Exp Gerontol. 2021 Jul 15:111473. doi: 10.1016/j.exger.2021.111473. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic lung fibrosing disease with high prevalence that has a prognosis worse than many cancers. There has been a recent influx of new observations aimed at explaining the mechanisms responsible for the initiation and progression of pulmonary fibrosis. However, despite this, the pathogenesis of the disease is largely unclear. Recent progress has been made in the characterization of specific pathologic and clinical features that have enhanced the understanding of pathologically activated molecular pathways during the onset and progression of IPF. This review highlights several of the advances that have been made and focus on the pathobiology of IPF. The work also details the different factors that are responsible for the disposition of the disease - these may be internal factors such as cellular mechanisms and genetic alterations, or they may be external factors from the environment. The changes that primarily occur in epithelial cells and fibroblasts that lead to the activation of profibrotic pathways are discussed in depth. Finally, a complete repertoire of the treatment therapies that have been used in the past as well as future medications and therapies is provided.

PMID:34274426 | DOI:10.1016/j.exger.2021.111473

Oral Surg Oral Med Oral Pathol Oral Radiol. 2021 Mar 28:4602. doi: 10.1016/j.oooo.2021.03.014. Online ahead of print.

ABSTRACT

OBJECTIVE: Patients with idiopathic pulmonary fibrosis (IPF) commonly present with sicca symptoms. This study aimed to assess labial minor salivary glands (LMSGs) in those patients to rule out Sjögren's syndrome (SS), in which sicca symptoms are the clinical hallmark.

STUDY DESIGN: Cases of patients with IPF with sicca symptoms referred to the oral medicine clinic at the University of Florida within the last 13 years were selected with institutional review board approval. Demographic characteristics, clinical findings, laboratory results, and histomorphologic parameters were retrospectively analyzed.

RESULTS: A total of 12 patients (9 men and 3 women, ages 55-76 years) were identified. History of exposure to asbestos or chemicals, smoking, and medication information was obtained. All patients reported sicca symptoms with 57% of those exhibiting objective or borderline dryness. Anti-SSA/Ro and anti-SSB/La were positive in 25% and 8% of the cases, respectively. Microscopically, 1 out of 12 patients was biopsy positive in the absence of anti-SSA/Ro, fulfilling the 2016 SS criteria with positive sialometry.

CONCLUSIONS: A LMSG biopsy is critical to identify SS in patients with diagnosed IPF and present sicca symptoms, especially those with negative serology, as revealed in our study.

PMID:34274288 | DOI:10.1016/j.oooo.2021.03.014

Pulmonology. 2021 Jul 15:S2531-0437(21)00126-4. doi: 10.1016/j.pulmoe.2021.06.006. Online ahead of print.

ABSTRACT

INTRODUCTION AND OBJECTIVES: Patients with idiopathic pulmonary fibrosis (IPF) present respiratory derangements at rest and during exercise, accompanied by exercise intolerance. Some patients may develop profound exertional desaturation even without resting hypoxemia. Evidence suggests the involvement of reduced cerebral-oxygenation in exercise intolerance. We aimed to examine (i) differences in cerebral-oxygenation during exercise between IPF patients with and without isolated exertional desaturation, (ii) whether the impairments in cerebral-oxygenation are detected at similar exercise intensity, and (iii) correlations between cerebral-oxygenation indices, disease severity, and 6-min walk test (6MWT).

MATERIALS AND METHODS: Patients with IPF (n = 24; 62.1 ± 9.3 years) without resting hypoxemia underwent cardiopulmonary exercise testing (CPET) with cerebral-oxygenation monitoring via near-infrared-spectroscopy (NIRS). Βased on their pulse-oxymetry saturation (SpO2) during CPET, patients were divided into the "exertional-desaturators" group (SpO2nadir≤89% and ≥6% drop in SpO2) and the "non-exertional-desaturators" group (SpO2nadir≥90% and ≤5% drop).

