Background

Acetylcysteine has been suggested as a beneficial treatment for idiopathic pulmonary fibrosis, although data from placebo-controlled studies are lacking.

Methods

In our initial double-blind, placebo-controlled trial, we randomly assigned patients who had idiopathic pulmonary fibrosis with mild-to-moderate impairment in pulmonary function to receive a three-drug regimen of prednisone, azathioprine, and acetylcysteine; acetylcysteine alone; or placebo. The study was interrupted owing to safety concerns associated with the three-drug regimen. The trial continued as a two-group study (acetylcysteine vs. placebo) without other changes; 133 and 131 patients were enrolled in the acetylcysteine and placebo groups, respectively. The primary outcome was the change in forced vital capacity (FVC) over a 60-week period.

Results

At 60 weeks, there was no significant difference in the change in FVC between the acetylcysteine group and the placebo group (-0.18 liters and -0.19 liters, respectively; P=0.77). In addition, there were no significant differences between the acetylcysteine group and the placebo group in the rates of death (4.9% vs. 2.5%, P=0.30 by the log-rank test) or acute exacerbation (2.3% in each group, P>0.99).

Conclusions

As compared with placebo, acetylcysteine offered no significant benefit with respect to the preservation of FVC in patients with idiopathic pulmonary fibrosis with mild-to-moderate impairment in lung function. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00650091.).

Background

The National Heart, Lung, and Blood Institute-sponsored IPF Clinical Research Network (IPFnet) studies enrolled subjects with idiopathic pulmonary fibrosis (IPF) to evaluate drug therapies in treatment trials. An adjudication committee (AC) provided a structured review of cases in which there was uncertainty or disagreement regarding diagnosis or clinical event classification. This article describes the diagnosis and adjudication processes.

Methods

The diagnostic process was based on review of clinical data and high-resolution CT scans with central review of lung biopsies when available. The AC worked closely with the data coordinating center to obtain clinical, radiologic, and histologic data and to communicate with the clinical centers. The AC used a multidisciplinary discussion model with four clinicians, one radiologist, and one pathologist to adjudicate diagnosis and outcome measures.

Results

The IPFnet trials screened 1,015 subjects; of these, 23 cases required review by the AC to establish eligibility. The most common diagnosis for exclusion was suspected chronic hypersensitivity pneumonitis. The AC reviewed 88 suspected acute exacerbations (AExs), 93 nonelective hospitalizations, and 16 cases of bleeding. Determination of AEx presented practical challenges to adjudicators, as necessary clinical data were often not collected, particularly when subjects were evaluated outside of the primary study site.

Conclusions

The IPFnet diagnostic process was generally efficient, but a multidisciplinary adjudication committee was critical to assure correct phenotype for study enrollment. The AC was key in adjudicating all adverse outcomes in two IPFnet studies terminated early because of safety issues. Future clinical trials in IPF should consider logistical and cost issues as they incorporate AExs and hospitalizations as outcome measures.

Trial registry

ClinicalTrials.gov; No.: NCT00517933, NCT00650091, NCT00957242; URL: www.clinicaltrials.gov.

Background

The beneficial outcome associated with the use of proton pump inhibitors (PPIs) in idiopathic pulmonary fibrosis (IPF) has been reported in retrospective studies. To date, no prospective study has been conducted to confirm these outcomes. In addition, the potential mechanism by which PPIs improve measures of lung function and/or transplant-free survival in IPF has not been elucidated.

Methods

Here, we used biochemical, cell biological and preclinical studies to evaluate regulation of markers associated with inflammation and fibrosis. In our in vitro studies, we exposed primary lung fibroblasts, epithelial and endothelial cells to ionizing radiation or bleomycin; stimuli typically used to induce inflammation and fibrosis. In addition, we cultured lung fibroblasts from IPF patients and studied the effect of esomeprazole on collagen release. Our preclinical study tested efficacy of esomeprazole in a rat model of bleomycin-induced lung injury. Furthermore, we performed retrospective analysis of interstitial lung disease (ILD) databases to examine the effect of PPIs on transplant-free survival.

