Quantitative Evaluation of Changes in Three-Dimensional CT Density Distributions in Pulmonary Alveolar Proteinosis after GM-CSF Inhalation.

BACKGROUND: A previous clinical trial for autoimmune pulmonary alveolar proteinosis (APAP) demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) inhalation reduced the mean density of the lung field on computed tomography (CT) across 18 axial slice planes at a two-dimensional level. In contrast, in this study, we challenged three-dimensional analysis for changes in CT density distribution using the same datasets. METHODS: As a sub-study of the trial, CT data of 31 and 27 patients who received GM-CSF and placebo, respectively, were analyzed. To overcome the difference between various shooting conditions, a newly developed automatic lung field segmentation algorithm was applied to CT data to extract the whole lung volume, and the accuracy of the segmentation was evaluated by five pulmonary physicians independently. For normalization, the percent pixel (PP) in a certain density range was calculated as a percentage of the total number of pixels from -1,000 to 0 HU. RESULTS: The automatically segmented images revealed that the lung field was accurately extracted except for 7 patients with minor deletion or addition. Using the change in PP from baseline to week 25 (ΔPP) as the vertical axis, we created a histogram with 143 HU bins set for each patient. The most significant difference in ΔPP between GM-CSF and placebo groups was observed in two ranges: from -1,000 to -857 and -143 to 0 HU. CONCLUSION: Whole lung extraction followed by density histogram analysis of ΔPP may be an appropriate evaluation method for assessing CT improvement in APAP.

A Novel Development of Sarcoidosis Following COVID-19 Vaccination and a Literature Review.

BNT162b2 (Pfizer/BioNTech) is a coronavirus disease 2019 (COVID-19) vaccine containing nucleoside-modified messenger RNA encoding the severe acute respiratory syndrome coronavirus 2 spike glycoprotein. Recently, ocular complications of mRNA vaccines have been reported increasingly frequently. However, immunological adverse events due to mRNA vaccines in real-world settings are not fully known. We herein report the novel development of sarcoidosis manifested as uveitis, bilateral hilar lymphadenopathy, angiotensin-converting enzyme elevation, and epithelioid and giant cell granuloma formation in the lung soon after the first BNT162b2 injection and review the current literature, including three reported cases of sarcoid-like reaction following COVID-19 vaccination.

Malnutrition, Airflow Limitation and Severe Emphysema are Risks for Exacerbation of Chronic Obstructive Pulmonary Disease in Japanese Subjects: A Retrospective Single-Center Study.

Background: Different characteristics of patients with chronic obstructive pulmonary disease (COPD) between Western and Japanese populations have been reported. Risk factors for COPD exacerbation have been reported in Western countries but have not been studied in Japan. Patients and Methods: We retrospectively examined risk factors for COPD exacerbation. A total of 156 Japanese patients were enrolled, and the records of 136 patients were analyzed. Results: In the exacerbation group (n=60), body mass index, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), the FEV1/FVC ratio (FEV1/FVC), the percent predicted values of FEV1 (%FEV1), and serum total protein (TP) and albumin concentrations were lower, and age, mortality rate, frequency of common cold and pneumonia, COPD severity rankings, modified Medical Research Council (mMRC) dyspnea score, and proportions of patients with severe emphysema (>50% of low attenuation area) and receiving long-term oxygen therapy were higher than those in the nonexacerbation group (n=76). However, the proportion of patients with a greater number of eosinophils (≥200/µL and/or ≥2%) and the exhaled nitric oxide concentration did not differ between the two groups. In the univariate analysis, the risk factors for exacerbation were age; long-term oxygen therapy; low FVC, FEV1, FEV1/FVC and %FEV1; high COPD severity ranking and mMRC score; severe emphysema; hypoproteinemia (<6.5 g/dL); hypoalbuminemia (<3.5 g/dL); leukocytosis; lymphocytopenia; and anemia. In the multivariate analysis, the risk factors were hypoalbuminemia, hypoproteinemia and low FEV1. Additionally, in patients in the exacerbation-induced mortality subgroup, age, exacerbation frequency, mMRC score and the proportion of patients with lymphocytopenia were higher, and FVC, %FVC, FEV1, serum TP concentration and the lymphocyte number were lower than those in the exacerbation survival subgroup. Conclusion: Malnutrition, airflow limitation and severe emphysema were risks for exacerbation and mortality associated with infection in Japanese patients with COPD.

A case of localized tracheobronchial relapsing polychondritis with positive matrilin-1 staining.

