) sites. Stereology metrics showed that IPF-affected small airways were significantly larger, more distorted, and more irregular than in IPF-less affected sites and control subjects. IPF less affected and control airways were statistically indistinguishable for all stereology parameters (P = 0.36-1.0). Conclusions: EB-OCT demonstrated marked bronchiolar loss in early IPF (between 30% and 50%), even in areas minimally affected by disease, compared with matched control subjects. These findings support small airway disease as a feature of early IPF, providing novel insight into pathogenesis and potential therapeutic targets.

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.

Characteristics of idiopathic pulmonary fibrosis -associated cough. a case-control study

BackgroundMost patients with idiopathic pulmonary fibrosis (IPF) complain of cough. IPF-associated cough is widely characterized as dry or non-productive. The aim of this study was to compare chronic cough in early stage IPF patients to cough in subjects with chronic cough from a community-based sample and, especially, to investigate whether cough in IPF is less productive than chronic cough in a community-based sample.MethodsThe IPF cough population consisted of 46 biopsy-confirmed patients who complained of chronic cough. Control population consisted of subjects with chronic cough, gathered by a community-based email survey sent to public service employees and the Finnish Pensioners’ Federation. A case-control setting was applied by having four age, gender, and smoking-status matched subjects from the community sample for each IPF cough patient. A cough specific quality of life questionnaire (Leicester Cough Questionnaire (LCQ)) was filled in by all subjects. The LCQ questionnaire contains 19 questions, each question is scored from 1 to 7 and total score from 3 to 21 with a smaller value indicating more severe impairment.ResultsThe sputum production frequency, as assessed by LCQ question 2, was 5.0 (3.0-6.0) in the IPF chronic cough population and 5.0 (3.0–6.0) in the community-based chronic cough population (median and interquartile range p= 0.72). The LCQ total score was 14.8 (11.5-18.1) in the IPF chronic cough population and 15.4 (13.0–17.5) in the community-based chronic cough population (p=0.76). The domain impact scores were physical, 4.9 (3.9–6.1) vs. 5.1 (4.5–5.6) (p=0.80); psychological, 4.6 (3.7–5.9) vs. 4.7 (3.9–5.7) (p=0.90); and social, 5.5 (3.7–6.5) vs. 5.5 (4.5–6.3) (p=0.84), respectively. Furthermore, cough response to paint or fumes, cough disturbing sleep, and cough frequency per day did not differ between the groups.ConclusionCough in early stage IPF patients was not distinguishable from chronic cough in the community-based population by LCQ. Especially, there was no difference in the self-reported frequency of cough-associated sputum production.

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

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

What parameters can be used to identify early idiopathic pulmonary fibrosis?

Elucidating the disease process of early idiopathic pulmonary fibrosis (IPF) will help clinicians in addressing the contentious issues of when and in which patients, therapeutic intervention should be initiated. Here, we discuss several possible parameters for diagnosing early IPF and their clinical impacts. Physiologically, early IPF can be considered as IPF with normal or mild impairment in pulmonary function. Radiologically, early IPF can be considered as IPF with a small extent and/or early features of fibrosis. Symptomatically, early IPF can be considered as asymptomatic or less symptomatic IPF. IPF at Gender-Age-Physiology index stage I can be considered early IPF. Interstitial lung abnormalities are defined as parenchymal abnormalities in more than 5% of the lung in patients with no prior history of interstitial lung disease, and in some cases, this seems to be equivalent to early IPF. Previous clinical trials showed the effect of antifibrotic therapies in early IPF, but the effects of therapy are uncertain in early IPF outside of clinical trials, such as in cases of IPF with normal pulmonary function, IPF without honeycombing or traction bronchiectasis, and asymptomatic IPF. Moreover, little has been reported on disease progression in such conditions. Because the conceptual framework of early IPF may vary depending on its definition, not only is a diagnosis of early IPF important but prediction of disease progression is also crucial. Further investigations are needed to identify biomarkers that can detect patients who may experience greater degrees of disease progression and require treatment even with those forms of early IPF.

Topographic heterogeneity of lung microbiota in end-stage idiopathic pulmonary fibrosis: the Microbiome in Lung Explants-2 (MiLEs-2) study

BackgroundLung microbiota profiles in patients with early idiopathic pulmonary fibrosis (IPF) have been associated with disease progression; however, the topographic heterogeneity of lung microbiota and their roles in advanced IPF...