RESULTS: During CPET, the "exertional-desaturators" group exhibited lower oxygenated-hemoglobin (-0.67 ± 1.48 vs. 0.69 ± 1.75 μmol/l; p < 0.05) and higher deoxygenated-hemoglobin (1.67 ± 1.13 vs. 0.17 ± 0.62 μmol/l; p < 0.001) than the "non-exertional-desaturators" group. A different pattern (p < 0.01) in cerebral-oxygenation responses was observed in the two groups. In exertional-desaturators oxygenated-hemoglobin declined below baseline even at low/moderate-intensity exercise (p < 0.05), whereas, in non-exertional-desaturators cerebral-oxygenation declined (p < 0.05) at high-intensity exercise. Cerebral-NIRS indices correlated (p < 0.05) with CPET-duration, dyspnea, diffusion capacity, and 6MWT.

CONCLUSIONS: During incremental exercise, patients with IPF and exertional desaturation present a significant decline in cerebral-oxygenation even during low-intensity exercise. Our findings support the implementation of longer-duration rehabilitation programs in IPF so that lower intensity exercise can be applied at the initial stages. (NCT03683082).

PMID:34274251 | DOI:10.1016/j.pulmoe.2021.06.006

BMC Pulm Med. 2021 Jul 17;21(1):239. doi: 10.1186/s12890-021-01607-2.

ABSTRACT

BACKGROUND: Idiopathic Pulmonary Fibrosis is a chronic, progressive interstitial lung disease for which there is no cure. However, lung function decline, hospitalizations, and mortality may be reduced with the use of the antifibrotic medications, nintedanib and pirfenidone. Historical outcomes for hospitalized patients with Idiopathic Pulmonary Fibrosis are grim; however there is a paucity of data since the approval of nintedanib and pirfenidone for treatment. In this study, we aimed to determine the effect of nintedanib and pirfenidone on mortality following respiratory-related hospitalizations, intensive care unit (ICU) admission, and mechanical ventilation.

METHODS: Using a large U.S. insurance database, we created a one-to-one propensity score matched cohort of patients with idiopathic pulmonary fibrosis treated and untreated with an antifibrotic who underwent respiratory-related hospitalization between January 1, 2015 and December 31, 2018. Mortality was evaluated at 30 days and end of follow-up (up to 2 years). Subgroup analyses were performed for all patients receiving treatment in an ICU and those receiving invasive and non-invasive mechanical ventilation during the index hospitalization.

RESULTS: Antifibrotics were not observed to effect utilization of mechanical ventilation or ICU treatment during the index admission or effect mortality at 30-days. If patients survived hospitalization, mortality was reduced in the treated cohort compared to the untreated cohort when followed up to two years (20.1% vs 47.8%).

CONCLUSIONS: Treatment with antifibrotic medications does not appear to directly improve 30-day mortality during or after respiratory-related hospitalizations. Post-hospital discharge, however, ongoing antifibrotic treatment was associated with improved long-term survival.

PMID:34273943 | DOI:10.1186/s12890-021-01607-2

Thorax. 2021 Jul 16:thoraxjnl-2020-216263. doi: 10.1136/thoraxjnl-2020-216263. Online ahead of print.

ABSTRACT

BACKGROUND: Some patients with idiopathic interstitial pneumonia (IIP) show autoimmune features. Interstitial pneumonia with autoimmune features (IPAF) was recently proposed as a research concept in these patients. However, retrospective studies reported conflicting results of its prognosis. Therefore, this study was conducted to prospectively evaluate the clinical significance of autoimmune features in patients with IIP.

METHODS: This nationwide multicentre study prospectively enrolled consecutive patients with IIP. At the diagnosis, we systematically evaluated 63 features suggestive of connective tissue diseases using a checklist including symptoms/signs and autoantibodies, which contained most items of the IPAF criteria and followed up with the patients. Clinical phenotypes were included in a cluster analysis.

