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

Radiological findings in gastrointestinal scleroderma

Gastrointestinal involvement is the most common visceral organ manifestation in systemic sclerosis. Symptoms from the gastrointestinal tract are very frequent among scleroderma patients and in many cases present a therapeutic challenge. However, gastrointestinal involvement may also be asymptomatic, presenting with complications later in the disease course. Early recognition of gastrointestinal scleroderma is therefore important both for symptomatic control and prevention of complications. Gastrointestinal imaging alongside clinical assessment forms the mainstay of diagnosis. Radiological investigations, traditionally plain radiographs and barium studies, with the more recent advances in computed tomography, magnetic resonance imaging and ultrasound, provide means for accurate evaluation of visceral organ involvement and more effective patient care. Awareness of the characteristic images is important not only for radiologists but also for the treating physicians and gastroenterologists.

The profibrotic effect of downregulated Na,K‑ATPase β1 subunit in alveolar epithelial cells during lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by progressive lung scarring and excessive extracellular matrix depositon. When stimulated, alveolar epithelial cells (AECs) are aberrantly activated, the expression of profibrotic molecules is enhanced, and lung fibrosis is promoted, but the mechanism for this is unclear. It has been reported that a downregulation of the Na,K‑ATPase β1 subunit in renal epithelial cells is involved in renal fibrosis development, but the role of this protein in lung fibrosis remains unknown. In the present study, the expression of the Na,K‑ATPase β1 subunit was revealed to be markedly decreased in AECs of patients with IPF and a bleomycin‑induced pulmonary fibrosis mouse model. Treatment with transforming growth factor β‑1 led to significantly downregulation of the Na,K‑ATPase β1 subunit in lung adenocarcioma A549 cells. Furthermore, the knockdown of the Na,K‑ATPase β1 subunit in A549 cells resulted in the upregulation of profibrotic molecules, activation of the neurogenic locus notch homolog protein 1 and extracellular signal‑regulated kinase 1/2 signaling pathways and induction of endoplasmic reticulum stress. These findings reveal that the downregulation of the Na,K‑ATPase β1 subunit enhances the expression of profibrotic molecules in AECs and may contribute to IPF pathogenesis.

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

BACKGROUND AND OBJECTIVE

Gastroesophageal reflux disease (GORD) is highly prevalent in idiopathic pulmonary fibrosis (IPF) and may play a role in its pathogenesis. Recent IPF treatment guidelines suggest that all patients with IPF be considered for antacid therapy. However, emerging evidence suggests that antacid therapy does not improve IPF patient outcomes and may increase the risk of pulmonary infection.

METHODS

Using prospectively collected data from the Australian IPF Registry including use of antacid therapy, GORD diagnosis and GORD symptoms, the relationship of these GORD variables to survival and disease progression was assessed. The severity of GORD symptoms using the frequency scale for symptoms of GORD (FSSG) and its relationships to outcomes was also assessed for the first time in an IPF cohort.

RESULTS

Five hundred eighty-seven (86%) of the 684 patients in the Australian IPF Registry were eligible for inclusion. Patients were mostly male (69%), aged 71.0 ± 8.5 years with moderate disease (FVC 81.7 ± 21.5%; DLco 48.5 ± 16.4%). Most patients were taking antacids (n = 384; 65%), though fewer had a diagnosis of GORD (n = 243, 41.4%) and typical GORD symptoms were even less common (n = 171, 29.1%). The mean FSSG score was 8.39 ± 7.45 with 43% (n = 251) having a score > 8. Overall, there was no difference in survival or disease progression, regardless of antacid treatment, GORD diagnosis or GORD symptoms.

CONCLUSIONS

Neither the use of antacid therapy nor the presence of GORD symptoms affects longer term outcomes in IPF patients. This contributes to the increasing evidence that antacid therapy may not be beneficial in IPF patients and that GORD directed therapy should be considered on an individual basis to treat the symptoms of reflux.

Long-Term Effects and Adverse Events of Nintedanib Therapy in Idiopathic Pulmonary Fibrosis Patients with Functionally Advanced Disease

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is one of the most common interstitial lung diseases with limited survival. The effect of IPF therapy in patients with severely impaired lung function is not well established. The aim of this study was to characterize IPF patients with a forced vital capacity (FVC) < 50% (group 1) and FVC 50-60% predicted (group 2) and analyze the effect and adverse events of nintedanib in Hungarian patients diagnosed between April 2015 and July 2017.

METHODS

The impact of nintedanib therapy on lung function, survival, and adverse events was analyzed longitudinally.

RESULTS

Twenty-two out of 103 patients were included in the analysis (group 1: N = 10; male/female = 6:4, age 62.6 ± 10.8 years and group 2: N = 12; male/female = 3:9, age 65.7 ± 11.6 years). Eighteen patients were treated with nintedanib (8 in group 1, 10 in group 2); treatment stabilized lung function in 42% and 50%, respectively, in the two groups. Median survival was 444 days for group 1 and 476 days for group 2. Adverse events were less common than in clinical trials; dose reduction was necessary in three cases, drug discontinuation in two cases. No differences between groups were identified regarding clinical parameters and radiological pattern; however, hypertension as comorbidity was more common in group 1 patients.

CONCLUSIONS

Nintedanib therapy was effective and well tolerated even among patients with severely impaired lung function. Longitudinal follow-up confirmed high mortality in patients with very severe and severe IPF; however, median survival was meaningful as it exceeded 1 year in both groups.

Economic burden of incident interstitial lung disease (ILD) and the impact of comorbidity on costs of care

INTRODUCTION

Evidence about the economic burden related to interstitial lung diseases (ILDs) and the cost-driving factors is sparse. In the knowledge that distinct comorbidities affect the clinical course of ILDs, our study investigates their impact on costs of care within first year after diagnosis.

METHODS

Using claims data of individuals diagnosed with Idiopathic Interstitial Pneumonia (IIP) (n = 14 453) or sarcoidosis (n = 9106) between 2010 and 2013, we calculated total and ILD-associated mean annual per capita costs adjusted by age, sex and comorbidity burden via Generalized Linear Gamma models. Then, we assessed the cost impact of chronic obstructive pulmonary disease (COPD), diabetes, coronary artery disease, depression, gastro-esophageal reflux disease, pulmonary hypertension (PH), obstructive sleep apnoea syndrome (OSAS) and lung cancer using the model-based parameter estimates.

