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

Epidemiology of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), a common disorder in Western society, is less seen in Asian countries, but there is an evidence that the incidence of GERD and its complications is rising. Many factors are believed to be responsible for the pathogenesis of GERD. In addition to some recognized factors, the role of other factors, such as obesity and Helicobacter pylori infection, in the pathogenesis of GERD is still unclear. Furthermore, GERD is believed to be associated with the development of many other diseases. This review summarizes the prevalence and risk factors of GERD and its complications.

Gastroesophageal reflux and altered motility in lung transplant rejection

BACKGROUND

Lung transplantation has become an effective therapeutic option for selected patients with end stage lung disease. Long-term survival is limited by chronic rejection manifest as bronchiolitis obliterans syndrome (BOS). The aspiration of gastric contents has been implicated as a causative or additive factor leading to BOS. Gastroesophageal reflux (GER) and altered foregut motility are common both before and after lung transplantation. Further, the normal defense mechanisms against reflux are impaired in the allograft. Recent studies using biomarkers of aspiration have added to previous association studies to provide a growing body of evidence supporting the link between rejection and GER. Further, the addition of high-resolution manometry (HRM) and impedance technology to characterize bolus transit and the presence and extent of reflux regardless of pH might better identify at-risk patients. Although additional prospective studies are needed, fundoplication appears useful in the prevention or treatment of post-transplant BOS.

PURPOSE

This review will highlight the existing literature on the relationship of gastroesophageal reflux and altered motility to lung transplant rejection, particularly BOS. The article will conclude with a discussion of the evaluation and management of patients undergoing lung transplantation at our center.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF; also known as cryptogenic fibrosing alveolitis) is a distinctive type of chronic fibrosing interstitial pneumonia of unknown cause associated with the histological pattern usual interstitial pneumonia (UIP). UIP is a distinct histological pattern observed in IPF but may also be found in other etiologies. The diagnosis of UIP can be established by surgical lung biopsy or by high-resolution thin-section CT scans (provided the radiographic features are classical). Historically, patients labeled as 'IPF' encompassed a group of disorders, including UIP, as well as other idiopathic interstitial pneumonias, which differ from UIP in prognosis and responsiveness to therapy. The term IPF should be restricted to patients with idiopathic UIP. The inciting cause(s) and pathogenesis of IPF have not been elucidated but alveolar epithelial cell injury and dysregulation or altered phenotypic expression of fibroblasts are key elements. Inflammatory cells may play minor roles in initiating or propagating the fibrotic process. The prognosis of idiopathic UIP is poor. Mean survival following diagnosis approximates at 3 years. Current medical therapies are of unproven value. Lung transplantation is a viable option for patients failing medical therapy.

Prevalence of gastroesophageal reflux disease in patients with idiopathic pulmonary fibrosis

OBJECTIVE

To determine the prevalence of gastroesophageal reflux disease (GERD) and to evaluate its clinical presentation, as well as the esophageal function profile in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

In this prospective study, 28 consecutive patients with IPF underwent stationary esophageal manometry, 24-h esophageal pH-metry and pulmonary function tests. All patients also completed a symptom and quality of life in GERD questionnaire.

RESULTS

In the study sample, the prevalence of GERD was 35.7%. The patients were then divided into two groups: GERD+ (abnormal pH-metry; n = 10) and GERD- (normal pH-metry; n = 18). In the GERD+ group, 77.7% of the patients presented at least one typical GERD symptom. The pH-metry results showed that 8 (80%) of the GERD+ group patients had abnormal supine reflux, and that the reflux was exclusively in the supine position in 5 (50%). In the GERD+ and GERD- groups, respectively, 5 (50.0%) and 7 (38.8%) of the patients presented a hypotensive lower esophageal sphincter, 7 (70.0%) and 10 (55.5%), respectively, presenting lower esophageal dysmotility. There were no significant differences between the groups regarding demographic characteristics, pulmonary function, clinical presentation or manometric findings.

CONCLUSIONS

The prevalence of GERD in the patients with IPF was high. However, the clinical and functional characteristics did not differ between the patients with GERD and those without.

Objective cough frequency in Idiopathic Pulmonary Fibrosis

Background

Cough is a common presenting symptom in patients with Idiopathic Pulmonary Fibrosis (IPF). This study measured cough rates in IPF patients and investigated the association between cough and measures of health related quality of life and subjective cough assessments. In addition, IPF cough rates were related to measures of physiological disease severity and compared to cough rates in health and other respiratory conditions.

Methods

Nineteen IPF patients, mean age 70.8 years ± 8.6, five female (26.3%) were studied. Subjects performed full pulmonary function testing, 24 hour ambulatory cough recordings, completed a cough related quality of life questionnaire (Leicester Cough Questionnaire) and subjectively scored cough severity with a visual analogue scale. Ambulatory cough recordings were manually counted and reported as number of coughs per hour.

Results

The 24hr cough rates were high (median 9.4, range 1.5-39.4), with day time rates much higher than night time (median 14.6, range 1.9-56.6 compared to 1.9, range 0-19.2, p = 0.003). Strong correlations were found between objective cough frequency and both the VAS (day r = 0.80, p < 0.001, night r = 0.71, p = 0.001) and LCQ (r = -0.80, p < 0.001), but not with measures of pulmonary function. Cough rates in IPF were higher than healthy subjects (p < 0.001) and asthma patients (p < 0.001) but similar to patients with chronic cough (p = 0.33).

Conclusions

This study confirms objectively that cough is a major, very distressing and disabling symptom in IPF patients. The strong correlations between objective cough counts and cough related quality of life measures suggest that in IPF patient's, perception of cough frequency is very accurate.