DIAGNOSING IDIOPATHIC PULMONARY FIBROSIS IN COMMUNITY-BASED PULMONOLARY PRACTICES: FACTORS INFLUENCING APPROACH TO DIAGNOSIS

SESSION TITLE: Diffuse Lung Disease Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Despite the increased awareness of Idiopathic Pulmonary Fibrosis (IPF) and refinement of the guidelines, there is still a significant delay in the diagnosis of IPF as many of these patients are cared for at non-Interstitial Lung Disease Centers of Excellence (ILD-CE). The purpose of this study is to gain further insight into the factors influencing the pulmonologists’ approach to diagnosing IPF at non-ILD-CE. METHODS: This study was approved by the Loma Linda University Institutional Review Board. An anonymous survey was emailed to pulmonologists throughout the United States using selected proprietary medical databases. Pulmonologists practicing at an ILD-CE were excluded. The survey evaluated the pulmonologist's approach related to referral to an ILD-CE, utilization of a Multi-Disciplinary Approach (MDA), and their attitude towards the importance of obtaining an early and accurate diagnosis. RESULTS: There were a total of 58 survey respondents: 35% in hospital-based practices and 65% in community-based practices. Only 55% of participants strongly agreed that obtaining an early and accurate diagnosis of IPF was important; no difference was noted between the practice settings. The median percentage of time the participants used an MDA was 45% (IQR: 10.75-90); 20% in hospital-based practice and 40% in community-based practice (p<0.05). In respondents with access to an ILD-CE, the median percentage of the time patients were referred to one was only 41%. CONCLUSIONS: Based on these preliminary results, the pulmonologist’s perspective on the importance of obtaining an early and accurate IPF diagnosis is low at non-ILD-CE. The utilization of an MDA was also very low despite this being the gold standard for diagnosis for all ILDs as recommended by the American Thoracic Society Task Force. Even with access to an ILD-CE, the referral rate was low. Further studies with higher sample sizes are needed to better understand the rationale behind low utilization rates of MDA and referrals to ILD-CE. CLINICAL IMPLICATIONS: This could reveal the reason behind the large number of patients with IPF that potentially go undiagnosed (or misdiagnosed) in the community-based practices. DISCLOSURES: Stock market shareholder relationship with ABT, ABBV, AZN, BMY, DOW,JNJ, LLY,PFE Please note: $1-$1000 Added 06/09/2020 by Abdullah Alismail, source=Web Response, value=only Quar.Div when applied No relevant relationships by Benjamin Becerra, source=Web Response No relevant relationships by Rodney Biehl, source=Web Response No relevant relationships by Niranjan Jeganathan, source=Web Response No relevant relationships by David Lopez, source=Web Response

Pirfenidone plus inhaled N-acetylcysteine for idiopathic pulmonary fibrosis: a randomised trial.

A randomised controlled trial in Japan showed that inhaled N-acetylcysteine monotherapy stabilised serial decline in forced vital capacity (FVC) in some patients with early idiopathic pulmonary fibrosis (IPF). However, the efficacy and tolerability of combination therapy with an antifibrotic agent and inhaled N-acetylcysteine are unknown. This 48-week, randomised, open-label, multicentre phase 3 trial compared the efficacy and tolerability of combination therapy with pirfenidone plus inhaled N-acetylcysteine 352.4 mg twice daily with the results for pirfenidone alone in patients with IPF. The primary end-point was annual rate of decline in FVC. Exploratory efficacy measurements included serial change in diffusing capacity of the lung for carbon monoxide (D LCO) and 6-min walk distance (6MWD), progression-free survival (PFS), incidence of acute exacerbation, and tolerability. 81 patients were randomly assigned in a 1:1 ratio to receive pirfenidone plus inhaled N-acetylcysteine (n=41) or pirfenidone (n=40). The 48-week rate of change in FVC was -300 mL and -123 mL, respectively (difference -178 mL, 95% CI -324--31 mL; p=0.018). Serial change in D LCO, 6MWD, PFS and incidence of acute exacerbation did not significantly differ between the two groups. The incidence of adverse events (n=19 (55.9%) for pirfenidone plus N-acetylcysteine; n=18 (50%) for pirfenidone alone) was similar between groups. Combination treatment with inhaled N-acetylcysteine and pirfenidone is likely to result in worse outcomes for IPF.

Obstacles to early treatment of idiopathic pulmonary fibrosis: current perspectives.

Idiopathic pulmonary fibrosis is a progressive and fatal fibrotic lung disease which has seen new opportunity for drug treatment in the last several years with the approval of nintedanib and pirfenidone, two antifibrotic agents aimed at slowing decline in lung function as defined by FVC on pulmonary function testing. Despite these promising effects, delays in drug initiation have been reported undermining the premise that earlier drug initiation may sustain lung function and prolong survival. This review explores obstacles to earlier treatment, inclusive of defining so-called early idiopathic pulmonary fibrosis, difficulties in achieving a confident diagnosis in that setting, and uncertainties regarding drug-related benefits among specific patient subgroups such as those with no symptoms or advanced disease at presentation. Goals of therapy balanced with the burdens associated with antifibrotic drug therapy are negotiated on an individual basis. We review the evidence for and against earlier initiation of antifibrotic drug therapy along with its role in patient-centered outcomes.

