Identification of kynurenine and quinolinic acid as promising serum biomarkers for drug-induced interstitial lung diseases.

BACKGROUND: Drug-induced interstitial lung disease (DILD) is a lung injury caused by various types of drugs and is a serious problem in both clinical practice and drug development. Clinical management of the condition would be improved if there were DILD-specific biomarkers available; this study aimed to meet that need. METHODS: Biomarker candidates were identified by non-targeted metabolomics focusing on hydrophilic molecules, and further validated by targeted approaches using the serum of acute DILD patients, DILD recovery patients, DILD-tolerant patients, patients with other related lung diseases, and healthy controls. RESULTS: Serum levels of kynurenine and quinolinic acid (and kynurenine/tryptophan ratio) were elevated significantly and specifically in acute DILD patients. The diagnostic potentials of these biomarkers were superior to those of conventional lung injury biomarkers, Krebs von den Lungen-6 and surfactant protein-D, in discriminating between acute DILD patients and patients with other lung diseases, including idiopathic interstitial pneumonia and lung diseases associated with connective tissue diseases. In addition to identifying and evaluating the biomarkers, our data showed that kynurenine/tryptophan ratios (an indicator of kynurenine pathway activation) were positively correlated with serum C-reactive protein concentrations in patients with DILD, suggesting the potential association between the generation of these biomarkers and inflammation. Our in vitro experiments demonstrated that macrophage differentiation and inflammatory stimulations typified by interferon gamma could activate the kynurenine pathway, resulting in enhanced kynurenine levels in the extracellular space in macrophage-like cell lines or lung endothelial cells. Extracellular quinolinic acid levels were elevated only in macrophage-like cells but not endothelial cells owing to the lower expression levels of metabolic enzymes converting kynurenine to quinolinic acid. These findings provide clues about the molecular mechanisms behind their specific elevation in the serum of acute DILD patients. CONCLUSIONS: The serum concentrations of kynurenine and quinolinic acid as well as kynurenine/tryptophan ratios are promising and specific biomarkers for detecting and monitoring DILD and its recovery, which could facilitate accurate decisions for appropriate clinical management of patients with DILD.

Clinical course of COPD patients with exercise-induced elevation of pulmonary artery pressure or less severe pulmonary hypertension presenting with respiratory symptoms and the impact of bosentan intervention-prospective, single-center, randomized, parallel-group study.

BACKGROUND: The data on bosentan were lacking for the treatment of exercise-induced elevation of pulmonary artery pressure (eePAP) or less severe PH in COPD. This study was conducted to investigate long-term efficacy and safety of bosentan for the treatment of eePAP or less severe PH in COPD. METHODS: COPD patients diagnosed at this hospital as having COPD (WHO functional class II, III or IV) with eePAP or less severe PH whose respiratory symptoms were stable but remained and gradually progressed even after COPD therapy were randomly assigned in a 1:1 ratio to receive either bosentan or no PH treatment for two years and assessed at baseline and every 6 months for respiratory failure, activities of daily living (ADL), lung and heart functions by right heart catheterization (RHC), and other parameters. RESULTS: A total of 29 patients who underwent RHC for detail examination were enrolled in the current study between August 2010 and October 2018.No death occurred in drug-treated group (n = 14) for 2 years; 5 patients died in untreated group (n = 15). Significant differences were noted between the 2 group in hospital-free survival (686.00 ± 55.87 days vs. 499.94 ± 53.27 days; hazard ratio [HR], 0.18; P = 0.026) and overall survival (727 days vs. 516.36 ± 55.38 days; HR, 0.095; P = 0.030) in all causes of death analysis, but not in overall survival in analysis of respiratory-related death. Bosentan was not associated with increased adverse events including requiring O2 inhalation. CONCLUSIONS: This study suggested that the prognosis for COPD patients with eePAP or less severe PH presenting with respiratory symptoms was very poor and that bosentan tended to improve their prognosis and suppress ADL deterioration without worsening respiratory failure. TRIAL REGISTRATION: This study was registered with UMIN-CTR Clinical Trial as UMIN000004749 . First trial registration at 18/12/2010.

