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

Elucidating shared biomarkers in gastroesophageal reflux disease and idiopathic pulmonary fibrosis: insights into novel therapeutic targets and the role of angelicae sinensis radix

Background: The etiological underpinnings of gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) remain elusive, coupled with a scarcity of effective therapeutic interventions for IPF. Angelicae sinensis radix (ASR, also named Danggui) is a Chinese herb with potential anti-fibrotic properties, that holds promise as a therapeutic agent for IPF. Objective: This study seeks to elucidate the causal interplay and potential mechanisms underlying the coexistence of GERD and IPF. Furthermore, it aims to investigate the regulatory effect of ASR on this complex relationship. Methods: A two-sample Mendelian randomization (TSMR) approach was employed to delineate the causal connection between gastroesophageal reflux disease and IPF, with Phennoscanner V2 employed to mitigate confounding factors. Utilizing single nucleotide polymorphism (SNPs) and publicly available microarray data, we analyzed potential targets and mechanisms related to IPF in GERD. Network pharmacology and molecular docking were employed to explore the targets and efficacy of ASR in treating GERD-related IPF. External datasets were subsequently utilized to identify potential diagnostic biomarkers for GERD-related IPF. Results: The IVW analysis demonstrated a positive causal relationship between GERD and IPF (IVW: OR = 1.002, 95%CI: 1.001, 1.003; p < 0.001). Twenty-five shared differentially expressed genes (DEGs) were identified. GO functional analysis revealed enrichment in neural, cellular, and brain development processes, concentrated in chromosomes and plasma membranes, with protein binding and activation involvement. KEGG analysis unveiled enrichment in proteoglycan, ERBB, and neuroactive ligand-receptor interaction pathways in cancer. Protein-protein interaction (PPI) analysis identified seven hub genes. Network pharmacology analysis demonstrated that 104 components of ASR targeted five hub genes (PDE4B, DRD2, ERBB4, ESR1, GRM8), with molecular docking confirming their excellent binding efficiency. GRM8 and ESR1 emerged as potential diagnostic biomarkers for GERD-related IPF (ESR1: AUCGERD = 0.762, AUCIPF = 0.725; GRM8: AUCGERD = 0.717, AUCIPF = 0.908). GRM8 and ESR1 emerged as potential diagnostic biomarkers for GERD-related IPF, validated in external datasets. Conclusion: This study establishes a causal link between GERD and IPF, identifying five key targets and two potential diagnostic biomarkers for GERD-related IPF. ASR exhibits intervention efficacy and favorable binding characteristics, positioning it as a promising candidate for treating GERD-related IPF. The potential regulatory mechanisms may involve cell responses to fibroblast growth factor stimulation and steroidal hormone-mediated signaling pathways.

Dehydrozingerone alleviates pulmonary fibrosis via inhibition of inflammation and epithelial-mesenchymal transition by regulating the Wnt/β-catenin pathway

In idiopathic pulmonary fibrosis (IPF), excessive collagen deposition predisposes to irreversible lung function decline, respiratory failure, and ultimately death. Due to the limited therapeutic efficacy of FDA-approved medications, novel drugs are warranted for better treatment outcomes. Dehydrozingerone (DHZ) is an analogue of curcumin that has been investigated against pulmonary fibrosis using a bleomycin-induced pulmonary fibrosis model in rats. In in vitro, TGF-β-induced differentiation models (NHLF, LL29, DHLF and A549 cells) were adopted to assess fibrotic markers expression and explored the mechanism of action. DHZ administration attenuated the bleomycin-induced elevation of lung index, inflammatory cell infiltrations, and hydroxyproline levels in lung tissues. Furthermore, treatment with DHZ mitigated the bleomycin-mediated elevation of extracellular matrix (ECM), epithelial-to-mesenchymal-transition (EMT), and collagen deposition markers and improved lung mechanics. In addition, treatment with DHZ significantly suppressed the BLM-induced apoptosis and rescued the BLM-induced pathological abnormalities in lung tissues. In-vitro assays revealed that DHZ suppressed the expression of TGF-β-elevated collagen deposition, EMT and ECM markers in both mRNA/protein levels. Our findings showed that DHZ has anti-fibrotic effect against pulmonary fibrosis by modulating Wnt/β-catenin signaling, suggesting that DHZ may serve as a potential treatment option for IPF.