Recent advances in understanding idiopathic pulmonary fibrosis.

Despite major research efforts leading to the recent approval of pirfenidone and nintedanib, the dismal prognosis of idiopathic pulmonary fibrosis (IPF) remains unchanged. The elaboration of international diagnostic criteria and disease stratification models based on clinical, physiological, radiological, and histopathological features has improved the accuracy of IPF diagnosis and prediction of mortality risk. Nevertheless, given the marked heterogeneity in clinical phenotype and the considerable overlap of IPF with other fibrotic interstitial lung diseases (ILDs), about 10% of cases of pulmonary fibrosis remain unclassifiable. Moreover, currently available tools fail to detect early IPF, predict the highly variable course of the disease, and assess response to antifibrotic drugs. Recent advances in understanding the multiple interrelated pathogenic pathways underlying IPF have identified various molecular phenotypes resulting from complex interactions among genetic, epigenetic, transcriptional, post-transcriptional, metabolic, and environmental factors. These different disease endotypes appear to confer variable susceptibility to the condition, differing risks of rapid progression, and, possibly, altered responses to therapy. The development and validation of diagnostic and prognostic biomarkers are necessary to enable a more precise and earlier diagnosis of IPF and to improve prediction of future disease behaviour. The availability of approved antifibrotic therapies together with potential new drugs currently under evaluation also highlights the need for biomarkers able to predict and assess treatment responsiveness, thereby allowing individualised treatment based on risk of progression and drug response. This approach of disease stratification and personalised medicine is already used in the routine management of many cancers and provides a potential road map for guiding clinical care in IPF.

Effect of inhaled N-acetylcysteine monotherapy on lung function and redox balance in idiopathic pulmonary fibrosis.

An oxidant-antioxidant imbalance is considered to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Therefore, administration of antioxidants, such as N-acetylcysteine (NAC), may represent a potential treatment option for IPF patients. The aim of this study was to evaluate the effect of inhaled NAC monotherapy on lung function and redox balance in patients with IPF. A retrospective observational study was done, involving 22 patients with untreated early IPF (19 men; mean [±S.D.] age, 71.8 [±6.3]y). At baseline and at 6 and 12 months after initiating inhaled NAC monotherapy, we assessed forced vital capacity (FVC) and measured the levels of total glutathione, oxidized glutathione (GSSG), and the ratio of reduced to oxidized glutathione in whole blood (hereafter referred to as the ratio), and of 8-hydroxy-2'-deoxyguanosine in urine. To evaluate response to treatment, we defined disease progression as a decrease in FVC of ≥5% from baseline and stable disease as a decrease in FVC of <5%, over a period of 6 months. Change in FVC in the stable group at 6 and 12 months were 95±170mL and -70±120mL, while those in the progressive group at 6 and 12 months were -210±80mL, -320±350mL, respectively. The serial mean change in GSSG from baseline decreased as the ratio of reduced to oxidized glutathione increased in patients with stable disease, while it increased as this ratio decreased in patients with progressive disease. Receiver operating characteristic curve analysis revealed that a baseline GSSG level of ≥1.579μM was optimal for identifying treatment responders. Inhaled NAC monotherapy was associated with improved redox imbalance in patients with early IPF.

Usefulness of a disease severity staging classification system for IPF in Japan: 20 years of experience from empirical evidence to randomized control trial enrollment.

Since 1991, the severity of idiopathic pulmonary fibrosis (IPF) has been classified into 4 stages-stage I (characterized by a resting PaO2 ≥ 80 Torr), stage II (70-79 Torr), stage III (60-69 Torr), or stage IV (<60 Torr)-to aid decisions on medical care subsidization in Japan. Among patients with stage II/III IPF, the severity should be increased by one stage if the lowest oxygen saturation on pulse oximetry (SpO2) is <90% during a 6-min walk test. Patients with stage III/IV IPF receive Japanese government subsidies for incurable diseases. This classification system highly correlates with serial changes in the percentage of vital capacity (%VC), the diffusing capacity for carbon monoxide, the incidence of acute exacerbation, and survival. A phase III trial of pirfenidone showed that IPF patients with an SpO2 on exertion of <90% and either a %VC ≥ 70% or a PaO2 ≥ 70 Torr (which includes most patients with stage III disease) at baseline would benefit from pirfenidone treatment. Recent post-marketing surveillance of 1370 patients--67.3% of whom had stage III/IV IPF--showed that pirfenidone was well-tolerated among those treated for longer than 6 months (63% of patients). A Japanese randomized controlled trial (RCT) demonstrated that inhaled N-acetylcysteine monotherapy benefitted patients with early IPF (stage I/II, with no desaturation on exertion). Thus, N-acetylcysteine monotherapy is suitable for early IPF, and pirfenidone is indicated for advanced disease. The classification of IPF severity is important in identifying clinically responsive patients and those suitable for RCT enrollment.

