Nobutaka Edakuni

Interleukin-18 expression, CD8(+) T cells, and eosinophils in lungs of nonsmokers with fatal asthma.

BACKGROUND The process of airway inflammation in the lungs of nonsmokers who die of asthma (fatal asthma) has not been reported in detail. OBJECTIVE To examine nonsmokers who had died of asthma to exclude chronic obstructive pulmonary disease and investigate pulmonary inflammatory cells and the expression of interleukin-18 (IL-18) and its receptor in lung tissues compared with those in patients with well-controlled mild asthma and nonsmokers. METHODS Lung tissues were obtained at autopsy examination from 12 nonsmokers with fatal asthma, excluding cases of chronic obstructive pulmonary disease, and from 5 nonsmokers with well-controlled mild asthma and 10 nonsmokers who had undergone surgical resection for lung cancer. Pulmonary inflammatory cells were examined and the expression of the proinflammatory cytokine IL-18 and its receptor in the lungs was evaluated. RESULTS The numbers of eosinophils and lymphocytes, but not basophils or macrophages, were significantly increased in the lungs of patients with fatal asthma compared with the other 2 groups. The lung neutrophil count did not differ significantly between the fatal and mild asthma groups but was significantly higher in the fatal asthma group than in nonsmokers. CD8(+) T cells, but not CD4(+) T cells, were significantly increased in the lungs of the fatal asthma group compared with the other 2 groups. IL-18 protein and IL-18 receptor were strongly expressed in the lungs in the fatal asthma group. CONCLUSION Caspase-1 inhibitors, anti-IL-18 antibodies, anti-IL-18 receptor antibodies, IL-18 binding protein, or inhibitors of genes downstream of the IL-18 signal transduction pathway may be of clinical benefit for the treatment of patients with severe asthma.

IL-18 Induces Airway Hyperresponsiveness and Pulmonary Inflammation via CD4+ T Cell and IL-13

IL-18 plays a key role in the pathogenesis of pulmonary inflammatory diseases including pulmonary infection, pulmonary fibrosis, lung injury and chronic obstructive pulmonary disease (COPD). However, it is unknown whether IL-18 plays any role in the pathogenesis of asthma. We hypothesized that overexpression of mature IL-18 protein in the lungs may exacerbate disease activities of asthma. We established lung-specific IL-18 transgenic mice on a Balb/c genetic background. Female mice sensitized– and challenged– with antigen (ovalbumin) were used as a mouse asthma model. Pulmonary inflammation and emphysema were not observed in the lungs of naïve transgenic mice. However, airway hyperresponsiveness and airway inflammatory cells accompanied with CD4+ T cells, CD8+ T cells, eosinophils, neutrophils, and macrophages were significantly increased in ovalbumin-sensitized and challenged transgenic mice, as compared to wild type Balb/c mice. We also demonstrate that IL-18 induces IFN-γ, IL-13, and eotaxin in the lungs of ovalbumin-sensitized and challenged transgenic mice along with an increase in IL-13 producing CD4+ T cells. Treatment with anti-CD4 monoclonal antibody or deletion of the IL-13 gene improves ovalbumin-induced airway hyperresponsiveness and reduces airway inflammatory cells in transgenic mice. Overexpressing the IL-18 protein in the lungs induces type 1 and type 2 cytokines and airway inflammation, and results in increasing airway hyperresponsiveness via CD4+ T cells and IL-13 in asthma.

Depression, but not sleep disorder, is an independent factor affecting exacerbations and hospitalization in patients with chronic obstructive pulmonary disease.

Background and objective:  Patients with chronic obstructive pulmonary disease (COPD) may experience depression and sleep disorders, which can adversely affect their health‐related quality of life (HRQOL). The aim of this study was to investigate depression and sleep disorders among 85 COPD patients and 46 control subjects, aged 40 years and over.

Positive association between the plasma levels of 5-hydroxyindoleacetic acid and the severity of depression in patients with chronic obstructive pulmonary disease

BackgroundThe role of plasma monoamines in patients with chronic obstructive pulmonary disease (COPD) with depression is unclear. To investigate monoamines in 20 depressed patients with COPD, the plasma concentrations of serotonin, 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid, and 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured and compared with those in 50 non-depressed COPD patients, and also with 23 age- and gender-matched non-smokers and 13 smokers as non-depressed healthy controls.MethodsDiagnosis of depression was assessed using the Centre for Epidemiologic Studies Depression Scale. Plasma concentrations of monoamines were measured by high-performance liquid chromatography.ResultsNone of the depressed COPD patients had suicidal ideation. The plasma 5-HIAA level [median, (25% and 75% quartiles)] in depressed COPD patients [6.8 ng/mL, (4.9 and 13.1)] was significantly higher than in non-depressed COPD patients [5.4, (4.2 and 7.5)] (p=0.022) and non-smokers [5.1 (3.8 and 7.2)] (p=0.041), but not smokers [4.7, (4.0 and 6.7)] (p>0.05). The plasma 5-HIAA level (r=0.24, p=0.049) was significantly associated with the severity of depression in patients with COPD. The plasma MHPG level was significantly higher in depressed COPD patients (p=0.043) than in smokers, but was not higher than that in non-depressed COPD patients or non-smokers, although the level of MHPG was not associated with the severity of depression.ConclusionThe plasma 5-HIAA level is increased in depressed COPD patients. Plasma monoamines may be a good biomarker for detection of depression in patients with COPD.

A trial of oral corticosteroids for persistent systemic and airway inflammation in severe asthma

The fraction of exhaled nitric oxide (FeNO) and blood eosinophils, markers of local and systemic eosinophilic inflammation, respectively, are increased in asthmatic patients. Little is known concerning the relationship between the FeNO levels and blood eosinophils in asthmatics.

Deep Sternal Wound Tuberculosis with Hypo-gamma-globulinemia

A 44-year-old man was referred to our hospital for the treatment of a pulmonary and deep sternal wound tuberculosis infection, which is an extremely rare type of extrapulmonary tuberculosis. Laboratory testing revealed a serum immunoglobulin (Ig) G level of 286 mg/dL, IgA of 22 mg/dL and IgM of 13 mg/dL. We therefore diagnosed him with hypo-gamma-globulinemia. He was treated with anti-tuberculosis medications and intravenous immunoglobulin. At present, the tuberculosis has not relapsed in the past six years. It may be useful to assess the humoral immunity status in tuberculosis patients with a normal T cell function, and immunoglobulin therapy may be beneficial for protecting such patients from reactivation of tuberculosis.

Response to Systemic Corticosteroids on Persistently High Exhaled Nitric Oxidein Severe Asthma

Nitric oxide (NO), a gaseous signaling molecule generated by NO synthase (NOS), is enhanced by inflammatory stimuli [1]. The exhaled nitric oxide fraction (FeNO) has been proposed as a marker of airway inflammation and a guide for anti-inflammatory therapy in asthma [1]. However, a persistently high FeNO is occasionally observed despite inhaled corticosteroids (ICS) therapy [2-4]. Excessive NO synthesis is well documented in severe asthma [5,6]. Also, it is suggested that some proportion of individuals are truly steroid resistant, which is defined as no clinical improvement after treatment with systemic steroids [7]. However, few studies have provided detailed data regarding the variability of change in FeNO by administration of systemic steroids and its impact on asthma control and lung function in patients with severe asthma and persistently high FeNO.