BACKGROUND: Relapsing polychondritis (RPC) is a rare progressive autoimmune disease characterized by inflammation in the cartilage of multiple organs. Tracheobronchial involvement appears in nearly half of RPC patients during the course of their disease and represents the main cause of death. Localized tracheobronchial RPC is much rarer, and the pathogenesis remains unclear. Matrilin-1 is a non-collagenous cartilage matrix protein and has been suggested to be a potent autoantigen that induces the airway disease of RPC in animal models. However, the expression of matrilin-1 in tracheobronchial tissue in human remains unclear. Therefore, we examined the expression of matrilin-1 in the tracheal and auricular tissues in a localized tracheobronchial RPC patient. CASE PRESENTATION: A 62-year-old man with systemic sclerosis presented with cough and dyspnea on exertion. The lung function test showed an expiratory flow limitation and chest computed tomography showed diffuse thickness from the trachea to the bronchiole. No other tests showed abnormal findings. To evaluate further, bronchoscopy was performed and endobronchial ultrasonography showed thickness in the fourth-marginal echo layer suggesting inflammation of the cartilage. However, the tracheal biopsy showed no specific findings. The subsequent surgical tracheal biopsies showed inflammatory cell infiltration with destruction of the cartilage. Neither auricular nor nasal deformity, except for a tracheobronchial lesion, was detected. Biopsy from the left auricular cartilage also did not show any inflammatory changes. Finally, we diagnosed the patient with localized tracheobronchial RPC. To address the hypothesis that autoimmunity against matrilin-1 is involved in the pathogenesis of localized tracheobronchial RPC, we evaluated the expression level of matrilin-1 in a tracheal and auricular specimen from this patient. Immunohistochemical staining with anti-matrilin-1 antibody showed matrilin-1 in the tracheal but not in the auricular cartilage. CONCLUSIONS: We first demonstrated the expression of matrilin-1 in tracheal but not in auricular cartilage in a localized tracheobronchial RPC patient. This result supports the possibility that matrilin-1 is involved in the pathogenesis of localized tracheobronchial RPC. However, this is only one case report and further observations will be needed to confirm this result.

Inhaled GM-CSF for Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary alveolar proteinosis is a disease characterized by abnormal accumulation of surfactant in the alveoli. Most cases are autoimmune and are associated with an autoantibody against granulocyte-macrophage colony-stimulating factor (GM-CSF) that prevents clearing of pulmonary surfactant by alveolar macrophages. An open-label, phase 2 study showed some therapeutic efficacy of inhaled recombinant human GM-CSF in patients with severe pulmonary alveolar proteinosis; however, the efficacy in patients with mild-to-moderate disease remains unclear. METHODS: We conducted a double-blind, placebo-controlled trial of daily inhaled recombinant human GM-CSF (sargramostim), at a dose of 125 µg twice daily for 7 days, every other week for 24 weeks, or placebo in 64 patients with autoimmune pulmonary alveolar proteinosis who had a partial pressure of arterial oxygen (Pao2) while breathing ambient air of less than 70 mm Hg (or <75 mm Hg in symptomatic patients). Patients with severe pulmonary alveolar proteinosis (Pao2 <50 mm Hg) were excluded to avoid possible exacerbation of the disease in patients who were assigned to receive placebo. The primary end point was the change in the alveolar-arterial oxygen gradient between baseline and week 25. RESULTS: The change in the mean (±SD) alveolar-arterial oxygen gradient was significantly better in the GM-CSF group (33 patients) than in the placebo group (30 patients) (mean change from baseline, -4.50±9.03 mm Hg vs. 0.17±10.50 mm Hg; P = 0.02). The change between baseline and week 25 in the density of the lung field on computed tomography was also better in the GM-CSF group (between-group difference, -36.08 Hounsfield units; 95% confidence interval, -61.58 to -6.99, calculated with the use of the Mann-Whitney U test and the Hodges-Lehmann estimate of confidence intervals for pseudo-medians). Serious adverse events developed in 6 patients in the GM-CSF group and in 3 patients in the placebo group. CONCLUSIONS: In this randomized, controlled trial, inhaled recombinant human GM-CSF was associated with a modest salutary effect on the laboratory outcome of arterial oxygen tension, and no clinical benefits were noted. (Funded by the Japan Agency for Medical Research and Development and the Ministry of Health, Labor, and Welfare of Japan; PAGE ClinicalTrials.gov number, NCT02835742; Japan Medical Association Center for Clinical Trials number, JMA-IIA00205.).

Peripheral alveolar nitric oxide concentration reflects alveolar inflammation in autoimmune pulmonary alveolar proteinosis.

Nitric oxide and alveolar macrophage inflammation http://ow.ly/czCx30i12n8.

Exome sequencing deciphers a germline MET mutation in familial epidermal growth factor receptor-mutant lung cancer.