RESULTS

Total mean annual per capita costs were €11 131 in the pooled cohort, €12 111 in IIP and €8793 in sarcoidosis, each with a 1/3 share of ILD-associated cost. Most comorbidities had a significant cost-driving effect, which was most pronounced for lung cancer in total (1.989 pooled, 2.491 sarcoidosis, 1.696 IIP) and for PH in ILD-associated costs (2.606 pooled, 2.347 IIP, 3.648 sarcoidosis). The lung-associated comorbidities COPD, PH, OSAS more strongly affected ILD-associated than total costs.

CONCLUSION

Comorbidities increase the already substantial costs of care in ILDs. To support patient-centred ILD care, not only highly cost-driving conditions that are inherent with high mortality themselves require systematic management. Moreover, conditions that are more rather restricting the patient's activities of daily living should be addressed - despite a low-cost impact.

Epidemiology of Pulmonary Fibrosis: A Cohort Study Using Healthcare Data in Sweden

Introduction

Data on the epidemiology of idiopathic pulmonary fibrosis (IPF) in Sweden are lacking. This study estimates the incidence and prevalence of IPF in Sweden, and describes the demographic and clinical characteristics and the overall survival of patients with IPF.

Methods

Two cohorts were studied: a national cohort of 17,247 patients with pulmonary fibrosis (ICD-10 code J84.1 with no competing diagnosis) from the Swedish National Patient Register (cohort 1 [C1]); and an electronic medical record-based regional subset of C1 comprising 1755 patients having pulmonary fibrosis and a radiology procedure (C2).

Results

The incidence of pulmonary fibrosis in C1 ranged from 10.4 to 15.4 cases per 100,000 population per year between 2001 and 2015. The prevalence increased from 15.4 to 68.0 cases per 100,000 population per year. Patients ≥ 70 years and men had a higher incidence and prevalence of pulmonary fibrosis. Common comorbidities included respiratory infections and cardiovascular disorders. Approximately one-third of patients in each cohort were hospitalised with pulmonary fibrosis within a year of diagnosis. The median survival time from disease diagnosis was 2.6 years in C1 and 5.2 years in C2. Older patients had a higher risk of hospitalisation and mortality. Women had a better prognosis than men.

Conclusion

This study underscores the importance of pulmonary fibrosis as a cause of respiratory-related morbidity and mortality in Sweden. The stable incidence and increasing prevalence over time suggests longer survival. The higher morbidity and mortality in older patients highlights the importance of early case detection, diagnosis and management for better prognosis.

Funding

F. Hoffmann-La Roche, Ltd./Genentech, Inc.

Electronic supplementary material

The online version of this article (10.1007/s41030-019-0087-9) contains supplementary material, which is available to authorized users.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 2. Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia, which presents with a progressive worsening dyspnea, and thus a poor outcome. The members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Korea Interstitial Lung Disease Study Group drafted this clinical practice guideline for IPF management. This guideline includes a wide range of topics, including the epidemiology, pathogenesis, risk factors, clinical features, diagnosis, treatment, prognosis, and acute exacerbation of IPF in Korea. Additionally, we suggested the PICO for the use of pirfenidone and nintendanib and for lung transplantation for the treatment of patients with IPF through a systemic literature review using experts' help in conducting a meta-analysis. We recommend this guideline to physicians, other health care professionals, and government personnel in Korea, to facilitate the treatment of patients with IPF.

Diabetes and Lung Disease: A Neglected Relationship

BACKGROUND

Diabetes mellitus is a systemic disorder associated with inflammation and oxidative stress which may target many organs such as the kidney, retina, and the vascular system. The pathophysiology, mechanisms, and consequences of diabetes on these organs have been studied widely. However, no work has been done on the concept of the lung as a target organ for diabetes and its implications for lung diseases.

AIM

In this review, we aimed to investigate the effects of diabetes and hypoglycemic agent on lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, and lung cancer. We also reviewed the potential mechanisms by which these effects may affect lung disease patients.

RESULTS

Our results suggest that diabetes can affect the severity and clinical course of several lung diseases.

CONCLUSIONS

Although the diabetes-lung association is epidemiologically and clinically well-established, especially in asthma, the underlying mechanism and pathophysiology are not been fully understood. Several mechanisms have been suggested, mainly associated with the pro-inflammatory and proliferative properties of diabetes, but also in relation to micro- and macrovascular effects of diabetes on the pulmonary vasculature. Also, hypoglycemic drugs may influence lung diseases in different ways. For example, metformin was considered a potential therapeutic agent in lung diseases, while insulin was shown to exacerbate lung diseases; this suggests that their effects extend beyond their hypoglycemic properties.

Idiopathic pulmonary fibrosis: unmasking cryptogenic environmental factors

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease of unknown origin that is associated with high morbidity and mortality. In this perspective, we briefly review the current understanding of the pathophysiology of IPF and the importance of environmental triggers as a precipitant of disease. We discuss occult intrinsic and extrinsic environmental factors that affect the lung microenvironment and may contribute to the development and progression of disease. The clinical implications of this framework need to be further elucidated, because prompt identification and elimination of occult exposures may represent a novel treatment modality.

Idiopathic Pulmonary Fibrosis: Epidemiology, Diagnosis andOutcomes

The incidence and prevalence of idiopathic pulmonary fibrosis (IPF) is increasing worldwide. This, combined with its poor prognosis and unpredictable natural history, has amplified the importance of an accurate diagnosis and monitoring. A diagnosis of exclusion, IPF requires a comprehensive clinical evaluation. This results in a clinical context that provides the backdrop for interpretation of the chest imaging and histopathology. A confident or probable usual interstitial pneumonia chest imaging pattern on high-resolution computerized tomography may be diagnostic in the correct clinical context. Outcomes for IPF are unpredictable, ranging from rapid progression with death within months to prolonged stability. Disease activity is monitored by clinical and physiology measures with a declining forced vital capacity, a recognized measure of progression. The available treatments, pirfenidone and nintedanib, are effective at reducing the expected decline in forced vital capacity.