Rictor-targeting exosomal microRNA-16 ameliorates lung fibrosis by inhibiting the mTORC2-SPARC axis.

Idiopathic pulmonary fibrosis (IPF), a progressive disorder of unknown etiology, is characterized by pathological lung fibroblast activation and proliferation resulting in abnormal deposition of extracellular matrix proteins within the lung parenchyma. The pathophysiological roles of exosomal microRNAs in pulmonary fibrosis remain unclear; therefore, we aimed to identify and characterize fibrosis-responsive exosomal microRNAs. We used microRNA array analysis and profiled the expression of exosome-derived miRNA in sera of C57BL/6 mice exhibiting bleomycin-induced pulmonary fibrosis. The effect of microRNAs potentially involved in fibrosis was then evaluated in vivo and in vitro. The expression of exosomal microRNA-16 was increased by up to 8.0-fold on day 14 in bleomycin-treated mice, compared to vehicle-treated mice. MicroRNA-16 mimic administration on day 14 after bleomycin challenge ameliorated pulmonary fibrosis and suppressed lung and serum expression of secreted protein acidic and rich in cysteine (SPARC). Pretreatment of human lung fibroblasts with the microRNA-16 mimic decreased the expression of rapamycin-insensitive companion of mTOR (Rictor) and TGF-ß1-induced expression of SPARC. This is the first study reporting the anti-fibrotic properties of microRNA-16 and demonstrating that these effects occur via the mTORC2 pathway. These findings support that microRNA-16 may be a promising therapeutic target for IPF.

Interstitial lung disease associated with nanoparticle albumin-bound paclitaxel treatment in patients with lung cancer.

BACKGROUND: Nanoparticle albumin-bound paclitaxel is indicated for the treatment of patients with lung cancer. It can induce interstitial lung disease, but the incidence of nanoparticle albumin-bound paclitaxel-associated interstitial lung disease in clinical practice has not been determined. We investigated the incidence of interstitial lung disease in patients with lung cancer who had received nanoparticle albumin-bound paclitaxel therapy at our institution. METHODS: We reviewed clinical data for patients with advanced lung cancer who received nanoparticle albumin-bound paclitaxel with or without carboplatin or bevacizumab therapy at the Nippon Medical School Main Hospital between April 2013 and September 2017. Interstitial lung disease was diagnosed based on clinical symptoms, radiographic findings and exclusion of other diseases. RESULTS: A total of 110 advanced lung cancer patients received nanoparticle albumin-bound paclitaxel, and nine of them (8.2%) developed interstitial lung disease. Of those who developed interstitial lung disease, eight were treated with corticosteroids and three received cyclophosphamide pulse therapy. High-resolution computed tomography images demonstrated diffuse alveolar damage pattern pneumonitis in seven patients and organized pneumonia pattern pneumonitis in two patients. Six of the patients with diffuse alveolar damage pattern pneumonitis died from respiratory failure. The two patients with organized pneumonia pattern pneumonitis recovered. The incidence of interstitial lung disease was 19.0% (8/42) among patients with preexisting interstitial pneumonia and 1.5% (1/68) among those without preexisting interstitial pneumonia. Six patients with preexisting interstitial pneumonia met the criteria for acute exacerbation of interstitial pneumonia (14.3%). CONCLUSION: Nanoparticle albumin-bound paclitaxel-associated interstitial lung disease was a severe and potentially fatal adverse event. We found it demonstrated diffuse alveolar damage or organized pneumonia pattern pneumonitis, and preexisting interstitial pneumonia was associated with higher rate of nanoparticle albumin-bound paclitaxel-associated interstitial lung disease.

ß-Catenin-dependent transcription is central to Bmp-mediated formation of venous vessels.

