High prevalence of abnormal acid gastro-oesophageal reflux in idiopathic pulmonary fibrosis

Natural history of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a parenchymal lung disease characterized by progressive interstitial fibrosis. IPF has a poor prognosis, with a median survival time of 2-3 years from diagnosis, but varying from a few months to a decade. The natural history of IPF is highly variable and the course of disease in an individual patient is difficult to predict. Some patients with IPF experience rapid decline, others progress much more slowly, and some patients show periods of relative stability interspersed with acute deteriorations in respiratory function. Many clinical, radiographic, serologic, and histopathologic variables have been shown to predict mortality in IPF. However, the accuracy of these predictors varies due to the retrospective nature of some of the studies and variations in study design. The ability to identify clinical characteristics that predict disease progression and survival would be useful for counseling patients, treatment decision-making, and prompt consideration for lung transplantation. A number of indices for predicting mortality in patients with IPF are available, but they require further validation. As high-resolution computed tomography scans become more widely available and patients with IPF are diagnosed earlier, survival times following diagnosis will improve. Early referral to interstitial lung disease specialty centers is important for accurate diagnosis and may be associated with improved outcomes. The goal of this review is to examine the natural history of IPF, discuss predictors of mortality, and highlight the importance of prompt diagnosis and referral for patients with IPF.

Idiopathic pulmonary fibrosis: an update

Idiopathic pulmonary fibrosis (IPF) is the most common and lethal form of idiopathic interstitial pneumonia. The disease, which occurs primarily in middle-aged and older adults, is thought to arise following an aberrant reparative response to alveolar epithelial cell injury characterized by secretion of excessive amounts of extracellular matrix components, resulting in scarring of the lung, architectural distortion, and irreversible loss of function. A complex interplay between environmental and host factors is thought to contribute to the development of the disease, although the cause of IPF remains elusive and its pathogenesis incompletely understood. Over the last decade, disease definition and diagnostic criteria have evolved significantly, and this has facilitated the design of a number of high-quality clinical trials evaluating novel therapeutic agents for IPF. This massive effort of the medical and industry community has led to the identification of two compounds (pirfenidone and nintedanib) able to reduce functional decline and disease progression. These promising results notwithstanding, IPF remains a major cause of morbidity and mortality and a largely unmet medical need. A real cure for this devastating disease has yet to emerge and will likely consist of a combination of drugs targeting the plethora of pathways potentially involved in disease pathogenesis.

Interstitial lung disease: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

Population-based, longitudinal studies spanning decades linking risk factors in childhood, adolescence and early adulthood to incident clinical interstitial lung disease (ILD) events in late adulthood have not been performed. In addition, no observational or randomized clinical trials have been conducted; therefore, there is presently no evidence to support the notion that reduction of risk factor levels in early life prevents ILD events in adult life. Primary prevention strategies are host-directed interventions designed to modify adverse risk factors (i.e., smoking) with the goal of preventing the development of ILD, whereas primordial prevention for ILD can be defined as the elimination of external risk factors (i.e., environmental pollutants). As no ILD primary prevention studies have been previously conducted, we propose that research studies that promote implementation of primary prevention strategies could, over time, make a subset of ILD preventable. Herein, we provide a number of initial steps required for the future implementation of prevention strategies; this statement discusses the rationale and available evidence that support potential opportunities for primordial and primary prevention, as well as fertile areas for future research of preventive intervention in ILD.

New therapeutic targets in idiopathic pulmonary fibrosis. Aiming to rein in runaway wound-healing responses

Idiopathic pulmonary fibrosis (IPF) is a devastating disease, with a median survival as short as 3 years from the time of diagnosis and no pharmacological therapies yet approved by the U.S. Food and Drug Administration. To address the great unmet need for effective IPF therapy, a number of new drugs have recently been, or are now being, evaluated in clinical trials. The rationales for most of these therapeutic candidates are based on the current paradigm of IPF pathogenesis, in which recurrent injury to the alveolar epithelium is believed to drive aberrant wound healing responses, resulting in fibrosis rather than repair. Here we discuss drugs in recently completed or currently ongoing phase II and III IPF clinical trials in the context of their putative mechanisms of action and the aberrant repair processes they are believed to target: innate immune activation and polarization, fibroblast accumulation and myofibroblast differentiation, or extracellular matrix deposition and stiffening. Placed in this context, the positive results of recently completed trials of pirfenidone and nintedanib, and results that will come from ongoing trials of other agents, should provide valuable insights into the still-enigmatic pathogenesis of this disease, in addition to providing benefits to patients with IPF.

Interstitial lung disease: raising the index of suspicion in primary care

Interstitial lung disease (ILD) describes a group of diseases that cause progressive scarring of the lung tissue through inflammation and fibrosis. The most common form of ILD is idiopathic pulmonary fibrosis, which has a poor prognosis. ILD is rare and mainly a disease of the middle-aged and elderly. The symptoms of ILD—chronic dyspnoea and cough—are easily confused with the symptoms of more common diseases, particularly chronic obstructive pulmonary disease and heart failure. ILD is infrequently seen in primary care and a precise diagnosis of these disorders can be challenging for physicians who rarely encounter them. Confirming a diagnosis of ILD requires specialist expertise and review of a high-resolution computed tomography scan (HRCT). Primary care physicians (PCPs) play a key role in facilitating the diagnosis of ILD by referring patients with concerning symptoms to a pulmonologist and, in some cases, by ordering HRCTs. In our article, we highlight the importance of prompt diagnosis of ILD and describe the circumstances in which a PCP’s suspicion for ILD should be raised in a patient presenting with chronic dyspnoea on exertion, once more common causes of dyspnoea have been investigated and excluded.

The potential of microfluidic lung epithelial wounding: towards in vivo-like alveolar microinjuries

Idiopathic pulmonary fibrosis (IPF) remains a major clinical challenge to date. Repeated alveolar epithelial microinjuries are considered as the starting point and the key event in both the development and the progression of IPF. Various pro-fibrotic agents have been identified and shown to cause alveolar damage. In IPF, however, no leading cause of alveolar epithelial microinjuries can be identified and the exact etiology remains elusive. New results from epidemiologic studies suggest a causal relation between IPF and frequent episodes of gastric refluxes resulting in gastric microaspirations into the lung. The effect of gastric contents on the alveolar epithelium has not been investigated in detail. Here, we present a microfluidic lung epithelial wounding system that allows for the selective exposure of alveolar epithelial cells to gastric contents. The system is revealed to be robust and highly reproducible. The thereby created epithelial microwounds are of tiny dimensions and best possibly reproduce alveolar damage in the lung. We further demonstrate that exposure to gastric contents, namely hydrochloric acid (HCl) and pepsin, directly damages the alveolar epithelium. Together, this novel in vitro wounding system allows for the creation of in vivo-like alveolar microinjuries with the potential to study lung injury and alveolar wound repair in vitro.