Lung cancer accompanied by somatic activating mutations in the epidermal growth factor receptor (EGFR) gene, which is associated with a significant clinical response to the targeted therapy, is frequently found in never-smoking Asian women with adenocarcinoma. Although this implies genetic factors underlying the carcinogenesis, the etiology remains unclear. To gain insight into the pathogenic mechanisms, we sequenced the exomes in the peripheral-blood DNA from six siblings, four affected and two unaffected siblings, of a family with familial EGFR-mutant lung adenocarcinoma. We identified a heterozygous missense mutation in MET proto-oncogene, p.Asn375Lys, in all four affected siblings. Combined with somatic loss of heterozygosity for MET, the higher allele frequency in a Japanese sequencing database supports a causative role of the MET mutation in EGFR-mutant lung cancer. Functional assays showed that the mutation reduces the binding affinity of MET for its ligand, hepatocyte growth factor, and damages the subsequent cellular processes, including proliferation, clonogenicity, motility and tumorigenicity. The MET mutation was further observed to abrogate the ERBB3-mediated AKT signal transduction, which is shared downstream by EGFR. These findings provide an etiological view that the MET mutation is involved in the pathogenesis of EGFR-mutant lung cancer because it generates oncogenic stress that induces compensatory EGFR activation. The identification of MET in a family with familial EGFR-mutant lung cancer is insightful to explore the pathogenic mechanism of not only familial, but also sporadic EGFR-mutant lung cancer by underscoring MET-related signaling molecules.

OX40 ligand newly expressed on bronchiolar progenitors mediates influenza infection and further exacerbates pneumonia.

Influenza virus epidemics potentially cause pneumonia, which is responsible for much of the mortality due to the excessive immune responses. The role of costimulatory OX40-OX40 ligand (OX40L) interactions has been explored in the non-infectious pathology of influenza pneumonia. Here, we describe a critical contribution of OX40L to infectious pathology, with OX40L deficiency, but not OX40 deficiency, resulting in decreased susceptibility to influenza viral infection. Upon infection, bronchiolar progenitors increase in number for repairing the influenza-damaged epithelia. The OX40L expression is induced on the progenitors for the antiviral immunity during the infectious process. However, these defense-like host responses lead to more extensive infection owing to the induced OX40L with α-2,6 sialic acid modification, which augments the interaction with the viral hemagglutinin. In fact, the specific antibody against the sialylated site of OX40L exhibited therapeutic potency in mitigating the OX40L-mediated susceptibility to influenza. Our data illustrate that the influenza-induced expression of OX40L on bronchiolar progenitors has pathogenic value to develop a novel therapeutic approach against influenza.

Improving Physical Activity Ensures the Long-Term Survival of Pneumonia Patients in a Super-Aged Society: A Retrospective Study in an Acute-Care Hospital in Japan.

Pneumonia is the third largest cause of death in Japan. Chest physicians have been struggling to improve the outcome of pneumonia treatment in acute care settings. However, a poor long-term prognosis after pneumonia has not been well recognized. Furthermore, the factors related to the poor prognosis, especially the possible involvement of senescence-related disability, have not been identified. In this study, long-term outcomes after discharge from hospital were retrospectively analyzed to identify factors related to the poor long-term prognosis. Outcomes of 958 pneumonia patients who were discharged from South Miyagi Medical Center (Miyagi, Japan) from June 1, 2008 to March 31, 2014 were determined through patient surveys or medical record reviews on September 26, 2014. Survival curves were constructed and compared according to various factors. Multivariate analysis revealed that all levels of decrease in physical activity, an age of 80 years old or more, the most severe status in Japanese Respiratory Society pneumonia severity grading system, the presence of antibiotic-resistant bacteria, and comorbid malignancy significantly reduced long-term survival. The effects of dementia, neuromuscular disease, heart disease, and nursing care residency on long-term survival were detected only with univariate analysis. Physical activity influenced the acute-phase and the long-term prognosis of pneumonia. This report provides information to assist physicians in giving better suggestions to disabled older patients when choosing pneumonia treatment options. In conclusion, we propose that death related to pneumonia can be prevented in the same way as non-communicable diseases by improving physical activity.

Syndecan 4 Mediates Nrf2-dependent Expansion of Bronchiolar Progenitors That Protect Against Lung Inflammation.

The use of lung progenitors for regenerative medicine appears promising, but their biology is not fully understood. Here, we found anti-inflammatory attributes in bronchiolar progenitors that were sorted as a multipotent subset of mouse club cells and found to express secretory leukocyte protease inhibitor (SLPI). Notably, the impaired expression of SLPI in mice increased the number of bronchiolar progenitors and decreased the lung inflammation. We determined a transcriptional profile for the bronchiolar progenitors of Slpi-deficient mice and identified syndecan 4, whose expression was markedly elevated as compared to that of wild-type mice. Systemic administration of recombinant syndecan 4 protein caused a substantial increase in the number of bronchiolar progenitors with concomitant attenuation of both airway and alveolar inflammation. The syndecan 4 administration also resulted in activation of the Keap1-Nrf2 antioxidant pathway in lung cells, which is critically involved in the therapeutic responses to the syndecan 4 treatment. Moreover, in 3D culture, the presence of syndecan 4 induced differentiated club cells to undergo Nrf2-dependent transition into bronchiolar progenitors. Our observations reveal that differentiative switches between bronchiolar progenitors and club cells are under the Nrf2-mediated control of SLPI and syndecan 4, suggesting the possibility of new therapeutic approaches in inflammatory lung diseases.