Results

The cell culture studies revealed that esomeprazole controls inflammation by suppressing the expression of pro-inflammatory molecules including vascular cell adhesion molecule-1, inducible nitric oxide synthase, tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1β and IL-6). The antioxidant effect is associated with strong induction of the stress-inducible cytoprotective protein heme oxygenase-1 (HO1) and the antifibrotic effect is associated with potent inhibition of fibroblast proliferation as well as downregulation of profibrotic proteins including receptors for transforming growth factor β (TGFβ), fibronectin and matrix metalloproteinases (MMPs). Furthermore, esomeprazole showed robust effect in mitigating the inflammatory and fibrotic responses in a murine model of acute lung injury. Finally, retrospective analysis of two ILD databases was performed to assess the effect of PPIs on transplant-free survival in IPF patients. Intriguingly, this data demonstrated that IPF patients on PPIs had prolonged survival over controls (median survival of 3.4 vs 2 years).

Conclusions

Overall, these data indicate the possibility that PPIs may have protective function in IPF by directly modulating the disease process and suggest that they may have other clinical utility in the treatment of extra-intestinal diseases characterized by inflammatory and/or fibrotic phases.

Background

Interstitial lung abnormalities (ILA) may represent undiagnosed early-stage or subclinical interstitial lung disease (ILD). ILA are often observed incidentally in patients who subsequently develop clinically overt ILD. There is limited information on consensus definitions for, and the appropriate evaluation of, ILA. Early recognition of patients with ILD remains challenging, yet critically important. Expert consensus could inform early recognition and referral.

Research question

Can consensus-based expert recommendations be identified to guide clinicians in the recognition, referral, and follow-up of patients with or at risk of developing early ILDs?

Study design and methods

Pulmonologists and radiologists with expertise in ILD participated in two iterative rounds of surveys. The surveys aimed to establish consensus regarding ILA reporting, identification of patients with ILA, and identification of populations that might benefit from screening for ILD. Recommended referral criteria and follow-up processes were also addressed. Threshold for consensus was defined a priori as ≥ 75% agreement or disagreement.

Results

Fifty-five experts were invited and 44 participated; consensus was reached on 39 of 85 questions. The following clinically important statements achieved consensus: honeycombing and traction bronchiectasis or bronchiolectasis indicate potentially progressive ILD; honeycombing detected during lung cancer screening should be reported as potentially significant (eg, with the Lung CT Screening Reporting and Data System "S-modifier" [Lung-RADS; which indicates clinically significant or potentially significant noncancer findings]), recommending referral to a pulmonologist in the radiology report; high-resolution CT imaging and full pulmonary function tests should be ordered if nondependent subpleural reticulation, traction bronchiectasis, honeycombing, centrilobular ground-glass nodules, or patchy ground-glass opacity are observed on CT imaging; patients with honeycombing or traction bronchiectasis should be referred to a pulmonologist irrespective of diffusion capacity values; and patients with systemic sclerosis should be screened with pulmonary function tests for early-stage ILD.

Interpretation

Guidance was established for identifying clinically relevant ILA, subsequent referral, and follow-up. These results lay the foundation for developing practical guidance on managing patients with ILA.

Rationale: Several common and rare genetic variants have been associated with idiopathic pulmonary fibrosis, a progressive fibrotic condition that is localized to the lung. Objectives: To develop an integrated understanding of the rare and common variants located in multiple loci that have been reported to contribute to the risk of disease. Methods: We performed deep targeted resequencing (3.69 Mb of DNA) in cases (n = 3,624) and control subjects (n = 4,442) across genes and regions previously associated with disease. We tested for associations between disease and 1) individual common variants via logistic regression and 2) groups of rare variants via sequence kernel association tests. Measurements and Main Results: Statistically significant common variant association signals occurred in all 10 of the regions chosen based on genome-wide association studies. The strongest risk variant is the MUC5B promoter variant rs35705950, with an odds ratio of 5.45 (95% confidence interval, 4.91-6.06) for one copy of the risk allele and 18.68 (95% confidence interval, 13.34-26.17) for two copies of the risk allele (P = 9.60 × 10^-295). In addition to identifying for the first time that rare variation in FAM13A is associated with disease, we confirmed the role of rare variation in the TERT and RTEL1 gene regions in the risk of IPF, and found that the FAM13A and TERT regions have independent common and rare variant signals. Conclusions: A limited number of common and rare variants contribute to the risk of idiopathic pulmonary fibrosis in each of the resequencing regions, and these genetic variants focus on biological mechanisms of host defense and cell senescence.