Gastroesophageal reflux and antacid therapy in IPF: analysis from the Australia IPF Registry

The impact of gastroesophageal reflux disease and its treatment on interstitial lung disease outcomes

BACKGROUND

To determine the relationship between gastroesophageal reflux disease (GORD) and its treatment and interstitial lung disease in patients with systemic sclerosis (SSc).

METHODS

SSc patients from the Australian Scleroderma Cohort Study (ASCS) were included. GORD was defined as self-reported GORD symptoms, therapy with a proton pump inhibitor (PPI) or histamine 2 receptor antagonist (H2RA) and/or the presence of reflux oesophagitis diagnosed endoscopically. The impact of GORD and its treatment on ILD features (including severity and time to ILD development) and survival was evaluated.

RESULTS

GORD was a common manifestation affecting 1539/1632 (94%) of SSc patients. GORD affected 450/469 (96%) of those with SSc-ILD cohort. In SSc-ILD, there was no relationship between the presence of GORD or its treatment and time to ILD development or ILD severity. However, GORD treatment was associated with improved survival in those with ILD (p = 0.002). Combination therapy with both a PPI and a H2RA was associated with a greater survival benefit than single agent therapy with PPI alone (HR 0.3 vs 0.5 p < 0.050 respectively).

CONCLUSION

GORD is a common SSc disease manifestation. While the presence or treatment of GORD does not influence the development or severity of ILD, aggressive GORD treatment, in particular with a combination of PPI and H2RA, is associated with improved survival in those with SSc-ILD.

Association between Antacid Exposure and Risk of Interstitial Lung Diseases

BACKGROUND

The mechanisms leading to lung fibrosis are still under investigation. This study aimed to demonstrate whether antacids could prevent the development of interstitial lung disease (ILD).

METHODS

This population-based longitudinal cohort study was conducted between January 2006 and December 2010 in South Korea. Eligible subjects were ≥40 years of age, exposed to proton pump inhibitors (PPI)±histamine-2 receptor antagonists (H-2 blockers) or H-2 blockers only, and had no history of ILD between 2004 and 2005. Exposure to antacids was defined as the administration of either PPI or H-2 receptor antagonists for >14 days, whereas underexposure was defined as antacid treatment administered for less than 14 days. Newly developed ILDs, including idiopathic pulmonary fibrosis (IPF), were counted during the 5-year observation period. The association between antacid exposure and ILD development was evaluated using adjusted Cox regression models with variables, such as age, sex, smoking history, and comorbidities.

RESULTS

The incidence rates of ILD with/without antacid use were 43.2 and 33.8/100,000 person-years, respectively and those of IPF were 14.9 and 22.9/100,000 person-years, respectively. In multivariable analysis, exposure to antacid before the diagnosis of ILD was independently associated with a reduced development of ILD (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.45 to 0.71; p<0.001), while antacid exposure was not associated with development of IPF (HR, 0.88; 95% CI, 0.72 to 1.09; p=0.06).

CONCLUSION

Antacid exposure may be independently associated with a decreased risk of ILD development.

Treatment of idiopathic pulmonary fibrosis and progressive pulmonary fibrosis: A position statement from the Thoracic Society of Australia and New Zealand 2023 revision

Idiopathic pulmonary fibrosis (IPF) is a progressive disease leading to significant morbidity and mortality. In 2017 the Thoracic Society of Australia and New Zealand (TSANZ) and Lung Foundation Australia (LFA) published a position statement on the treatment of IPF. Since that time, subsidized anti-fibrotic therapy in the form of pirfenidone and nintedanib is now available in both Australia and New Zealand. More recently, evidence has been published in support of nintedanib for non-IPF progressive pulmonary fibrosis (PPF). Additionally, there have been numerous publications relating to the non-pharmacologic management of IPF and PPF. This 2023 update to the position statement for treatment of IPF summarizes developments since 2017 and reaffirms the importance of a multi-faceted approach to the management of IPF and progressive pulmonary fibrosis.

Mendelian randomization analysis suggests no causal influence of gastroesophageal reflux disease on the susceptibility and prognosis of idiopathic pulmonary fibrosis

BACKGROUND

The relationship between gastroesophageal reflux disease (GERD) and the susceptibility as well as the prognosis of idiopathic pulmonary fibrosis (IPF) has been previously suggested, with the potential confounding factor of smoking not adequately addressed. In light of this, we conducted a Mendelian randomization (MR) study to investigate the causal effects of GERD on the susceptibility and prognosis of IPF while excluding smoking.