Genetics and Early Detection in Idiopathic Pulmonary Fibrosis

Genetic studies hold promise in helping to identify patients with early idiopathic pulmonary fibrosis (IPF). Recent studies using chest computed tomograms (CTs) in smokers and in the general population have demonstrated that imaging abnormalities suggestive of an early stage of pulmonary fibrosis are not uncommon and are associated with respiratory symptoms, physical examination abnormalities, and physiologic decrements expected, but less severe than those noted in patients with IPF. Similarly, recent genetic studies have demonstrated strong and replicable associations between a common promoter polymorphism in the mucin 5B gene (MUC5B) and both IPF and the presence of abnormal imaging findings in the general population. Despite these findings, it is important to note that the definition of early-stage IPF remains unclear, limited data exist to definitively connect abnormal imaging findings to IPF, and genetic studies assessing early-stage pulmonary fibrosis remain in their infancy. In this perspective we provide updated information on interstitial lung abnormalities and their connection to IPF. We summarize information on the genetics of pulmonary fibrosis by focusing on the recent genetic findings of MUC5B. Finally, we discuss the implications of these findings and suggest a roadmap for the use of genetics in the detection of early IPF.

Efficacy of Inhaled N-Acetylcysteine Monotherapy on Lung Function and Redox Balance in Early Idiopathic Pulmonary Fibrosis

SESSION TITLE: ILD Posters

Neglected evidence in idiopathic pulmonary fibrosis: from history to earlier diagnosis

This perspective highlights some evidence that has hitherto been neglected, especially because it may not have been sufficiently explicated in the clinical respiratory medicine literature. Idiopathic pulmonary fibrosis (IPF) has appeared only in the second half of the 20th century and, like lung cancer and chronic obstructive pulmonary disease, may be a direct consequence of the cigarette smoking epidemic. It is a disease of lung ageing, with most affected patients being >70 years of age. The relationship between lung ageing and pulmonary fibrosis is further illustrated in the bleomycin mouse model, in which older males develop more fibrosis than young female mice. Earlier diagnosis of IPF is a prerequisite for significant progress to be made in the long-term outcome and prognosis. We consider that only two different yet complementary and realistic approaches could lead to earlier diagnosis of IPF and possibly to allowing more efficient disease management: 1) investigating any patients with early Velcro crackles at lung auscultation through proactive education of, and commitment from, primary care physicians; and 2) using current large-scale lung cancer screening strategies with low-dose high-resolution computed tomography in smokers for the detection of subclinical interstitial lung disease and especially early IPF.

Who and what should we rely on in early diagnosis of idiopathic pulmonary fibrosis?

To the Editor: In a recent European Respiratory Journal editorial, Cottin and Cordier [1] ranked velcro crackles among diagnostic clues in early idiopathic pulmonary fibrosis (IPF). We agree that auscultation is essential for early detection of IPF, but physical examinations should be integrated into a more comprehensive diagnostic strategy. This raises a question: who identifies IPF patients, and by what means? IPF is a cryptogenic form of usual interstitial pneumonia (UIP), which is best confirmed pathologically or, to a lesser extent, by a radiographic UIP pattern [2]. However, the low …

Efficacy of inhaled N‐acetylcysteine monotherapy in patients with early stage idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal disorder for which there are currently no specific or effective medical treatments. A multicentre, prospective, randomized, controlled clinical trial was conducted to assess the efficacy of inhaled N-acetylcysteine (NAC) monotherapy in Japanese patients with early stage IPF. Eligible patients had well-defined IPF of mild-to-moderate severity, with no desaturation on exercise. Of 100 patients screened, 76 were randomly assigned to an NAC treatment group (group A; n = 38) that received 352.4 mg of NAC by inhalation twice daily or to a control group (group B; n = 38) that received no therapy. The primary endpoint was the change from baseline in forced vital capacity (FVC) at 48 weeks. There were no significant overall differences in the change in FVC between groups A and B. Post hoc exploratory analyses showed that NAC therapy was associated with stability of FVC in (i) a subset of patients with initial FVC <95% of predicted (n = 49; difference in FVC decline 0.12 L; P = 0.02) and (ii) in patients with initial diffusing capacity of carbon monoxide <55% of predicted (n = 21; difference in FVC decline 0.17 L; P = 0.009). These findings indicate that NAC monotherapy may have some beneficial effect in patients with early stage IPF. Further trials in more select IPF populations with progressive disease are required to prove the efficacy of inhaled NAC.