Current clinical trials for the treatment of idiopathic pulmonary fibrosis

Most pulmonary consultants are called upon to discuss IPF management with their patients. The gravity of IPF treatment discussion is immense in view of the data that 3- and 5-year mortality rates are approximately 50% and 80%, respectively. Although IPF occurs in older patients with comorbid diseases, most patients with IPF die as a direct consequence of their lung fibrosis. Here, the results of recently completed IPF trials and the rationale for ongoing studies are succinctly reviewed. There are a number of novel agents in clinical trials that are in the earlier stages of development, and there is new evidence supporting palliative therapies, which may help in managing symptoms of IPF, such as cough, without necessarily altering the course of the disease. The information provided herein should facilitate informed physician-patient dialogue.

Gastroesophageal reflux incites interstitial lung disease in systemic sclerosis: clinical, radiologic, histopathologic, and treatment evidence

OBJECTIVES

Interstitial lung disease (ILD) is currently the main cause of death in systemic sclerosis (SSc) and has an unknown pathogenesis. Gastroesophageal reflux (GER) has been strongly implicated as a cause of ILD in several lung diseases, including SSc-ILD. This review summarizes clinical, radiologic, histopathologic, and treatment aspects of GER in SSc-ILD.

METHODS

The PubMed database was searched using the following keywords: "systemic sclerosis, scleroderma, interstitial lung disease, and gastroesophageal reflux." The research was limited to English-language studies that included SSc patients with ILD.

RESULTS

Pulmonary function tests were related with the presence of GER in several esophageal functional tests (esophageal endoscopy, pH monitoring, and manometric analysis). Regarding the histopathologic data, a pattern called centrilobular fibrosis was described in 21% of 28 lung biopsies, with a bronchocentric distribution and with an intraluminal content resembling gastric fluid. Radiologic evidence of esophageal dilation is very frequent in SSc patients, and consolidation with a patchy distribution was almost exclusively found in SSc patients with centrilobular fibrosis lung pattern. Furthermore, high levels of serum KL-6, a marker of epithelial injury, are indicative of active ILD in SSc disease.

CONCLUSIONS

The association of GER with SSc-ILD is strongly supported by several studies. An aggressive treatment for reflux is recommended in all SSc patients with ILD; however, future studies need to be performed to prove a long-term benefit.

Reflux-induced collagen type v sensitization: potential mediator of bronchiolitis obliterans syndrome

BACKGROUND

Lung transplantation continues to have poor long-term survival partly because of the high incidence of bronchiolitis obliterans syndrome (BOS). Gastroesophageal reflux disease (GERD) has been implicated in BOS pathogenesis. We investigated the role of collagen type V [col(V)] sensitization in this process.

METHODS

Only primary lung transplant recipients were included. Reflux status was assessed with pH monitoring, impedance plethysmography, and esophagogastroduodenoscopy. Sensitivity to col(V) was determined with trans vivo delayed-type hypersensitivity reaction (DTH). Kaplan-Meier analyses were performed.

RESULTS

Of the 54 recipients, 26 had proven GERD. There were no significant between-group differences in diagnosis; donor and recipient age; sex; ischemic time; single vs bilateral; human leukocyte antigen A, B, and DR matching cytomegalovirus status; acute rejections; or mean follow-up period. The mean DTH response in the GERD group was 25.7 x 10(-4) inches vs 18.3 x 10(-4) inches in the non-GERD group (P = .023). There was a significant reduction in BOS-free survival in the GERD group for both BOS-I (GERD+, 28.3%; GERD-, 86.6%; P = .0001) and BOS-II/III (GERD+, 66.2%; GERD-, 91.7%; P = .0374). A second cohort of 53 patients awaiting lung transplantation also was assayed. The mean DTH response in the GERD group was 24.0 x 10(-4) inches vs 13.1 x 10(-4) inches in the non-GERD group (P = .003). There were no differences in age or sex.

CONCLUSIONS

GERD is strongly associated with the development of BOS after primary lung transplantation. Col(V) sensitization is associated with reflux and BOS and may play an intermediary role in the pathogenesis of BOS. Trials using col(V) reactivity to assess the impact of antireflux procedures in patients with lung transplantation and idiopathic pulmonary fibrosis are warranted.

[Boundaries of the lung - Relationship to the gastrointestinal system]

The relation between the respiratory and gastrointestinal systems has been long recognized and depends on various anatomical, physiological and pathological mechanisms. The certain recognition of some interactions, such as the relation between asthma and gastroesophageal reflux, is more or less intuitive to the pulmonogist, whereas other areas of confluence are more easily missed, such as the relation between airway disorders and inflammatory bowel disease. The purpose of this article is to review the interaction between the lung and the gastrointestinal systems, as far as anatomy, physiology, pathology, clinical manifestations and therapeutical options go.

Advances in the management of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a common form of interstitial lung disease and usually results in progressive respiratory insufficiency and death. Steady progress has been made in understanding the pathogenesis of IPF and multiple clinical trials are ongoing, but effective therapy remains elusive.

Does chronic microaspiration cause idiopathic pulmonary fibrosis?