METHODS

We chose GERD as the exposure variable and employed genome-wide association data to examine its association with susceptibility, forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLco), and transplant-free survival (TFS) in patients with IPF as the outcome variables. MR analyses were performed using the inverse variance weighted (IVW) method, and sensitivity analyses were conducted using the MR-PRESSO outlier test, Cochran's Q test, MR-Egger intercept test, and leave-one-out sensitivity analysis. Additionally, to mitigate the potential effects of smoking on our MR estimates, we conducted a multivariable MR (MVMR) analysis by adjusting for smoking.

RESULTS

The univariable MR analysis demonstrated no causal effect of GERD on FVC (βIVW = 26.63, SE = 48.23, P = 0.581), DLco (βIVW = 0.12, SE = 0.12, P = 0.319), and TFS (HRIVW = 0.87, 95% CI = 0.56 to 1.35, P = 0.533) in patients with IPF. Furthermore, sensitivity analysis revealed no evidence of heterogeneity, horizontal pleiotropy, or outlier single nucleotide polymorphisms. The MVMR analysis showed no causal effect of GERD on susceptibility to IPF after adjusting for smoking (ORIVW = 1.30, 95% CI = 0.93 to 1.68, P = 0.071). These findings were consistent in the replication cohort.

CONCLUSIONS

The link between GERD and its potential impact on susceptibility to IPF may not be of a direct causal nature and could be influenced by factors such as smoking. Our findings did not reveal any evidence of a causal relationship between GERD and the FVC, DLco, and TFS of patients with IPF.

Assessment and Management of Cough in Idiopathic Pulmonary Fibrosis: A Narrative Review

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal disease with an unknown cause. It is characterized by symptoms such as cough and breathlessness, which significantly impact patients' quality of life. Cough, in particular, has emerged as a burdensome symptom for individuals with IPF. The etiology of cough in IPF patients is believed to be complex, involving factors related to the disease itself, such as increased sensitivity of cough nerves, lung structural changes, inflammation, and genetic factors, as well as comorbidities and medication effects. Unfortunately, effective treatment options for cough in IPF remain limited, often relying on empirical approaches based on studies involving chronic cough patients in general and the personal experience of physicians. Medications such as opioids and neuromodulators are commonly prescribed but have shown suboptimal efficacy, imposing significant physical, psychological, and economic burdens on patients. However, there is hope on the horizon, as specific purinergic P2 receptor ligand-gated ion channel (P2X3) inhibitors have demonstrated promising antitussive effects in ongoing clinical trials. This review aims to provide a comprehensive overview of the evaluation and management of cough in IPF patients, as well as highlight emerging pharmacological and non-pharmacological approaches that target the cough reflex and are currently being investigated in clinical settings.

Impact of concomitant gastroesophageal reflux disease symptomology on prognosis and pulmonary function of chronic hypersensitivity pneumonitis

Background and Objectives

Comorbid risk factors in chronic hypersensitivity pneumonitis (CHP) are poorly characterised. Gastroesophageal reflux disease (GERD) is linked to interstitial lung diseases like idiopathic pulmonary fibrosis (IPF), but its association and treatment in CHP is less understood. This study aims to understand the role and prevalence of GERD in CHP, plus the effect of GERD treatment on lung function and mortality.

Methods

A tertiary referral centre panel was retrospectively reviewed for 214 patients diagnosed with CHP based on clinical history, bronchoalveolar lavage fluid analysis, imaging and histopathology. GERD diagnostic criteria included symptomology, acid suppressive therapy use and diagnostic testing. CHP patients with GERD (n = 89) and without GERD (n = 125) were compared via descriptive statistical analysis. Pulmonary function, GERD diagnosis plus treatment and other comorbidities were evaluated against CHP outcomes.

Results

Respective differences between diagnosis and study termination dates in the GERD population versus without GERD for functional vital capacity (FVC) were - 1 L vs - 2.5 L, diffusing capacity of the lungs for carbon monoxide (DLCO) were - 2 mL/min/mmHg versus - 1 mL/min/mmHg, per cent alive at the time of study 88% versus 81%, median date of survival 574.5 versus 850 and supplemental oxygen requirement 41% versus 37%. GERD prevalence was higher in CHP patients relative to the general population. No statistical significance was found between survival curves, oxygen requirement, smoking history, FVC, or DLCO.