Idiopathic Pulmonary Fibrosis for Cardiologists: Differential Diagnosis, Cardiovascular Comorbidities, and Patient Management

The presence of rare comorbidities in patients with cardiovascular disease (CVD) presents a diagnostic challenge to cardiologists. In evaluating these patients, cardiologists are faced with a unique opportunity to shorten diagnosis times and direct patients towards correct treatment pathways. Idiopathic pulmonary fibrosis (IPF), a type of interstitial lung disease (ILD), is an example of a rare disease where patients frequently demonstrate comorbid CVD. Both CVD and IPF most commonly affect a similar patient demographic: men over the age of 60 years with a history of smoking. Moreover, IPF and heart failure (HF) share a number of symptoms. As a result, patients with IPF can be misdiagnosed with HF and vice versa. This article aims to increase awareness of IPF among cardiologists, providing an overview for cardiologists on the differential diagnosis of IPF from HF, and describing the signs and symptoms that would warrant referral to a pulmonologist with expertise in ILD. Once patients with IPF have received a diagnosis, cardiologists can have an important role in managing patients who are candidates for a lung transplant or those who develop pulmonary hypertension (PH). Group 3 PH is one of the most common cardiovascular complications diagnosed in patients with IPF, its prevalence varying between reports but most often cited as between 30% and 50%. This review summarizes the current knowledge on Group 3 PH in IPF, discusses data from clinical trials assessing treatments for Group 1 PH in patients with IPF, and highlights that treatment guidelines recommend against these therapies in IPF. Finally, this article provides the cardiologist with an overview on the use of the two approved treatments for IPF, the antifibrotics pirfenidone and nintedanib, in patients with IPF and CVD comorbidities. Conversely, the impact of treatments for CVD comorbidities on patients with IPF is also discussed.Funding: F. Hoffmann-La Roche, Ltd.Plain Language Summary: Plain language summary available for this article.

Randomised, double-blind, placebo-controlled pilot trial of omeprazole in idiopathic pulmonary fibrosis

Background

Cough is a common, disabling symptom of idiopathic pulmonary fibrosis (IPF), which may be exacerbated by acid reflux. Inhibiting gastric acid secretion could potentially reduce cough. This study aimed to determine the feasibility of a larger, multicentre trial of omeprazole for cough in IPF, to assess safety and to quantify cough.

Methods

Single-centre, double-blind, randomised, placebo-controlled pilot trial of the proton pump inhibitor (PPI) omeprazole (20 mg twice daily for 3 months) in patients with IPF. Primary objectives were to assess feasibility and acceptability of trial procedures. The primary clinical outcome was cough frequency.

Results

Forty-five participants were randomised (23 to omeprazole, 22 to placebo), with 40 (20 in each group) having cough monitoring before and after treatment. 280 patients were screened to yield these numbers, with barriers to discontinuing antacids the single biggest reason for non-recruitment. Recruitment averaged 1.5 participants per month. Geometric mean cough frequency at the end of treatment, adjusted for baseline, was 39.1% lower (95% CI 66.0% lower to 9.3% higher) in the omeprazole group compared with placebo. Omeprazole was well tolerated and adverse event profiles were similar in both groups, although there was a small excess of lower respiratory tract infection and a small fall in forced expiratory volume and forced vital capacity associated with omeprazole.

Conclusions

A large randomised controlled trial of PPIs for cough in IPF appears feasible and justified but should address barriers to randomisation and incorporate safety assessments in relation to respiratory infection and changes in lung function.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

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

Association between Pepsin in Bronchoalveolar Lavage Fluid and Prognosis of Chronic Fibrosing Interstitial Lung Disease

Chronic fibrosing interstitial lung disease (ILD)s are characterized by chronic progressive fibrosis of lung which include idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia (NSIP), and connective tissue disease-associated interstitial lung disease (CTD-ILD). IPF is an irreversible fibrotic lung disease which results in respiratory failure. Although NSIP and CTD-ILD can be improved or stable by treatment with corticosteroid or immunosuppressant, some of them progress to fibrotic lung diseases. Aspiration of gastric contents is suggested as an aggravating factor of ILDs. We measured pepsin, a marker of gastric aspiration, in bronchoalveolar lavage (BAL) fluid of chronic fibrosing ILD patients to evaluate the association between BAL fluid pepsin and prognosis of chronic fibrosing ILDs. Patients with chronic fibrosing ILDs, who underwent bronchoscopy between December 2010 and April 2015 were prospectively enrolled. Pepsin levels were measured using a commercial ELISA kit. Clinical characteristics, lung function data, and mortality were analyzed. Fifty-one patients with chronic fibrosing ILDs were enrolled (26 with IPF, 15 with NSIP, and 10 with CTD-ILD). Pepsin levels in BAL fluid were 69.87 ± 74.16 ng/mL in IPF, 110.68 ± 94.93 ng/mL in NSIP, and 101.87 ± 88.44 ng/mL in CTD-ILDs. There were no statistically significant differences in BAL fluid pepsin levels among patients with the different chronic fibrosing ILDs. In multivariate regression analysis, higher BAL pepsin levels were associated with higher mortality (adjusted odds ratio [aOR] = 1.021, p = 0.025). BAL fluid pepsin may be used as a prognostic marker for predicting mortality in chronic fibrosing ILD patients.

Usual Interstitial Pneumonia Pattern in the Lower Lung Lobes as a Prognostic Factor in Idiopathic Pleuroparenchymal Fibroelastosis

BACKGROUND

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare interstitial pneumonia that is characterized by stiffness in both the upper lobes and pleura, which is evident on high resolution computed tomography (HRCT) of the chest. However, prognostic factors for IPPFE have not been identified yet.

OBJECTIVE

We aimed to investigate the clinical prognostic factors affecting survival in patients with IPPFE.

METHODS

Between April 2009 and September 2017, we enrolled 36 patients who were clinically diagnosed with IPPFE, using HRCT. These patients were classified as either short survival (dead within 12 months from the diagnosis of IPPFE) or long survival (survived for greater than 12 months) groups. We retrospectively analyzed the clinical characteristics, serum markers, pulmonary function test results, and HRCT findings.