Transforming growth factor β regulates β-catenin expression in lung fibroblast through NF-κB dependent pathway

β-catenin contributes to the pathogenesis of lung fibrosis. However, the expression of β-catenin in fibroblasts under fibrotic conditions has not been studied. We investigated the expression of β-catenin in lung fibroblasts from bleomycin (BLM)-challenged mice and human lung fibroblasts treated with transforming growth factor β (TGF-β) or lysophosphatidic acid (LPA) by western blot analysis. The result showed that the expression of β-catenin was significantly increased in lung fibrotic foci and lung fibroblasts from bleomycin-challenged mice. TGF-β stimulated β-catenin expression and induced differentiation in human lung fibroblasts in vitro. Pretreatment of the NF-κB activation inhibitor attenuated the TGF-β-induced expression of β-catenin and differentiation in human lung fibroblasts. Similarly, LPA induced β-catenin expression in human lung fibroblasts, and pre-treatment of the neutralized anti-TGF-β antibody attenuated the LPA-induced expression of β-catenin and differentiation in human lung fibroblasts. The results suggested that β-catenin expression is upregulated in lung fibroblast during differentiation, and that TGF-β induced β-catenin expression in human lung fibroblasts through the activation of NF-κB.

The role of the microbiome in exacerbations of chronic lung diseases

Culture-independent microbiological techniques have shown a previously unappreciated complexity to the bacterial microbiome of the respiratory tract that forces reconsideration of the interactions between host, bacteria, and the pathogenesis of exacerbations of chronic lung disease. The composition of the lung microbiome is determined by microbial immigration, elimination, and relative growth rates of its members. All these factors change dramatically in chronic lung disease and further during exacerbations. Exacerbations lack the features of bacterial infections, including increased bacterial burden and decreased diversity of microbial communities. We propose that exacerbations are occasions of respiratory tract dysbiosis--a disorder of the respiratory tract microbial ecosystem with negative effects on host biology. Respiratory tract dysbiosis provokes a dysregulated host immune response, which in turn alters growth conditions for microbes in airways, promoting further dysbiosis and perpetuating a cycle of inflammation and disordered microbiota. Differences in the composition of baseline respiratory tract microbiota might help to explain the so-called frequent-exacerbator phenotype observed in several disease states, and might provide novel targets for therapeutic intervention.

Gastroesophageal reflux disease and patterns of reflux in patients with idiopathic pulmonary fibrosis using hypopharyngeal multichannel intraluminal impedance

Idiopathic pulmonary fibrosis (IPF) is a diffuse fibrotic lung disease of unknown etiology. The association between IPF and gastroesophageal reflux disease (GERD) has been suggested. The objective of this study was to determine the prevalence of GERD and assess the proximity of reflux events in patients with histologically proven IPF using hypopharyngeal multichannel intraluminal impedance (HMII). This is a retrospective review of prospectively collected data from patients with histologically confirmed IPF (via lung biopsy) who underwent objective esophageal physiology testing including high-resolution manometry and HMII. Defective lower esophageal sphincter (LES) was defined as either LES pressure of <5.0 mmHg, total length of LES of <2.4 cm, or intra-abdominal length of LES of <0.9 cm. Abnormal esophageal motility was considered present when failed swallows ≥30% and/or mean wave amplitude <30 mmHg was present. HMII used a specialized impedance catheter to directly measure laryngopharyngeal reflux (LPR) and full column reflux (reflux 2 cm distal to the upper esophageal sphincter). Based on the previous study of healthy subjects, abnormal proximal exposure was considered present when LPR ≥1/day and/or full column reflux ≥5/day were present. From October 2009 to June 2011, 46 patients were identified as having pulmonary fibrosis and sufficient HMII data. Of 46, 10 patients were excluded because of concomitant connective tissue diseases, and 8 patients were excluded because they had undergone lung transplantation, which may impact the patterns of reflux. The remaining 28 patients with histologically confirmed IPF (male 16, female 12) were included in this study. Mean age and BMI were 60.4 years (range, 41-78) and 28.4 (range, 21.1-38.1), respectively. All patients except one were symptomatic; 23 (82%) patients had concomitant typical GERD symptoms such as heartburn, whereas 4 (14%) patients had isolated pulmonary symptoms such as cough. Esophageal mucosal injury such as esophagitis and Barrett's esophagus was found in 17 (71%) patients, whereas hiatal hernia was found in 19 (73%) patients. Abnormal proximal exposure, which occurred almost exclusively in the upright position, was present in 54% (15/28) of patients. There was no significant difference in clinical symptoms, objective findings of GERD, and pulmonary functions such as forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and diffusing capacity of the lung for carbon monoxide (DLCO) between patients with and without abnormal proximal exposure. Although the total number of reflux events was significantly higher in patients with abnormal proximal exposure, a large number of patients had a negative DeMeester score regardless of whether abnormal proximal exposure was present (patients with, 80%; those without, 85%). Patients with abnormal proximal exposure more likely had a defective LES compared with those without (93% vs. 75%). Fourteen patients (56%) had abnormal esophageal motility including aperistaltic esophagus (n = 9). This first study of HMII in patients with IPF demonstrated that GERD is highly prevalent (>70%), and abnormal proximal reflux events such as LPR and full column reflux are common despite a frequently negative DeMeester score. HMII may be beneficial in the work-up of GERD in patients with IPF.

Idiopathic pulmonary fibrosis: evolving concepts

Idiopathic pulmonary fibrosis (IPF) occurs predominantly in middle-aged and older adults and accounts for 20% to 30% of interstitial lung diseases. It is usually progressive, resulting in respiratory failure and death. Diagnostic criteria for IPF have evolved over the years, and IPF is currently defined as a disease characterized by the histopathologic pattern of usual interstitial pneumonia occurring in the absence of an identifiable cause of lung injury. Understanding of the pathogenesis of IPF has shifted away from chronic inflammation and toward dysregulated fibroproliferative repair in response to alveolar epithelial injury. Idiopathic pulmonary fibrosis is likely a heterogeneous disorder caused by various interactions between genetic components and environmental exposures. High-resolution computed tomography can be diagnostic in the presence of typical findings such as bilateral reticular opacities associated with traction bronchiectasis/bronchiolectasis in a predominantly basal and subpleural distribution, along with subpleural honeycombing. In other circumstances, a surgical lung biopsy may be needed. The clinical course of IPF can be unpredictable and may be punctuated by acute deteriorations (acute exacerbation). Although progress continues in unraveling the mechanisms of IPF, effective therapy has remained elusive. Thus, clinicians and patients need to reach informed decisions regarding management options including lung transplant. The findings in this review were based on a literature search of PubMed using the search terms idiopathic pulmonary fibrosis and usual interstitial pneumonia, limited to human studies in the English language published from January 1, 2000, through December 31, 2013, and supplemented by key references published before the year 2000.