Injured Endothelial Cell: A Risk Factor for Pulmonary Fibrosis

The pathological features of pulmonary fibrosis (PF) are the abnormal activation and proliferation of myofibroblasts and the extraordinary deposition of the extracellular matrix (ECM). However, the pathogenesis of PF is still indistinct. In recent years, many researchers have realized that endothelial cells had a crucial role in the development of PF. Studies have demonstrated that about 16% of the fibroblasts in the lung tissue of fibrotic mice were derived from endothelial cells. Endothelial cells transdifferentiated into mesenchymal cells via the endothelial-mesenchymal transition (E(nd)MT), leading to the excessive proliferation of endothelial-derived mesenchymal cells and the accumulation of fibroblasts and ECM. This suggested that endothelial cells, a significant component of the vascular barrier, played an essential role in PF. Herein, this review discusses E(nd)MT and its contribution to the activation of other cells in PF, which could provide new ideas for further understanding the source and activation mechanism of fibroblasts and the pathogenesis of PF.

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.

Tumor necrosis factor-α coordinates with transforming growth factor-β1 to induce epithelial-mesenchymal transition and migration via the NF-κB/NOX4 pathway in bronchial epithelial cells

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is the process by which epithelial cells transform into mesenchymal cells, which plays a significant role in lung fibrotic disease. Transforming growth factor-β1(TGF-β1) is considered to be the most effective EMT inducer. The purpose of this study was to investigate the effect of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) on TGF-β1-induced EMT and the underlying mechanisms in the human bronchial epithelial cell line BEAS-2B.

METHODS

Human bronchial epithelial BEAS-2B cells were treated with TGF-β1 and TNF-α separately or in combination for 24 h, and qRT-PCR, western blotting, immunofluorescence staining, and migration assays were used to investigate the EMT process. Moreover, to further explore the effect of the NF-κB pathway on the EMT process, inhibitor assays (BAY-117082, NF-κB inhibitor), wound healing assays, and western blotting were performed.

RESULTS

The results showed that both cytokines enhanced the transformation of BEAS-2B cells from epithelial to mesenchymal cells. In addition, combined treatment with TNF-α and TGF-β1 further reduced E-cadherin expression, which conversely elevated α-SMA and vimentin mRNA and protein levels. Correspondingly, the migration rate of BEAS-2B cells was also increased. Furthermore, inhibiting the NF-κB signaling pathway blocked the expression of EMT-related markers and NOX4 induced by TGF-β1 and TNF-α, as well as cell migration.

CONCLUSION

Taken together, TNF-α and TGF-β1 cooperatively promoted EMT and cell migration in BEAS-2B cells through the NF-κB/NOX4 signaling pathway.

Engineering of Stimulus-Responsive Pirfenidone Liposomes for Pulmonary Delivery During Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by progressive and irreversible loss of lung function. Clinically safe and efficacious drug treatments for IPF are lacking. Pirfenidone (an anti-inflammatory, antioxidant and anti-fibrotic small-molecule drug) is considered a promising treatment for IPF. Unfortunately, several disadvantages of pirfenidone caused by traditional administration (e.g., gastrointestinal reactions, short elimination half-life) hinder its implementation. We designed pirfenidone pH-sensitive liposomes (PSLs) to target the acidic microenvironment of IPF and act directly at the disease site through pulmonary administration. Pirfenidone was encapsulated in liposomes to extend its half-life, and modified with polyethylene glycol on the surface of liposomes to improve the permeability of the mucus layer in airways. In vitro, the cytotoxicity of pirfenidone PSLs to pulmonary fibroblasts was increased significantly at 48 h compared with that using pirfenidone. In a murine and rat model of bleomycin-induced pulmonary fibrosis, pirfenidone PSLs inhibited IPF development and increased PSL accumulation in the lungs compared with that using pirfenidone solution or phosphate-buffered saline. Pirfenidone PSLs had potentially fewer side effects and stronger lung targeting. These results suggest that pirfenidone PSLs are promising preparations for IPF treatment.

The Impact of Erosive Reflux Esophagitis on the Decline of Lung Function in the General Population

BACKGROUND

The impact of reflux esophagitis on the decline of lung function has been rarely reported. This study was performed to evaluate the association between erosive reflux esophagitis and lung function changes.

METHODS

We included patients with normal lung function who underwent esophagogastroduodenoscopy for health screening from a health screening center. Patients with persistent erosive reflux esophagitis on two discrete endoscopic examinations were designated as the erosive reflux esophagitis group. We also selected patients without erosive reflux esophagitis and matched them 1:4 with patients from the erosive reflux esophagitis group. We estimated annual forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) changes from baseline and compared these estimates by the linear mixed regression model. We also estimated the biannual incidence of chronic obstructive pulmonary disease (COPD).