RESULTS

Twelve patients were classified into the short survival and 24 were categorized into long survival categories. At the time of diagnosis, the incidence of coexistence of a usual interstitial pneumonia (UIP) pattern in the lower lobes on HRCT in the short survival was significantly higher than that in the long survival. Multivariate analysis revealed that a UIP pattern in the lower lobes on HRCT was the only independent variable for poor prognosis. The median survival time from diagnosis in patients with IPPFE was 24 months. Of these patients with IPPFE, the survival time with a UIP pattern was significantly shorter than in those without a UIP pattern.

CONCLUSION

Our findings suggest that a UIP pattern in the lower lobes at the time of diagnosis was an independent prognostic factor for IPPFE.

Idiopathic Pulmonary Fibrosis: Epidemiology, Natural History, Phenotypes

Idiopathic pulmonary fibrosis (IPF) is the most common of the idiopathic interstitial pneumonias. It is characterized by a chronic, progressive, fibrotic interstitial lung disease of unknown cause that occurs primarily in older adults. Its prevalence and incidence have appeared to be increasing over the last decades. Despite its unknown nature, several genetic and environmental factors have been associated with IPF. Moreover, its natural history is variable, but could change depending on the currently suggested phenotypes: rapidly progressive IPF, familial, combined pulmonary fibrosis and emphysema, pulmonary hypertension, and that associated with connective tissue diseases. Early recognition and accurate staging are likely to improve outcomes and induce a prompt initiation of antifibrotics therapy. Treatment is expected to be more effective in the early stages of the disease, while developments in treatment aim to improve the current median survival of 3⁻4 years after diagnosis.

Interstitial lung diseases in dogs and cats part II: Known cause and other discrete forms

In addition to idiopathic interstitial pneumonias, interstitial lung diseases (ILDs) can occur secondary to known causes or be classified as discrete syndromes. Also known as diffuse parenchymal lung diseases, the ILDs represent a heterogenous group of non-infectious, non-neoplastic disorders characterized by varied patterns of inflammation and fibrosis. Characteristically associated with the true interstitium (i.e. the anatomic space lined by alveolar epithelial cells and capillary endothelial cells and the loose-binding connective tissue), it is important to understand ILDs are associated with pathology of the distal lung parenchyma and thus lesions can be bronchiolocentric or resemble alveolar filling disorders. Injury to the distal lung can occur via inhalation or hematogenous routes. This review will build on a proposed classification scheme adapted from human medicine to describe known cause and discrete forms of ILDs in dogs and cats.

Reflux in idiopathic pulmonary fibrosis: treatment informed by an integrated approach

Despite recent therapeutic advances, the prognosis for patients with idiopathic pulmonary fibrosis (IPF) remains poor. The link with gastro-oesophageal reflux disease (GORD) has been identified as a research priority, as GORD appears to be common in IPF and may be associated with adverse outcomes [1]. GORD is often clinically silent in IPF, so detection is challenging [2].

After MDT work-up and review, gastro-oesophageal reflux and pulmonary aspiration were found to be common in IPF patients; surgery was recommended in only 10%http://ow.ly/rO3T30lU17o

Reflux aspiration in lungs of dogs with respiratory disease and in healthy West Highland White Terriers

BACKGROUND

Gastroesophageal reflux and microaspiration (MA) of gastric juice are associated with various human respiratory diseases but not in dogs.

OBJECTIVE

To detect the presence of bile acids in bronchoalveolar lavage fluid (BALF) of dogs with various respiratory diseases.

ANIMALS

Twenty-seven West Highland White Terriers (WHWTs) with canine idiopathic pulmonary fibrosis (CIPF), 11 dogs with bacterial pneumonia (BP), 13 with chronic bronchitis (CB), 9 with eosinophilic bronchopneumopathy (EBP), 19 with laryngeal dysfunction (LD), 8 Irish Wolfhounds (IWHs) with previous BPs, 13 healthy WHWTs, all privately owned dogs, and 6 healthy research colony Beagles METHODS: Prospective cross-sectional observational study with convenience sampling of dogs. Bile acids were measured by mass spectrometry in BALF samples. Total bile acid (TBA) concentration was calculated as a sum of 17 different bile acids.

RESULTS

Concentrations of TBA were above the limit of quantification in 78% of CIPF, 45% of BP, 62% of CB, 44% of EBP, 68% of LD, and 13% of IWH dogs. In healthy dogs, bile acids were detected less commonly in Beagles (0/6) than in healthy WHWTs (10/13). Concentrations of TBA were significantly higher in CIPF (median 0.013 μM, range not quantifiable [n.q.]-0.14 μM, P < .001), healthy WHWTs (0.0052 μM, n.q.-1.2 μM, P = .003), LD (0.010 μM, n.q.-2.3 μM, P = .015), and CB (0.0078 μM, n.q.-0.073 μM, P = .018) groups compared to Beagles (0 μM, n.q.).

CONCLUSION AND CLINICAL IMPORTANCE

These results suggest that MA occurs in various respiratory diseases of dogs and also in healthy WHWTs.

Risk factors for the development of idiopathic pulmonary fibrosis: A review

Purpose of Review

Idiopathic pulmonary fibrosis (IPF) is an invariably progressive disease. Current treatment options simply slow disease progression and better therapeutic options are needed. We aimed to review emerging literature on risk factors associated with the development of IPF.

Recent findings

There is increasing data to support the role of intrinsic risk factors (e.g. genetics, aging, sex, lung microbiome), co-morbidities (e.g. gastroesophageal reflux, obstructive sleep apnea, diabetes mellitus, herpes virus infection), and extrinsic risk factors (e.g. cigarette smoking, environmental exposures, air pollution) in IPF development. These risk factors may independently increase susceptibility for IPF or act in a synergistic fashion to contribute to increased risk for disease development.

Summary

Various risk factors have been identified in IPF development that fit within the current paradigm of disease pathogenesis. Further investigation in to these risk factors may help us better understand the pathophysiology of IPF and may guide future therapeutic interventions.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Uncertainties and Controversies

The mechanisms of idiopathic pulmonary fibrosis (IPF), a rare, devastating disease with a median survival of 3-5 years, are not fully understood. Gastroesophageal reflux disease (GERD) is a frequent comorbidity encountered in IPF. Hypothetically, GERD-associated microaspiration may lead to persistent inflammation impairing lung infrastructure, thereby possibly accelerating the progression of IPF. IPF may increase intrathoracic pressure, which can aggravate GERD and vice versa. On the basis of the possible beneficial effects of antireflux or antacid therapy on lung function, acute exacerbation, and survival, the recent international IPF guideline recommends antacid therapies for patients with IPF, regardless of symptomatic GERD. However, due to newer conflicting data, several national guidelines do not support this recommendation. Elucidation of these questions by further clinical and bench-to-bedside research may provide us with rational clinical diagnostic and therapeutic approaches concerning GERD in IPF. The present review aims to discuss the latest data on the controversial association of IPF and GERD.