ß-catenin regulates the transcription of genes involved in diverse biological processes, including embryogenesis, tissue homeostasis and regeneration. Endothelial cell (EC)-specific gene-targeting analyses in mice have revealed that ß-catenin is required for vascular development. However, the precise function of ß-catenin-mediated gene regulation in vascular development is not well understood, since ß-catenin regulates not only gene expression but also the formation of cell-cell junctions. To address this question, we have developed a novel transgenic zebrafish line that allows the visualization of ß-catenin transcriptional activity specifically in ECs and discovered that ß-catenin-dependent transcription is central to the bone morphogenetic protein (Bmp)-mediated formation of venous vessels. During caudal vein (CV) formation, Bmp induces the expression of aggf1, a putative causative gene for Klippel-Trenaunay syndrome, which is characterized by venous malformation and hypertrophy of bones and soft tissues. Subsequently, Aggf1 potentiates ß-catenin transcriptional activity by acting as a transcriptional co-factor, suggesting that Bmp evokes ß-catenin-mediated gene expression through Aggf1 expression. Bmp-mediated activation of ß-catenin induces the expression of Nr2f2 (also known as Coup-TFII), a member of the nuclear receptor superfamily, to promote the differentiation of venous ECs, thereby contributing to CV formation. Furthermore, ß-catenin stimulated by Bmp promotes the survival of venous ECs, but not that of arterial ECs. Collectively, these results indicate that Bmp-induced activation of ß-catenin through Aggf1 regulates CV development by promoting the Nr2f2-dependent differentiation of venous ECs and their survival. This study demonstrates, for the first time, a crucial role of ß-catenin-mediated gene expression in the development of venous vessels.

Resolution of bleomycin-induced murine pulmonary fibrosis via a splenic lymphocyte subpopulation.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with high mortality, and the pathogenesis of the disease is still incompletely understood. Although lymphocytes, especially CD4+CD25+FoxP3+ regulatory T cells (Tregs), have been implicated in the development of IPF, contradictory results have been reported regarding the contribution of Tregs to fibrosis both in animals and humans. The aim of this study was to investigate whether a specific T cell subset has therapeutic potential in inhibiting bleomycin (BLM)-induced murine pulmonary fibrosis. METHODS: C57BL/6 mice received BLM (100 mg/kg body weight) with osmotic pumps (day 0), and pulmonary fibrosis was induced. Then, splenocytes or Tregs were adoptively transferred via the tail vein. The lungs were removed and subjected to histological and biochemical examinations to study the effects of these cells on pulmonary fibrosis, and blood samples were collected by cardiac punctures to measure relevant cytokines by enzyme-linked immunosorbent assay. Tregs isolated from an interleukin (IL)-10 knock-out mice were used to assess the effect of this mediator. To determine the roles of the spleen in this model, spleen vessels were carefully cauterized and the spleen was removed either on day 0 or 14 after BLM challenge. RESULTS: Splenocytes significantly ameliorated BLM-induced pulmonary fibrosis when they were administered on day 14. This effect was abrogated by depleting Tregs with an anti-CD25 monoclonal antibody. Adoptive transfer of Tregs on day 14 after a BLM challenge significantly attenuated pulmonary fibrosis, and this was accompanied by decreased production of fibroblast growth factor (FGF) 9-positive cells bearing the morphology of alveolar epithelial cells. In addition, BLM-induced plasma IL-10 expression reverted to basal levels after adoptive transfer of Tregs. Moreover, BLM-induced fibrocyte chemoattractant chemokine (CC motif) ligand-2 production was significantly ameliorated by Treg adoptive transfer in lung homogenates, accompanied by reduced accumulation of bone-marrow derived fibrocytes. Genetic ablation of IL-10 abrogated the ameliorating effect of Tregs on pulmonary fibrosis. Finally, splenectomy on day 0 after a BLM challenge significantly ameliorated lung fibrosis, whereas splenectomy on day 14 had no effect. CONCLUSIONS: These findings warrant further investigations to develop a cell-based therapy using Tregs for treating IPF.

XPLN is modulated by HDAC inhibitors and negatively regulates SPARC expression by targeting mTORC2 in human lung fibroblasts.