Sleep in patients with restrictive lung disease

Restrictive lung disease leads to ventilatory defects and diffusion impairments. These changes may contribute to abnormal nocturnal pathophysiology, including sleep architecture disruption and impaired ventilation and oxygenation. Patients with restrictive lung disease may suffer significant daytime fatigue and dysfunction. Hypercarbia and hypoxemia during sleep may impact progression of lung disease and related symptoms. Little is known about the impact of treatment of sleep disruption on sleep quality and overall prognosis in restrictive lung disease. This review discusses the pathophysiology of sleep and comorbid sleep disorders in restrictive lung diseases including interstitial lung disease, neuromuscular disease, and obesity hypoventilation syndrome.

Long-term results of electrical stimulation of the lower esophageal sphincter for treatment of proximal GERD

INTRODUCTION

Electrical stimulation of the lower esophageal sphincter (LES) in gastroesophageal reflux disease (GERD) patients, using EndoStim(®) LES stimulation system (EndoStim BV, the Hague, Netherlands), enhances LES pressure, decrease distal esophageal acid exposure, improves symptoms, and eliminates the need in many patients for daily GERD medications.

AIM

To evaluate, in a post hoc analysis, the effect of LES stimulation on proximal esophageal acid exposure in a subgroup of patients with abnormal proximal esophageal acid exposure.

METHODS

Nineteen patients (median age 54 years; IQR 47-64; men-10) with GERD partially responsive to proton pump inhibitors (PPI), hiatal hernia ≤ 3 cm, esophagitis ≤ LA grade C underwent laparoscopic implantation of the LES stimulator. LES stimulation at 20 Hz, 215 μs, 5-8 m Amp sessions was delivered in 6-12, 30 min sessions each day. Esophageal pH at baseline and after 12-months of LES stimulation was measured 5 and 23 cm above the manometric upper border of LES.

RESULTS

Total, upright and supine values of median (IQR) proximal esophageal pH at baseline were 0.4 (0.1-1.4), 0.6 (0.2-2.3), and 0 (0.0-0.2) %, respectively, and at 12 months on LES-EST were 0 (0-0) % (p = 0.001 total and upright; p = 0.043 supine comparisons). 24-hour distal esophageal acid exposure improved from 10.2 (7.6-11.7) to 3.4 (1.6-7.0) % (p = 0.001). Seven (37%) patients had abnormal (>1.1%) 24-hour proximal acid exposure at baseline; all normalized at 12 months (p = 0.008). In these 7 patients, total, upright, and supine median proximal acid exposure values at baseline were 1.7 (1.3-4.1), 2.9 (1.9-3.7), and 0.3 (0-4.9) %, respectively, and after 12 months of LES-EST were 0 (0-0.0), 0 (0-0.1), and 0 (0-0) % (p = 0.018 total and upright; p = 0.043 supine comparisons). Distal esophageal pH for this group improved from 9.3 (7.8-17.2) at baseline to 3.2 (1.1-3.7) % at 12-months (p = 0.043). There were no GI side effects such as dysphagia, gas-bloat or diarrhea or device or procedure related serious adverse events with LES-EST. There was also a significant improvement in their GERD-HRQL scores.

CONCLUSION

LES-EST is associated with normalization of proximal esophageal pH in patients with GERD and may be useful in treating those with proximal GERD. The LES-EST is safe without typical side effects associated with traditional antireflux surgery.

Idiopathic pulmonary fibrosis in Saudi Arabia: Demographic, clinical, and survival data from two tertiary care hospitals

BACKGROUND:

Idiopathic pulmonary fibrosis (IPF) is rare and can be challenging to diagnose. Limited data is available from the Middle Eastern region, especially Saudi Arabia.

METHODS:

This was a retrospective study that looked at all the patients diagnosed with IPF between 2007 and 2012 at two tertiary care hospitals in Saudi Arabia. We collected the demographical, clinical, laboratory and radiological data from the patients’ medical records. Medications administered and 1 year survival was also assessed.

RESULTS:

Between 2007and 2012, 134 IPF patients were identified. Their baseline characteristics (Mean ± SD) included: age 64 ± 13 years, body mass index 29 ± 8 kg/m², FEV₁ 56 ± 15 percent of predicted, FVC 53 ± 13 percent of predicted, FEV₁/FVC 0.81 ± 0.09, total lung capacity 75 ± 13 percent of predicted, diffusing capacity of the lung for carbon monoxide 57 ± 15 percent of predicted, on home oxygen at presentation 71 (53%), mean ejection fraction 0.50 ± 0.07, mean pulmonary artery systolic pressure (via echocardiogram) 40 + 22 mmHg, presentation mean S_pO292 ± 7%, presentation 6-min walk distance 338 ± 64 m and lowest S_pO2 during 6-min walk test 88 ± 5%. Patients were predominantly female (56%), and 42% of patients had diabetes and were active smokers. The IPF patients’ frequency of hospital admission (n = 99) was 2.4 ± 1.7 per year and duration of hospital stay (n = 99) was 17.4 ± 23.8 days. Overall 1 year survival in all IPF patients was good, 93% (124) patients remained alive after 1 year.

CONCLUSIONS:

In Saudi Arabia, IPF patients tended to be slightly older and the disease progression was somewhat slower than reported IPF cohorts in other populations. They had frequent hospital admissions and a long hospital length of stay. The influence of genetics and co-morbid diseases on the incidence and outcome of IPF should be explored further.

Effect of acid suppression therapy on gastroesophageal reflux and cough in idiopathic pulmonary fibrosis: an intervention study

Background

Chronic cough affects more than 70 percent of patients with Idiopathic Pulmonary Fibrosis and causes significant morbidity. Gastroesophageal reflux is the cause of some cases of chronic cough; and also has a postulated role in the aetiology of Idiopathic Pulmonary Fibrosis. A high prevalence of acid; and more recently non-acid, reflux has been observed in Idiopathic Pulmonary Fibrosis cohorts. Therefore, gastroesophageal reflux may be implicated in the pathogenesis of cough in Idiopathic Pulmonary Fibrosis.