RESULTS

In total, 1,050 patients (210 patients with erosive reflux esophagitis, and 840 matched controls) were included. The median follow-up duration for spirometry was six years. In patients with erosive reflux esophagitis, mild reflux esophagitis (A grade) was most common (165 patients, 78.6%). The adjusted annual FEV₁ change in patients with erosive reflux esophagitis was -51.8 mL/yr, while it decreased by 46.8 mL/yr in controls (P = 0.270). The adjusted annual FVC decline was similar between the two groups (-55.8 vs. -50.5 mL/yr, P = 0.215). The estimated COPD incidence during the follow-up period was not different between the erosive reflux esophagitis and control groups.

CONCLUSION

In patients with normal lung function, the presence of erosive reflux esophagitis did not affect the annual declines in FEV₁ or FVC.

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.

Inflammatory response induced by Helicobacter pylori infection in lung

Helicobacter pylori is a microorganism that in the last years has been associated with extragastric disorders such as respiratory diseases, however, its impact on lung is partially understood. The aim of this work was to study infection impact of H. pylori on the inflammatory markers expression at the pulmonary level using an animal model. Infection was performed by BALB/c wild type (WT) mice orotracheal instillation with 20 μl of 1 × 108H. pylori reference strain suspension once per day throughout 3 days. Inflammatory response was evaluated at 3, 7, 14, 21 and 30 days post infection. Lung was aseptically removed and pulmonary edema index values showed a significant change at 30 days of infection. Hematoxylin-Eosin (H-E) stain allowed to visualizing H. pylori presence in lung samples at 3 days of infection near the phagocytic cells or in the alveoli lumen. Bronchoalveolar lavage (BAL) was used for inflammatory response evaluation. Lactate dehydrogenase values showed a gradual increase in infected animals along infection time. Protein concentrations in mg/ml from BAL increased significantly at 7 days in infected animals. Macrophages viability obtained from BAL, decreased at the first moment of infection, maintaining constant values along contamination time. Results obtained demonstrate an inflammatory response in lung after orotracheal H. pylori infection and suggest that the pathogenic mechanism is strongly evidenced by tissue damage, endothelial dysfunction inflammatory mediators and markers expression at the pulmonary level.

Epidemiology and Clinico-radiological features of Interstitial Lung Diseases

Objective:

The literature on interstitial lung diseases is limited. The aim of this research was to make this entity of diseases more understandable to clinicians and general population of the region of Pakistan.

Methods:

We conducted a cross-sectional study on 253 Pakistani subjects who are a part of the hospital-based registry of JPMC. We performed statistical analyses on SPSS version 22.0. We included patients above 15 years of age who exhibited clinical clues and radiological signs of ILD during March 2016 through February 2018 and excluded those who were on tuberculosis treatment, suspected to be suffering from post-infection bronchiectasis, expectant females or had failed to follow-up.

Results:

There was a 2:3 male to female ratio. Mean age was 49.0±13.2 years. Majority were non-smokers. Idiopathic Pulmonary Fibrosis (IPF) was the commonest ILD (38.8%) followed by Non-Specific Interstitial Pneumonitis (NSIP) (15.1%). Most patients presented with dyspnea and dry cough and about half were clubbed (47.3%). Substantial IPF cases (52.6%) were suffering from GERD symptoms.

Conclusion:

IPF and NSIP were the major ILDs, GERD was the only predictor of IPF. This entity of lung diseases needs to be explored further to identify patterns of presentation and to make diagnosis at a manageable stage.

Idiopathic pulmonary fibrosis and GERD: links and risks

Gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) are two pathological conditions often strictly related, even if a clear relationship of causality has not been demonstrated. GERD is a frequent comorbidity in IPF patients, as demonstrated using combined multichannel intraluminal impedance-pH, despite being mostly clinically silent. According to that, it has been hypothesized that microaspiration of gastric material may play a fundamental role in the fibrotic transformation of pulmonary parenchyma. In contrast, it cannot be excluded that IPF may favor GERD by increasing the negative intrathoracic pressure. Therefore, this relationship is uncertain as well as not univocal. Nevertheless, the latest international guidelines recommend the use of proton pump inhibitors (PPIs) in IPF based on several data showing that PPIs can stabilize lung function, reduce disease flares and hospitalizations. On the contrary, recent studies not only question the relevance of these results, but also associate the use of PPIs with an increased risk of lung infections and a negative prognostic outcome. The aim of this review is to analyze the possible links between GERD and IPF and their possible therapeutic implications, trying to translate this scientific evidence into useful information for clinical practice.