Pathogenesis of idiopathic pulmonary fibrosis (IPF) remains unclear. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that participates in the assembly and turnover of the extracellular matrix, whose expression is regulated by transforming growth factor (TGF)-ß1 through activation of mammalian target of rapamycin complex 2 (mTORC2). Exchange factor found in platelets, leukemic, and neuronal tissues (XPLN) is an endogenous inhibitor of mTORC2. However, whether XPLN modulates SPARC expression remains unknown. Herein, we investigated the regulatory mechanisms of XPLN in human lung fibroblasts. Effect of XPLN on mTORC2 activity was evaluated by silencing XPLN in human foetal lung fibroblasts (HFL-1 cells), using small interfering RNA. SPARC expression was quantified by quantitative real-time RT-PCR and western blotting. Fibroblasts were treated with TGF-ß1, histone deacetylase (HDAC) inhibitors, entinostat, or vorinostat, to assess their effects on XPLN expression. Moreover, the effect of mTORC1 inhibition on SPARC and XPLN was examined. XPLN depletion stimulated SPARC expression and Akt phosphorylation on Ser473. TGF-ß1 treatment down-regulated XPLN via Smad 2/3. XPLN mRNA expression was up-regulated upon treatment with HDAC inhibitors in a concentration-dependent manner, and TGF-ß1-induced SPARC expression was reversed by entinostat treatment. mTORC1 inhibition by rapamycin and Raptor depletion stimulated SPARC expression. In conclusion, this is the first study describing the involvement of XPLN in the regulation of SPARC. These findings may help uncover the regulatory mechanisms of the mTORC2-SPARC axis. The up-regulation of XPLN by HDAC inhibitors may be a novel therapeutic approach in patients with IPF.

The parallel growth of motoneuron axons with the dorsal aorta depends on Vegfc/Vegfr3 signaling in zebrafish.

Blood vessels and neurons grow often side by side. However, the molecular and cellular mechanisms underlying their parallel development remain unclear. Here, we report that a subpopulation of secondary motoneurons extends axons ventrally outside of the neural tubes and rostrocaudally as a fascicle beneath the dorsal aorta (DA) in zebrafish. We tried to clarify the mechanism by which these motoneuron axons grow beneath the DA and found that Vegfc in the DA and Vegfr3 in the motoneurons were essential for the axon growth. Forced expression of either Vegfc in arteries or Vegfr3 in motoneurons resulted in enhanced axon growth of motoneurons over the DA. Both vegfr3 morphants and vegfc morphants lost the alignment of motoneuron axons with DA. In addition, forced expression of two mutant forms of Vegfr3 in motoneurons, potentially trapping endogenous Vegfc, resulted in failure of growth of motoneuron axons beneath the DA. Finally, a vegfr3 mutant fish lacked the motoneuron axons beneath the DA. Collectively, Vegfc from the preformed DA guides the axon growth of secondary motoneurons.

Combination of plasma MMPs and PD-1-binding soluble PD-L1 predicts recurrence in gastric cancer and the efficacy of immune checkpoint inhibitors in non-small cell lung cancer.

Background: The tumor microenvironment (TME) impacts the therapeutic efficacy of immune checkpoint inhibitors (ICIs). No liquid biomarkers are available to evaluate TME heterogeneity. Here, we investigated the clinical significance of PD-1-binding soluble PD-L1 (bsPD-L1) in gastric cancer (GC) patients and non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 blockade. Methods: We examined bsPD-L1, matrix metalloproteinases (MMPs), and IFN-γ levels in plasma samples from GC patients (n = 117) prior to surgery and NSCLC patients (n = 72) prior to and 2 months after ICI treatment. We also examined extracellular matrix (ECM) integrity, PD-L1 expression, and T cell infiltration in tumor tissues from 25 GC patients by Elastica Masson-Goldner staining and immunohistochemical staining for PD-L1 and CD3, respectively. Results: bsPD-L1 was detected in 17/117 GC patients and 16/72 NSCLC patients. bsPD-L1 showed strong or moderate correlations with plasma MMP13 or MMP3 levels, respectively, in both GC and NSCLC patients. bsPD-L1 expression in GC was associated with IFN-γ levels and intra-tumoral T cell infiltration, whereas MMP13 levels were associated with loss of ECM integrity, allowing tumor cells to access blood vessels. Plasma MMP3 and MMP13 levels were altered during ICI treatment. Combined bsPD-L1 and MMP status had higher predictive accuracy to identify two patient groups with favorable and poor prognosis than tumor PD-L1 expression: bsPD-L1+MMP13high in GC and bsPD-L1+(MMP3 and MMP13)increased in NSCLC were associated with poor prognosis, whereas bsPD-L1+MMP13low in GC and bsPD-L1+(MMP3 or MMP13)decreased in NSCLC were associated with favorable prognosis. Conclusion: Plasma bsPD-L1 and MMP13 levels indicate T cell response and loss of ECM integrity, respectively, in the TME. The combination of bsPD-L1 and MMPs may represent a non-invasive tool to predict recurrence in GC and the efficacy of ICIs in NSCLC.