Methods

Eighteen subjects with Idiopathic Pulmonary Fibrosis underwent 24-hour oesophageal impedance and cough count monitoring after the careful exclusion of causes of chronic cough other than gastroesophageal reflux. All 18 were then treated with high dose acid suppression therapies. Fourteen subjects underwent repeat 24-hour oesophageal impedance and cough count monitoring after eight weeks.

Results

Total reflux and acid reflux frequencies were within the normal range in the majority of this cohort. The frequencies of non-acid and proximal reflux events were above the normal range. Following high dose acid suppression therapy there was a significant decrease in the number of acid reflux events (p = 0.02), but an increase in the number of non-acid reflux events (p = 0.01). There was no change in cough frequency (p = 0.70).

Conclusions

This study confirms that non-acid reflux is prevalent; and that proximal oesophageal reflux occurs in the majority, of subjects with Idiopathic Pulmonary Fibrosis. It is the first study to investigate the effect of acid suppression therapy on gastroesophageal reflux and cough in patients with Idiopathic Pulmonary Fibrosis. The observation that cough frequency does not improve despite verifiable reductions in oesophageal acid exposure challenges the role of acid reflux in Idiopathic Pulmonary Fibrosis associated cough. The finding that non-acid reflux is increased following the use of acid suppression therapies cautions against the widespread use of acid suppression in patients with Idiopathic Pulmonary Fibrosis given the potential role for non-acid reflux in the pathogenesis of cough and Idiopathic Pulmonary Fibrosis itself.

Study registration

The study was registered with the Cardiff and Vale University Local Health Board Research and Development Committee (09/CMC/4619) and the South East Wales Ethics Committee (09/WSE04/57).

Regulation of TGF-β1-driven differentiation of human lung fibroblasts: emerging roles of cathepsin B and cystatin C

Lung matrix homeostasis partly depends on the fine regulation of proteolytic activities. We examined the expression of human cysteine cathepsins (Cats) and their relative contribution to TGF-β1-induced fibroblast differentiation into myofibroblasts. Assays were conducted using both primary fibroblasts obtained from patients with idiopathic pulmonary fibrosis and human lung CCD-19Lu fibroblasts. Pharmacological inhibition and genetic silencing of Cat B diminished α-smooth muscle actin expression, delayed fibroblast differentiation, and led to an accumulation of intracellular 50-kDa TGF-β1. Moreover, the addition of Cat B generated a 25-kDa mature form of TGF-β1 in Cat B siRNA-pretreated lysates. Inhibition of Cat B decreased Smad 2/3 phosphorylation but had no effect on p38 MAPK and JNK phosphorylation, indicating that Cat B mostly disturbs TGF-β1-driven canonical Smad signaling pathway. Although mRNA expression of cystatin C was stable, its secretion, which was inhibited by brefeldin A, increased during TGF-β1-induced differentiation of idiopathic pulmonary fibrosis and CCD-19Lu fibroblasts. In addition, cystatin C participated in the control of extracellular Cats, because its gene silencing restored their proteolytic activities. These data support the notion that Cat B participates in lung myofibrogenesis as suggested for stellate cells during liver fibrosis. Moreover, we propose that TGF-β1 promotes fibrosis by driving the effective cystatin C-dependent inhibition of extracellular matrix-degrading Cats.

A roadmap to promote clinical and translational research in rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis (RA) is a systemic inflammatory disorder affecting approximately 1.3 million adults in the United States. Approximately 10% of these individuals with RA have clinically evident interstitial lung disease (RA-ILD), and an additional one-third demonstrate subclinical ILD on chest CT scan. The risk of death for individuals with RA-ILD is three times higher than for patients with RA without ILD, with a median survival after ILD diagnosis of only 2.6 years. Despite the high prevalence and mortality of RA-ILD, little is known about its molecular features and its natural history. At present, we lack a standard validated approach to the definition, diagnosis, risk stratification, and management of RA-ILD. In this perspective, we discuss the importance of clinical and translational research and how ongoing research efforts can address important gaps in our knowledge over the next few years. Furthermore, recommendations are made to design multicenter collaborative studies that will expedite the development of clinical trials designed to decrease the significant morbidity and mortality associated with RA-ILD.

Measuring response in the gastrointestinal tract in systemic sclerosis

PURPOSE OF REVIEW

Gastrointestinal tract (GIT) involvement in systemic sclerosis (scleroderma, SSc) is the most common internal complication. This review discusses the outcome measures to capture GIT involvement in clinical care and trials.

RECENT FINDINGS

Patient-reported outcome measures have been validated (UCLA Scleroderma Clinical Trial Consortium GIT 2.0 and NIH PROMIS scales) in SSc-GIT. Multiple objective measures are available to assess mucosal involvement and motility in GIT. However, these need to be validated in SSc for trials.

SUMMARY

GIT is a common cause of morbidity and has negative impact on quality of life in SSc. Recommendations are given for trial design and evaluation of GIT involvement in SSc.

Lung microbiome and disease progression in idiopathic pulmonary fibrosis: an analysis of the COMET study

BACKGROUND

The role of the lung microbiome in the pathogenesis of idiopathic pulmonary fibrosis is unknown. We investigated whether unique microbial signatures were associated with progression of idiopathic pulmonary fibrosis.

METHODS

Patients (aged 35-80 years) with idiopathic pulmonary fibrosis within 4 years of diagnosis from the Correlating Outcomes with biochemical Markers to Estimate Time-progression (COMET) in idiopathic pulmonary fibrosis study were followed up for a maximum of 80 weeks. Progression-free survival was defined as time to death, acute exacerbation, lung transplant, or decrease in forced vital capacity (FVC) of 10% or greater or decrease in diffusion capacity of the lung (DLCO) of 15% or greater. DNA was isolated from 55 samples of bronchoscopic alveolar lavage. 454 pyrosequencing was used to assign operational taxonomic units (OTUs) to bacteria based on a 3% sequence divergence. Adjusted Cox models were used to identify OTUs that were significantly associated with progression-free survival at a p<0.10. These OTUs were then used in the analysis of the principal components. The association between principal components and microbes with high factor loadings and progression-free survival were assessed with Cox regression analyses. The COMET study is registered with ClinicalTrials.gov, number NCT01071707.

