Pretreatment mortality risk prediction model in patients with polymyositis/dermatomyositis-associated interstitial lung disease.

OBJECTIVES: Risk prediction for patients with polymyositis/dermatomyositis-associated interstitial lung disease (PM/DM-ILD) is challenging due to heterogeneity in the disease course. We aimed to develop a mortality risk prediction model for PM/DM-ILD. METHODS: This prognostic study analysed patients with PM/DM-ILD admitted to Nanjing Drum Hospital from 2016 to 2021. The primary outcome was mortality within 1 year. We used a least absolute shrinkage and selection operator (LASSO) logistic regression model to identify predictive laboratory indicators. These indicators were used to create a laboratory risk score, and we developed a mortality risk prediction model by incorporating clinical factors. The evaluation of model performance encompassed discrimination, calibration, clinical utility and practical application for risk prediction and prognosis. RESULTS: Overall, 418 patients with PM/DM-ILD were enrolled and randomly divided into development (n=282) and validation (n=136) cohorts. LASSO logistic regression identified four optimal features in the development cohort, forming a laboratory risk score: C reactive protein, lactate dehydrogenase, CD3+CD4+ T cell counts and PO2/FiO2. The final prediction model integrated age, arthralgia, anti-melanoma differentiation-associated gene 5 antibody status, high-resolution CT pattern and the laboratory risk score. The prediction model exhibited robust discrimination (area under the receiver operating characteristic: 0.869, 95% CI 0.811 to 0.910), excellent calibration and valuable clinical utility. Patients were categorised into three risk groups with distinct mortality rates. The internal validation, sensitivity analyses and comparative assessments against previous models further confirmed the robustness of the prediction model. CONCLUSIONS: We developed and validated an evidence-based mortality risk prediction model with simple, readily accessible clinical variables in patients with PM/DM-ILD, which may inform clinical decision-making.

Novel 3D-based deep learning for classification of acute exacerbation of idiopathic pulmonary fibrosis using high-resolution CT.

PURPOSE: Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is the primary cause of death in patients with IPF, characterised by diffuse, bilateral ground-glass opacification on high-resolution CT (HRCT). This study proposes a three-dimensional (3D)-based deep learning algorithm for classifying AE-IPF using HRCT images. MATERIALS AND METHODS: A novel 3D-based deep learning algorithm, SlowFast, was developed by applying a database of 306 HRCT scans obtained from two centres. The scans were divided into four separate subsets (training set, n=105; internal validation set, n=26; temporal test set 1, n=79; and geographical test set 2, n=96). The final training data set consisted of 1050 samples with 33 600 images for algorithm training. Algorithm performance was evaluated using accuracy, sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve and weighted κ coefficient. RESULTS: The accuracy of the algorithm in classifying AE-IPF on the test sets 1 and 2 was 93.9% and 86.5%, respectively. Interobserver agreements between the algorithm and the majority opinion of the radiologists were good (κw=0.90 for test set 1 and κw=0.73 for test set 2, respectively). The ROC accuracy of the algorithm for classifying AE-IPF on the test sets 1 and 2 was 0.96 and 0.92, respectively. The algorithm performance was superior to visual analysis in accurately diagnosing radiological findings. Furthermore, the algorithm's categorisation was a significant predictor of IPF progression. CONCLUSIONS: The deep learning algorithm provides high auxiliary diagnostic efficiency in patients with AE-IPF and may serve as a useful clinical aid for diagnosis.

The gene expression of CALD1, CDH2, and POSTN in fibroblast are related to idiopathic pulmonary fibrosis.