RESULTS: In 376 patients with IIP enrolled, 70 patients (18.6%) met the IPAF criteria. The proportion of patients with IPAF was significantly lower in idiopathic pulmonary fibrosis (IPF) than in non-IPF (6.0% vs 24.3%, respectively). During a median observation period of 35 months, patients with IPAF more frequently developed systemic autoimmune diseases and had less frequent acute exacerbation of IIPs than patients with non-IPAF. IPAF diagnosis was significantly associated with better survival and was an independent positive prognostic factor in total and patients with non-IPF. Cluster analysis by similarity of clinical phenotypes identified a cluster in which there was a higher number of women, and patients had more autoimmune features and a better prognosis than other clusters.

INTERPRETATION: These observations suggest that some patients with IIP show autoimmune features with distinct characteristics and favourable prognosis. However, we were not able to determine the appropriate therapies for these patients.

PMID:34272335 | DOI:10.1136/thoraxjnl-2020-216263

Thorax. 2021 Jul 16:thoraxjnl-2020-215918. doi: 10.1136/thoraxjnl-2020-215918. Online ahead of print.

ABSTRACT

BACKGROUND: Peripheral blood leucocyte telomere length (PBL-TL) is associated with outcomes in patients with idiopathic pulmonary fibrosis. Whether PBL-TL is associated with progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is unknown.

METHODS: A retrospective observational cohort study was performed using prospectively collected data from 213 patients with SSc followed at the University of California San Francisco (UCSF) Scleroderma Center. PBL-TL was measured by quantitative PCR of DNA isolated from peripheral blood. Associations between PBL-TL and pulmonary function test trends in patients with SSc-ILD were assessed by longitudinal analysis using Generalised Linear Mixed Models. Findings were validated in a cohort of 61 patients with SSc-ILD enrolled in the Stanford University Scleroderma Center database.

RESULTS: Patients with UCSF SSc with ILD were found to have shorter PBL-TL compared with those without ILD (6554±671 base pairs (bp) vs 6782±698 bp, p=0.01). Shorter PBL-TL was associated with the presence of ILD (adjusted OR 2.1 per 1000 bp TL decrease, 95% CI [1.25 to 3.70], p=0.006). PBL-TL was shorter in patients with SSc-ILD lacking SSc-specific autoantibodies compared with seropositive subjects (6237±647 bp vs 6651±653 bp, p=0.004). Shorter PBL-TL was associated with increased risk for lung function deterioration with an average of 67 mL greater loss in per year for every 1000 bp decrease in PBL-TL in the combined SSc-ILD cohorts (longitudinal analysis, adjusted model: 95% CI -104 mL to -33 mL, p<0.001).

CONCLUSIONS: These findings suggest that telomere dysfunction may be associated with SSc-ILD progression and that PBL-TL measurement may be useful for stratifying risk for SSc-ILD progression.

PMID:34272332 | DOI:10.1136/thoraxjnl-2020-215918

J Nucl Med. 2021 Jul 16:jnumed.121.261925. doi: 10.2967/jnumed.121.261925. Online ahead of print.