FINDINGS

Mean FVC was 70.1% (SD 17.0) and DLCO 42.3% (14.0) of predicted. Disease progression was significantly associated with increased relative abundance of two OTUs-Streptococcus OTU 1345 (relative risk 1.11, 95% CI 1.04-1.18; p=0.0009) and Staphylococcus OTU 1348 (1.16, 1.03-1.31, p=0.012). Thresholds for relative abundance of each OTU associated with progression-free survival were more than 3.9% for Streptococcus OTU 1345 (10.19, 2.94-35.35; p=0.0002) and more than 1.8% for Staphylococcus OTU 1348 (5.06, 1.71-14.93; p=0.003).

INTERPRETATION

These preliminary data suggest progression of idiopathic pulmonary fibrosis is associated with the presence of specific members within the Staphylococcus and Streptococcus genera. Additional research will be needed to identify the specific bacterial species and to ascertain whether this is a causal association.

FUNDING

National Institutes of Health.

Idiopathic pulmonary fibrosis: early detection and referral

Idiopathic pulmonary fibrosis (IPF), a devastating progressive interstitial lung disease (ILD) with no known cause or cure, is the most common and deadly of the idiopathic interstitial pneumonias. With a median survival of 3-5 years following diagnosis, IPF is characterized by a progressive decline in lung function and quality of life in most patients. Vigilance among clinicians in recognizing IPF early in the disease course remains critical to properly caring for these patients, as this provides the widest range of management options. When IPF is suspected, a multidisciplinary evaluation (MDE) by a clinician, radiologist and pathologist with ILD expertise should occur, as this improves diagnostic agreement in both community and academic settings. When community MDE is not possible, or diagnostic doubt exists, referral to an ILD center should be considered. ILD center referral may also provide access specialized care, including clinical trials and lung transplantation, and should be considered for any patient with an established diagnosis of IPF.

Severity of cough in idiopathic pulmonary fibrosis is associated with MUC5 B genotype

Background

A polymorphism (rs35705950) in the promoter region of the mucin MUC5B is associated with both familial and sporadic forms of idiopathic pulmonary fibrosis. (IPF) We hypothesize that this common MUC5B variant will impact the expression of cough, a frequent disabling symptom seen in subjects with IPF.

Methods

We genotyped 136 subjects with IPF. All living subjects were provided with a Leicester Cough Questionnaire (LCQ) to measure cough severity. We assessed allele effects of the MUC5B polymorphism on the LCQ scores using SAS General Linear Models (GLM) in the patients with IPF.

Results

In the 68 of the total 136 IPF patients who returned the LCQ, MUC5B minor allele frequency (T) is consistent with prior published studies (31%). We found a significant independent effect of the T allele on the LCQ score (p = 0.002 for subjects with IPF). This effect is independent of other common causes of cough, including gastroesophogeal reflux disease and upper airway cough syndrome.

Conclusions

Cough severity, a common disabling phenotypic component of IPF, is significantly associated with the presence of the minor allele of a MUC5B promoter polymorphism. This study highlights a possible genetic mechanism for phenotypic heterogeneity in pulmonary fibrosis.

Idiopathic pulmonary fibrosis acute exacerbations: where are we now?

Considerable controversy is haunting the treatment of IPF 'acute exacerbation', its most devastating complication. The consensus coined term 'acute exacerbation' implies that on an unknown etiology disease such as IPF, an unknown etiology superimposed acute lung injury/acute respiratory distress syndrome (ALI/ARDS) represents the end-life event in a consistent proportion of patients and are treated by high dose steroids despite unproven benefit. Inversely, ALI/ARDS treatment recommendations are based on the provision of excellent supportive care plus an extensive search and appropriate treatment of the etiologic precipitant and all intensive care clinicians in the absence of an obvious etiology, considering that occult infection is the most probable and also the most treatable underlying condition, universally administer extensive spectrum antimicrobials. Viewing the persistent high mortality in IPF 'acute exacerbations' treated with steroids we strongly believe that a study comparing the two arms of the steroid and non-steroid approach is greatly awaited by scientists and owed to the patients.

Identification and treatment of comorbidities in idiopathic pulmonary fibrosis and other fibrotic lung diseases

PURPOSE OF REVIEW

The interstitial lung diseases (ILDs) frequently result in considerable disability and reduced survival in affected patients. Unfortunately, they are often poorly responsive to available therapies. Comorbidities, both pulmonary and nonpulmonary, frequently accompany ILDs and contribute to adverse outcomes.

RECENT FINDINGS

Multiple comorbidities, including gastroesophageal reflux disease, venous thromboembolism, coronary artery disease, sleep-disordered breathing, depression, emphysema, pulmonary hypertension, and lung cancer contribute to the morbidity and mortality of fibrotic lung disease.

SUMMARY

The identification and treatment of comorbidities may improve morbidity and potentially impact mortality in patients with ILD. A high index of suspicion and an awareness of the spectrum of comorbidities are important in optimizing outcomes in this group of patients.

Bronchoalveolar pH and inflammatory biomarkers in newly diagnosed IPF and GERD patients: a case-control study

Background

Several studies have suggested that idiopathic pulmonary fibrosis (IPF) may be related to repeated aspiration of gastric contents over long periods of time. We aimed to investigate differences between pH measured directly in the lung, and biomarkers of acute inflammation in patients with newly diagnosed IPF and in patients with newly diagnosed GERD.

Material/Methods

All subjects (N=61) underwent collection of medical history, physical examination, pulmonary function testing, bronchoscopy, endoscopy, arterial blood gas analyses, and biochemical testing.

Results

Previously diagnosed GERD was found in 56.7%, typical symptoms of reflux in 80%, and Helicobacter pylori in gastric biopsy specimens in 76.6% of the cases. pH in peripheral branches of bronchi in the cases was 5.32±0.44 and was 6.27±0.31 (p<0.001) in the control group. The average values of LDH, ALP, and CRP in bronchoalveolar aspirate and in serum, as well as TNF-α in bronchoalveolar aspirate, were significantly higher in IPF patients.

Conclusions

The more acidic environment in the bronchoalveolar aspirate of the IPF subjects could contribute to the development or progression of IPF, possibly via changes in local metabolism or by damaging local cells and tissue. However, further studies with larger numbers of patients are required to clarify the role of gastric fluid aspiration in IPF pathogenesis. Our preliminary work has identified inflammatory biomarkers LDH, ALP, and TNF-α as potentially important in the pathologic processes in IPF. Further research is needed to determine their importance in clinical intervention and patient care.