Clinicopathological Characteristics of Everolimus-Associated Interstitial Lung Disease: A Single-Center Consecutive Analysis.

BACKGROUND: Everolimus, a mammalian target of rapamycin inhibitor used as an antineoplastic drug, is associated with a remarkably high incidence of interstitial lung disease (ILD). The clinical and pathological characteristics of ILD caused by everolimus have not been thoroughly investigated; therefore, we aimed to elucidate the features of everolimus-associated ILD. METHODS: We retrospectively reviewed the medical records of patients who received everolimus for cancer treatment at our hospital. Patient backgrounds were compared between the ILD and non-ILD groups. Chest computed tomography (CT), changes in biomarkers, and lung histopathological features were analyzed for ILD cases. RESULTS: Sixty-six patients were reviewed, and ILD developed in 19. There were no differences in patient demographics between the ILD and non-ILD groups. The severity of ILD was grade 1 (G1) in 9 and grade 2 (G2) in 10 cases. Chest CT showed organizing pneumonia (OP) or a hypersensitive pneumonia pattern. The levels of lactate dehydrogenase, C-reactive protein, Krebs von den lungen-6, and surfactant protein-D (SP-D) at the onset of ILD were significantly higher than those at baseline. Analysis of G1 and G2 ILD subgroups showed a higher SP-D levels in the G2 subgroup. Five patients underwent lung biopsies; all specimens demonstrated alveolitis with lymphocytic infiltration and granulomatous lesions, and some had OP findings. CONCLUSIONS: Everolimus-associated ILD is mild and has a favorable prognosis. Patients with symptomatic ILD were more likely to have higher SP-D levels than those with asymptomatic ILD. Granulomatous lesions are an important pathological feature of everolimus-associated ILD.

Lysosomal degradation of PD-L1 is associated with immune-related adverse events during anti-PD-L1 immunotherapy in NSCLC patients.

Background: Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events (irAEs). Liquid biomarkers to predict irAE occurrence are urgently needed. We previously developed an ELISA system to specifically detect soluble PD-L1 (sPD-L1) with PD-1-binding capacity (bsPD-L1). Here, we investigated the relationship between sPD-L1 and bsPD-L1 in gastric cancer (GC) and non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 blockade and their association with irAEs. Methods: We examined sPD-L1, bsPD-L1, matrix metalloproteinases (MMPs), and proinflammatory cytokine levels by ELISA in plasma samples from 117 GC patients prior to surgery and 72 NSCLC patients prior to and at 2 months after ICI treatment (anti-PD-1, n = 48; anti-PD-L1, n = 24). In mice treated with anti-PD-1/PD-L1 antibodies (Abs), sPD-L1 levels and localization of Abs were examined by ELISA and immunohistochemistry, respectively. Results:sPD-L1 was detected with higher frequency in GC patients than in NSCLC patients, whereas bsPD-L1 was detected with similar frequencies in GC and NSCLC patients. sPD-L1 levels were correlated with IL-1α, IL-1ß, TNF-α, and IL-6 levels, while bsPD-L1 levels were correlated with MMP13, MMP3, and IFN-γ levels. In NSCLC patients, anti-PD-L1, but not anti-PD-1, treatment increased sPD-L1, which was associated with irAE development, but not with clinical outcomes. In mice, trafficking of anti-PD-L1 Abs to lysosomes in F4/80+ macrophages resulted in sPD-L1 production, which was suppressed by treatment with lysosomal degradation inhibitor chloroquine and macrophage depletion. Conclusion: Anti-PD-L1-mediated lysosomal degradation induces sPD-L1 production, which can serve as an indicator to predict irAE development during anti-PD-L1 treatment.