ABSTRACT

Purpose: Interstitial lung diseases (ILD) comprise over 200 parenchymal lung disorders. Among them, fibrosing ILDs, especially idiopathic pulmonary fibrosis (IPF) in particular are associated with a poor prognosis, while some others ILDs like sarcoidosis have a much better prognosis. A high proportion of ILD manifests as fibrotic ILD (fILD). Lung cancer (LC) is a frequent complication of fILD. Activated fibroblasts are crucial for fibrotic processes in fILD. The aim of this exploratory study was to evaluate the imaging properties of static and dynamic FAPI-PET/CT in various types of fILD and to confirm FAP expression of fILD lesions by FAP immunohistochemistry of human fILD biopsy samples and of lung sections of genetically engineered (Nedd4-2 -/- ) mice with an idiopathic pulmonary fibrosis (IPF) -like lung disease. Patients and Methods: PET-Scans of 15 patients with fILD and suspected LC were acquired 10, 60 and 180 minutes after the administration of 150-250 MBq of a 68Ga labelled FAPI tracer (FAPI-46). In three patients, dynamic scans over 40 mins were performed instead of imaging after 10 minutes. Standardized uptake values (SUVmax and SUVmean) of fibrotic lesions and LC were measured and CT-density-corrected. Target-to-background ratios (TBR) were calculated. PET imaging was correlated with CT-based fibrosis scores. Time-activity curves derived from dynamic imaging were analyzed. FAP immunohistochemistry of 4 human fILD biopsy samples and of fibrotic lungs of Nedd4-2-/- mice was carried out. Results: FILD lesions as well as LC showed markedly elevated FAPI-uptake (density corrected SUVmax / mean values 60 minutes post injection: 11,12 +/- 6,71 and 4,29 +/- 1,61 for fILD lesions and 16,69 +/- 9,35 and 6,44 +/- 3,29 for LC) and high TBR (TBR of density corrected SUVmax/SUVmean values 60 minutes post injection: 2,30 +/- 1,47 and 1,67 +/- 0,79 for fILD and 3,90 +/- 2,36 and 2,37 +/- 1,14 for LC). SUVmax and SUVmean values decreased over time with stable TBR of fILD and increasing TBR in LC on trend. Dynamic imaging showed differing time activity curves of fILD and LC. FAPI uptake showed a positive correlation with the CT-based fibrosis index (FIBI). Immunohistochemistry of human biopsy samples and lungs of Nedd4-2-/- mice showed a patchy expression of FAP in fibrotic lesions, preferentially in the transition zone to healthy lung parenchyma. Conclusion: FAPI-PET/CT imaging is a promising new imaging modality for fILD and LC. Its potential clinical value for monitoring and therapy evaluation of fILD should be investigated in future studies.

PMID:34272325 | DOI:10.2967/jnumed.121.261925

Respir Investig. 2021 Jun 30:S2212-5345(21)00116-7. doi: 10.1016/j.resinv.2021.06.007. Online ahead of print.

ABSTRACT

We conducted a study to examine the effect of COVID-19 on the acute exacerbation of interstitial lung disease (AE-ILD) early in the COVID-19 epidemic (January 1-April 30, 2020). An online questionnaire survey was conducted, which was completed by 134 hospitals. During this period, 854 patients with AE-ILD (including 12 cases of COVID-AE-idiopathic pulmonary fibrosis were hospitalized at 128 hospitals. In comparison, the total number of AE-ILD hospitalizations during the same period in 2019 was 894. The number of hospitalizations increased at 17 hospitals, decreased at 27, and remained the same at 88 hospitals in 2020 compared to the same period in 2019. In 2020, COVID-19-related acute exacerbations had a significantly worse prognosis than non-COVID-19-related acute exacerbations in both 30-day and 90-day mortality. Because the prognosis of AE-ILD associated with COVID-19 is extremely poor, prevention of COVID-19 is especially important for patients with ILD.

PMID:34272158 | DOI:10.1016/j.resinv.2021.06.007

Respir Med. 2021 Jul 8;186:106539. doi: 10.1016/j.rmed.2021.106539. Online ahead of print.

ABSTRACT

RATIONALE: The pathophysiology of interstitial lung disease (ILD) impacts body composition, whereby ILD severity is linked to lower lean mass.

OBJECTIVES: To determine i) if pectoralis muscle area (PMA) is a surrogate for whole-body lean mass in ILD, ii) whether PMA is associated with ILD severity, and iii) if the longitudinal change in PMA is associated with pulmonary function and mortality in ILD.

METHODS: Patients with ILD (n = 164) were analyzed retrospectively. PMA was quantified from a chest computed tomography scan. Peripheral oxygen saturation (SpO2), 6-min walk distance (6MWD), and pulmonary function were obtained as part of routine clinical care. Dyspnea and quality of life were assessed using the UCSD Shortness of Breath Questionnaire and European Quality of Life 5 Dimensions questionnaire, respectively.