Conclusions

GERD could be a harmful comorbidity in CHP though may not necessarily affect survival or functional outcomes. This aligns with previous IPF studies, though remains controversial. Further research is needed regarding this association and treatment benefit.

Anti-acid therapy in SSc-associated interstitial lung disease: long-term outcomes from the German Network for Systemic Sclerosis

OBJECTIVES

Gastroesophageal reflux disease (GERD) occurs frequently in patients with SSc. We investigated whether the presence of GERD and/or the use of anti-acid therapy, specifically proton-pump inhibitors (PPIs), are associated with long-term outcomes, especially in SSc-associated interstitial lung disease (SSc-ILD).

METHODS

We retrospectively analysed patients with SSc and SSc-ILD from the German Network for Systemic Sclerosis (DNSS) database (2003 onwards). Kaplan-Meier analysis compared overall survival (OS) and progression-free survival (PFS) in patients with GERD vs without GERD (SSc and SSc-ILD), and PPI vs no PPI use (SSc-ILD only). Progression was defined as a decrease in either percentage predicted forced vital capacity of ≥10% or single-breath diffusing capacity for carbon monoxide of ≥15%, or death.

RESULTS

It was found that 2693/4306 (63%) registered patients with SSc and 1204/1931 (62%) with SSc-ILD had GERD. GERD was not associated with decreased OS or decreased PFS in patients in either cohort. In SSc-ILD, PPI use was associated with improved OS vs no PPI use after 1 year [98.4% (95% CI: 97.6, 99.3); n = 760 vs 90.8% (87.9-93.8); n = 290] and after 5 years [91.4% (89.2-93.8); n = 357 vs 70.9% (65.2-77.1); n = 106; P < 0.0001]. PPI use was also associated with improved PFS vs no PPI use after 1 year [95.9% (94.6-97.3); n = 745 vs 86.4% (82.9-90.1); n = 278] and after 5 years [66.8% (63.0-70.8); n = 286 vs 45.9% (39.6-53.2); n = 69; P < 0.0001].

CONCLUSION

GERD had no effect on survival in SSc or SSc-ILD. PPIs improved survival in patients with SSc-ILD. Controlled, prospective trials are needed to confirm this finding.

Relationship Between Esophageal Disease and Pulmonary Fibrosis

Esophageal disorders are prevalent among patients with chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). Gastroesophageal reflux disease (GERD) has been associated with IPF prevalence, severity, and respiratory decline. The pathophysiologic relationship between GERD and IPF is likely bidirectional, with aspiration of refluxate leading to lung inflammation and fibrosis, while the restrictive pulmonary physiology may contribute to altered transdiaphragmatic pressure gradient and increased reflux. Esophageal symptoms are frequently absent and do not predict esophageal dysfunction or pathologic reflux in patients with IPF, and objective diagnostic tools including upper endoscopy, ambulatory reflux monitoring, and high-resolution manometry are often needed. Impedance-based testing that identifies both weakly/non-acidic and acid reflux may provide important additional diagnostic value beyond pH-based acid testing alone. Novel metrics and maneuvers, including advanced impedance measures on impedance-pH study and provocative testing on HRM, may hold promise to future diagnostic advancements. The main treatment options include medical therapy with acid suppressants and anti-reflux surgery, although their potential benefits in pulmonary outcomes of IPF require further validations. Future directions of research include identifying phenotypes of IPF patients who may benefit from esophageal testing and treatment, determining the optimal testing strategy and protocol, and prospectively assessing the value of different esophageal therapies to improve outcomes while minimizing risks. This review will discuss the pathophysiology, evaluation, and management of esophageal diseases, particularly GERD, in patients with IPF, as informed by the most recent publications in the field, in hopes of identifying targets for future study and research.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Viewer or Actor? To Treat or Not to Treat?

Background: Idiopathic pulmonary fibrosis (IPF) is a rare and severe disease with a median survival of ∼3 years. Several risk factors have been identified, such as age, genetic predisposition, tobacco exposure, and gastro-oesophageal reflux disease (GERD). Prevalence of GERD in IPF is high and may affect 87% of patients, of whom only half (47%) report symptoms. Objective: The aim of this study is to review current evidence regarding the correlation between GERD and IPF and to evaluate the current studies regarding treatments for GERD-IPF. Methods: A review to identify research papers documenting an association between GERD and IPF was performed. Results: We identified several studies that have confirmed the association between GERD and IPF, with an increased acid exposure, risk of gastric aspiration and bile acids levels in these patients. Few studies focused their attention on GERD treatment, showing how antiacid therapy was not able to change IPF evolution. Conclusions: This review investigating the correlation between GERD and IPF has confirmed the hypothesized association. However, further large prospective studies are needed to corroborate and elucidate these findings with a focus on preventative and treatment strategies.

Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline

Background: This American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana de Tórax guideline updates prior idiopathic pulmonary fibrosis (IPF) guidelines and addresses the progression of pulmonary fibrosis in patients with interstitial lung diseases (ILDs) other than IPF. Methods: A committee was composed of multidisciplinary experts in ILD, methodologists, and patient representatives. 1) Update of IPF: Radiological and histopathological criteria for IPF were updated by consensus. Questions about transbronchial lung cryobiopsy, genomic classifier testing, antacid medication, and antireflux surgery were informed by systematic reviews and answered with evidence-based recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. 2) Progressive pulmonary fibrosis (PPF): PPF was defined, and then radiological and physiological criteria for PPF were determined by consensus. Questions about pirfenidone and nintedanib were informed by systematic reviews and answered with evidence-based recommendations using the GRADE approach. Results:1) Update of IPF: A conditional recommendation was made to regard transbronchial lung cryobiopsy as an acceptable alternative to surgical lung biopsy in centers with appropriate expertise. No recommendation was made for or against genomic classifier testing. Conditional recommendations were made against antacid medication and antireflux surgery for the treatment of IPF. 2) PPF: PPF was defined as at least two of three criteria (worsening symptoms, radiological progression, and physiological progression) occurring within the past year with no alternative explanation in a patient with an ILD other than IPF. A conditional recommendation was made for nintedanib, and additional research into pirfenidone was recommended. Conclusions: The conditional recommendations in this guideline are intended to provide the basis for rational, informed decisions by clinicians.

Antacid Medication and Antireflux Surgery in Patients with Idiopathic Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Rationale: Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial pneumonia with impaired survival. Previous guidelines recommend antacid medication to improve respiratory outcomes in patients with IPF. Objectives: This systematic review was undertaken during the development of an American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax guideline. The clinical question was, "Should patients with IPF who have documented abnormal gastroesophageal reflux (GER) with or without symptoms of GER disease 1) be treated with antacid medication or 2) undergo antireflux surgery to improve respiratory outcomes?" Methods: Medline, Embase, the Cochrane Central Register of Controlled Trials, and the gray literature were searched through June 30, 2020. Studies that enrolled patients with IPF and 1) compared antacid medication to placebo or no medication or 2) compared antireflux surgery to no surgery were selected. Meta-analyses were performed when possible. Outcomes included disease progression, mortality, exacerbations, hospitalizations, lung function, respiratory symptoms, GER severity, and adverse effects/complications. Results: For antacid medication, when two studies were aggregated, there was no statistically significant effect on disease progression, defined as a 10% or more decline in FVC, more than 50-m decline in 6-minute walking distance, or death (risk ratio [RR], 0.88; 95% confidence interval [CI], 0.76-1.03). A separate study that could not be included in the meta-analysis found no statistically significant effect on disease progression when defined as a 5% or more decline in FVC or death (RR, 1.10; 95% CI, 1.00-1.21) and an increase in disease progression when defined as a 10% or more decline in FVC or death (RR, 1.28; 95% CI, 1.08-1.51). For antireflux surgery, there was also no statistically significant effect on disease progression (RR, 0.29; 95% CI, 0.06-1.26). Neither antacid medications nor antireflux surgery was associated with improvements in the other outcomes. Conclusions: There is insufficient evidence to conclude that antacid medication or antireflux surgery improves respiratory outcomes in patients with IPF, most of whom had not had abnormal GER confirmed. Well-designed and adequately powered prospective studies with objective evaluation for GER are critical to elucidate the role of antacid medication and antireflux surgery for respiratory outcomes in patients with IPF.