Serum-derived exosomal miR-125a-3p predicts the response to anti-programmed cell death-1/programmed cell death-ligand 1 monotherapy in patients with non-small cell lung cancer.

BACKGROUND: Versatile biomarkers for immune checkpoint inhibitors (ICI) efficacy in patients with cancer remain to be identified. Liquid biopsy using serum-derived exosomal microRNAs (miRNAs) are widely investigated as diagnostic and therapeutic outcome predictors in patients with cancer. However, exosomal miRNAs linked to the response to ICI in patients with non-small cell lung cancer (NSCLC) remain elusive thus far. METHODS: The value of serum-derived exosomal miRNAs in predicting the effect of anti-programmed cell death-1 (PD-1)/anti-programmed cell death-ligand 1 (PD-L1) monotherapy in 41 patients with advanced NSCLC was assessed. We performed functional analysis of candidate miRNAs using NSCLC cell lines. RESULTS: Exosomal miR-125a-3p was associated with response to treatment with ICI. Exosomal miR-125a-3p was more useful in predicting response to ICI versus tumoral PD-L1 in patients with low PD-L1 expression <50 %). Moreover, high expression of miR-125a-3p was associated with worse progression-free and overall survival. In H1975 and H441 cells, induction of miR-125a-3p regulated PD-L1 expression via suppression of neuregulin 1 (NRG1). CONCLUSIONS: Exosomal miR-125a-3p is a potential predictor of response to anti-PD-1/PD-L1 therapy in advanced NSCLC patients with low PD-L1 expression.

Kikuchi-Fujimoto disease can present as delayed lymphadenopathy after COVID-19 vaccination.

Following COVID-19 vaccination, ipsilateral axillary and cervical lymphadenopathy may occur, called vaccine-related hypermetabolic lymphadenopathy, which is considered reactive lymphadenopathy. We report here a case of Kikuchi-Fujimoto disease, which occurred three months after vaccination with COVID-19 vaccine. The patient had cervical and axillary lymph node enlargement and a short-term fever that resolved spontaneously after the first and second vaccines. On the 90th day after the first vaccination, the patient developed a high fever and pathologically diagnosed necrotizing lymphadenitis in the axilla, which was diagnosed as Kikuchi-Fujimoto disease. Gallium scintigraphy showed localized swelling and strong uptake in the ipsilateral axilla. It implies the possibility of Kikuchi-Fujimoto Disease in axillary drainage lymph nodes in association with COVID-19 vaccine. Although only a few cases have been reported so far, this case is novel because of its later onset and diagnosis based on pathological and gallium scintigraphy imaging findings.

Effectiveness of Corticosteroid Therapy for Non-Severe COVID-19 in Patients Not Requiring Supplemental Oxygen Who Have Risk Factors for Severe Disease.

BACKGROUND: Because they suppress cytokine production, corticosteroids are a candidate therapy for coronavirus disease 2019 (COVID-19). However, the effectiveness of corticosteroids is unclear for non-severe COVID-19 that does not require supplemental oxygen. This study investigated the effectiveness of corticosteroid therapy for patients with non-severe COVID-19. METHODS: This retrospective observational study analyzed data from 10 patients with non-severe COVID-19 who received corticosteroid therapy at our center between July 1, 2020 and January 31, 2021. RESULTS: The median age of the 10 patients was 60 years, and nine were male. Nine of the 10 patients had multiple comorbid conditions (e.g., hypertension, diabetes, and obesity). Although blood oxygen saturation was maintained above 95%, all patients had persistent fever and deterioration in chest imaging findings, which led to initiation of corticosteroid treatment. The median duration symptom onset to initiation of corticosteroid therapy was 8 days. All patients received dexamethasone 6 mg/day as corticosteroid therapy, and the median period was 7.5 days. After the start of corticosteroid therapy, clinical improvement was rapid in all patients, and no patient developed severe disease. CONCLUSION: The latest World Health Organization guidance recommends against corticosteroid treatment for patients with non-severe COVID-19. In this report, early administration of corticosteroids during the non-critical phase, when oxygen supplementation was not required, was associated with early improvement and prevention of severe disease in patients with risk factors for severe COVID-19 and worsening clinical symptoms.