Anti-acid therapy in idiopathic pulmonary fibrosis: insights from the INPULSIS® trials

Background

The benefits and risks of anti-acid medication in patients with idiopathic pulmonary fibrosis (IPF) remain a topic of debate. We investigated whether use of anti-acid medication at baseline was associated with differences in the natural course of disease or influenced the treatment effect of nintedanib in patients with IPF.

Methods

Post-hoc analyses of outcomes in patients receiving versus not receiving anti-acid medication (proton pump or histamine-2 receptor inhibitor) at baseline using pooled data from the two Phase III randomized placebo-controlled INPULSIS® trials of nintedanib in patients with IPF.

Results

At baseline, 406 patients were receiving anti-acid medication (244 nintedanib; 162 placebo) and 655 were not (394 nintedanib; 261 placebo). In an analysis of the natural course of IPF by anti-acid medication use at baseline, the adjusted annual rate of decline in FVC was − 252.9 mL/year in placebo-treated patients who were receiving anti-acid medication at baseline and − 205.4 mL/year in placebo-treated patients who were not (difference of − 47.5 mL/year [95% CI: –105.1, 10.1]; p = 0.1057). In an analysis of the potential influence of anti-acid medication use on the treatment effect of nintedanib, the adjusted annual rates of decline in FVC were − 124.4 mL/year in the nintedanib group and − 252.9 mL/year in the placebo group (difference of 128.6 mL/year [95% CI: 74.9, 182.2]) in patients who were receiving anti-acid medication at baseline and − 107.0 mL/year in the nintedanib group and − 205.3 mL/year in the placebo group (difference of 98.3 mL/year [95% CI: 54.1, 142.5]) in patients who were not (treatment-by-time-by-subgroup interaction p = 0.3869). The proportions of patients who had ≥1 investigator-reported acute exacerbation were 11.7% and 5.0% in placebo-treated patients, and 4.9% and 4.8% of nintedanib-treated patients, among patients who were and were not receiving anti-acid medication at baseline, respectively.

Conclusions

In post-hoc analyses of data from the INPULSIS® trials, anti-acid medication use at baseline was not associated with a more favorable course of disease, and did not impact the treatment effect of nintedanib, in patients with IPF.

Trial registration

ClinicalTrials.gov identifiers: NCT01335464 and NCT01335477.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0866-0) contains supplementary material, which is available to authorized users.

Comorbidities and Complications in Idiopathic Pulmonary Fibrosis

Though idiopathic pulmonary fibrosis (IPF) is characterized by single-organ involvement, many comorbid conditions occur within other organ systems. Patients with IPF may present during evolution different complications and comorbidities that influence the prognosis and modify the natural course of their disease. In this chapter, we highlight common comorbid conditions encountered in IPF, discuss disease-specific diagnostic modalities, and review the current treatment data for several key comorbidities. The diagnosis and treatment of these comorbidities is a challenge for the pulmonologist specialized in interstitial lung diseases (ILDs). We will focus on pulmonary emphysema, lung cancer, gastroesophageal reflux, pulmonary hypertension, obstructive sleep apnea (sleep disorders), and acute exacerbation of IPF.

Lung Transplantation in Idiopathic Pulmonary Fibrosis

Despite the advances in recent years in the treatment of idiopathic pulmonary fibrosis (IPF), it continues to be a progressive disease with poor prognosis. In selected patients, lung transplantation may be a treatment option, with optimal results in survival and quality of life. Currently, pulmonary fibrosis is the main cause of lung transplantation. However, mortality on the waiting list of these patients is high, since many patients are referred to the transplant units with advanced disease. There is not a parameter that can predict the survival of a specific patient. Different variables are to be considered in order to decide the right time to send them to a transplant unit. It is also very difficult to decide when to include these patients on the waiting list. Every patient diagnosed with IPF, without contraindications for surgery, should be referred early to a transplant unit for assessment. A uni or bilateral transplantation will be decided based on the characteristics of the patient and the experience of each center. The post-transplant survival of recipients with IPF is lower than that observed in other diseases, such as cystic fibrosis or chronic obstructive pulmonary disease as a consequence of their older age and the frequent presence of associated comorbidity. Post-transplant follow-up must be tight in order to assure optimal level of immunosuppressive treatment, detect complications associated with it, and avoid graft rejection. The main cause of long-term mortality is late graft dysfunction as a consequence of chronic rejection. Other complications, such as infections and tumors, must be considered.

Meta-analysis of Gastroesophageal Reflux Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND

The relationship between gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) is controversial. Current guidelines recommend that clinicians use regular antacid treatment, while two recent meta-analyses of antacid therapy in IPF were inconclusive. The objective of this study was to examine the evidence regarding the association between GERD and IPF through a systematic review and a meta-analysis, with special reference to the methodologic quality of the observational studies.

METHODS

The MEDLINE, EMBASE, Ovid, and Web of Science (1966-May 2018) databases were searched for original articles published in any language, and we then systematically reviewed the bibliographies of the retrieved articles. Observational studies (cohort and case-control studies) were selected if they allowed the calculation of a measure of association relating GERD to IPF.

RESULTS

Eighteen case-control studies including 3,206 patients with IPF and 9,368 control subjects met the inclusion criteria of the meta-analysis. The meta-analysis indicated that GERD is associated with IPF (OR, 2.94 [95% CI, 1.95-4.42]; P homogeneity < .0001). Overall, the results remained consistent whatever the data source (clinical studies vs databases) or the type of control subject (healthy volunteers, patients with respiratory diseases other than interstitial lung disease, or patients with non-IPF interstitial lung disease). In a meta-regression, after controlling for smoking, GERD and IPF were not related.

CONCLUSIONS

GERD and IPF may be related, but this association is most likely confounded, especially by smoking. Our confidence in the estimate of association is low because it is exclusively from case-control studies.