Introduction: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive lung dysfunction due to excessive collagen production and tissue scarring. Despite recent advancements, the molecular mechanisms remain unclear. Methods: RNA sequencing identified 475 differentially expressed genes (DEGs) in the TGF-ß1-induced primary lung fibrosis model. Gene expression chips GSE101286 and GSE110147 from NCBI gene expression omnibus (GEO) database were analyzed using GEO2R, revealing 94 DEGs in IPF lung tissue samples. The gene ontology (GO) and pathway enrichment, Protein-protein interaction (PPI) network construction, and Maximal Clique Centrality (MCC) scoring were performed. Experimental validation included RT-qPCR, Immunohistochemistry (IHC), and Western Blot, with siRNA used for gene knockdown. A co-expression network was constructed by GeneMANIA. Results: GO enrichment highlighted significant enrichment of DEGs in TGF-ß cellular response, connective tissue development, extracellular matrix components, and signaling pathways such as the AGE-RAGE signaling pathway and ECM-receptor interaction. PPI network analysis identified hub genes, including FN1, COL1A1, POSTN, KIF11, and ECT2. CALD1 (Caldesmon 1), CDH2 (Cadherin 2), and POSTN (Periostin) were identified as dysregulated hub genes in both the RNA sequencing and GEO datasets. Validation experiments confirmed the upregulation of CALD1, CDH2, and POSTN in TGF-ß1-treated fibroblasts and IPF lung tissue samples. IHC experiments probed tissue-level expression patterns of these three molecules. Knockdown of CALD1, CDH2, and POSTN attenuated the expression of fibrotic markers (collagen I and α-SMA) in response to TGF-ß1 stimulation in primary fibroblasts. Co-expression analysis revealed interactions between hub genes and predicted genes involved in actin cytoskeleton regulation and cell-cell junction organization. Conclusions: CALD1, CDH2, and POSTN, identified as potential contributors to pulmonary fibrosis, present promising therapeutic targets for IPF patients.

Animal models of acute exacerbation of pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive scarring interstitial lung disease with an unknown cause. Some patients may experience acute exacerbations (AE), which result in severe lung damage visible on imaging or through examination of tissue samples, often leading to high mortality rates. However, the etiology and pathogenesis of AE-IPF remain unclear. AE-IPF patients exhibit diffuse lung damage, apoptosis of type II alveolar epithelial cells, and an excessive inflammatory response. Establishing a reliable animal model of AE is critical for investigating the pathogenesis. Recent studies have reported a variety of animal models for AE-IPF, each with its own advantages and disadvantages. These models are usually established in mice with bleomycin-induced pulmonary fibrosis, using viruses, bacteria, small peptides, or specific drugs. In this review, we present an overview of different AE models, hoping to provide a useful resource for exploring the mechanisms and targeted therapies for AE-IPF.

Alveolar macrophages in pulmonary alveolar proteinosis: origin, function, and therapeutic strategies.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disorder that is characterized by the abnormal accumulation of surfactant within the alveoli. Alveolar macrophages (AMs) have been identified as playing a pivotal role in the pathogenesis of PAP. In most of PAP cases, the disease is triggered by impaired cholesterol clearance in AMs that depend on granulocyte-macrophage colony-stimulating factor (GM-CSF), resulting in defective alveolar surfactant clearance and disruption of pulmonary homeostasis. Currently, novel pathogenesis-based therapies are being developed that target the GM-CSF signaling, cholesterol homeostasis, and immune modulation of AMs. In this review, we summarize the origin and functional role of AMs in PAP, as well as the latest therapeutic strategies aimed at addressing this disease. Our goal is to provide new perspectives and insights into the pathogenesis of PAP, and thereby identify promising new treatments for this disease.

Prediction of progressive pulmonary fibrosis in patients with anti-synthetase syndrome-associated interstitial lung disease.