Idiopathic pulmonary fibrosis is a diffuse fibrotic lung disease of unknown etiology with no effective treatment. Emerging data support a role for chronic microaspiration (ie, subclinical aspiration of small droplets) in the pathogenesis and natural history of idiopathic pulmonary fibrosis. However, the precise relationship between chronic microaspiration and idiopathic pulmonary fibrosis remains unknown. Gastroesophageal reflux, a presumed risk factor for microaspiration, has been strongly associated with idiopathic pulmonary fibrosis with an estimated prevalence of up to 90%. This review aims to describe the relationship between chronic microaspiration and idiopathic pulmonary fibrosis by laying out the clinical and biologic rationale for this relationship and exploring the scientific evidence available. The gaps in our current understanding of the diagnosis of chronic microaspiration and idiopathic pulmonary fibrosis and the ongoing uncertainties in management and treatment will be highlighted. Defining the role of chronic microaspiration in idiopathic pulmonary fibrosis is essential as it has potential clinical, pathobiological, and treatment implications for this deadly disease.

[Acute exacerbation of idiopathic pulmonary fibrosis]

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease. Its natural history may have episodes of acute exacerbation (AE-IPF), whose best accepted definition would be a clinically significant acute worsening, without identified cause, in patients with an underlying IPF. The incidence of AE-IPF ranges from 5%-19% of patients per year. It is estimated that acute deterioration of the respiratory status occurred in 47% of these patients before death. A rapidly progressive dyspnoea is the most prominent symptom, with associated cough, fever and flu-like symptoms. The diagnosis is strengthened by the presence of leukocytosis on the blood count, neutrophilia on the bronchoalveolar lavage, and development of new diffuse bilateral ground-glass opacities superimposed on the pre-existing radiographic findings. The major histological finding is diffuse alveolar damage. Methylprednisolone seems to be the best therapeutic option, although the treatment response is usually poor.

Guidelines for the diagnosis and management of gastroesophageal reflux disease: an evidence-based consensus

Gastroesophageal reflux disease (GERD) is one of the most common disorders in medical practice. A number of guidelines and recommendations for the diagnosis and management of GERD have been published in different countries, but a Brazilian accepted directive by the standards of evidence-based medicine is still lacking. As such, the aim of the Brazilian GERD Consensus Group was to develop guidelines for the diagnosis and management of GERD, strictly using evidence-based medicine methodology that could be clinically used by primary care physicians and specialists and would encompass the needs of physicians, investigators, insurance and regulatory bodies. A total of 30 questions were proposed. Systematic literature reviews, which defined inclusion and/or exclusion criteria, were conducted to identify and grade the available evidence to support each statement. A total of 11,069 papers on GERD were selected, of which 6,474 addressed the diagnosis and 4,595, therapeutics. Regarding diagnosis, 51 met the requirements for the analysis of evidence-based medicine: 19 of them were classified as grade A and 32 as grade B. As for therapeutics, 158 met the evidence-based medicine criteria; 89 were classified as grade A and 69 as grade B. In the topic Diagnosis, answers supported by publications grade A and B were accepted. In the topic Treatment only publications grade A were accepted: answers supported by publications grade B were submitted to the voting by the Consensus Group. The present publication presents the most representative studies that responded to the proposed questions, followed by pertinent comments. Follow examples. In patients with atypical manifestations, the conventional esophageal pH-metry contributes little to the diagnosis of GERD. The sensitivity, however, increases with the use of double-channel pH-metry. In patients with atypical manifestations, the impedance-pHmetry substantially contributes to the diagnosis of GERD. The examination, however, is costly and scarcely available in our country. The evaluation of the histological signs of esophagitis increases the diagnostic probability of GERD; hence, the observation of the dimensions of the intercellular space of the esophageal mucosa increases the probability of diagnostic certainty and also allows the analysis of the therapeutic response. There is no difference in the clinical response to the treatment with PPI in two separate daily doses when compared to a single daily dose. In the long term (>1 year), the eradication of H. pylori in patients with GERD does not decrease the presence of symptoms or the high recurrence rates of the disease, although it decreases the histological signs of gastric inflammation. It seems very likely that there is no association between the eradication of the H. pylori and the manifestations of GERD. The presence of a hiatal hernia requires larger doses of proton-pump inhibitor for the clinical treatment. The presence of permanent migration from the esophagogastric junction and the hernia dimensions (>2 cm) are factors of worse prognosis in GERD. In this case, hiatal hernias associated to GERD, especially the fixed ones and larger than 2 cm, must be considered for surgical treatment. The outcomes of the laparoscopic fundoplication are adequate.

Gastroesophageal reflux disease and graft failure after lung transplantation

In spite of advances in lung transplantation, the median survival after lung transplant remains less than 5 years, an outcome that is significantly worse than other solid organ transplants. Efforts to understand the unique hurdles faced in lung transplant have revealed gastroesophageal reflux disease (GERD) as a risk factor for ultimate graft failure. The link between GERD and chronic lung rejection parallels the association between GERD and other forms of lung disease such as idiopathic pulmonary fibrosis. Understanding how GERD predisposes to graft failure is an important issue as it may lead to therapies such as surgical correction that aim to lessen the exposure of the pulmonary epithelium to gastric contents. Here, we review the link between GERD and lung disease and discuss the preclinical and clinical studies that are starting to elucidate a mechanism for this association.

Quality of life in patients with chronic cough

Chronic cough is a relatively common symptom for which effective, acceptable treatments are lacking. Many patients suffer frequent coughing over several years without resolution and this has significant physical, social and psychological consequences. The recent development of cough-specific quality-of-life tools now allows quantification of the burden of coughing both in patients specifically presenting with chronic cough and also in common respiratory conditions.