RESULTS: PMA was associated with whole-body lean mass (p < 0.001). After adjusting for age, sex, height, body mass, and prednisone status, PMA was associated with %-predicted forced vital capacity (FVC), %-predicted diffusion capacity (DLCO), resting and exertional SpO2, and dyspnea (all p < 0.05), but not forced expiratory volume in 1 s (FEV1), FEV1/FVC, 6MWD, or quality of life (all p > 0.05). The annual negative PMA slope was associated with annual negative slopes in FVC, FEV1, and DLCO (all p < 0.05), but not FEV1/FVC (p = 0.46). Annual slope in PMA was associated with all-cause mortality (hazard ratio = -0.80, 95% CI:0.889-0.959; p < 0.001).

CONCLUSION: In patients with ILD, PMA is a suitable surrogate for whole-body lean mass. A lower PMA is associated with indices of ILD severity, which supports the notion that ILD progression may involve sarcopenia.

PMID:34271524 | DOI:10.1016/j.rmed.2021.106539

Int Immunol. 2021 Jul 16:dxab040. doi: 10.1093/intimm/dxab040. Online ahead of print.

ABSTRACT

Pulmonary fibrosis is a disease in which excessive extracellular matrix (ECM) accumulation occurs in the lungs, which induces thickening of the alveolar walls, ultimately leading to the destruction of alveolar structures and respiratory failure. Idiopathic pulmonary fibrosis, the cause of which is unknown, has a poor prognosis with a median survival of 2-4 years after diagnosis. There is currently no known curative treatment. The mechanism underlying pulmonary fibrosis is thought to be initiated by the dysfunction of type II alveolar epithelial cells, which leads to ECM overproduction through the activation of fibroblasts. In addition, it has been suggested that a variety of cells contribute to fibrotic processes. In particular, clinical and basic research findings examining the roles of macrophages suggest that they may be pivotal regulators of pulmonary fibrosis. In this review, we discuss the characteristics, functions and origins of subsets of macrophages involved in pulmonary fibrosis, including resident alveolar, interstitial and monocyte-derived macrophages.

PMID:34270737 | DOI:10.1093/intimm/dxab040

Ann Transl Med. 2021 May;9(9):739. doi: 10.21037/atm-21-414.

ABSTRACT

BACKGROUND: The associations of serum monomeric periostin (M-PN) level and serial change in M-PN with acute exacerbation of chronic fibrosing interstitial pneumonia (AE-FIP) are unclear.

METHODS: We prospectively measured serum M-PN level from onset of AE to day 14 in 37 patients with AE-FIP and evaluated its association with outcome. To determine localization of periostin expression, immunohistochemical staining of pathological lung tissue from autopsy cases of AE-IPF was evaluated.

RESULTS: Data from 37 AE-FIP patients (28 men; age 73.9±7.8 years) were analyzed. With healthy controls as reference, serum M-PN level was significantly higher in patients with AE-FIP (P=0.02) but not in those with stable idiopathic pulmonary fibrosis (P=1.00). M-PN was significantly lower on day 7 than at AE-FIP onset in survivors [14.6±5.8 vs. 9.3±2.8 ng/mL (onset to day 7: P<0.001)] but not in non-survivors [14.6±5.1 vs. 13.2±5.1 ng/mL (onset to day 7: P=0.07)]. In analysis using a cut-off value for serial change in M-PN (ΔM-PN), 3-month survival was 92.3% in the ΔM-PN decrease group and 36% in the ΔM-PN increase group (P=0.002). In multivariate analysis, 3-month survival tended to be associated with high ΔM-PN (OR: 12.4, 95% CI: 0.82-187.9, P=0.069).

CONCLUSIONS: Serial change in serum M-PN level may be a prognostic indicator of AE-FIP.

PMID:34268352 | PMC:PMC8246219 | DOI:10.21037/atm-21-414

Nat Commun. 2021 Jul 14;12(1):4314. doi: 10.1038/s41467-021-24467-0.