Molecular pathways and role of epigenetics in the idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with unknown etiological factors that can progress to other dangerous diseases like lung cancer. Environmental and genetic predisposition are the two major etiological or risk factors involved in the pathology of the IPF. Among the environmental risk factors, smoking is one of the major causes for the development of IPF. Epigenetic pathways like nucleosomes remodeling, DNA methylation, histone modifications and miRNA mediated genes play a crucial role in development of IPF. Mutations in the genes make the epigenetic factors as important drug targets in IPF. Transcriptional changes due to environmental factors are also involved in the progression of IPF. The mutations in human telomerase reverse transcriptase (hTERT) have shown decreased life expectancy in IPF patients. The TERT-gene is highly expressed in chronic smokers and makes the role of epigenetics evident. Drug like nintedanib acts through vascular endothelial growth factor receptors (VEGFR), while drug pirfenidone acts through transforming growth factor (TGF), which is useful in IPF. Gefitinib, a tyrosine kinase inhibitor of EGFR, is useful as an anti-fibrosis agent in preclinical models. Newer drugs such as Celgene-CC90001 and FibroGen-FG-3019 are currently under investigations acts through the modulating epigenetic mechanisms. Thus, the study on epigenetics opens a wide window for the discovery of newer drugs. This study provides an elementary analysis of multiple regulators of epigenetics and their roles associated with the pathology of IPF. Further, this review also includes epigenetic drugs under development in preclinical and clinical stages.

Effect of anti-reflux therapy on pulmonary function in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

Current guideline conditionally recommends regular use of anti-reflux medication in idiopathic pulmonary fibrosis (IPF). However, the effect of anti-reflux therapy in this group remains controversial. We systematically reviewed literatures to evaluate whether anti-reflux therapy could ameliorate pulmonary function in IPF.

Methods

We performed electronic search in PubMed, Embase and CENTRAL (Cochrane Central Register of Controlled Trials) to identify original articles published in English language. We included randomized controlled trials (RCTs) and observational studies regarding anti-reflux therapy on pulmonary function in IPF. Qualitative and quantitative analyses were conducted. In quantitative analysis, the inverse-variance method with fixed-effect model was used to analyze pooled data.

Results

Fifteen studies (2 RCTs and 13 observational studies) including 3,891 patients with IPF were included. Pooled analysis suggested that anti-reflux therapy did not improve forced vital capacity (FVC)% predicted [mean difference (MD) =0.88, 95% confidence interval (CI): −0.22 to 1.98, P=0.12, I² =0%, 8 studies, n=3,076], diffusing capacity of the lung for carbon monoxide (DLCO) % predicted (MD =0.75, 95% CI: −0.13 to 1.62, P=0.10, I² =0%, 8 studies, n=3,073), and FVC decline (MD =0.02, 95% CI: −0.01 to 0.04, P=0.29, I² =17%, 5 studies, n=1,586) in IPF.

Discussion

Anti-reflux therapy may not ameliorate pulmonary function in IPF. However, adequately powered studies are warranted to validate the present findings.

Cough in Idiopathic Pulmonary Fibrosis

Chronic cough is experienced by most patients with idiopathic pulmonary fibrosis (IPF). It is often the first symptom and is associated with reduced quality of life, increased rates of depression and anxiety, more severe physiological impairment, and disease progression. Although not fully understood, recent gains in understanding the pathophysiology of chronic cough in IPF have been made. The pathophysiology is likely multifactorial and includes alterations in mucous production and clearance, architectural distortion, and increased cough reflex sensitivity, suggesting a role for targeted therapies and multidisciplinary treatment. Modifiable comorbidities can also induce cough in patients with IPF. There is a renewed emphasis on measuring cough in IPF, with clinical trials of novel and repurposed therapies for chronic cough emerging in this population. This review provides an update on the clinical characteristics, pathophysiology, and measurement of chronic cough in patients with IPF and summarizes recent developments in non-pharmacological and pharmacological therapies.

Comparing New-User Cohort Designs: The Example of Proton Pump Inhibitor Effectiveness in Idiopathic Pulmonary Fibrosis

The prevalent new-user cohort design is useful for assessing the effectiveness of a medication in the absence of an active comparator. Alternative approaches, particularly in the presence of informative censoring, include a variant of this design based on never users of the study drug and the marginal structural Cox model approach. We compared these approaches in assessing the effectiveness of proton pump inhibitors (PPIs) in reducing mortality among patients with idiopathic pulmonary fibrosis (IPF) using a cohort of IPF patients identified in the United Kingdom's Clinical Practice Research Datalink and diagnosed between 2003 and 2016. The cohort included 2,944 IPF patients, 1,916 of whom initiated use of PPIs during follow-up. There were 2,136 deaths (mortality rate = 25.8 per 100 person-years). Using the conventional prevalent new-user design, we found a hazard ratio for death associated with PPI use compared with nonuse of 1.07 (95% confidence interval (CI): 0.94, 1.22). The variant of the prevalent new-user design comparing PPI users with never users found a hazard ratio of 0.82 (95% CI: 0.73, 0.91), while the marginal structural Cox model found a hazard ratio of 1.08 (95% CI: 0.85, 1.38). The marginal structural model and the conventional prevalent new-user design, both accounting for informative censoring, produced similar results. However, the prevalent new-user design variant based on never users introduced selection bias and should be avoided.