Determinants of initiation and progression of idiopathic pulmonary fibrosis

IPF is a devastating disease with few therapeutic options. The precise aetiology of IPF remains elusive. However, our understanding of the pathologic processes involved in the initiation and progression of this disease is improving. Data on the mechanisms underlying IPF have been generated from epidemiologic investigations as well as cellular and molecular studies of human tissues. Although no perfect animal model of human IPF exists, pre-clinical animal studies have helped define pathways which are likely important in human disease. Epithelial injury, fibroblast activation and repetitive cycles of injury and abnormal repair are almost certainly key events. Factors which have been associated with initiation and/or progression of IPF include viral infections, abnormal cytokine, chemokine and growth factor production, oxidant stress, autoimmunity, inhalational of toxicants and gastro-oesophageal reflux disease. Furthermore, recent evidence identifies a role for a variety of genetic and epigenetic abnormalities ranging from mutations in surfactant protein C to abnormalities in telomere length and telomerase activity. The challenge remains to identify additional inciting agents and key dysregulated pathways that lead to disease progression so that we can develop targeted therapies to treat or prevent this serious disease.

[Lung diseases and gastro-oesophageal reflux disease]

Gastro -oesophageal Reflux Disease is a consequence of pathological reflux from stomach to oesophagus. Whenever the refluxed contents extended beyond the oesophagus itself, is called Extraoesophageal Reflux Disease. The author proposes a review about pulmonary disorders and gastroesophageal reflux. Previously, it is evaluated in an abridged way, the concepts of each diseases and after that, in a systematic form, it is discussed the prevalence of gastro -oesophageal reflux in lung diseases, all the mechanisms studies and the impact of gastro -oesophageal treatment on lung disorders. The author concludes that is undeniable the link between Gastro -oesophageal reflux and lung diseases and further reaserch is mandatory in order to corroborate this association.

Risk factors for idiopathic pulmonary fibrosis in a Mexican population. A case-control study

The etiology of idiopathic pulmonary fibrosis (IPF) remains poorly understood, but some studies have suggested that cigarette smoking or other occupational or environmental exposures, diabetes mellitus, or gastroesophageal reflux may play a role. In this study we evaluated the clinical records of a group of 97 consecutive patients with IPF, and 560 patients suffering 5 different respiratory disorders that were examined as controls: asthma (n=111), chronic obstructive pulmonary disease (n=132), squamous cell lung carcinoma (n=118), lung adenocarcinoma (n=101) and patients with otorhinolaryngology problems but without lung disease (n=98). In bivariate analyses male sex, diabetes mellitus and being former cigarette smoker were associated with IPF. After adjusting by these variables, multivariate analysis revealed that type 2 diabetes mellitus [11.3% in IPF patients vs 2.9% in controls, OR=4.3 (95% CI: 1.9-9.8), p<0.0001] was an independent risk factor associated to IPF. Our results provide additional evidence of a putative relationship between DM2 and idiopathic pulmonary fibrosis. Experimental research is necessary for thorough assessment of the pathogenic mechanisms involved in this association.

Phosphatidylinositol-3-kinase/akt regulates bleomycin-induced fibroblast proliferation and collagen production

Abnormal repair and dysregulated angiogenesis have been implicated in the pathogenesis of pulmonary fibrosis, but the underlying mechanisms of regulation are not well understood. The present study investigated the role of phosphatidylinositol-3-kinase (PI3K)/Akt in fibrogenesis of human lung fibroblasts and its regulation by reactive oxygen species (ROS). Exposure of lung fibroblasts to bleomycin, a known inducer of fibrosis, resulted in rapid activation of PI3K/Akt and a parallel increase in fibroblast proliferation and collagen production, characteristics of lung fibrosis. Bleomycin had no significant effect on total Akt protein expression but induced phosphorylation of the protein at threonine 308 and serine 473 positions. Inhibition of this phosphorylation by PI3K inhibitors or by dominant-negative Akt (T308A/S473A) expression abrogated the effects of bleomycin on fibroblast proliferation and collagen production, suggesting the role of PI3K/Akt in the fibrogenic process. Activation of PI3K/Akt by bleomycin also led to transcriptional activation and protein expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor, which contributed to the fibroproliferative and collagen-inducing effects of bleomycin. The fibrogenic effects of bleomycin were dependent on ROS generation, particularly superoxide anion and hydrogen peroxide, which were induced by bleomycin. Inhibition of ROS generation by antioxidant enzymes, catalase and superoxide dismutase mimetic MnTBAP, abrogated the fibrogenic effects of bleomycin as well as its induction of PI3K/Akt and HIF-1alpha activation. Together, our results indicate a novel role of PI3K/Akt in fibrogenesis of human lung fibroblasts and its regulation by ROS, which could be exploited for the treatment of pulmonary fibrosis and related disorders.

Gastroesophageal reflux disease and idiopathic pulmonary fibrosis

Gastroesophageal reflux disease occurs with a higher prevalence in patients with idiopathic pulmonary fibrosis than in matched controls. Silent reflux occurs in about a third of patients with significant gastroesophageal reflux disease; thus, objective measurements are required to evaluate gastroesophageal reflux disease in patients with advanced lung diseases. We provide here a detailed description of acid and non-acid reflux and the diagnostic evaluation for pulmonologists and lung transplant surgeons suspecting reflux as a contributing factor in advanced lung diseases. We review the evidence for gastroesophageal reflux disease causing idiopathic pulmonary fibrosis and other select pulmonary diseases and the potential role of antireflux surgery in the management of advanced lung disease and transplant patients.