ABSTRACT

Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyze the transcriptomes of 611,398 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observe a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD AT2 cells express higher levels of genes linked directly to the efficiency of viral replication and the innate immune response. Additionally, we identify basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection.

PMID:34262047 | DOI:10.1038/s41467-021-24467-0

J Palliat Med. 2021 Jul 14. doi: 10.1089/jpm.2021.0327. Online ahead of print.

ABSTRACT

Prognostication has been described as "Medicine's Lost Art." Taken with diagnosis and treatment, prognostication is the third leg on which medical care rests. As research leads to additional beneficial treatments for vexing conditions like cancer, dementia, and lung disease, prognostication becomes even more difficult. This article, written by a group of palliative care clinicians with backgrounds in geriatrics, pulmonology, and oncology, aims to offer a useful framework for consideration of prognosis in these conditions. This article will serve as the first in a three-part series on prognostication in adults and children.

PMID:34264746 | DOI:10.1089/jpm.2021.0327

Am J Respir Cell Mol Biol. 2021 Jul 15. doi: 10.1165/rcmb.2021-0012OC. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is characterized by the invariably progressive deposition of fibrotic tissue in the lungs and overall poor prognosis. Transglutaminase 2 (TG2) is an enzyme that crosslinks glutamine and lysine residues and is involved in IPF pathogenesis. Despite the accumulating evidence implicating TG2 as a critical enzyme, the causative function and direct target of TG2 relating to this pathogenesis remain unelucidated. Here, we clarified the distributions of TG2 protein/activity and conducted quantitative proteomics analyses of possible substrates crosslinked by TG2 on unfixed lung sections in a mouse pulmonary fibrosis model. We identified 126 possible substrates as markedly increased TG2-dependently in fibrotic lung. Gene ontology analysis revealed that these identified proteins were mostly enriched in the lipid metabolic process, immune system process, and protein transport. In addition, these proteins enriched in the 21 pathways including phagosome, lipid metabolism, several immune responses, and protein processing in endoplasmic reticulum. Furthermore, the network analyses screened out the 6 clusters and top 20 hub proteins with higher scores, which are related to ER stress and peroxisome proliferator-activated receptor signals. Several enriched pathways and categories were identified, and some of which were the same terms based on transcription analysis in IPF. Our results provide novel pathological molecular networks driven by protein crosslinking via TG2, which can lead to the development of new therapeutic targets for IPF.

PMID:34264172 | DOI:10.1165/rcmb.2021-0012OC

Respir Res. 2021 Jul 15;22(1):205. doi: 10.1186/s12931-021-01801-0.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of fibrillar collagens in the alveolar space resulting in reduced pulmonary function and a high mortality rate. Biomarkers measuring the turnover of type I and III collagen could provide valuable information for prognosis and treatment decisions in IPF.

METHODS: Serological biomarkers reflecting the formation of type III collagen (PRO-C3) and degradation of type I (C1M) and III collagen (C3M) were evaluated in a real-world cohort of 178 newly diagnosed IPF patients. Blood samples and clinical data were collected at baseline, six, and 12 months. Baseline and longitudinal biomarker levels were related to disease progression of IPF (defined as ≥ 5% decline in forced vital capacity (FVC) and/or ≥ 10% decline in diffusing capacity for carbon monoxide (DLco) and/or all-cause mortality at 12 months). Furthermore, we analysed differences in percentage change of biomarker levels from baseline between patients receiving antifibrotic treatment or not.

RESULTS: Increased baseline levels of type I and III collagen turnover biomarkers were associated with a greater risk of disease progression within 12 months compared to patients with a low baseline type I and III collagen turnover. Patients with progressive disease had higher serum levels of C1M (P = 0.038) and PRO-C3 (P = 0.0022) compared to those with stable disease over one year. There were no differences in biomarker levels between patients receiving pirfenidone, nintedanib, or no antifibrotics.

