Yasuko Fuchimoto

Inhibition of neutrophil elastase attenuates airway hyperresponsiveness and inflammation in a mouse model of secondary allergen challenge: neutrophil elastase inhibition attenuates allergic airway responses

BackgroundChronic asthma is often associated with neutrophilic infiltration in the airways. Neutrophils contain elastase, a potent secretagogue in the airways, nonetheless the role for neutrophil elastase as well as neutrophilic inflammation in allergen-induced airway responses is not well defined. In this study, we have investigated the impact of neutrophil elastase inhibition on the development of allergic airway inflammation and airway hyperresponsiveness (AHR) in previously sensitized and challenged mice.MethodsBALB/c mice were sensitized and challenged (primary) with ovalbumin (OVA). Six weeks later, a single OVA aerosol (secondary challenge) was delivered and airway inflammation and airway responses were monitored 6 and 48 hrs later. An inhibitor of neutrophil elastase was administered prior to secondary challenge.ResultsMice developed a two-phase airway inflammatory response after secondary allergen challenge, one neutrophilic at 6 hr and the other eosinophilic, at 48 hr. PAR-2 expression in the lung tissues was enhanced following secondary challenge, and that PAR-2 intracellular expression on peribronchial lymph node (PBLN) T cells was also increased following allergen challenge of sensitized mice. Inhibition of neutrophil elastase significantly attenuated AHR, goblet cell metaplasia, and inflammatory cell accumulation in the airways following secondary OVA challenge. Levels of IL-4, IL-5 and IL-13, and eotaxin in BAL fluid 6 hr after secondary allergen challenge were significantly suppressed by the treatment. At 48 hr, treatment with the neutrophil elastase inhibitor significantly reduced the levels of IL-13 and TGF-β1 in the BAL fluid. In parallel, in vitro IL-13 production was significantly inhibited in spleen cells from sensitized mice.ConclusionThese data indicate that neutrophil elastase plays an important role in the development of allergic airway inflammation and hyperresponsiveness, and would suggest that the neutrophil elastase inhibitor reduced AHR to inhaled methacholine indicating the potential for its use as a modulator of the immune/inflammatory response in both the neutrophil- and eosinophil-dominant phases of the response to secondary allergen challenge.

Hyaluronic acid in the pleural fluid of patients with malignant pleural mesothelioma

BACKGROUND We retrospectively analyzed hyaluronic acid (HA) concentrations in pleural fluid and evaluated its utility for the differential diagnosis of malignant pleural mesothelioma (MPM). METHODS Pleural fluid HA concentrations were measured in 334 patients, including 50, 48, 85, 18, 86, 6, and 41 patients with MPM, benign asbestos pleurisy (BAP), lung cancer (LC), other malignant conditions (OMCs), infectious pleuritis (IP), collagen disease (CD), and other conditions, respectively. RESULTS The median (range) HA concentrations in pleural fluid were 78,700 (7920-2,630,000)ng/ml in the MPM group, 35,950 (900-152,000)ng/ml in the BAP group, 19,500 (2270-120,000)ng/ml in the LC group, 14,200 (900-101,000)ng/ml in the OMC group, 23,000 (900-230,000)ng/ml in the IP group, 24,600 (9550-80,800)ng/ml in the CD group, and 8140 (900-67,800)ng/ml in the other diseases group. HA levels were significantly higher in the MPM group than in the other groups. Receiver operating characteristic (ROC) analysis revealed an area under the ROC curve value of 0.832 (95% confidence interval, 0.765-0.898) for the differential diagnosis of MPM. With a cutoff value of 100,000ng/ml, the sensitivity and specificity were 44.0 and 96.5%, respectively. In the MPM group, HA values were significantly higher for the epithelioid subtype than for the sarcomatous subtype (p=0.007), and higher in earlier stages (I and II) than in advanced stages (III and IV) (p=0.007). CONCLUSIONS A diagnosis of MPM should be strongly considered in patients with pleural fluid HA concentrations exceeding 100,000ng/ml.

Prognostic significance of the lymphocyte-to-monocyte ratio in patients with malignant pleural mesothelioma.

OBJECTIVES Chronic inflammation plays a key role in the pathogenesis of malignant pleural mesothelioma (MPM) as a result of asbestos exposure. Several inflammation-based prognostic scores including the lymphocyte-to-monocyte ratio (LMR), Glasgow Prognostic Score (GPS), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) reportedly predict survival in many malignancies, while the role of LMR in MPM remains unclear. The aim of this study was to evaluate the clinical value of LMR and to compare the prognostic value of these inflammation-based scores in predicting overall survival (OS) in MPM. MATERIALS AND METHODS One hundred and fifty patients with histologically proven MPM were included in this retrospective study. Kaplan-Meier curves and multivariate Cox-regression analyses were calculated for OS. The area under the receiver operating characteristics curve (AUC) was calculated to compare the discriminatory ability of each scoring system. RESULTS An elevated LMR was significantly associated with prolonged OS. Patients with LMR <2.74 had significantly poor survival compared with LMR ≥2.74 (median, 5.0 versus 14.0 months; p=0.000). The LMR consistently had a higher AUC value at 6 months (0.722), 12 months (0.712), and 24 months (0.670), compared with other scores. Multivariate analysis showed that the LMR was independently associated with OS. CONCLUSIONS The LMR is an independent prognostic marker for OS in patients with MPM and is superior to other inflammation-based prognostic scores with respect to prognostic ability.