TRIAL REGISTRY

PROSPERO; No.: CRD42016053728; URL: http://www.crd.york.ac.uk/PROSPERO.

Laparoscopic anti-reflux surgery for the treatment of idiopathic pulmonary fibrosis (WRAP-IPF): a multicentre, randomised, controlled phase 2 trial

BACKGROUND

Abnormal acid gastro-oesophageal reflux (GER) is hypothesised to play a role in progression of idiopathic pulmonary fibrosis (IPF). We aimed to determine whether treatment of abnormal acid GER with laparoscopic anti-reflux surgery reduces the rate of disease progression.

METHODS

The WRAP-IPF trial was a randomised controlled trial of laparoscopic anti-reflux surgery in patients with IPF and abnormal acid GER recruited from six academic centres in the USA. We enrolled patients with IPF, abnormal acid GER (DeMeester score of ≥14·7; measured by 24-h pH monitoring) and preserved forced vital capacity (FVC). We excluded patients with a FVC below 50% predicted, a FEV₁/FVC ratio of less than 0·65, a history of acute respiratory illness in the past 12 weeks, a body-mass index greater than 35, and known severe pulmonary hypertension. Concomitant therapy with nintedanib and pirfenidone was allowed. The primary endpoint was change in FVC from randomisation to week 48, in the intention-to-treat population with mixed-effects models for repeated measures. This trial is registered with ClinicalTrials.gov, number NCT01982968.

FINDINGS

Between June 1, 2014, and Sept 30, 2016, we screened 72 patients and randomly assigned 58 patients to receive surgery (n=29) or no surgery (n=29). 27 patients in the surgery group and 20 patients in the no surgery group had an FVC measurement at 48 weeks (p=0·041). Intention-to-treat analysis adjusted for baseline anti-fibrotic use demonstrated the adjusted rate of change in FVC over 48 weeks was -0·05 L (95% CI -0·15 to 0·05) in the surgery group and -0·13 L (-0·23 to -0·02) in the non-surgery group (p=0·28). Acute exacerbation, respiratory-related hospitalisation, and death was less common in the surgery group without statistical significance. Dysphagia (eight [29%] of 28) and abdominal distention (four [14%] of 28) were the most common adverse events after surgery. There was one death in the surgery group and four deaths in the non-surgery group.

INTERPRETATION

Laparoscopic anti-reflux surgery in patients with IPF and abnormal acid GER is safe and well tolerated. A larger, well powered, randomised controlled study of anti-reflux surgery is needed in this population.

FUNDING

US National Institutes of Health National Heart, Lung and Blood Institute.

The Management of Patients With Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), the most common form of fibrosing idiopathic interstitial pneumonia, is an inexorably progressive disease with a 5-year survival of ~20%. In the last decade, our understanding of disease pathobiology has increased significantly and this has inevitably impacted on the approach to treatment. Indeed, the paradigm shift from a chronic inflammatory disorder to a primarily fibrotic one coupled with a more precise disease definition and redefined diagnostic criteria have resulted in a massive increase in the number of clinical trials evaluating novel candidate drugs. Most of these trials, however, have been negative, probably because of the multitude and redundancy of cell types, growth factors and profibrotic pathways involved in disease pathogenesis. As a consequence, until recently IPF has lacked effective therapies. Finally, in 2014, two large phase 3 clinical trials have provided robust evidence that pirfenidone, a compound with anti-fibrotic, anti-oxidant and anti-inflammatory properties, and nintedanib, a tyrosine kinase inhibitor with selectivity for vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor receptors are able to slow down functional decline and disease progression with an acceptable safety profile. While this is a major achievement, neither pirfenidone nor nintedanib cures IPF and most patients continue to experience disease progression and/or exacerbation despite treatment. Therefore, in recent years increasingly more attention has been paid to preservation of quality of life and, in the advanced phase of the disease, palliation of symptoms. Lung transplantation, the only curative treatment, remains a viable option for only a minority of highly selected patients. The unmet medical need in IPF remains high, and more efficacious and better tolerated drugs are urgently needed. However, a truly effective therapeutic approach should also address quality of life and highly prevalent concomitant conditions and complications of IPF.

The effect of anti-acid therapy on survival in idiopathic pulmonary fibrosis: a methodological review of observational studies

International treatment guidelines for idiopathic pulmonary fibrosis (IPF) give a conditional recommendation for anti-acid therapy. As some observational studies reported discrepant findings on the effectiveness of anti-acid therapy on mortality in IPF, we reviewed all studies to evaluate whether immortal time bias explains these discrepancies.We searched the Embase and MEDLINE databases up to July 2017 for observational studies assessing the effectiveness of anti-acid therapy on mortality in IPF. Hazard ratios of mortality with anti-acid therapy were pooled across studies using random-effect models, stratified by the presence of immortal time bias.We identified 10 observational studies. Four of the five studies reporting beneficial effects of anti-acid therapy use on mortality were affected by immortal time bias (pooled hazard ratio 0.46; 95% CI 0.30-0.69), while it was unclear whether the fifth was affected. The five studies that avoided immortal time bias reported no effect of anti-acid therapy on mortality (pooled hazard ratio 0.99; 95% CI 0.81-1.22).The apparent beneficial effects of anti-acid therapy on mortality in patients with IPF result from observational studies affected by immortal time bias. Thus, the effectiveness of anti-acid therapy in IPF remains uncertain and needs to be reassessed with more accurate observational study methods and randomised trials.

Symptom prevalence of patients with fibrotic interstitial lung disease: a systematic literature review

Background

Those affected by advanced fibrotic interstitial lung diseases have limited treatment options and in the terminal stages, the focus of care is on symptom management. However, quantitatively, little is known about symptom prevalence. We aimed to determine the prevalence of symptoms in Progressive Idiopathic Fibrotic Interstitial Lung Disease (PIF-ILD).

Methods

Searches on eight electronic databases including MEDLINE for clinical studies between 1966 and 2015 where the target population was adults with PIF-ILD and for whom the prevalence of symptoms had been calculated.