Identification and characterization of lysophosphatidylcholine 14:0 as a biomarker for drug-induced lung disease.

Drug-induced interstitial lung disease (DILD) occurs when drug exposure causes inflammation of the lung interstitium. DILD can be caused by different types of drugs, and some DILD patterns results in a high mortality rate; hence, DILD poses a serious problem in clinical practice as well as drug development, and strategies to diagnose and distinguish DILD from other lung diseases are necessary. We aimed to identify novel biomarkers for DILD by performing lipidomics analysis on plasma samples from patients with acute and recovery phase DILD. Having identified lysophosphatidylcholines (LPCs) as candidate biomarkers for DILD, we determined their concentrations using validated liquid chromatography/mass spectrometry biomarker assays. In addition, we evaluated the ability of LPCs to discriminate patients with acute phase DILD from those with recovery phase DILD, DILD-tolerant, or other lung diseases, and characterized their association with clinical characteristics. Lipidomics analysis revealed a clear decrease in LPC concentrations in the plasma of patients with acute phase DILD. In particular, LPC(14:0) had the highest discriminative index against recovery phase and DILD-tolerant patients. LPC(14:0) displayed no clear association with causal drugs, or subjects' backgrounds, but was associated with disease severity. Furthermore, LPC(14:0) was able to discriminate between patients with DILD and other lung diseases, including idiopathic interstitial pneumonia and lung disease associated with connective tissue disease. LPC(14:0) is a promising biomarker for DILD that could improve the diagnosis of DILD and help to differentiate DILD from other lung diseases, such as idiopathic interstitial pneumonia and connective tissue disease.

Stratifin as a novel diagnostic biomarker in serum for diffuse alveolar damage.

Among the various histopathological patterns of drug-induced interstitial lung disease (DILD), diffuse alveolar damage (DAD) is associated with poor prognosis. However, there is no reliable biomarker for its accurate diagnosis. Here, we show stratifin/14-3-3σ (SFN) as a biomarker candidate found in a proteomic analysis. The study includes two independent cohorts (including totally 26 patients with DAD) and controls (total 432 samples). SFN is specifically elevated in DILD patients with DAD, and is superior to the known biomarkers, KL-6 and SP-D, in discrimination of DILD patients with DAD from patients with other DILD patterns or other lung diseases. SFN is also increased in serum from patients with idiopathic DAD, and in lung tissues and bronchoalveolar lavage fluid of patients with DAD. In vitro analysis using cultured lung epithelial cells suggests that extracellular release of SFN occurs via p53-dependent apoptosis. We conclude that serum SFN is a promising biomarker for DAD diagnosis.

Detection of cardiac involvement in pulmonary sarcoidosis using high-resolution Holter electrocardiogram.

BACKGROUND: Early detection of cardiac involvement in patients with sarcoidosis is important but currently unresolved. The aim of this study was to elucidate the utility of frequency domain microvolt T-wave alternans (TWA), signal-averaged ECG (SAECG), and heart rate turbulence (HRT) using 24-hour Holter ECG for detecting cardiac involvement in patients with pulmonary sarcoidosis. METHODS: This study consisted of consecutive 40 pulmonary sarcoidosis patients (11 males, 62 ± 13 years) who underwent 24-hour Holter monitoring with and without cardiac involvement. All patients underwent frequency domain TWA, SAECG, and HRT using 24-hour Holter monitoring. Patients with atrial fibrillation pacing or wide QRS electrocardiogram were excluded. RESULTS: After 14 patients were excluded, a total of 26 patients (six males, 59 ± 14 years) were evaluated. Seven patients had cardiac involvement (cardiac sarcoidosis [CS] group). On the Holter SAECG, duration of low-amplitude signals <40 µV in the terminal filtered QRS complex (LAS40) was significantly higher, and root mean square voltage of the terminal 40 ms of the filtered QRS complex (RMS40) was significantly lower in the CS group compared with the non-CS group (LAS40: 61.4 ± 35.9 vs 37.6 ± 9.2 ms; P = .018, RMS40: 11.4 ± 10.3 vs 23.6 ± 13.2 ms; P = .023). Prevalence of positive late potential (LP) was also significantly higher in the CS group than that in the non-CS group (85.7% vs 31.5%; P = .026). The sensitivity, specificity, positive, and negative predictive values of LP for identifying patients with cardiac involvement were 85.7%, 68.4%, 50.0%, and 92.8%, respectively. CONCLUSION: Holter SAECG may be useful for detecting cardiac involvement in patients with pulmonary sarcoidosis.