Gastroesophageal Reflux Disease and Idiopathic Lung Fibrosis. From Heartburn to Lung Transplant, and Beyond

Idiopathic pulmonary fibrosis (IPF) and gastroesophageal reflux disease (GERD) are undoubtedly related. Even though it is not clear yet which one is the primary disease, they certainly interact increasing each other's severity. Symptoms are unreliable to diagnose GERD in patients with IPF, and objective evaluation with pH monitoring and/or bronchoalveolar lavage analysis is mandatory. Pharmacological treatment with proton pump inhibitors (PPIs) may bring control of IPF in few patients, but PPIs do not control reflux but just change the pH of the gastric refluxate. Surgical therapy based on a fundoplication is safe and effective as it controls any type of reflux, independently from the pH of the gastric refluxate. In patients waiting for lung transplantation (if they can tolerate a laparoscopic operation under general anesthesia), a fundoplication before the operation might block the progression of IPF, while after transplantation it might prevent rejection by preventing the bronchiolitis obliterans syndrome.

Reflux-Aspiration in Chronic Lung Disease

Microaspiration, or silent aspiration, is commonly suspected in patients with refractory respiratory symptoms, including unexplained chronic cough, asthma, chronic obstructive pulmonary disease, bronchiolitis, bronchiectasis, and idiopathic pulmonary fibrosis. This suspicion is driven by the high prevalence of gastroesophageal reflux in these otherwise disparate disorders. Frequently, patients receive aggressive treatment for gastroesophageal reflux disease as a means of treating their underlying respiratory conditions, even in the absence of overt symptoms of reflux. However, clinical trials have not demonstrated a clear impact on outcomes with this strategy, and in some instances there may be potential for harm. Mechanistic studies have increasingly used gastric biomarkers obtained directly from the airways to confirm the association between reflux and respiratory disease, but results are limited by methodologic flaws and correlation. The best evidence of aspiration directly causing respiratory disorders is the histopathologic detection of foreign bodies. For most of the other chronic respiratory disorders, microaspiration may be uncommon or a secondary aggravating factor, as in patients with acute exacerbations of chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. In some cases, microaspiration is probably not a significant factor at all, such as in unexplained chronic cough. It is important to distinguish between conditions in which aspiration is primarily or directly causal and conditions in which aspiration may be indirectly aggravating, to help identify whether interventions targeting reflux and aspiration precautions should be recommended to patients. Our clinical review examines some of the evidence supporting reflux-aspiration as a mechanism for several chronic respiratory disorders and offers some management considerations when reflux-aspiration is suspected.

Idiopathic pulmonary fibrosis and gastroesophageal reflux disease: A population-based, case-control study

BACKGROUND

It is unknown whether gastroesophageal reflux disease (GERD) is a risk factor or consequence of idiopathic pulmonary fibrosis (IPF). This study aimed to determine whether patients with IPF were more likely to have GERD compared with age- and sex-matched controls who either had 1) interstitial lung disease (ILD) other than IPF or 2) no diagnosed lung disease (population control).

METHODS

We used the medical records-linkage system of the Rochester Epidemiology Project (REP) to identify patients with IPF who resided in Olmsted County, Minnesota, from January 1, 1997, through June 30, 2017. IPF cases were each matched with patients from 2 control groups (non-IPF ILD controls and population controls). We used conditional logistic regression to model associations between GERD diagnosis and IPF case status. P values were adjusted for multiple comparisons by using the Bonferroni adjustment (P values < .025 were considered statistically significant).

RESULTS

One hundred thirteen IPF cases were identified and matched to 226 population controls and 226 controls with non-IPF ILD. After multivariable adjustment, the odds of having GERD were 1.78 times higher (95% CI, 1.09-2.91; P = .02) in IPF cases compared with population controls. After multivariable adjustment, the odds of having GERD were 0.46 times lower (95% CI, 0.23-0.94; P = .03) in IPF cases compared with non-IPF ILD controls.

