Katsuichiro Ono

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.

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.

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.

Extrapulmonary small cell carcinoma mimicking malignant pleural mesothelioma.

We report a case with a history of occupational asbestos exposure in which malignant pleural mesothelioma (MPM) was suspected clinically and diagnosed postmortem as pleural involvement of extrapulmonary small cell carcinoma (SCC). An 85-year-old man with a 65 pack-year history of smoking was referred to our hospital in June 2011. The patient had been exposed to asbestos in the iron production industry over the course of 30 years, and an irregular thickening of the right pleura was observed on chest CT at a medical check-up. The patient had a history of chronic hepatitis C and had been undergone transurethral resection for urothelial bladder cancer five times since 2006. Chest CT revealed neoplastic thickening of the right pleura, which had grown over 6 months (figure 1). The CT scan demonstrated bilateral pleural plaques, but no mass-like lesion in other organs, including the lungs, or mediastinal lymphadenopathy. The patient was suspected as having MPM and scheduled for thoracoscopic pleural biopsy, but his general condition worsened rapidly and he …

Successful treatment with pemetrexed, Carboplatin, and bevacizumab for platinum-resistant adenocarcinoma of the lung.

We present two cases of relapsed adenocarcinoma of the lung: a 50-year-old male and a 67-year-old male. Both patients had previously been treated with platinum-containing systemic chemotherapy. In both cases, significant clinical efficacy was demonstrated with combination chemotherapy consisting of pemetrexed, carboplatin, and bevacizumab as salvage treatment. Adverse events were mild. This regimen might be a viable therapeutic option even after heavy treatment such as platinum-containing chemotherapy, especially for patients with preserved organ function and good performance status.