Results

A total of 4086 titles were screened for eligibility criteria; 23 studies were included for analysis. The highest prevalence was that for breathlessness (54–98%) and cough (59–100%) followed by heartburn (25–65%) and depression (10–49%). The heterogeneity of studies limited their comparability, but many of the symptoms present in patients with other end-stage disease were also seen in PIF-ILD.

Conclusions

This is the first quantitative review of symptoms in people with Progressive Idiopathic Fibrotic Interstitial Lung Diseases. Symptoms are common, often multiple and have a comparable prevalence to those experienced in other advanced diseases. Quantification of these data provides valuable information to inform the allocation of resources.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0651-3) contains supplementary material, which is available to authorized users.

Proton Pump Inhibitors in IPF: A Call for Clinical Trials

The recent FDA approval of two drugs, pirfenidone and nintedanib, for the treatment of idiopathic pulmonary fibrosis (IPF) has fueled interest in the development of additional drugs to treat the disease or its major clinical complications including cough and acute exacerbations. Since 2015, there are at least a dozen active interventional studies that are testing the efficacy of novel pharmacotherapies, exercise or stem cells in modifying the disease process in IPF. Additionally, there are combinatorial studies evaluating the effectiveness of pirfenidone or nintedanib in combination with other agents. However, there remains an urgent need for clinical trials to prospectively evaluate the efficacy of existing drugs with promising retrospective data, such as proton pump inhibitors (PPIs), in IPF. Several retrospective cohorts have provided tantalizing data supporting the beneficial effect of PPIs in patients with well-defined IPF. This review provides the general outlook of pharmacotherapies in IPF, and highlights preclinical and retrospective clinical data to make a case for randomized controlled clinical trials of PPIs in IPF.

Changes in the pattern of fibrosis in the rat lung with repetitive orotracheal instillations of gastric contents: evidence of persistent collagen accumulation

Recurrent aspiration of gastric contents has been associated with several interstitial lung diseases. Despite this association, the pathogenic role of aspiration in these diseases has been poorly studied and little is known about extracellular matrix (ECM) changes in animal models of repetitive events of aspiration. Our aim was to study the repair phase of lung injury induced by each of several instillations of gastric fluid in Sprague-Dawley rats to evaluate changes in ECM and their reversibility. Anesthetized animals received weekly orotracheal instillations of gastric fluid for 1, 2, 3, and 4 wk and were euthanized at day 7 after last instillation. For reversibility studies, another group received 7 weekly instillations and was euthanized at day 7 or 60 after last instillation. Biochemical and histological measurements were used to evaluate ECM changes. Lung hydroxyproline content increased progressively and hematoxylin and eosin, Masson's trichrome, and alpha-SMA stains showed that after a single instillation, intra-alveolar fibrosis predominated, whereas with repetitive instillations this fibrosis pattern became less prominent and interstitial fibrosis progressively became evident. Both type I and III collagen increased in intra-alveolar and interstitial fibrosis. Imbalance between matrix metalloproteinase-2 (MMP-2) activity and tissue inhibitor of metalloproteinase-2 (TIMP-2) expression was observed, favoring either collagen degradation or accumulation depending on the number of instillations. Caspase-3 activation was also dose dependent. ECM changes were partially reversible at long-term evaluation, since Masson bodies, granulomas, and foreign body giant cells disappeared, whereas interstitial collagen accumulated. In conclusion, repetitive lung instillations of gastric fluid induce progressive fibrotic changes in rat lung ECM that persist at long-term evaluation.

Gastroesophageal reflux symptoms are not sufficient to guide esophageal function testing in lung transplant candidates

Gastroesophageal reflux disease and esophageal dysmotility are prevalent in patients with advanced lung disease and are associated with graft dysfunction following lung transplantation. As a result, many transplant centers perform esophageal function testing as part of the wait-listing process but guidelines for testing in this population are lacking. The aim of this study is to describe whether symptoms of gastroesophageal reflux correlate with abnormal results on pH-metry and high-resolution manometry and can be used to identify those who require testing. We performed a retrospective cohort study of 226 lung transplant candidates referred for high-resolution manometry and pH-metry over a 12-month period in 2015. Demographic data, results of a standard symptom questionnaire and details of esophageal function testing were obtained. Associations between the presence of symptoms and test results were analyzed using Fisher's exact tests and multivariable logistic regression. The most common lung disease diagnosis was interstitial lung disease (N = 131, 58%). Abnormal pH-metry was seen in 116 (51%) patients and the presence of symptoms was significantly associated with an abnormal study (p < 0.01). Dysmotility was found in 98 (43%) patients, with major peristaltic or esophageal outflow disorders in 45 (20%) patients. Symptoms were not correlated with findings on esophageal high-resolution manometry. Fifteen of 25 (60%) asymptomatic patients had an abnormal manometry or pH-metry. These results demonstrate that in patients with advanced lung disease, symptoms of gastroesophageal reflux increase the likelihood of elevated acid exposure on pH-metry but were not associated with dysmotility. Given the proportion of asymptomatic patients with abnormal studies and associated post-transplant risks, a practice of universal high-resolution manometry and pH-metry testing in this population is justifiable.

Personalized medicine in interstitial lung diseases

PURPOSE OF REVIEW

A number of recent studies have explored the possibility to apply personalized medicine to interstitial lung diseases (ILDs), particularly idiopathic pulmonary fibrosis (IPF), the most common and deadly of the idiopathic interstitial pneumonias. In our review, we summarize and discuss the most recent literature on personalized medicine in IPF as well as hypersensitivity pneumonitis and sarcoidosis, with emphasis on patient subgroups for which a personalized approach to disease prognostication and management may become a reality in the near future.

RECENT FINDINGS

Most of the studies that have explored the applicability of personalized medicine to ILDs have been conducted in patients with IPF. Such studies have suggested the existence of several distinct disease subgroups defined by similar genetic profiles, molecular pathways, exposures and individual lifestyles. Personalized medicine in hypersensitivity pneumonitis is in its infancy. The development and applicability of personalized medicine to sarcoidosis, on the other hand, remains problematic for several reasons, including the lack of a diagnostic gold standard, the highly variable and unpredictable disease course, particularly across patients of different ethnicities, the poor correlation between disease activity and disease severity and the lack of a validated management algorithm.

SUMMARY

A number of distinct patient subgroups have been identified in ILDs. Although available data need to be validated longitudinally, the possibility to study homogeneous groups of patients may allow prediction of disease behavior and response to treatment with dramatic clinical implications.