Growth Factors Temporally Associate with Airway Responsiveness and Inflammation in Allergen-Exposed Mice

Background: To clarify whether growth factors play critical roles in the development of airway hyperresponsiveness (AHR) and airway inflammation in the early stages of asthma, the relationship between growth factors and AHR and airway inflammation were analyzed in a mouse model of asthma. Methods: Following ovalbumin (OVA) sensitization and challenge, airway function, inflammation, cytokine and growth factor levels were monitored. Results: AHR to inhaled methacholine increased at 6 h, peaked at 48 h, and remained elevated for 14 days. IL-4 and IL-5 levels in bronchoalveolar lavage (BAL) fluid were increased at 6 h, peaked at 24 h, but returned to baseline quickly. IL-13 levels increased up to 14 days, peaking at 48 h. Increases in BAL fluid transforming growth factor-β1 and platelet-derived growth factor were observed at 12 h, and remained elevated at 14 days. Nerve growth factor levels were increased at 24–28 days. BAL fluid hepatocyte growth factor (HGF) was detected at 12 h, peaked at 24 h, and returned to baseline by 72 h. c-Met/HGF receptor was detected in the airways at 6 h, before HGF in the BAL, and continued to be observed 96 h after the last OVA challenge. Conclusions: These data identify a temporal association between growth factor production and Th2 cytokine production and the kinetics of AHR. Growth factors may play important roles in the development of allergic airway inflammation and AHR even in the early stages of asthma, before remodeling is initiated.

Effect of a Cysteinyl Leukotriene Receptor Antagonist on Experimental Emphysema and Asthma Combined with Emphysema

The incidence of overlapping bronchial asthma and chronic obstructive pulmonary disease has increased in recent years. Cysteinyl leukotrienes (CysLTs) play an important role in asthma, and the type 1 CysLT receptor (CysLT1R) is expressed by many inflammatory cells. We evaluated the effect of montelukast, a CysLT1R antagonist, on mouse models of asthma, porcine pancreatic elastase (PPE)-induced emphysema, and asthma combined with emphysema. Mice were sensitized with ovalbumin (OVA) on Days 0 and 14 and subsequently challenged with OVA on Days 28, 29, and 30. Pulmonary emphysema was induced by intratracheal instillation of PPE on Day 25. Mice were treated subcutaneously with montelukast or vehicle from Day 25 to Day 31. Airway hyperresponsiveness (AHR), static compliance; the number of inflammatory cells, the levels of cytokines, chemokines, LTs, and perforin in the bronchoalveolar lavage fluid, and the quantitative morphometry of lung sections were analyzed on Day 32. Treatment with montelukast significantly attenuated the AHR and eosinophilic airway inflammation in OVA-sensitized and OVA-challenged mice. Administration of montelukast significantly reduced the AHR, static compliance, and neutrophilic airway inflammation, while attenuating emphysematous lung changes, in PPE-treated mice. In PPE-treated mice subjected to allergen sensitization and challenges, montelukast significantly suppressed the AHR, static compliance, and eosinophilic and neutrophilic airway inflammation in addition to the development of experimentally induced emphysema in the lungs. Our data suggest that CysLT1R antagonists may be effective in ameliorating the consequences of PPE-induced lung damage and the changes that follow allergen sensitization and challenges.

Blocking the Leukotriene B4 Receptor 1 Inhibits Late-Phase Airway Responses in Established Disease

Most of the studies investigating the effectiveness of blocking the leukotriene B4 (LTB4) receptor 1 (BLT1) have been performed in models of primary or acute allergen challenge. The role of the LTB4-BLT1 pathway in secondary challenge models, where airway hyperresponsiveness (AHR) and airway inflammation have been established, has not been defined. We investigated the effects of blocking BLT1 on early- and late-phase development of AHR and airway inflammation in previously sensitized and challenged mice. Female BALB/c mice were sensitized (Days 1 and 14) and challenged (primary, Days 28-30) with ovalbumin. On Day 72, mice were challenged (secondary) with a single OVA aerosol, and the early and late phases of AHR and inflammation were determined. Specific blockade of BLT1 was attained by oral administration of a BLT1 antagonist on Days 70 through 72. Administration of the antagonist inhibited the secondary ovalbumin challenge-induced alterations in airway responses during the late phase but not during the early phase, as demonstrated by decreases in AHR and in bronchoalveolar lavage neutrophilia and eosinophilia 6 and 48 hours after secondary challenge. The latter was associated with decreased levels of KC protein, macrophage inflammatory protein 2, and IL-17 in the airways. These data identify the importance of the LTB4-BLT1 pathway in the development of late-phase, allergen-induced airway responsiveness after secondary airway challenge in mice with established airway disease.