OBJECTIVE: Interstitial lung disease (ILD) is a common extramuscular manifestation of the anti-synthetase syndrome (ASS). Patients with ASS-ILD are at risk in developing a progressive fibrosing phenotype despite appropriate treatments. This study investigated the risk factors and the predictive value of multiple risk factors for progressive pulmonary fibrosis (PPF) in patients with ASS-ILD. METHODS: Ninety patients with a diagnosis of ASS and evidence of ILD on high-resolution computed tomography (HRCT) were recruited. Among them, 72 participants completed follow-up for more than 12 months. These patients were further divided into a PPF-ASS group (n = 18) and a non-PPF-ASS group (n = 54). Logistic regression analysis was performed to investigate the risk factors for PPF. The predictive value of the combined risk factors for predicting PPF were analyzed by a ROC curve. RESULTS: The PPF-ASS group had a higher rate of positive non-Jo-1 antibodies, a significantly higher neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (LDH), and a significantly lower PaO2/FiO2 ratio and diffusing capacity for carbon monoxide (DLCO%pred) than the non-PPF-ASS group. In addition, elevated serum Krebs von den Lungen-6 (KL-6) level and reticular opacities were significantly more common, and corticosteroid monotherapy at onset was administered more frequently in the PPF-ASS group. The median duration of follow-up was 37.4 months, survival was poorer in the PPF-ASS group, and the overall survival was 88.9%. Multivariate regression analysis further revealed that positive non-Jo-1 antibodies, NLR, and KL-6 were independent risk factors for PPF. These combined indexes had good accuracy (area under the curve = 0.874) in predicting PPF in patients with ASS-ILD. CONCLUSION: Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors for PPF in patients with ASS-ILD. Monitoring these markers can potentially predict PPF in this group of patients. Key Points • Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors associated with PPF in patients with ASS-ILD. • Monitoring non-Jo-1 antibodies, NLR, and serum KL-6 can potentially predict PPF in patients with ASS-ILD.

A Self-Propagating c-Met-SOX2 Axis Drives Cancer-Derived IgG Signaling That Promotes Lung Cancer Cell Stemness.

SIGNIFICANCE: Sialylated cancer IgG activates c-Met-SOX2 signaling to promote stemness properties in cancer cells and can be targeted to suppress tumor growth.

Prediction model for the pretreatment evaluation of mortality risk in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease.

Background: Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease (anti-MDA5 DM-ILD) is a disease with high mortality. We sought to develop an effective and convenient prediction tool to estimate mortality risk in patients with anti-MDA5 DM-ILD and inform clinical decision-making early. Methods: This prognostic study included Asian patients with anti-MDA5 DM-ILD hospitalized at the Nanjing Drum Hospital from December 2016 to December 2020. Candidate laboratory indicators were retrospectively collected. Patients hospitalized from 2016 to 2018 were used as the discovery cohort and applied to identify the optimal predictive features using a least absolute shrinkage and selection operator (LASSO) logistic regression model. A risk score was determined based on these features and used to construct the mortality risk prediction model in combination with clinical characteristics. Results were verified in a temporal validation comprising patients treated between 2019 and 2020. The primary outcome was mortality risk within one year. The secondary outcome was overall survival. The prediction model's performance was assessed in terms of discrimination, calibration, and clinical usefulness. Results: This study included 127 patients, (72 men [56.7%]; median age, 54 years [interquartile range, 48-63 years], split into discovery (n = 87, 70%) and temporal validation (n=37, 30%) cohorts. Five optimal features were selected by LASSO logistic regression in the discovery cohort (n = 87) and used to construct a risk score, including lymphocyte counts, CD3+CD4+ T-cell counts, cytokeratin 19 fragment (CYFRA21-1), oxygenation index, and anti-Ro52 antibody. The retained predictive variables in the final prediction model were age, Heliotrope, fever, and risk score, and the most predictive factor was the risk score. The prediction model showed good discrimination (AUC: 0.915, 95% CI: 0.846-0.957), good calibration (Hosmer-Lemeshow test, P = 0.506; Brier score, 0.12), and fair clinical usefulness in the discovery cohort. The results were verified among patients in the temporal validation cohort (n = 38). We successfully divided patients into three risk groups with very different mortality rates according to the predictive score in both the discovery and validation cohorts (Cochran-Armitage test for trend, P < 0.001). Conclusions: We developed and validated a mortality risk prediction tool with good discrimination and calibration for Asian patients with anti-MDA5 DM-ILD. This tool can offer individualized mortality risk estimation and inform clinical decision-making.

Elevated Expression of Growth Differentiation Factor-15 Is Associated With Acute Exacerbation of Idiopathic Pulmonary Fibrosis.