Comorbidities of advanced lung disease

Lung disease in advanced stages is often accompanied by multiple comorbidities. Often, these processes lead to significant morbidity and occasionally mortality. Symptoms of pulmonary comorbidities, including pulmonary embolus, pulmonary hypertension, sleep-disordered breathing, and lung malignancy, may be intertwined with symptoms of advancing lung disease. However, the occurrence of extrapulmonary processes, including depression, diabetes mellitus, osteoporosis, and gastroesophageal reflux disease, may be subtle. Clinicians caring for advanced lung disease should be aware of the many comorbid processes that may accompany advancing lung disease.

Treatment of idiopathic interstitial pneumonias

The idiopathic interstitial pneumonias can be grouped, for treatment purposes, into primary inflammatory disorders, fibrotic nonspecific interstitial pneumonia (in which inflammation is thought to precede and progress to fibrosis) as well as the most common of the idiopathic interstitial pneumonia subgroups, idiopathic pulmonary fibrosis. Over the past decade, there have been several paradigm shifts in the understanding of idiopathic interstitial pneumonias and their treatment. In particular, we highlight changes in the use of prognostic markers, clinical trial end points and the understanding of pathogenesis of idiopathic pulmonary fibrosis. We outline a practical approach to the treatment of these three patient groups.

Gastroesophageal reflux and pulmonary fibrosis in scleroderma: a study using pH-impedance monitoring

RATIONALE

Interstitial lung disease (ILD) in patients with systemic sclerosis (SSc) is associated with increased morbidity and mortality. Gastroesophageal reflux (GER) is considered a contributing factor in the pathogenesis of ILD.

OBJECTIVES

To characterize GER (acid and nonacid) in patients with SSc with and without ILD.

METHODS

Patients with SSc underwent pulmonary high-resolution computer tomography (HRCT) scan and 24-hour impedance-pH monitoring off-proton pump inhibitor therapy. The presence of pulmonary fibrosis was assessed using validated HRCT-scores. Reflux monitoring parameters included number of acid and nonacid reflux episodes, proximal migration of the refluxate, and distal esophageal acid exposure. Unless otherwise specified, data are presented as median (25th-75th percentile).

MEASUREMENTS AND MAIN RESULTS

Forty consecutive patients with SSc (35 female; mean age, 53 yr; range, 24-71; 15 patients with diffuse and 25 with limited SSc) were investigated; 18 (45%) patients with SSc had pulmonary fibrosis (HRCT score >or= 7). Patients with SSc with ILD had higher (P < 0.01) esophageal acid exposure (10.3 [7.5-15] vs. 5.2 [1.5-11]), higher (P < 0.01) number of acid (41 [31-58] vs. 19 [10-23]) and nonacid (25 [20-35] vs. 17 [11-19]) reflux episodes, and higher (P < 0.01) number of reflux episodes reaching the proximal esophagus (42.5 [31-54] vs. 15 [8-22]) compared with patients with SSc with normal HRCT scores. Pulmonary fibrosis scores (HRCT score) correlated well with the number of reflux episodes in the distal (r(2) = 0.637) and proximal (r(2) = 0.644) esophagus.

CONCLUSIONS

Patients with SSc with ILD have more severe reflux (i.e., more reflux episodes and more reflux reaching the proximal esophagus). Whether or not the development of ILD in patients with SSc can be prevented by reflux-reducing treatments needs to be investigated.

Role of diabetes mellitus and gastro-oesophageal reflux in the aetiology of idiopathic pulmonary fibrosis

BACKGROUND

The aetiology of idiopathic pulmonary fibrosis remains poorly understood, but recent studies have suggested that diabetes mellitus and gastro-oesophageal reflux may be risk factors.

OBJECTIVE

To test possible associations between diabetes mellitus and gastro-oesophageal reflux with idiopathic pulmonary fibrosis in the general population.

METHODS

We designed a case-control study in the setting of UK general practices contributing data to The Health Improvement Network primary care database (THIN). We selected patients over 40 years of age with a first diagnosis of idiopathic pulmonary fibrosis, and up to 4 controls per case matched by age, gender, and general practice. We estimated odds ratios for exposure to gastro-oesophageal reflux, gout, hypercholesterolaemia and diabetes mellitus using conditional logistic regression. We explored the role of confounding by smoking habit, socio-economic status, and medication with prednisolone.

RESULTS

Amongst our 920 cases we found increased risks of use of insulin (odds ratio (OR) 2.36; 95% confidence interval (CI) 1.46-3.83) and use of ulcer drugs (OR 2.20; 95% CI 1.88-2.58). These were almost unchanged when we excluded cases and controls who had been prescribed prednisolone. We found no association with hypercholesterolaemia or gout, nor with smoking status or socio-economic status.

CONCLUSIONS

The study provides further evidence of an association between idiopathic pulmonary fibrosis and both diabetes mellitus and gastro-oesophageal reflux.

Morphological and molecular markers in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a progressive, lethal, interstitial lung disease with no proven effective therapy other than lung transplantation. A definitive diagnosis of the disease requires surgical lung biopsy to show a histological appearance of usual interstitial pneumonia. The main histological features include temporal and spatial heterogeneity, fibroblastic foci, extracellular matrix deposition with vessel remodeling and honeycomb changes. There are some morphological aspects that have recently been taken into account as possible prognostic markers for disease progression. Although the cellular and molecular pathways driving disease pathogenesis are complex and not fully delineated, increasing evidence suggests that a key event is ongoing alveolar epithelial injury in association with an abnormal host repair response. Inflammation seems to play a less important role and remains largely debated while increased attention has been on the role of noninflammatory structural cells, such as fibroblasts, epithelial cells and endothelial cells. The modifications and interactions among these cells are complex and regulated by various molecular factors. This article reviews the morphology of the disease, focusing on some new facets and on the principal molecular factors involved in the different aspects of parenchymal remodeling.