CONCLUSION

GERD may be an important contributor to the development of lung fibrosis. Thus, it should be investigated and addressed adequately when detected in patients with IPF and patients with non-IPF ILD.

Idiopathic pulmonary fibrosis: Molecular mechanisms and potential treatment approaches

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease with high mortality that commonly occurs in middle-aged and older adults. IPF, characterized by a decline in lung function, often manifests as exertional dyspnea and cough. Symptoms result from a fibrotic process driven by alveolar epithelial cells that leads to increased migration, proliferation, and differentiation of lung fibroblasts. Ultimately, the differentiation of fibroblasts into myofibroblasts, which synthesize excessive amounts of extracellular matrix proteins, destroys the lung architecture. However, the factors that induce the fibrotic process are unclear. Diagnosis can be a difficult process; the gold standard for diagnosis is the multidisciplinary conference. Practical biomarkers are needed to improve diagnostic and prognostic accuracy. High-resolution computed tomography typically shows interstitial pneumonia with basal and peripheral honeycombing. Gas exchange and diffusion capacity are impaired. Treatments are limited, although the anti-fibrotic drugs pirfenidone and nintedanib can slow the progression of the disease. Lung transplantation is often contraindicated because of age and comorbidities, but it improves survival when successful. The incidence and prevalence of IPF has been increasing and there is an urgent need for improved therapies. This review covers the detailed cellular and molecular mechanisms underlying IPF progression as well as current treatments and cutting-edge research into new therapeutic targets.

Esophageal Evaluation for Patients Undergoing Lung Transplant Evaluation: What Should We Do for Evaluation and Management

Lung transplantation is a high-risk, but lifesaving, procedure for patients with end-stage lung disease. Although 1-year survival is high, long-term survival is not nearly as high, due mainly to acute and chronic rejection. Bronchiolitis obliterans syndrome is the most common type of chronic rejection and often leads to poor outcomes. For this reason, esophageal testing in the lung transplant population has become a major issue, and this article discusses the evidence behind esophageal testing, the importance of esophageal dysmotility gastroesophageal reflux disease, both acidic and nonacidic reflux, and aspiration and the treatment of these findings.

Effectiveness of Proton Pump Inhibitors in Idiopathic Pulmonary Fibrosis: A Population-Based Cohort Study

BACKGROUND

Gastroesophageal reflux disease is a common comorbidity in idiopathic pulmonary fibrosis (IPF) and may contribute to its progression. Anti-acid therapy, such as proton pump inhibitors (PPIs), has been considered as a potential treatment option for IPF. The evidence for this treatment comes from several observational studies affected by time-related bias.

RESEARCH QUESTION

Is use of PPIs in patients with IPF associated with a reduction in all-cause mortality, respiratory-related mortality, and respiratory-related hospitalization?

STUDY DESIGN AND METHODS

We used the UK Clinical Practice Research Datalink to identify a cohort of patients diagnosed with IPF between 2003 and 2016. The prevalent new-user cohort design was used to match patients initiating PPIs with non-users using time-conditional propensity scores, with follow-up until death or end of observation. Cox models were used to estimate hazard ratios (HR) and 95% CIs of death and of a respiratory-related hospitalization, correcting for informative censoring by inverse probability weighting.

RESULTS

There were 1,852 PPI users who were matched to 1,852 non-users identified among the cohort of patients with IPF, with a median survival of 2.8 years (mortality rate, 26.7 per 100 per year). The HR of all-cause mortality with PPI use was 1.07 (95% CI, 0.94-1.22), relative to non-use. For respiratory-related mortality, the HR was 1.10 (95% CI, 0.94-1.28) and 1.00 (95% CI, 0.86-1.16) for respiratory-related hospitalizations.

INTERPRETATION

PPI use was not associated with lower mortality or hospitalization incidence in this large study conducted among patients with IPF within a real-world setting of clinical practice and designed to avoid the time-related biases affecting previous studies. PPIs may not be as beneficial in treating IPF as suggested by some studies and conditionally recommended in treatment guidelines.