Backgrounds: Growth differentiation factor 15 (GDF-15) is a highly divergent member of the TGF-ß superfamily and has been implicated in various biological functions. However, the expression of GDF-15 in patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is unclear. Method: The study included 47 AE-IPF patients, 61 stable IPF (S-IPF) subjects, and 31 healthy controls (HCs). Serum GDF-15 levels and their expression in the lung were measured. The correlation between serum GDF-15 and other clinical parameters and the risk factors for AE occurrence and the survival of IPF patients were analyzed. Results: Serum GDF-15 levels were significantly elevated in AE-IPF patients (1279.22 ± 540.02 pg/ml) as compared with HCs (891.30 ± 479.90 pg/ml) or S-IPF subjects (107.82 ± 14.21 pg/ml) (both p < 0.001). The protein and mRNA expressions of GDF-15 in the lung of AE-IPF patients were significantly increased as compared with S-IPF cases (p = 0.007 and p = 0.026, respectively). The serum GDF-15 level was correlated with the clinical variables of inflammation, metabolism, and disease severity in IPF subjects (all p < 0.05). The GDF-15 serum concentration was significantly higher in decedents than in survivors (p = 0.005). A serum GDF-15 level above 989.3 pg/ml was a risk factor for AE occurrence (p = 0.04), and the level above 1,075.76 pg/ml was an independent predictor for survival in IPF cases (p = 0.007). Conclusions: The GDF-15 level was significantly elevated in subjects with AE-IPF. GDF-15 could be a promising biomarker for AE occurrence and survival in IPF patients.

Anti-Ro52 antibodies are associated with the prognosis of adult idiopathic inflammatory myopathy-associated interstitial lung disease.

OBJECTIVES: In the present study, we aimed to assess the prevalence and clinical significance of anti-Ro52 antibodies in a cohort of patients with idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) with different myositis-specific autoantibodies (MSAs). METHODS: A cohort of 267 IIM-ILD patients, including 62 patients with PM, 126 patients with DM and 79 patients with clinically amyopathic DM (CADM) were retrospectively analysed in this study. Clinical and laboratory findings, pulmonary function tests (PFTs), HRCT patterns and treatment information were compared between patients with and without anti-Ro52 antibodies. The association between prognosis and anti-Ro52 antibodies was also evaluated based on different MSA subgroups. RESULTS: Anti-Ro52 antibodies were more frequent in patients with anti-MDA5 (62.1%, P < 0.01) and anti-Jo1 (64.9%, P < 0.01) antibodies than in those with other MSAs. The proportion of patients with anti-Jo1 antibodies was higher in the anti-Ro52 antibody-positive group than in the anti-Ro52 antibody-negative group. Patients with anti-Ro52 antibodies were more likely to exhibit the Gottron sign than the anti-Ro52 antibody-negative group (P < 0.001). Furthermore, it was a predictive factor for rapid progression interstitial lung disease (RP-ILD) (P = 0.001) and was also associated with a higher mortality rate (log-rank test, P = 0.001). Furthermore, RP-ILD was more frequently exhibited in anti-MDA5- and anti-Ro52-positive patients. Moreover, anti-Ro52 antibody positivity was closely associated with a higher mortality rate in anti-MDA5-ILD patients (log-rank test, P < 0.05). CONCLUSIONS: Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5 and anti-Jo1 antibodies. Within all patients with IIM-ILD, those with anti-Ro52 autoantibodies had a higher frequency of RP-ILD and a poorer prognosis, especially in the anti-MDA5 antibody subgroup.

Impairment of µ-calpain activation by rhTNFR:Fc reduces severe burn-induced membrane disruption in the heart.