New approaches to modulating idiopathic pulmonary fibrosis

Until recently, idiopathic pulmonary fibrosis (IPF) has been a devastating and generally fatal disease with no effective therapeutic. New developments in understanding the biology of the disease include a growing consensus that the lesions are mainly composed of cells that originated from resident fibroblasts. New developments in therapeutics include recommendations against several treatment regimes that have been previously used. On a positive note, the orally available drug pirfenidone has been approved for use in IPF in China, Japan, India, and the European Union, but not yet in the United States. Other possibilities for managing IPF include managing gastrointestinal reflux, and limiting excessive salt intake. A variety of potential therapeutics for IPF are in clinical trials; for instance, in a Phase 1b trial, intravenous injections of a recombinant version of the normal human serum protein Serum Amyloid P (SAP, also known as PTX2) improved lung function in IPF patients.

Lysophosphatidic acid receptor-2 deficiency confers protection against bleomycin-induced lung injury and fibrosis in mice

Idiopathic pulmonary fibrosis is a devastating disease characterized by alveolar epithelial cell injury, the accumulation of fibroblasts/myofibroblasts, and the deposition of extracellular matrix proteins. Lysophosphatidic acid (LPA) signaling through its G protein-coupled receptors is critical for its various biological functions. Recently, LPA and LPA receptor 1 were implicated in lung fibrogenesis. However, the role of other LPA receptors in fibrosis remains unclear. Here, we use a bleomycin-induced pulmonary fibrosis model to investigate the roles of LPA2 in pulmonary fibrogenesis. In the present study, we found that LPA2 knockout (Lpar2(-/-)) mice were protected against bleomycin-induced lung injury, fibrosis, and mortality, compared with wild-type control mice. Furthermore, LPA2 deficiency attenuated the bleomycin-induced expression of fibronectin (FN), α-smooth muscle actin (α-SMA), and collagen in lung tissue, as well as levels of IL-6, transforming growth factor-β (TGF-β), and total protein in bronchoalveolar lavage fluid. In human lung fibroblasts, the knockdown of LPA2 attenuated the LPA-induced expression of TGF-β1 and the differentiation of lung fibroblasts to myofibroblasts, resulting in the decreased expression of FN, α-SMA, and collagen, as well as decreased activation of extracellular regulated kinase 1/2, Akt, Smad3, and p38 mitogen-activated protein kinase. Moreover, the knockdown of LPA2 with small interfering RNA also mitigated the TGF-β1-induced differentiation of lung fibroblasts. In addition, LPA2 deficiency significantly attenuated the bleomycin-induced apoptosis of alveolar and bronchial epithelial cells in the mouse lung. Together, our data indicate that the knockdown of LPA2 attenuated bleomycin-induced lung injury and pulmonary fibrosis, and this may be related to an inhibition of the LPA-induced expression of TGF-β and the activation and differentiation of fibroblasts.

Idiopathic pulmonary fibrosis and gastroesophageal reflux. Implications for treatment

BACKGROUND

Even though the pathogenesis of idiopathic pulmonary fibrosis (IPF) is unknown, there is mounting evidence that abnormal reflux (GERD) and aspiration of gastric contents may play a role in the pathogenesis of this disease.

AIMS

The aims of this study were to determine in patients with GERD and IPF: (a) the clinical presentation, (b) the esophageal function, and (c) the reflux profile.

METHODS

We compared the clinical presentation, the esophageal function (as defined by high-resolution manometry), and the reflux profile (by dual sensor pH monitoring) in 80 patients with GERD (group A) and in 22 patients with GERD and IPF (group B).

RESULTS

Heartburn was present in less than 60 % of patients with GERD and IPF. Lower esophageal sphincter pressure and peristalsis were normal in both groups, while the upper esophageal sphincter (UES) was more frequently hypotensive in IPF patients (p = 0.008). In patients with GERD and IPF, the proximal esophageal acid exposure was higher (p = 0.047) and the supine acid clearance was slower as compared with patients with GERD only (p < 0.001).

CONCLUSIONS

The results of this study show that in patients with GERD and IPF: (a) reflux is frequently silent, (b) with the exception of a weaker UES, the esophageal function is preserved, and (c) proximal reflux is more common, and in the supine position, it is coupled with a slower acid clearance. Because these factors predisposing IPF patients to the risk of aspiration, antireflux surgery should be considered early after the diagnosis of IPF and GERD is established.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis: A Proposal

Acute exacerbation of idiopathic pulmonary fibrosis (IPF) occurs in roughly 10% of patients annually, and is a leading cause of morbidity and mortality in this disease. While currently defined as idiopathic acute worsenings, acute exacerbations of IPF may in fact have a variety of causes, in particular infection and aspiration. Central to the pathobiology of clinically meaningful events is a diffuse injury to the IPF lung manifest histopathologically as diffuse alveolar damage, and biologically as accelerated alveolar epithelial cell injury or repair. Based on these recent observations, we propose a new paradigm for acute exacerbation of IPF that removes the idiopathic requirement and focuses on the pathophysiological mechanism involved.

Epidemiology of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic fibrotic lung disease of unknown cause that occurs in adults and has a poor prognosis. Its epidemiology has been difficult to study because of its rarity and evolution in diagnostic and coding practices. Though uncommon, it is likely underappreciated both in terms of its occurrence (ie, incidence, prevalence) and public health impact (ie, health care costs and resource utilization). Incidence and mortality appear to be on the rise, and prevalence is expected to increase with the aging population. Potential risk factors include occupational and environmental exposures, tobacco smoking, gastroesophageal reflux, and genetic factors. An accurate understanding of its epidemiology is important, especially as novel therapies are emerging.

Human cystatin C: a new biomarker of idiopathic pulmonary fibrosis?

PURPOSE

Human idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disorder with a poor prognosis. The identification of a new and specific biomarker in bronchoalveolar lavage fluids (BALFs) may assist in the diagnosis of the disease.

EXPERIMENTAL DESIGN

Characterization of cysteine Cats and their endogenous inhibitor, cystatin C, was conducted by immunochemical analysis and measurement of endopeptidase activity of control (n = 11) and IPF (n = 25) BALFs (normalized conditions, 20 μg protein/assay).

RESULTS

Cathepsin (Cat) B was detected as proform and mature enzyme for both control and IPF samples, while Cats K, L, and S were found as zymogens with a strengthened staining in IPF BALFs. The overall endopeptidase activity related mainly to Cat B and did not vary significantly between control and IPF samples. Conversely a significant increase of immunoreactive cystatin C was measured in BALFs for each of three IPF grades.