The profibrotic effects of chronic microaspiration of bile acids on lungs of rats at different stages

This study aimed to explore the profibrotic effects of chronic microaspiration of two major bile acids, including chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA), on lungs of rats at different stages, as well as the underlying mechanisms in vivo. A rat model was induced by weekly intratracheal instillation of DCA and CDCA. Our results showed that chronic microaspiration of bile acids resulted in alveolar structure disorder, and inflammatory cells infiltration in the pulmonary interstitium at the early stage. Subsequently, numerous fibroblasts were proliferated, and collagen deposition was profoundly increased over the interstitium of the airways and vessels. Compared with control group, the expression of α-smooth muscle actin, type I collagen, hydroxyproline, transforming growth factor-β1 (TGF-β1), and matrix metalloproteinase-9 in the lung tissues were remarkably elevated at the 2nd week, reached the highest level at the 6th week, and maintained high at the 8th week in both DCA- and CDCA-treated groups (P < 0.05). Furthermore, chronic microaspiration of bile acids led to higher levels of glutathione and malondialdehyde, while lower level of superoxide dismutase in lung tissues compared with controls (P < 0.05), thereby resulting in the oxidant/antioxidant enzyme imbalance in the formation of fibrosis. In addition, we also found a consistent growth in the expression of farnesoid X receptor (FXR) in both DCA- and CDCA-treated groups. Our findings suggested that chronic microaspiration of bile acids could initiate the process of pulmonary fibrosis from the early phase and promote its progression in a time-dependent manner, which likely involved the TGF-β1, oxidative stress, and FXR-related pathways.

Phenotypes of Gastroesophageal Reflux Disease: Where Rome, Lyon, and Montreal Meet

Gastroesophageal reflux disease (GERD) is now one of the most common diagnoses made in a gastroenterology practice. From a conventional pathophysiological perspective, GERD is conceptualized as incompetence of the antireflux barrier at the esophagogastric junction; the more severe that incompetence, the worse the disease. However, it is increasingly clear that many presentations of GERD represent distinct phenotypes with unique predisposing cofactors and pathophysiology outside of this paradigm. Three major consensus initiatives have grappled with this dilemma (the Montreal Consensus, The Rome Foundation, and the Lyon Consensus), each from a different perspective. Montreal struggled to define the disease, Rome sought to characterize its functional attributes, while Lyon examined its physiological attributes. Here, we merge the 3 perspectives, developing the concept that what has come to be known as GERD is actually a family of syndromes with a complex matrix of contributing pathophysiology. A corollary to this is that the concept of one size fits all to therapeutics does not apply, and that although escalating treatment with proton pump inhibitors (PPIs) may be pertinent to healing esophagitis, its applicability beyond that is highly questionable. Similarly, failing to recognize the modulating effects of anxiety, hypervigilance, and visceral and central hypersensitivity on symptom severity has greatly oversimplified the problem. That oversimplification has led to excessive use of PPIs for everything captured under the GERD umbrella and shown a broad spectrum of syndromes less amenable to PPI therapy in any dose. It is with this in mind that we delineate this precision medicine concept of GERD.

Brazilian guidelines for the pharmacological treatment of idiopathic pulmonary fibrosis. Official document of the Brazilian Thoracic Association based on the GRADE methodology

Idiopathic pulmonary fibrosis (IPF) is a form of chronic interstitial lung disease of unknown cause, which predominantly affects elderly men who are current or former smokers. Even though it is an uncommon disease, it is of great importance because of its severity and poor prognosis. In recent decades, several pharmacological treatment modalities have been investigated for the treatment of this disease, and the classic concepts have therefore been revised. The purpose of these guidelines was to define evidence-based recommendations regarding the use of pharmacological agents in the treatment of IPF in Brazil. We sought to provide guidance on the practical issues faced by clinicians in their daily lives. Patients of interest, Intervention to be studied, Comparison of intervention and Outcome of interest (PICO)-style questions were formulated to address aspects related to the use of corticosteroids, N-acetylcysteine, gastroesophageal reflux medications, endothelin-receptor antagonists, phosphodiesterase-5 inhibitors, pirfenidone, and nintedanib. To formulate the PICO questions, a group of Brazilian specialists working in the area was assembled and an extensive review of the literature on the subject was carried out. Previously published systematic reviews with meta-analyses were analyzed for the strength of the compiled evidence, and, on that basis, recommendations were developed by employing the Grading of Recommendations Assessment, Development and Evaluation approach. The authors believe that the present document represents an important advance to be incorporated in the approach to patients with IPF, aiming mainly to improve its management, and can become an auxiliary tool for defining public policies related to IPF.