CONCLUSION: Baseline levels of type I and III collagen turnover were associated with disease progression within 12 months in a real-world cohort of IPF patients. Longitudinal biomarker levels of type I and III collagen turnover were related to progressive disease. Moreover, antifibrotic therapy did not affect type I and III collagen turnover biomarkers in these patients. PRO-C3 and C1M may be potential biomarkers for a progressive disease behavior in IPF.

PMID:34261485 | DOI:10.1186/s12931-021-01801-0

Phytomedicine. 2021 May 21;89:153599. doi: 10.1016/j.phymed.2021.153599. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis is a chronic, progressive, fibrotic disease. Although the pathogenesis remains unclear, the effect of endoplasmic reticulum (ER) stress in type II alveolar epithelial cells (AEC IIs) is increasingly thought to be a critical mechanism.

PURPOSE: We investigated the effects of citrus alkaline extracts (CAE) on AEC IIs and elucidated the underlying mechanism for their possible use in ameliorating pulmonary fibrosis (PF).

METHODS: A bleomycin-induced mouse model of PF, and an in vitro tunicamycin (TM) -induced ER stress model in A549 cells were successfully established. Accumulation of collagen in lung tissues in vivo was assessed using histological analysis and western blotting. The expression levels of the ER-stress marker BiP and other related proteins were assessed by western blotting and immunofluorescence staining. Mitochondrial membrane potential was assessed to evaluate mitochondrial homeostasis.

RESULTS: CAE mitigated collagen deposition to ameliorate PF in vivo. CAE suppressed the bleomycin or TM-induced increases in ER-stress biomarker, BiP, and PERK pathway proteins, resulting in a decrease in ER stress in mouse lung tissues and A549 cells, respectively. Additionally, CAE treatment suppressed the bleomycin or TM-induced increase in the ER-stress downstream proteins, activating ATF3 and increased the levels of PINK1 in AEC IIs, both in vivo and in vitro. The reduced mitochondrial homeostasis induced by TM was restored by CAE-treatment in A549 cells. Furthermore, conditioned media from TM-treated A549 cells increased collagen deposition in MRC5 cells mainly via TGF-β1. The increased collagen deposition was not seen using conditioned media from CAE-treated A549 cells.

CONCLUSION: These results provide novel insights into the potential mechanism of CAE in inhibiting ER stress in AEC IIs, and suggests that it has great potential to ameliorate PF via the ATF3/PINK1 pathway.

PMID:34260993 | DOI:10.1016/j.phymed.2021.153599

Respir Med. 2021 Jul 7;186:106534. doi: 10.1016/j.rmed.2021.106534. Online ahead of print.

ABSTRACT

BACKGROUND: Acute exacerbation (AE) of interstitial lung disease (ILD) is an acute respiratory deterioration of unknown etiology, associated with high mortality. Currently, bronchoalveolar lavage (BAL) has been no longer required for the diagnosis of AE-ILD; however, the clinical utility of BAL fluid (BALF) cellular analysis in AE-ILD remains unclear.

METHODS: A retrospective study of 71 patients who underwent BAL at our institution between 2005 and 2019 and were diagnosed with AE-ILD was conducted. We performed BALF cellular analysis and evaluated its prognostic significance.

RESULTS: There were 26 patients with AE of idiopathic pulmonary fibrosis (IPF) and 45 with AE of non-IPF, including idiopathic interstitial pneumonias/non-IPF (n = 22), ILD associated with collagen tissue disease (n = 20) and fibrotic hypersensitivity pneumonia (n = 3). All patients were treated with high-dose corticosteroids, and the 90-day mortality after AE was 31%. Most patients showed a high percentage of lymphocytes and/or neutrophils in BALF regardless of the underlying ILD. There was a significant negative correlation between BALF neutrophils and the PaO2/FiO2 ratio, and patients with UIP pattern or diffuse AE pattern on HRCT had a significantly higher percentage of BALF neutrophils than those with other patterns. Multivariate analysis revealed that lower and higher percentage of lymphocytes and neutrophils, respectively, in BALF were independent poor prognostic factors for 90-day survival. BALF lymphocyte and neutrophil count ≥25% and <20%, respectively, predicted favorable survival after AE.