Mesenchymal stem cells correct inappropriate epithelial-mesenchyme relation in pulmonary fibrosis using stanniocalcin-1.

Current hypotheses suggest that aberrant wound healing has a critical role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). In these hypotheses, continuous TGF-ß1 secretion by alveolar epithelial cells (AECs) in abnormal wound healing has a critical role in promoting fibroblast differentiation into myofibroblasts. Mesenchymal stem cells (MSCs) home to the injury site and reduce fibrosis by secreting multifunctional antifibrotic humoral factors in IPF. In this study, we show that MSCs can correct the inadequate-communication between epithelial and mesenchymal cells through STC1 (Stanniocalcin-1) secretion in a bleomycin-induced IPF model. Inhalation of recombinant STC1 shows the same effects as the injection of MSCs. Using STC1 plasmid, it was possible to enhance the ability of MSCs to ameliorate the fibrosis. MSCs secrete large amounts of STC1 in response to TGF-ß1 in comparison to AECs and fibroblasts. The antifibrotic effects of STC1 include reducing oxidative stress, endoplasmic reticulum (ER) stress, and TGF-ß1 production in AECs. The STC1 effects can be controlled by blocking uncoupling protein 2 (UCP2) and the secretion is affected by the PI3/AKT/mTORC1 inhibitors. Our findings suggest that STC1 tends to correct the inappropriate epithelial-mesenchymal relationships and that STC1 plasmid transfected to MSCs or STC1 inhalation could become promising treatments for IPF.

Human marrow stromal cells downsize the stem cell fraction of lung cancers by fibroblast growth factor 10.

The functional interplay between cancer cells and marrow stromal cells (MSCs) has attracted a great deal of interest due to the MSC tropism for tumors but remains to be fully elucidated. In this study, we investigated human MSC-secreted paracrine factors that appear to have critical functions in cancer stem cell subpopulations. We show that MSC-conditioned medium reduced the cancer stem cell-enriched subpopulation, which was detected as a side population and quiescent (G0) cell cycle fraction in human lung cancer cells by virtue of fibroblast growth factor 10 (FGF10). This reduction of the stem cell-enriched fraction was also observed in lung cancer cells supplemented with recombinant human FGF10 protein. Moreover, supplementary FGF10 attenuated the expression of stemness genes encoding transcription factors, such as OCT3/4 and SOX2, and crippled the self-renewal capacity of lung cancer cells, as evidenced by the impaired formation of floating spheres in the suspension culture. We finally confirmed the therapeutic potential of the FGF10 treatment, which rendered lung cancer cells prone to a chemotherapeutic agent, probably due to the reduced cancer stem cell subpopulation. Collectively, these results add further clarification to the molecular mechanisms underlying MSC-mediated cancer cell kinetics, facilitating the development of future therapies.

Targeting lysophosphatidic acid signaling retards culture-associated senescence of human marrow stromal cells.

Marrow stromal cells (MSCs) isolated from mesenchymal tissues can propagate in vitro to some extent and differentiate into various tissue lineages to be used for cell-based therapies. Cellular senescence, which occurs readily in continual MSC culture, leads to loss of these characteristic properties, representing one of the major limitations to achieving the potential of MSCs. In this study, we investigated the effect of lysophosphatidic acid (LPA), a ubiquitous metabolite in membrane phospholipid synthesis, on the senescence program of human MSCs. We show that MSCs preferentially express the LPA receptor subtype 1, and an abrogation of the receptor engagement with the antagonistic compound Ki16425 attenuates senescence induction in continually propagated human MSCs. This anti-aging effect of Ki16425 results in extended rounds of cellular proliferation, increased clonogenic potential, and retained plasticity for osteogenic and adipogenic differentiation. Expressions of p16(Ink4a), Rb, p53, and p21(Cip1), which have been associated with cellular senescence, were all reduced in human MSCs by the pharmacological inhibition of LPA signaling. Disruption of this signaling pathway was accompanied by morphological changes such as cell thinning and elongation as well as actin filament deformation through decreased phosphorylation of focal adhesion kinase. Prevention of LPA receptor engagement also promoted ubiquitination-mediated c-Myc elimination in MSCs, and consequently the entry into a quiescent state, G(0) phase, of the cell cycle. Collectively, these results highlight the potential of pharmacological intervention against LPA signaling for blunting senescence-associated loss of function characteristic of human MSCs.