CONCLUSIONS AND CLINICAL RELEVANCE

An excessive deposition of extracellular matrix proteins is the hallmark of fibrotic disorders. Cats are potent collagenases and might be essential for lung homeostasis. Taken together, increase of cystatin C in IPF BALFs may reflect abnormal regulation of proteolytic activity of Cats in lung, which in turn can promote the development of fibrosis.

Is the sinonasal questionnaire a useful screening instrument for chronic sinonasal diseases in pulmonary clinics?

Dixon and coworkers (Dixon AE, Sugar EA, Zinreich SJ, et al. Criteria to screen for chronic sinonasal disease. Chest 2009; 136: 1324-1332.) recently developed a five-item questionnaire for diagnosing chronic sinonasal disease in patients with asthma. Our study was designed to determine how frequently patients attending pulmonary clinics have chronic sinonasal disease and the relationship between questionnaire results and a history of sinus disease and current treatment for sinus disease. The participants were patients in pulmonary clinics at Texas Tech University Health Science Center, who answered the sinonasal questionnaire (SNQ). Additional information included a history of sinus disease or sinus/nasal surgery, smoking status, and current relevant medications. The participants included 28 men and 51 women. Patient ages ranged from 38 to 94 years (mean 62.2 years). Of all the patients, 28 patients (35.4%) had prior sinus disease, 10 (12.7%) had history of sinus or nasal surgery, 24 (30.4%) had history of asthma, and 10 (12.7%) were current smokers. Of them, 14 patients (17.7%) used nasal steroids, 12 (15.2%) used antihistamines, four (5.1%) used decongestants, nine (11.4%) used leukotriene inhibitors, 13 (16.5%) used oral corticosteroids, and two (2.5%) used combinations. The SNQ identified 39 patients (49.4%) as having chronic sinonasal diseases. Therefore, 14% of the participants had sinonasal symptoms but no prior diagnosis of sinus disease. Patients with prior sinus disease and nasal steroid use were more likely to have positive questionnaire result (p<0.001 and p<0.032, respectively). The SNQ can identify patients with chronic sinonasal disease in pulmonary clinics. However, the significance of sinonasal disease and its treatment in these patients needs more study.

Pathogenesis of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial lung disease associated with aging that is characterized by the histopathological pattern of usual interstitial pneumonia. Although an understanding of the pathogenesis of IPF is incomplete, recent advances delineating specific clinical and pathologic features of IPF have led to better definition of the molecular pathways that are pathologically activated in the disease. In this review we highlight several of these advances, with a focus on genetic predisposition to IPF and how genetic changes, which occur primarily in epithelial cells, lead to activation of profibrotic pathways in epithelial cells. We then discuss the pathologic changes within IPF fibroblasts and the extracellular matrix, and we conclude with a summary of how these profibrotic pathways may be interrelated.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation of idiopathic pulmonary fibrosis (IPF) is a clinically important complication of IPF that carries a high morbidity and mortality. In the last decade, we have learned much about this event, but there are many remaining questions: What is it? Why does it happen? How can we prevent it? How can we treat it? This chapter attempts to summarize our current understanding of the epidemiology, etiology, and management of acute exacerbation of IPF and point out areas where additional data are sorely needed.

The role of the adenosinergic system in lung fibrosis

Adenosine (ADO) is a retaliatory metabolite that is expressed in conditions of injury or stress. During these conditions ATP is released at the extracellular level and is metabolized to adenosine. For this reason, adenosine is defined as a "danger signal" for cells and organs, in addition to its important role as homeostatic regulator. Its physiological functions are mediated through interaction with four specific transmembrane receptors called ADORA1, ADORA2A, ADORA2B and ADORA3. In the lungs of mice and humans all four adenosine receptors are expressed with different roles, having pro- and anti-inflammatory roles, determining bronchoconstriction and regulating lung inflammation and airway remodeling. Adenosine receptors can also promote differentiation of lung fibroblasts into myofibroblasts, typical of the fibrotic event. This last function suggests a potential involvement of adenosine in the fibrotic lung disease processes, which are characterized by different degrees of inflammation and fibrosis. Idiopathic pulmonary fibrosis (IPF) is the pathology with the highest degree of fibrosis and is of unknown etiology and burdened by lack of effective treatments in humans.

The pulmonary side of reflux disease: from heartburn to lung fibrosis

INTRODUCTION

Gastroesophageal reflux disease (GERD) is the most prevalent gastrointestinal disorder in the USA. Heartburn is the symptom most commonly associated with this disease, and the highly commercialized medical treatment directed toward relief of this symptom represents a 10-billion-dollar-per-year industry.

DISCUSSION

Unfortunately, there is often little awareness that GERD can be potentially a lethal disease as it can cause esophageal cancer. Furthermore, there is even less awareness about the relationship between GERD and respiratory disorders with the potential for severe morbidity and even mortality.

Depression in patients with idiopathic pulmonary fibrosis

Depression carries enormous global morbidity and is 1.5–7 times likelier to occur in individuals with chronic illness than in the general population. Idiopathic pulmonary fibrosis (IPF) has a rising incidence with a severe impact on quality of life. An indication of the prevalence of depression in this group is therefore of paramount interest. A prospective study was performed. A total of 118 participants with IPF who attended the interstitial lung disease clinic in Ninewells Hospitals, Dundee, Scotland, from May 2010 to September 2011 were recruited. Informed consent was obtained. The male to female ratio was 60:58. The Wakefield Self-assessment of Depression Inventory was used (scores ≥15 denote a depressed state). Pulmonary function tests were measured to correlate disease severity with depression scores. Of them, 58 patients had significant depressive symptoms scoring ≥15; only nine were taking antidepressant medication. The mean depression score of female participants was 15.0 ± 0.77 (SD 5.9), compared with a mean male score of 13.1 ± 0.99 (SD 7.5). Disease severity, age, duration since diagnosis and number of co-morbidities were not significantly correlated with depression. The study population had a high prevalence of depressive symptoms. Medical therapy for pulmonary fibrosis is limited and therefore palliation of symptoms and pulmonary rehabilitation form the main strategy for management. Depression should be actively screened in patients with IPF.

Pepsin concentrations are elevated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis after lung transplantation

BACKGROUND

Aspiration of gastroesophageal refluxate has been implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and the progression of bronchiolitis obliterans syndrome after lung transplantation. The goals of the present study were to identify lung transplant patients at the greatest risk of aspiration and to investigate the causative factors.