The Role of Immune and Inflammatory Cells in Idiopathic Pulmonary Fibrosis

The contribution of the immune system to idiopathic pulmonary fibrosis (IPF) remains poorly understood. While most sources agree that IPF does not result from a primary immunopathogenic mechanism, evidence gleaned from animal modeling and human studies suggests that innate and adaptive immune processes can orchestrate existing fibrotic responses. This review will synthesize the available data regarding the complex role of professional immune cells in IPF. The role of innate immune populations such as monocytes, macrophages, myeloid suppressor cells, and innate lymphoid cells will be discussed, as will the activation of these cells via pathogen-associated molecular patterns derived from invading or commensural microbes, and danger-associated molecular patterns derived from injured cells and tissues. The contribution of adaptive immune responses driven by T-helper cells and B cells will be reviewed as well. Each form of immune activation will be discussed in the context of its relationship to environmental and genetic factors, disease outcomes, and potential therapies. We conclude with discussion of unanswered questions and opportunities for future study in this area.

Idiopathic pulmonary fibrosis: pathogenesis and management

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the aberrant accumulation of fibrotic tissue in the lungs parenchyma, associated with significant morbidity and poor prognosis. This review will present the substantial advances achieved in the understanding of IPF pathogenesis and in the therapeutic options that can be offered to patients, and will address the issues regarding diagnosis and management that are still open.

Main body

Over the last two decades much has been clarified about the pathogenic pathways underlying the development and progression of the lung scarring in IPF. Sustained alveolar epithelial micro-injury and activation has been recognised as the trigger of several biological events of disordered repair occurring in genetically susceptible ageing individuals. Despite multidisciplinary team discussion has demonstrated to increase diagnostic accuracy, patients can still remain unclassified when the current diagnostic criteria are strictly applied, requiring the identification of a Usual Interstitial Pattern either on high-resolution computed tomography scan or lung biopsy.

Outstanding achievements have been made in the management of these patients, as nintedanib and pirfenidone consistently proved to reduce the rate of progression of the fibrotic process. However, many uncertainties still lie in the correct use of these drugs, ranging from the initial choice of the drug, the appropriate timing for treatment and the benefit-risk ratio of a combined treatment regimen. Several novel compounds are being developed in the perspective of a more targeted therapeutic approach; in the meantime, the supportive care of these patients and their carers should be appropriately prioritized, and greater efforts should be made toward the prompt identification and management of relevant comorbidities.

Conclusions

Building on the advances in the understanding of IPF pathobiology, the further investigation of the role of gene variants, epigenetic alterations and other molecular biomarkers reflecting disease activity and behaviour will hopefully enable earlier and more confident diagnosis, improve disease phenotyping and support the development of novel agents for personalized treatment of IPF.

Evaluation of Gastroesophageal Reflux Disease

INTRODUCTION

Gastroesophageal reflux disease (GERD) may present with heartburn, regurgitation, dysphagia, chronic cough, laryngitis, or even asthma. The clinical presentation of GERD is therefore varied and poses certain challenges to the physician, especially given the limitations of the diagnostic testing.

DISCUSSION

The evaluation of patients with suspected GERD might be challenging. It is based on the evaluation of clinical features, objective evidence of reflux on diagnostic testing, correlation of symptoms with episodes of reflux, evaluation of anatomical abnormalities, and excluding other causes that might account for the presence of the patient's symptoms.

CONCLUSIONS

The diagnostic evaluation should include multiple tests, in addition to a thorough clinical examination.

Gastroesophageal Reflux and Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown origin that affects about 40,000 new patients every year in the USA. Albeit the disease is labelled as idiopathic, it is thought that pathologic reflux, often silent, plays a role in its pathogenesis through a process of microaspiration of gastric contents.

AIMS

The aim of this study was to review the available evidence linking reflux to IPF, and to study the effect of medical and surgical therapy on the natural history of this disease.

RESULTS

Medical therapy with acid-reducing medications controls the production of acid and has some benefit. However, reflux and aspiraion of weakly acidic or alkaline gastric contents can still occur. Better results have been reported after laparoscopic anti-reflux surgery, as this form of therapy re-establishes the competence of the lower esophageal sphincter, therefore stopping any type of reflux.

CONCLUSIONS

A phase II NIH study in currently in progress in the USA to determine the role of antireflux surgery in patients with GERD and IPF. The hope is that this simple operations might alter the natural history of IPF, avoiding progression and the need for lung transplantation.

Anti-parietal cell autoimmunity is associated with an accelerated decline of lung function in IPF patients

BACKGROUND

Autoantibodies against lung epithelial antigens are often detected in patients with Idiopathic Pulmonary Fibrosis (IPF). Anti-Parietal Cell Antibodies (APCA) target the H+/K+ATPase (proton pump). APCA prevalence and lung H+/K+ATPase expression was never studied in IPF patients.

METHODS

We retrospectively collected clinical, lung function and imaging data from APCA positive patients (APCA+IPF) and compared them with APCA negative IPF patients matched on the date of diagnostic assessment. H+/K+ATPase expression was assessed with immunohistochemistry and PCR.

RESULTS

Among 138 IPF patients diagnosed between 2007 and 2014 and tested for APCA, 19 (13.7%) APCA+ patients were identified. APCA+IPF patients were 16 men and 3 women, mean age 71 years. The median titer of APCA was 1:160. A pernicious anemia was present in 5 patients and preceded the fibrosis in 3 cases. With a mean follow up of 31 months, 2 patients had an exacerbation and 7 patients died. As compared with 19 APCA- IPF patients, APCA+IPF patients had a less severe disease with better DLCO (57% vs 43% predicted), preserved PaO₂ (85 ± 8 mmHg vs 74 ± 11 mmHg), a lower rate of honeycombing on HRCT (58% vs 89%), but they experienced an accelerated decline of FVC (difference 61.4 ml/year; p = .0002). The H+/K+ATPase was strongly expressed by hyperplastic alveolar epithelial cells in the fibrotic lung.

CONCLUSION

Anti-parietal cell autoimmunity is detected in some IPF patients and is associated with an accelerated decline of lung function. Anti-parietal cell autoimmunity may promote lung fibrosis progression.