Bronchoalveolar pH and inflammatory biomarkers in patients with acute exacerbation of chronic obstructive pulmonary disease

Objectives

This study aimed to directly measure pH in the lungs, determine lactate dehydrogenase (LDH), C-reactive protein (CRP), and glucose levels in serum and bronchoalveolar aspirate, and identify bacterial pathogens from bronchoalveolar fluid during acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

We performed an observational, analytical case–control study from February 2015 to March 2017. We included 84 patients with AECOPD and 42 with stable chronic obstructive pulmonary disease (COPD). All participants underwent detailed medical anamnesis, a clinical examination, chest radiography, spirometry, an arterial blood gas test, bronchoscopy, bacterial culture, and serum/bronchiolar aspirate laboratory testing.

Results

The mean pH of bronchoalveolar fluid was significantly higher in patients with AECOPD than in patients with stable COPD. The mean lung pH value, bronchoalveolar and serum LDH levels, and serum CRP levels in patients with isolated bacteria were higher than those in patients without isolated bacteria in the AECOPD patient group. Lung pH values in patients with AECOPD were significantly correlated with bronchoalveolar LDH and glucose levels.

Conclusions

AECOPD is associated with local cell and tissue injury in the lungs, especially in the presence of bacterial pathogens, which is accompanied by a low systemic inflammatory response.

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.

Crude leaf extracts of Piperaceae species downmodulate inflammatory responses by human monocytes

In this study, we aimed to evaluate the immunomodulatory effects of crude leaf extracts from Piper gaudichaudianum Kunth, P. arboreum Aub., P. umbellata L., P. fuligineum Kunth, and Peperomia obtusifolia A. Dietr. on an in vitro model of inflammatory response. The crude extracts were previously obtained by maceration of the leaves. The half-maximal inhibitory concentration was determined by the MTT assay using human peripheral blood mononuclear cells. Human monocytes were simultaneously challenged with each crude extract and lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, to induce a strong inflammatory response. After 24 h of incubation, cell-free supernatants were used for evaluating the mediators involved in inflammation: H₂O₂, TNF-α, IL-8, IL-6, IL-1β, IL-10, IL-12, FGF-b, and TGF-β1. We also compared the results with the effects of ketoprofen, a well-known anti-inflammatory drug. The P. gaudichaudianum crude extract downmodulated the production of H₂O₂, IL-1β, IL-6, IL-8, and TGF-β1 by LPS-stimulated monocytes; P. arboreum, IL-1β, IL-6, IL-8, and TNF-α; P. umbellata and P. fuligineum, H₂O₂, IL-1β, IL-6, IL-8, IL-10, and TNF-α; and P. obtusifolia, H₂O₂, IL-6, IL-8, IL-10, and TNF-α. In general, the crude leaf extracts amplified the anti-inflammatory response when compared with ketoprofen, particularly reducing the production of IL-8, a mediator involved in neutrophil recruitment during tissue damage. Thus, the crude leaf extracts of P. gaudichaudianum, P. arboreum, P. umbellata, P. fuligineum, and Peperomia obtusifolia elicited an anti-inflammatory response against LPS-challenged monocytes. These findings show the anti-inflammatory properties of these crude leaf extracts and offer new perspectives for their use in the treatment of inflammatory diseases.

Long-Term Effects of TCM Yangqing Kangxian Formula on Bleomycin-Induced Pulmonary Fibrosis in Rats via Regulating Nuclear Factor-κB Signaling

Objective

We aimed to evaluate the therapeutic effects and long-term effects of YKF and dissect the potential mechanisms.

Materials and Methods

IPF rats were given YKF, prednisone, or pirfenidone, respectively, from day 1 to day 42, followed by a 28-day nonintervention interval through day 70. Forced vital capacity (FVC), histopathology, hydroxyproline (HYP) contents, lung coefficient, blood inflammatory cell populations, inflammatory cytokine levels of the lung tissues, and the expression of proteins involved in nuclear factor- (NF-) κB signaling pathway were evaluated on days 7, 14, 28, 42, and 70.