Stress cardiomyopathy is a major clinical complication after severe burn. Multiple upstream initiators have been identified; however, the downstream targets are not fully understood. This study assessed the role of the plasma membrane in this process and its relationship with the protease µ-calpain and tumor necrosis factor-alpha (TNF-α). Here, third-degree burn injury of approximately 40% of the total body surface area was established in rats. Plasma levels of LDH and cTnI and cardiac cell apoptosis increased at 0.5 h post burn, reached a peak at 6 h, and gradually declined at 24 h. This effect correlated well with not only the disruption of cytoskeletal proteins, including dystrophin and ankyrin-B, but also with the activation of µ-calpain, as indicated by the cleaved fragments of α-spectrin and membrane recruitment of the catalytic subunit CAPN1. More importantly, these alterations were diminished by blocking calpain activity with MDL28170. Burn injury markedly increased the cellular uptake of Evans blue, indicating membrane integrity disruption, and this effect was also reversed by MDL28170. Compared with those in the control group, cardiac cells in the burn plasma-treated group were more prone to damage, as indicated by a marked decrease in cell viability and increases in LDH release and apoptosis. Of note, these alterations were mitigated by CAPN1 siRNA. Moreover, after neutralizing TNF-α with rhTNFR:Fc, calpain activity was blocked, and heart function was improved. In conclusion, we identified µ-calpain as a trigger for severe burn-induced membrane disruption in the heart and provided evidence for the application of rhTNFR:Fc to inhibit calpain for cardioprotection.

Protective function of interleukin-22 in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive scarring disease with unknown etiology. The evidence of a pathogenic role for transforming growth factor-beta (TGF-ß) in the development and progression of IPF is overwhelming. In the present study, we investigated the role of interleukin-22 (IL-22) in the pathogenesis of IPF by regulating the TGF-ß pathway. We measured parameters and tissue samples from a clinical cohort of IPF. IL-22R knock out (IL-22RA1-/- ) and IL-22 supplementation mouse models were used to determine if IL-22 is protective in vivo. For the mechanistic study, we tested A549, primary mouse type II alveolar epithelial cell, human embryonic lung fibroblast, and primary fibroblast for their responses to IL-22 and/or TGF-ß1. In a clinical cohort, the expression level of IL-22 in the peripheral blood and lung tissues of IPF patients was lower than healthy controls, and the lower IL-22 expression was associated with poorer pulmonary function. IL-22R-/- mice demonstrated exacerbated inflammation and fibrosis. Reciprocally, IL-22 augmentation by intranasal instillation of recombinant IL-22 repressed inflammation and fibrotic phenotype. In vitro, IL-22 treatment repressed TGF-ß1 induced gene markers representing epithelial-mesenchymal-transition and fibroblast-myofibroblast-transition, likely via the inhibition of TGF-ß receptor expression and subsequent Smad2/3 activation. IL-22 appears to be protective against pulmonary fibrosis by inhibiting TGF-ß1 signaling, and IL-22 augmentation may be a promising approach to treat IPF.

Clioquinol Attenuates Pulmonary Fibrosis through Inactivation of Fibroblasts via Iron Chelation.

Strict control of iron homeostasis is critical for the maintenance of normal lung function. Iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (PF), but the characteristics of iron metabolism in the pathogenesis of PF and related targeting therapeutics are not well studied. In this study, we investigated the cellular and molecular characteristics of iron metabolism in fibrotic lungs and further explored the efficacy of clioquinol (CQ) for the treatment of PF as well as its functional mechanism. Iron aggregates accumulated in the lungs of patients with idiopathic PF, and FTL (ferritin light chain) transcripts were increased in their pulmonary fibroblasts. In the bleomycin (BLM)-induced PF (BLM-PF) mouse model, pulmonary iron accumulation is a very early and concomitant event of PF. Labile iron pool levels in both fibroblasts and macrophages from the BLM-PF model were elevated, and iron metabolism was dysregulated. CQ attenuated PF induced by BLM and FITC, and iron-saturated CQ did not alleviate BLM-PF. Furthermore, CQ inhibited the activation of fibroblasts, including proliferation, fibrotic differentiation, proinflammatory cytokine secretion, and migration. In conclusion, our study demonstrated that CQ, acting as an iron chelator, attenuates experimental PF through inactivation of fibroblasts, providing support for targeting iron metabolism as a basis for PF treatment.

Cytokeratin 19 fragment is associated with severity and poor prognosis of interstitial lung disease in anti-MDA5 antibody-positive dermatomyositis.