Non-acidic supraesophageal reflux associated with diffuse alveolar damage and allograft dysfunction after lung transplantation: a case report

Advances in lung transplantation have improved 1-year survival rates, but allograft dysfunction continues to be a significant cause of post-transplant death. Diffuse alveolar damage is an early indication of allograft dysfunction and has been linked to gastroesophageal reflux. We report a case of diffuse alveolar damage-associated allograft dysfunction in a patient found to have significant non-acid gastroesophageal reflux.

Lung transplantation in patients with connective tissue disorders and esophageal dysmotility

Lung and esophageal dysfunction are common in patients with connective tissue disease (CTD). Recent reports have suggested a link between pathologic gastroesophageal reflux and bronchiolitis obliterans syndrome (BOS) after lung transplant. Because patients with CTD have a high incidence of esophageal dysmotility and reflux, this group may be at increased risk of allograft dysfunction after lung transplantation. Little is known about antireflux surgery in these patients. Our aims were to describe: (i) the esophageal motility and reflux profile of patients with CTD referred for lung transplantation; and (ii) the safety and outcomes of laparoscopic fundoplication in this group. A retrospective review of 26 patients with CTD referred for lung transplantation between July 2003 and June 2007 at a single center. Esophageal studies included manometry and ambulatory 24-h pH monitoring. Twenty-three patients had esophageal manometry and ambulatory 24-h pH monitoring. Nineteen patients (83%) had pathologic distal reflux and 7 (30%) also had pathologic proximal reflux. Eighteen patients (78%) had impaired or absent peristalsis. Eleven of 26 patients underwent lung transplantation. Ten patients are alive at a median follow-up of 26 months (range 3-45) and one has bronchiolitis obliterans syndrome-1. Six patients had a laparoscopic fundoplication, 1 before transplantation and 5 after. All fundoplication patients are alive at median follow-up of 25 months (range 19-45). In conclusion, esophageal dysmotility and reflux are common in CTD patients referred for lung transplant. For this group, laparoscopic fundoplication is safe in experienced hands.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a non-neoplastic pulmonary disease that is characterized by the formation of scar tissue within the lungs in the absence of any known provocation. IPF is a rare disease which affects approximately 5 million persons worldwide. The prevalence is estimated to be slightly greater in men (20.2/100,000) than in women (13.2/100,000). The mean age at presentation is 66 years. IPF initially manifests with symptoms of exercise-induced breathless and dry coughing. Auscultation of the lungs reveals early inspiratory crackles, predominantly located in the lower posterior lung zones upon physical exam. Clubbing is found in approximately 50% of IPF patients. Cor pulmonale develops in association with end-stage disease. In that case, classic signs of right heart failure may be present. Etiology remains incompletely understood. Some environmental factors may be associated with IPF (cigarette smoking, exposure to silica and livestock). IPF is recognized on high-resolution computed tomography by peripheral, subpleural lower lobe reticular opacities in association with subpleural honeycomb changes. IPF is associated with a pathological lesion known as usual interstitial pneumonia (UIP). The UIP pattern consists of normal lung alternating with patches of dense fibrosis, taking the form of collagen sheets. The diagnosis of IPF requires correlation of the clinical setting with radiographic images and a lung biopsy. In the absence of lung biopsy, the diagnosis of IPF can be made by defined clinical criteria that were published in guidelines endorsed by several professional societies. Differential diagnosis includes other idiopathic interstitial pneumonia, connective tissue diseases (systemic sclerosis, polymyositis, rheumatoid arthritis), forme fruste of autoimmune disorders, chronic hypersensitivity pneumonitis and other environmental (sometimes occupational) exposures. IPF is typically progressive and leads to significant disability. The median survival is 2 to 5 years from the time of diagnosis. Medical therapy is ineffective in the treatment of IPF. New molecular therapeutic targets have been identified and several clinical trials are investigating the efficacy of novel medication. Meanwhile, pulmonary transplantation remains a viable option for patients with IPF. It is expected that, during the next decade, considerable progress will be made toward the understanding and treatment of this devastating illness.

Exposure of airway epithelium to bile acids associated with gastroesophageal reflux symptoms: a relation to transforming growth factor-beta1 production and fibroblast proliferation

RATIONALE

Gastroesophageal reflux (GER) is common in patients with various airway diseases. Airway epithelial cells can release growth factors that promote fibroblast proliferation. Exposure of airway epithelium to bile acids may induce a fibrotic response.

OBJECTIVES

To determine how bile acids interact with airway epithelium; particularly, whether transforming growth factor-beta1 secretion and fibroblast proliferation are affected.

METHODS

Induced sputum from patients with asthma, GER, or asthma associated with GER symptoms, or from healthy control subjects was collected. Total bile acids were measured by a spectrophotometric enzymatic assay. The major components of bile acids, chenodeoxycholic acid (CD) and glycochenodeoxycholic acid (GCD), were used to stimulate primary airway epithelial cells. Quantitative polymerase chain reaction and Western blotting were applied for messenger RNA expression and signal pathway analysis, respectively. Conditioned medium following CD stimulation was coincubated with fibroblasts for proliferation study.