Requirement for chemokine receptor 5 in the development of allergen-induced airway hyperresponsiveness and inflammation.

Chemokine receptor (CCR) 5 is expressed on dendritic cells, macrophages, CD8 cells, memory CD4 T cells, and stromal cells, and is frequently used as a marker of T helper type 1 cells. Interventions that abrogate CCR5 or interfere with its ligand binding have been shown to alter T helper type 2-induced inflammatory responses. The role of CCR5 on allergic airway responses is not defined. CCR5-deficient (CCR5(-/-)) and wild-type (CCR5(+/+)) mice were sensitized and challenged with ovalbumin (OVA) and allergic airway responses were monitored 48 hours after the last OVA challenge. Cytokine levels in lung cell culture supernatants were also assessed. CCR5(-/-) mice showed significantly lower airway hyperresponsiveness (AHR) and lower numbers of total cells, eosinophils, and lymphocytes in bronchoalveolar lavage (BAL) fluid compared with CCR5(+/+) mice after sensitization and challenge. The levels of IL-4 and IL-13 in BAL fluid of CCR5(-/-) mice were lower than in CCR5(+/+) mice. Decreased numbers of lung T cells were also detected in CCR5(-/-) mice after sensitization and challenge. Transfer of OVA-sensitized T cells from CCR5(+/+), but not transfer of CCR5(-/-) cells, into CCR5(-/-) mice restored AHR and numbers of eosinophils in BAL fluid after OVA challenge. Accordingly, the numbers of airway-infiltrating donor T cells were significantly higher in the recipients of CCR5(+/+) T cells. Taken together, these data suggest that CCR5 plays a pivotal role in allergen-induced AHR and airway inflammation, and that CCR5 expression on T cells is essential to the accumulation of these cells in the airways.

Bilateral Pleural Effusions as an Initial Presentation in Primary Sjögren's Syndrome

Sjögrens syndrome (SS) is a systemic autoimmune disease characterized by sicca symptoms. Interstitial pulmonary fibrosis and tracheobronchial sicca are the most common symptoms of pulmonary involvement in primary SjS, and they are rarely accompanied by serositis such as pleuritis or pericarditis. We report a case of SS presenting initially with bilateral pleural effusions. A 63-year old man was admitted to our hospital with a one-month history of cough, dyspnea, and right chest pain. Chest-computed tomography revealed bilateral pleural effusions. Serum anti-SS-A antibody titer was 1 : 256. Ophthalmological examination revealed a positive Schirmer test. Lip biopsy showed atrophy and plasmacytic infiltration of the salivary gland. Corticosteroid treatment was initiated. Pleural effusions were almost completely resolved by day 30. The patient has not experienced any recurrence.

Brain abscess mimicking lung cancer metastases; a case report

A 76-year-old woman came to us because of staggering, fever, dysarthria, and appetite loss. Magnetic resonance imaging (MRI) of the brain revealed multiple masses with surrounding edema. Chest X-ray and computed tomography demonstrated a mass-like lesion in the left lung and left pleural effusion. Lung cancer and multiple brain metastases were suspected. However, the brain lesions demonstrated a high intensity through diffusion-weighted MRI. The finding was an important key to differentiate brain abscesses from lung cancer metastases.

Angiosarcoma of the thoracic wall responded well to nanoparticle albumin-bound paclitaxel: A case report.

An 81-year-old woman visited a local clinic due to chest pain and a skin induration on the right precordia. She had a history of right breast cancer, and she had undergone a mastectomy and radiation therapy 10 years prior. Computed tomography (CT) imaging of the chest demonstrated a lobular mass that involved the right anterior thoracic wall and partially extruded from the thoracic cavity into the subcutaneous tissue. The tumor was surgically excised, and pathological analyses yielded a diagnosis of angiosarcoma. Five months after the operation, CT imaging showed multiple masses on the right pleura, indicating a local relapse and pleural dissemination of the angiosarcoma. Systemic chemotherapy composed of nanoparticle albumin-bound paclitaxel (nab-PTX) (80 mg/m(2)) was delivered weekly. After 4 courses of chemotherapy, the tumors regressed remarkably. Nab-PTX may be an effective treatment option for recurrent or metastatic angiosarcoma.