MATERIALS AND METHODS

From September 2009 to November 2011, 252 bronchoalveolar lavage fluid (BALF) samples were collected from 100 lung transplant patients. The BALF pepsin concentrations and the results of transbronchial biopsy, esophageal function testing, barium swallow, and gastric emptying scan were compared among those with the most common end-stage lung diseases requiring lung transplantation: IPF, chronic obstructive pulmonary disease, cystic fibrosis, and α1-antitrypsin deficiency.

RESULTS

Patients with IPF had higher BALF pepsin concentrations and a greater frequency of acute rejection than those with α1-antitrypsin deficiency, cystic fibrosis, or chronic obstructive pulmonary disease (P = 0.037). Moreover, the BALF pepsin concentrations correlated negatively with a lower esophageal sphincter pressure and distal esophageal amplitude; negatively with distal esophageal amplitude and positively with total esophageal acid time, longest reflux episode, and DeMeester score in those with chronic obstructive pulmonary disease; and negatively with the upright acid clearance time in those with IPF.

CONCLUSIONS

Our results suggest that patients with IPF after lung transplantation are at increased risk of aspiration and a greater frequency of acute rejection episodes, and that the risk factors for aspiration might be different among those with the most common end-stage lung diseases who have undergone lung transplantation. These results support the role of evaluating the BALF for markers of aspiration in assessing lung transplant patients as candidates for antireflux surgery.

Anti-acid treatment and disease progression in idiopathic pulmonary fibrosis: an analysis of data from three randomised controlled trials

BACKGROUND

Abnormal acid gastro-oesophageal reflux is common in patients with idiopathic pulmonary fibrosis (IPF) and is considered a risk factor for development of IPF. Retrospective studies have shown improved outcomes in patients given anti-acid treatment. The aim of this study was to investigate the association between anti-acid treatment and disease progression in IPF.

METHODS

In an analysis of data from three randomised controlled trials, we identified patients with IPF assigned to receive placebo. Case report forms had been designed to prospectively obtain data about diagnosis and treatment of abnormal acid gastro-oesophageal reflux in each trial. The primary outcome was estimated change in forced vital capacity (FVC) at 30 weeks (mean follow-up) in patients who were and were not using a proton-pump inhibitor or histamine-receptor-2 (H2) blocker.

FINDINGS

Of the 242 patients randomly assigned to the placebo groups of the three trials, 124 (51%) were taking a proton-pump inhibitor or H2 blocker at enrolment. After adjustment for sex, baseline FVC as a percentage of predicted, and baseline diffusing capacity of the lung for carbon monoxide as a percentage of predicted, patients taking anti-acid treatment at baseline had a smaller decrease in FVC at 30 weeks (-0·06 L, 95% CI -0·11 to -0·01) than did those not taking anti-acid treatment (-0·12 L, -0·17 to -0·08; difference 0·07 L, 95% CI 0-0·14; p=0·05).

INTERPRETATION

Anti-acid treatment could be beneficial in patients with IPF, and abnormal acid gastro-oesophageal reflux seems to contribute to disease progression. Controlled clinical trials of anti-acid treatments are now needed.

FUNDING

National Institutes of Health.

Gastro-oesophageal reflux and respiratory symptoms in Busselton adults: the effects of bodyweight and sleep apnoea

BACKGROUND/AIM

Respiratory symptoms and gastro-oesophageal reflux disease (GORD) are common within the general population. Although a number of epidemiological studies have addressed their relationship, none has investigated the confounding effects of body mass index (BMI) and obstructive sleep apnoea (OSA), both of which are associated with reflux.

METHODS

Men and women (2700) from the 2005-2007 cross-sectional Busselton health survey were included. Questionnaire data included demography, information on general health, asthma, cough, wheeze, dyspnoea and reflux symptoms (never, monthly or less often and weekly or more often). BMI, risk of OSA (Berlin questionnaire definition), spirometry and airway hyperresponsiveness (AHR) were recorded. The effects of BMI and OSA on the relationship between respiratory and reflux symptoms were examined using logistic regression models, expressed as adjusted odds ratios for risk of respiratory symptoms by reflux symptom category.

RESULTS

Fifty per cent had reflux symptoms (5-10% weekly or more often). Reflux symptoms had strong positive, dose-related associations with cough/phlegm, breathlessness, chest tightness and wheeze in the last 12 months (P < 0.001), but were not related to diagnosed asthma or AHR. Twenty-three per cent were at high risk of OSA and 63% had a BMI of >25 (22% > 30). Increased weight or high risk of OSA did not affect the relationship between respiratory symptoms and reflux symptoms.

CONCLUSION

The relationship between reflux and respiratory symptoms was independent of BMI, high risk of OSA or AHR. These findings suggest that reflux contributes directly to respiratory symptoms.

Association of gastroesophageal factors and worsening of forced vital capacity in systemic sclerosis

OBJECTIVE

Interstitial lung disease (ILD) is a common complication of systemic sclerosis (SSc) and causes death. Once lung fibrosis occurs, disease course may become stable or decline. Little is known about risks for progression. We studied SSc-gastroesophageal (GE) involvement in relation to worsening forced vital capacity (FVC) on pulmonary function tests (PFT) to investigate whether it was related to progression. Our objective was to determine whether GE reflux and dysphagia are associated with progressive moderate/severe ILD as measured by PFT over 3 years.

METHODS

The Canadian Scleroderma Research Group is a multicenter SSc database that collects data annually. Using indicators of GE involvement and annual PFT, comparisons were made between no/mild ILD, stable moderate/severe ILD, and progressive moderate/severe ILD groups based on changes of FVC. Multivariate analyses determined associations between GE factors and ILD development and progression.

RESULTS

There were 1043 patients with SSc (mean age 55.7 yrs, mean disease duration 10.8 yrs); one-quarter had pulmonary fibrosis on chest radiograph that was related to FVC percentage predicted (Spearman's rho -0.39; p < 0.01). Physician indicators such as esophageal dysmotility (p = 0.009) and postesophageal dilatation (p = 0.041), and patient indicators such as difficulty swallowing (p = 0.016) and waking up choking (p = 0.026) were associated with low FVC. In comparing progressive and stable moderate/severe FVC (< 70% predicted), early satiety (p = 0.018) and a combination term of postdilatation and choking (p = 0.042) increased risk of progression of ILD. Topoisomerase I was not associated with progression over followup.

CONCLUSION

Symptoms of esophageal dysmotility were associated with worsening FVC in SSc, especially if both need for esophageal dilatation and choking were present.