OBJECTIVES: In the present study, we aimed to assess the clinical significance of cytokeratin 19 fragment (CYFRA21-1) in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM-interstitial lung disease (MDA5-DM-ILD). METHODS: A total of 73 MDA5-DM-ILD patients were retrospectively analysed in this work. Their clinical characteristics, including clinical manifestations, laboratory findings, peripheral blood lymphocyte subsets and lung function, were compared between patients with acute/subacute interstitial pneumonia (A/SIP) and chronic interstitial pneumonia (CIP). The level of serum CYFRA21-1 was also compared between the above-mentioned two groups of patients, and its association with the clinical features and mortality of MDA5-DM-ILD was also evaluated. RESULTS: Of the 73 MDA5-DM-ILD patients, 26 patients exhibited the A/SIP pattern. The level of serum CYFRA21-1 was higher in MDA5-DM patients with A/SIP compared with the CIP group (P = 0.009). Lower oxygenation index (OI), CD3+CD4+ T cell counts and percentage of CD3+CD4+ cells were also observed in MDA5-DM patients with A/SIP compared with the CIP group. Higher serum CYFRA21-1, lower OI, and lower zone consolidation were associated with a higher risk of A/SIP in MDA5-DM-ILD. In addition, 38 decedents with MDA5-DM-ILD exhibited a greater level of CYFRA21-1 compared with 35 survivors (P < 0.001). Furthermore, it was a prognostic factor and also associated with a higher mortality rate (log-rank test, P < 0.001). CONCLUSIONS: CYFRA21-1 could be a useful serum indicator associated with occurrence of A/SIP in MDA5-DM-ILD. Moreover, it was associated with a poor survival in MDA5-DM-ILD patients.

Radix Astragali and Radix Angelicae Sinensis in the Treatment of Idiopathic Pulmonary Fibrosis: A Systematic Review and Meta-analysis.

INTRODUCTION: There are many clinical studies in the treatment of idiopathic pulmonary fibrosis (IPF) with herbal medicine including Astragalus mongholicus Bunge, Radix Astragali (RA) and Angelica sinensis (Oliv.) Diels, Radix Angelicae Sinensis (RAS). These have obtained good curative effect. There is no systematic evaluation on the clinical efficacy of RA and RAS in patients with IPF. The aim of this systematic review and meta-analysis was to critically evaluate the current evidence of efficacy and safety of RA and RAS in IPF. METHODS: We searched the primary database for randomized controlled trial (RCT) of RA and RAS treating IPF. We assessed the quality of included studies using the Jadad rating scale and referred to the Cochrane Reviewer's Handbook for guidelines to assess the risk of bias. We extracted the main outcomes of included RCTs and a meta-analysis was conducted using the Cochrane Collaboration's RevMan5.3 software. RESULTS: Seventeen eligible RCTs were identified and made a systematic review and meta-analysis. Risk of bias and quality of included RCTs were carried out. The results of meta-analysis showed that total effective rate and traditional Chinese medicine syndrome effective rate were statistically significantly higher in the experimental group than the control group, main pulmonary function index, six minute walking distance and Borg scale questionnaire score were statistically significantly better in the experimental group than the control group and incidence of adverse reactions was statistically significantly lower in the experimental group than the control group. CONCLUSION: RA and RAS are effective and safe in the treatment of IPF, which is beneficial to pulmonary function and exercise tolerance of these patients.

Prognostic Value of Serum Osteopontin in Acute Exacerbation of Idiopathic Pulmonary Fibrosis.