RESULTS

The amount of total bile acids in induced sputum was significantly higher in patients with GER and asthma-associated GER symptoms compared to that of healthy control subjects (p<0.005). CD, but not GCD, significantly induced TGF-beta1 production. TGF-beta1 messenger RNA expression was 2.5-fold increased compared to unstimulated cells. This occurred via p38 mitogen-activated protein (MAP) kinase and activating transcription factor-2 activation. Pretreatment with dexamethasone inhibited TGF-beta1 production at both messenger RNA and protein levels by inhibiting p38 MAP kinase phosphorylation. Conditioned medium from CD-treated epithelial cells enhanced fibroblast proliferation.

CONCLUSIONS

Aspiration of bile acids may induce airway fibrosis through the production of TGF-beta1 and fibroblast proliferation. Early intervention to attenuate these processes may reduce fibrogenesis in various airway diseases associated with GER.

Antireflux surgery for patients with end-stage lung disease before and after lung transplantation

BACKGROUND

Gastroesophageal reflux disease (GERD) is prevalent among patients with end-stage lung disease (ESLD). This disease can lead to microaspiration and may be a risk factor for lung damage before and after transplantation. A fundoplication is the best way to stop reflux, but little is known about the safety of elective antireflux surgery for patients with ESLD. This study aimed to report the safety of laparoscopic fundoplication for patients with ESLD and GERD before or after lung transplantation.

METHODS

Between January 1997 and January 2007, 305 patients were listed for lung transplantation, and 189 patients underwent the procedure. In 2003, routine esophageal studies were added to the pretransplantation evaluation. After the authors' initial experience, gastric emptying studies were added as well.

RESULTS

A total of 35 patients with GERD or delayed gastric emptying were referred for surgical intervention. A laparoscopic fundoplication was performed for 32 patients (27 total and 5 partial). For three patients, a pyloroplasty also was performed. Two patients had a pyloroplasty without fundoplication. Of the 35 operations, 15 were performed before and 20 after transplantation. Gastric emptying of solids or liquids was delayed in 12 (92%) of 13 posttransplantation studies and 3 (60%) of 5 pretransplantation studies. All operations were completed laparoscopically, and 33 patients recovered uneventfully (94%). The median hospital length of stay was 2 days (range, 1-34 days) for the patients admitted to undergo elective operations. Hospitalization was not prolonged for the three patients who had fundoplications immediately after transplantation.

CONCLUSIONS

The results of this study show that laparoscopic antireflux surgery can be performed safely by an experienced multidisciplinary team for selected patients with ESLD before or after lung transplantation, and that gastric emptying is frequently abnormal and should be objectively measured in ESLD patients.

Acute exacerbations of idiopathic pulmonary fibrosis

The natural history of idiopathic pulmonary fibrosis (IPF) has been characterized as a steady, predictable decline in lung function over time. Recent evidence suggests that some patients may experience a more precipitous course, with periods of relative stability followed by acute deteriorations in respiratory status. Many of these acute deteriorations are of unknown etiology and have been termed acute exacerbations of IPF. This perspective is the result of an international effort to summarize the current state of knowledge regarding acute exacerbations of IPF. Acute exacerbations of IPF are defined as acute, clinically significant deteriorations of unidentifiable cause in patients with underlying IPF. Proposed diagnostic criteria include subjective worsening over 30 days or less, new bilateral radiographic opacities, and the absence of infection or another identifiable etiology. The potential pathobiological roles of infection, disordered cell biology, coagulation, and genetics are discussed, and future research directions are proposed.

Prevalence of Gastroesophageal Reflux Disease in Patients With Nontuberculous Mycobacterial Lung Disease

BACKGROUND

Knowledge of the relationship between respiratory disorders and gastroesophageal reflux disease (GERD) is increasing. However, the association between GERD and pulmonary disease caused by nontuberculous mycobacteria (NTM) has not been studied in detail. We investigated the prevalence of GERD in patients with the nodular bronchiectatic form of NTM lung disease.

METHODS

Fifty-eight patients with the nodular bronchiectatic form of NTM lung disease underwent ambulatory 24-h esophageal pH monitoring. Of the 58 patients, 27 patients were identified as having Mycobacterium avium complex infection (15 with Mycobacterium intracellulare and 12 with M avium), and 31 patients had Mycobacterium abscessus pulmonary infection.

RESULTS

The prevalence of GERD in patients with the nodular bronchiectatic form of NTM lung disease was 26% (15 of 58 patients). Only 27% (4 of 15 patients) had typical GERD symptoms. No statistically significant differences were found between patients with GERD and those without GERD with regard to age, sex, body mass index, or pulmonary function test results. However, patients with GERD were more likely to have a sputum smear that was positive for acid-fast bacilli (12 of 15 patients, 80%), compared with patients without GERD (19 of 43 patients, 44%) [p = 0.033]. In addition, bronchiectasis and bronchiolitis were observed in more lobes in patients with GERD than in patients without GERD (p = 0.008 and p = 0.005, respectively).

CONCLUSIONS

Patients with the nodular bronchiectatic form of NTM lung disease have a high prevalence of increased esophageal acid exposure, usually without typical GERD symptoms.

Gastroesophageal Reflux Disease, Acid Suppression, and Mycobacterium avium Complex Pulmonary Disease

BACKGROUND

Weekly symptoms of gastroesophageal reflux disease (GERD) occur in 20% of the population, and GERD has been implicated in the pathophysiology of many respiratory diseases. Microaspiration of contaminated water is a potential portal of entry for Mycobacterium avium complex (MAC) organisms into the respiratory tract, and acid-suppression therapy may enhance the survival of mycobacteria in the stomach. This study aimed to assess the prevalence of GERD, swallowing disorders, reflux symptoms, and acid-suppression therapy in patients with MAC lung disease (MAC positive [MAC+]), and to compare these patients to control subjects without MAC lung disease (MAC negative [MAC-]).