CONCLUSIONS: Cellular analysis of BALF in AE-ILD is a potential biomarker for predicting prognosis after AE.

PMID:34260978 | DOI:10.1016/j.rmed.2021.106534

J Mol Med (Berl). 2021 Jul 13. doi: 10.1007/s00109-021-02113-y. Online ahead of print.

ABSTRACT

Pulmonary fibrosis is a chronic debilitating condition characterized by progressive deposition of connective tissue, leading to a steady restriction of lung elasticity, a decline in lung function, and a median survival of 4.5 years. The leading causes of pulmonary fibrosis are inhalation of foreign particles (such as silicosis and pneumoconiosis), infections (such as post COVID-19), autoimmune diseases (such as systemic autoimmune diseases of the connective tissue), and idiopathic pulmonary fibrosis. The therapeutics currently available for pulmonary fibrosis only modestly slow the progression of the disease. This review is centered on the interplay of damage-associated molecular pattern (DAMP) molecules, Toll-like receptor 4 (TLR4), and inflammatory cytokines (such as TNF-α, IL-1β, and IL-17) as they contribute to the pathogenesis of pulmonary fibrosis, and the possible avenues to develop effective therapeutics that disrupt this interplay.

PMID:34258628 | DOI:10.1007/s00109-021-02113-y

Dtsch Med Wochenschr. 2021 Jul;146(13-14):927-932. doi: 10.1055/a-1449-5158. Epub 2021 Jul 13.

ABSTRACT

Acute COVID-19 pneumonia may result in persistent changes with various imaging and histopathological patterns, including organizing pneumonia and pulmonary fibrosis. In addition, SARS-CoV-2 infection is associated with increased risk of pulmonary vascular endothelialitis and thrombosis. Herein, current findings on pulmonary consequences of COVID-19 with implications for clinical management are summarized based on a selective literature review.

PMID:34256411 | DOI:10.1055/a-1449-5158

Chest. 2021 Jul 9:S0012-3692(21)01317-9. doi: 10.1016/j.chest.2021.06.067. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is associated with a poor prognosis with variable clinical course. Early identification of patients at high risk for disease progression and death would lead to early therapeutic intervention and thereby improvement of outcomes. Cold-inducible RNA-binding protein (CIRBP) is produced in response to cellular stresses, which is implicated in multiple biological processes, including cell survival and proliferation.

RESEARCH QUESTION: Is CIRBP a useful biomarker for predicting the outcomes of patients with IPF?

STUDY DESIGN AND METHODS: This study included 95 and 93 patients with IPF from two independent hospitals (derivation and validation cohorts, respectively). The associations of serum CIRBP level upon IPF diagnosis with disease progression within 1 year after diagnosis (i.e. ≥10% relative decline in percent predicted forced vital capacity or death) and all-cause mortality were retrospectively analysed. Discrimination performances for predicting these outcomes were evaluated using the c-index.

RESULTS: Serum and lung tissue CIRBP levels were higher in patients with IPF than in control subjects. In the derivation cohort, the CIRBP high sub-group had significantly higher 1-year disease progression rates and lower cumulative survival rates than the CIRBP low sub-group, and the results were replicated in the validation cohort. In multivariate analyses, high serum CIRBP level was independently associated with higher 1-year disease progression and all-cause mortality rates in both cohorts. Combining the Gender-Age-Physiology and serum CIRBP models improved the c-indices for predicting 1-year disease progression and all-cause mortality compared with that of each model alone. The c-indices of serum CIRBP were particularly high in patients with Gender-Age-Physiology stage I.

INTERPRETATION: This study successfully validated that serum CIRBP level was an independent predictor of 1-year disease progression and all-cause mortality in IPF. CIRBP is a promising biomarker that can help identify high-risk patients with IPF, especially in the early stage.

PMID:34252438 | DOI:10.1016/j.chest.2021.06.067