Results

HYP contents, Ashcroft scores, lung coefficient, and pulmonary fibrosis blood cell populations increased significantly in IPF rats, while FVC declined. All the above-mentioned parameters were improved in treatment groups from day 7 up to day 70, especially in YKF group. The mRNA and protein expressions of tumor necrosis factor- (TNF-) α significantly decreased, while interferon- (IFN-) γ significantly increased, and phosphorylations of cytoplasm inhibitor of nuclear factor kappa-B kinase β (IKKβ), inhibitor of nuclear factor kappa-B α (IκBα), and NF-κB were obviously downregulated in YKF group from day 7 to day 70.

Conclusion

YKF has beneficial protective and long-term effects on pulmonary fibrosis by anti-inflammatory response and alleviating fibrosis.

Anti-TNFα therapy in inflammatory lung diseases

Increased levels of tumor necrosis factor (TNF) α have been linked to a number of pulmonary inflammatory diseases including asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), sarcoidosis, and interstitial pulmonary fibrosis (IPF). TNFα plays multiple roles in disease pathology by inducing an accumulation of inflammatory cells, stimulating the generation of inflammatory mediators, and causing oxidative and nitrosative stress, airway hyperresponsiveness and tissue remodeling. TNFα-targeting biologics, therefore, present a potentially highly efficacious treatment option. This review summarizes current knowledge on the role of TNFα in pulmonary disease pathologies, with a focus on the therapeutic potential of TNFα-targeting agents in treating inflammatory lung diseases.

Role of gastroesophageal reflux disease in lung transplantation

Lung transplantation is one of the highest risk solid organ transplant modalities. Recent studies have demonstrated a relationship between gastroesophageal reflux disease (GERD) and lung transplant outcomes, including acute and chronic rejection. The aim of this review is to discuss the pathophysiology, evaluation, and management of GERD in lung transplantation, as informed by the most recent publications in the field. The pathophysiology of reflux-induced lung injury includes the effects of aspiration and local immunomodulation in the development of pulmonary decline and histologic rejection, as reflective of allograft injury. Modalities of reflux and esophageal assessment, including ambulatory pH testing, impedance, and esophageal manometry, are discussed, as well as timing of these evaluations relative to transplantation. Finally, antireflux treatments are reviewed, including medical acid suppression and surgical fundoplication, as well as the safety, efficacy, and timing of such treatments relative to transplantation. Our review of the data supports an association between GERD and allograft injury, encouraging a strategy of early diagnosis and aggressive reflux management in lung transplant recipients to improve transplant outcomes. Further studies are needed to explore additional objective measures of reflux and aspiration, better compare medical and surgical antireflux treatment options, extend follow-up times to capture longer-term clinical outcomes, and investigate newer interventions including minimally invasive surgery and advanced endoscopic techniques.

Protective Effect of Proton Pump Inhibitor for Survival in Patients with Gastroesophageal Reflux Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND/AIMS

The prevalence of gastroesophageal reflux disease (GERD) is high in patients with idiopathic pulmonary fibrosis (IPF). GERD may cause chronic microaspiration that leads to repeated subclinical lung injury, which leads to pulmonary fibrosis. Although some studies have suggested that proton pump inhibitors (PPI) were associated with a good prognosis in IPF, their effects remain unclear.

METHODS

We retrospectively reviewed 786 consecutive adult patients with IPF at Seoul National University Bundang Hospital between April 2003 and March 2015.

RESULTS

Mean duration of follow-up was 2.6 ± 2.8 years. Of the 786 patients with IPF, 107 (13.6%) were given diagnoses of GERD, and 103 (13.1%) died due to IPF-related pneumonia or respiratory failure. The prevalence of GERD and the cumulative incidence of de novo GERD increased depending on the period of follow-up in patients with IPF. Patients administered PPI for more than four months had a lower IPF-related mortality rate than patients on PPI less than 4 months (Log-rank P -value = 0.024 in Kaplan-Meier curve). In a univariate and multivariate Cox regression hazard model, younger age (hazard ratio [HR], 1.06; 95% CI, 1.03-1.10; P = 0.001), higher initial forced vital capacity (HR, 0.98; 95% CI, 0.96-0.99; P = 0.004), and longer duration of PPI use (HR, 0.97; 95% CI, 0.95-1.00; P = 0.022), but not a diagnosis of GERD, were significantly associated with lower IPF-related mortality.

CONCLUSIONS

In Korean patients with IPF, the prevalence of GERD was lower than in other countries. PPI use for at least 4 months may have a protective effect against IPF-related mortality.

Comorbidities in idiopathic pulmonary fibrosis patients: a systematic literature review

Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.

This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identifiedviaMEDLINE and EMBASE were included; bibliographies of articles were also searched.

Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3–86%, 6–91% for obstructive sleep apnoea, 3–48% for lung cancer and 6–67% for chronic obstructive pulmonary disease (COPD). Nonrespiratory comorbidities included ischaemic heart disease (IHD) (3–68%) and gastro-oesophageal reflux (GER) (0–94%). Mortality was highest among patients with IPF and lung cancer. Most studies assessed relatively small samples of patients with IPF.

PH, COPD, lung cancer, GER and IHD are significant comorbidities; differences in IPF severity, case definitions and patient characteristics limited the comparability of findings. The identification and prompt treatment of comorbidities may have a clinically significant impact on overall outcome that is meaningful for patients with IPF.

Managing comorbidities in idiopathic pulmonary fibrosis

Major risk factors for idiopathic pulmonary fibrosis (IPF) include older age and a history of smoking, which predispose to several pulmonary and extra-pulmonary diseases. IPF can be associated with additional comorbidities through other mechanisms as either a cause or a consequence of these diseases. We review the literature regarding the management of common pulmonary and extra-pulmonary comorbidities, including chronic obstructive pulmonary disease, lung cancer, pulmonary hypertension, venous thromboembolism, sleep-disordered breathing, gastroesophageal reflux disease, coronary artery disease, depression and anxiety, and deconditioning. Recent studies have provided some guidance on the management of these diseases in IPF; however, most treatment recommendations are extrapolated from studies of non-IPF patients. Additional studies are required to more accurately determine the clinical features of these comorbidities in patients with IPF and to evaluate conventional treatments and management strategies that are beneficial in non-IPF populations.

Inflammatory response mechanisms exacerbating hypoxemia in coexistent pulmonary fibrosis and sleep apnea

Mediators of inflammation, oxidative stress, and chemoattractants drive the hypoxemic mechanisms that accompany pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis commonly have obstructive sleep apnea, which potentiates the hypoxic stimuli for oxidative stress, culminating in systemic inflammation and generalized vascular endothelial damage. Comorbidities like pulmonary hypertension, obesity, gastroesophageal reflux disease, and hypoxic pulmonary vasoconstriction contribute to chronic hypoxemia leading to the release of proinflammatory cytokines that may propagate clinical deterioration and alter the pulmonary fibrotic pathway. Tissue inhibitor of metalloproteinase (TIMP-1), interleukin- (IL-) 1α, cytokine-induced neutrophil chemoattractant (CINC-1, CINC-2α/β), lipopolysaccharide induced CXC chemokine (LIX), monokine induced by gamma interferon (MIG-1), macrophage inflammatory protein- (MIP-) 1α, MIP-3α, and nuclear factor- (NF-) κB appear to mediate disease progression. Adipocytes may induce hypoxia inducible factor (HIF) 1α production; GERD is associated with increased levels of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and tumor necrosis factor alpha (TNF-α); pulmonary artery myocytes often exhibit increased cytosolic free Ca2+. Protein kinase C (PKC) mediated upregulation of TNF-α and IL-1β also occurs in the pulmonary arteries. Increased understanding of the inflammatory mechanisms driving hypoxemia in pulmonary fibrosis and obstructive sleep apnea may potentiate the identification of appropriate therapeutic targets for developing effective therapies.

Endobronchial valves in treatment of persistent air leaks: a systematic review of clinical evidence

Background

Persistent air leak is one of the most common complications of lung diseases and pulmonary resections. Prolonged hospitalization, increased morbidity, and increased overall treatment costs arise from persistent air leaks. The use of endobronchial valves (EBVs) in the management of air leaks is an important alternative, especially for patients who are not candidates for surgical treatment.

Material/Methods

We retrieved the included studies by performing a systematic search in PubMed and Scopus databases. The references of the included studies were also hand-searched.

Results

We retrieved 25 case reports and 3 case series from our literature search. The most common cause of persisting air leaks was spontaneous secondary pneumothorax (12/39, 31%). The left upper lobe (13/39, 33%) and right upper lobe (14/39, 36%) were the most frequent locations of air leaks. Most air leaks treated with EBVs ceased in less than 24 h. Three recurrences of air leak were reported and 2 cases of EBV migration were described. No deaths were reported in correlation with EBVs.

Conclusions

EBVs are a minimally invasive therapeutical option that may be suitable for the treatment of persistent air leaks regardless of the initial cause, especially in high-risk patients. Nevertheless, studies with better methodological quality are essential to standardize this technique and to provide more evidence on EBV safety issues.