Effect of Adding Inhaled Corticosteroid to Long-Acting Muscarinic Antagonist/Long-Acting Beta-Agonist Therapy Among Patients With Chronic Obstructive Pulmonary Disease.

Background The role of inhaled corticosteroid (ICS) in chronic obstructive pulmonary disease (COPD) is unclear. Hence, this study aimed to evaluate the efficacy of ICS as an add-on to long-acting muscarinic antagonist (LAMA)/long-acting beta 2 agonist (LABA), which was assessed using the impulse oscillation system (IOS), in patients with COPD. Methodology We included patients with COPD whose treatment was changed from LAMA/LABA (≥four weeks) to ICS/LAMA/LABA between April 2019 and March 2021. To gain insight into the effect and safety of ICS-containing triple therapy for COPD, pulmonary function; Short-Form 36, St. George's Respiratory Questionnaire, COPD Assessment Test, and modified Medical Research Council scores; and airway resistance assessed using the IOS from one week before LAMA/LABA was switched to ICS/LAMA/LABA therapy until more than eight but less than twelve weeks after switching were evaluated. Results In total, 46 patients with COPD (mean age: 72.28 ± 7.81 years) were included in the study. None of the pulmonary function test parameters significantly changed from baseline values (mean difference in forced expiratory volume in one second [FEV1.0]: +0.032, P = 0.12; percentage FEV1.0 [FEV1.0%]/forced vital capacity [FVC]: -0.58, P = 0.42; and FVC: +0.087, P = 0.058). Meanwhile, the IOS showed that resonant frequency (mean difference from baseline: -2.12, P < 0.0001) and bodily pain scores in the St. George's Respiratory Questionnaire (mean difference: -7.03, P = 0.031) significantly decreased. Conclusions Switching from LAMA/LABA to ICS/LAMA/LABA therapy reduces airway elasticity-to-inertial resistance ratios, which may lead to structural airway improvements in patients with COPD.

A Possible, Non-Invasive Method of Measuring Dynamic Lung Compliance in Patients with Interstitial Lung Disease Using Photoplethysmography.

BACKGROUND: Measuring lung compliance is useful for evaluating progression of interstitial lung disease (ILD), because reduced lung compliance due to fibrosis progression is the main cause of decreased vital capacity. However, because insertion of a balloon into the esophagus is invasive, lung compliance is rarely measured. A recently developed method uses fingertip photoplethysmography to estimate intrathoracic pressure. This method non-invasively measures lung dynamic compliance (Cdyn) by simultaneously measuring tidal volume. We evaluated the efficacy of this method in assessing ILD. METHODS: This single-center, cross-sectional, observational study evaluated the efficacy of this method in patients with ILD and healthy controls. The primary outcome was estimated Cdyn (eCdyn), as determined with this method. We also evaluated baseline characteristics that are potential confounding factors for eCdyn. RESULTS: Median eCdyn was significantly lower in the ILD group (n = 14) than in the control group (n = 49) (0.122 vs. 0.183; P = 0.011). In univariate regression analysis, eCdyn was significantly correlated with height, weight, forced vital capacity, forced expiratory volume in 1 second, diffusing capacity for carbon monoxide, and usual interstitial pneumonia. In multivariate regression analysis, weight (ß = 0.49, P = 0.011) and usual interstitial pneumonia (ß = 0.52, P = 0.007) were significantly correlated with eCdyn. CONCLUSIONS: Using photoplethysmography, we noted a significant reduction in Cdyn in patients with ILD. This novel non-invasive method is a promising tool for evaluating fibrosis progression in ILD.