BACKGROUND: Acute exacerbation (AE) is a common cause of rapid deterioration and high mortality in idiopathic pulmonary fibrosis (IPF) patients. Osteopontin (OPN) plays an important role in IPF, but the studies about serum OPN in AE-IPF are unclear. We aimed to investigate whether OPN had a potential prognostic value in acute exacerbation and mortality in IPF. METHODS: Thirty-two patients with AE-IPF, 39 with S-IPF, and 20 healthy controls were included. Serum OPN and KL-6 levels were compared between AE-IPF and S-IPF. Logistic regression analysis was applied to identify the predicted value of OPN for AE. Kaplan-Meier curves were used to display survival, and Cox proportional hazards regression was used to identify risk for mortality. RESULTS: In AE-IPF patients, serum OPN levels were significantly higher than in S-IPF subjects (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (p < 0.001) or healthy controls (. CONCLUSION: Elevated OPN could be a potential serum predictor for AE status and survival in IPF patients.

Acute exacerbations of fibrosing interstitial lung disease associated with connective tissue diseases: a population-based study.

BACKGROUND: Acute exacerbation (AE) is the major cause of morbidity and mortality in patients with idiopathic pulmonary fibrosis (IPF). AEs also occur in other forms of fibrosing interstitial lung disease (fILD). The clinical features and prognosis of AE patients with connective tissue diseases (CTDs) associated-ILD has not been fully described. METHODS: We retrospectively reviewed 177 patients with either IPF or a characterized CTD-ILD admitted to Nanjing Drum Tower Hospital with an AE from January 2010 to December 2016. RESULTS: The study cohort included 107 subjects with AE-IPF and 70 cases with AE-CTD-ILD. Female gender, prior use of corticosteroid and immunosupressants, lower serum albumin, higher D-dimer level, TLC% pred, survival, and treatment with immunosupressants and caspofungin were more common in the CTD-ILD group (all p<0.05). The incidences of AE-CTD-ILD and AE-IPF were similar in our single center (p = 0.526). TLC% pred was the risk factor for AE after ILD diagnosis for 1 year in CTD patients (p = 0.018). Log-rank tests showed patients with CTD-ILD had a significantly lower mortality rate compared with IPF patients after AEs (p = 0.029). No significant difference in survival was noted among CTD subgroups (p = 0.353). The survival was negatively correlated with WBC count, LDH and CT score, (p = 0.006, p = 0.013 and p = 0.035, respectively), and positively correlated with PaO2/FiO2 ratio (p<0.001) in the CTD-ILD group. WBC count and PO2/FiO2 ratio were the independent predictors for survival in AE-CTD-ILD after adjusting for other clinical variates in Cox regression Models (p = 0.038 and p < 0.001, respectively). CONCLUSIONS: The clinical characteristics of patients with AE-CTD-ILD differed from those with AE-IPF, while AE incidences were similar between the two groups. Subjects with AE-CTD-fILD tended to have a better prognosis, and WBC count and PO2/FiO2 ratio were the independent survival predictors for these patients.

PTEN loss regulates alveolar epithelial cell senescence in pulmonary fibrosis depending on Akt activation.

Idiopathic pulmonary fibrosis (IPF) is an aging-associated disease with poor prognosis. The mechanisms underlying the role of alveolar epithelial cell (AEC) senescence in IPF remain poorly understood. We aimed to investigate if PTEN/Akt activates AEC senescence to induce pulmonary fibrosis. We investigated the association between PTEN/Akt and cellular senescence in lung tissues from IPF patients. As a result, decreased PTEN and activated Akt pathway were found in AECs in fibrotic lung tissues detected by immunohistochemistry (IHC) and immunofluorescence (IF). Increased expression levels of aging-associated markers (P21WAF1 and SA-ß-gal) in AECs treated with bleomycin were found. AEC senescence was accelerated by PTEN knockdown and attenuated by PTEN overexpression. Bleomycin induced AEC senescence was reversed by Akt2 knockdown and the pharmacological inhibitors (LY294002 and MK2206) of the Akt pathway. Reducing Akt activation dramatically improved lung fibrosis in a fibrotic mice model. In addition, a co-immunoprecipitation (co-IP) assay demonstrated that PTEN physically associated with Akt. These indicated that senescent AECs modulated by the PTEN/Akt pathway promote lung fibrosis. In conclusion, our study demonstrated that as a trigger indicator in IPF, the senescence process in AECs should be a potential therapeutic target and that the PTEN/Akt pathway may be a promising candidate for intervention.