METHODS

Clinical information was collected on 58 MAC+ patients and 58 age- and sex-matched MAC- patients who were asked to complete a DeMeester questionnaire of reflux symptoms and to identify any acid-suppressive medication consumed.

RESULTS

A clinical diagnosis of GERD was documented in 23 of 52 MAC+ patients (44.2%), compared to 16 MAC- patients (27.6%) [p = 0.019]. MAC+ patients consumed significantly more histamine type 2 receptor antagonists and prokinetic agents, and MAC- patients consumed more antacids. The mean DeMeester questionnaire score (+/- SD) for MAC+ patients was 1.39 +/- 1.8, and for MAC- patients was 0.88 +/- 1.4. (p = 0.098). Aspiration was suspected in nine MAC+ patients (15.5%), compared to three MAC- patients (5.2%) [p = 0.032]. There was no association between GERD and radiologic presentation of MAC disease. Consolidation and nodules > 5 mm were more common in those receiving acid suppression than those who were not.

CONCLUSIONS

GERD, acid suppression, and clinically suspected aspiration are more common in patients with MAC lung disease than in similar patients without MAC disease.

High prevalence of proximal and distal gastroesophageal reflux disease in advanced COPD

BACKGROUND

Gastroesophageal reflux disease (GERD) is common in a variety of chronic respiratory diseases, but little is known about GERD in the setting of COPD. The aims of this study were to determine the prevalence, presentation, and predictors of GERD based on proximal and distal esophageal pH monitoring in patients with severe COPD.

METHODS

Forty-one COPD patients with a mean FEV1 of 24% of predicted underwent dual-probe 24-h esophageal pH monitoring, and 1 patient underwent esophagogastroduodenoscopy.

RESULTS

The prevalence of GERD was 57%. Elevated distal and proximal reflux were present in 41% and 46% of patients undergoing esophageal pH studies, respectively. Fifteen percent of these patients had abnormal proximal reflux despite having normal distal probe results. Most patients with GERD were not receiving acid blockers at the time of their referral, and only one third reported heartburn and/or acid regurgitation during the pH study. Only higher body mass index was predictive of reflux on regression analysis (odds ratio, 1.2; 95% confidence interval, 1.0 to 1.5; p = 0.05).

CONCLUSIONS

GERD is common in advanced COPD. Patients are often asymptomatic and have a relatively high prevalence of isolated abnormal proximal reflux. Dual-probe monitoring is therefore well suited for detecting GERD in patients with advanced COPD.

Gastroesophageal reflux in patients with idiopathic pulmonary fibrosis referred for lung transplantation

OBJECTIVES

The association between gastroesophageal reflux disease and idiopathic pulmonary fibrosis has not been fully characterized. The aims of this study were to determine in patients with idiopathic pulmonary fibrosis (1) the prevalence of reflux symptoms, (2) the esophageal manometric profile, and (3) the prevalence of proximal and distal esophageal reflux.

METHODS

Between May 1999 and March 2006, 30 patients with idiopathic pulmonary fibrosis were referred to the Swallowing Center at the University of California San Francisco. Each patient underwent a structured symptom assessment, esophageal manometry, and 24-hour dual sensor ambulatory pH monitoring.

RESULTS

Twenty (67%) patients had abnormal esophageal reflux. Typical reflux symptoms, although more common in those with reflux, were not reliable as a screening test (sensitivity 65%, specificity 71%). Sixty-five percent of patients with abnormal reflux had a hypotensive lower esophageal sphincter. Abnormal esophageal peristalsis was more common among those with reflux (50% vs 10%; P = .03). In 9 (30%) patients, acid refluxed into the proximal esophagus for over 1% of the study time.

CONCLUSIONS

A majority of patients with idiopathic pulmonary fibrosis have pathologic reflux. Symptoms do not distinguish between those with and without reflux. In these patients, reflux is associated with a hypotensive lower esophageal sphincter and abnormal esophageal peristalsis, and often extends into the proximal esophagus.

The prevalence of distal and proximal gastroesophageal reflux in patients awaiting lung transplantation

OBJECTIVE

To determine the prevalence and proximal extent of gastroesophageal reflux (GERD) in patients awaiting lung transplantation.

BACKGROUND

GERD has been postulated to contribute to accelerated graft failure in patients who have had lung transplantations. However, the prevalence of reflux symptoms, esophageal motility abnormalities, and proximal esophageal reflux among patients with end-stage lung disease awaiting lung transplantation are unknown.

METHODS

A total of 109 patients with end-stage lung disease awaiting lung transplantation underwent symptomatic assessment, esophageal manometry, and esophageal pH monitoring (using a probe with 2 sensors located 5 and 20 cm above the lower esophageal sphincter).

RESULTS

Reflux symptoms were not predictive of the presence of reflux (sensitivity, 67%; specificity, 26%). Esophageal manometry showed a high prevalence of a hypotensive lower esophageal sphincter (55%) and impaired esophageal peristalsis (47%) among patients with reflux. Distal reflux was present in 68% of patients and proximal reflux was present in 37% of patients.

CONCLUSIONS

These data show that in patients with end-stage lung disease: 1) symptoms were insensitive and nonspecific for diagnosing reflux; 2) esophageal motility was frequently abnormal; 3) 68% of patients had GERD; 4) in 50% of the patients with GERD, acid refluxed into the proximal esophagus. We conclude that patients with end-stage lung disease should be screened with pH monitoring for GERD.