Nobuko Matsuo

Correlation between airway hyperresponsiveness and airway inflammation in a young adult population : eosinophil, ECP, and cytokine levels in induced sputum

BACKGROUND Eosinophil counts and eosinophil cationic protein (ECP) levels in the airway are elevated in asthmatic patients. However, few studies have examined the correlation between various cytokines in the sputum and airway hyperresponsiveness (AHR) in young adults with or without asthma. OBJECTIVE We examined the correlation between AHR and eosinophil counts or ECP, and levels of several cytokines in the sputum. METHODS We studied 120 nonsmoker students (group 1: intermittent mild asthmatic patients; group 2: subjects with history of childhood asthma; group 3: subjects sensitized by Dermatophagoides farinae with atopic disease; group 4: normal subjects sensitized by D. farinae; group 5: subjects with cedar pollinosis; and group 6: normal subjects). In each subject, AHR and lung function tests were measured, together with eosinophil count, ECP, granulocyte-macrophage colony-stimulating factor, TNF-alpha, IL-5, and interleukin-1beta in induced sputum. RESULTS AHR in groups 1 and group 2 were high, in groups 5 and 6 low, and in groups 3 and 4 lower than in groups 1 and 2 but higher than groups 5 and 6. Percentages of eosinophils, ECP, and TNF-alpha in induced sputum in groups 1 and 2 were high, those in groups 5 and 6 were below detection limits, and those in groups 3 and 4 were lower than the percentages in groups 1 and 2. Granulocyte-macrophage colony-stimulating factor in the sputum was elevated only in group 1. The correlations between AHR and sputum eosinophil count, ECP, and TNF-alpha were significant, with the strongest correlation with TNF-alpha. CONCLUSIONS Our results suggest that TNF-alpha levels in the sputum play an important role in determining the severity of AHR in young individuals. Further once AHR develops, it does not disappear, and the severity of airway inflammation influences the extent of AHR.

Sensitivity to the house dust mite and airway hyperresponsiveness in a young adult population

BACKGROUND The pathogenic mechanisms of airway hyperresponsiveness (AHR) in asthma are unknown and only a few studies have examined the importance of sensitivity to antigens in AHR in young adults. OBJECTIVE We investigated the correlation between AHR and sensitivity to specific antigens, atopy, history of childhood asthma and spirometry in a young adult population. METHODS Based on the results of interviews with 447 students at our university, 308 non-smoker students were classified into six groups. Group 1 comprised subjects with intermittent mild bronchial asthma; group 2, subjects with history of childhood asthma; group 3, subjects with atopic disease, and a RAST score for Dermatophagoides farinae (Def) of > or = 2; group 4, normal subjects with a RAST score for Def of > or = 2; group 5, subjects with cedar pollinosis; and group 6, normal subjects. We measured AHR to methacholine (MCh), spirometry, immunoglobulin E-radioimmunosorbent test (IgE-RIST), IgE-radioallergosorbent test to six common antigens, eosinophil cationic protein (ECP), and eosinophil count in peripheral blood in each subject. RESULTS Airway hyperresponsiveness to MCh did not correlate with IgE-RIST, eosinophil count, or ECP. The highest AHR to MCh was present in groups 1 and 2 and lowest in groups 5 and 6. Multiple regression analysis showed that sensitivity to Def was the only factor that significantly influenced AHR to MCh. Airway hyperresponsiveness to MCh of groups with a RAST score for Def of 0/1 was lower than groups with a RAST score of 2 to 6. Airway hyperresponsiveness to MCh did not correlate with the degree of positivity to Def antigen among positive sensitized groups (RAST score 2 to 6). CONCLUSIONS Sensitivity to mite antigen may be important in the pathogenesis of AHR and Def is a major contributing antigen in young adults in Japan. Once asthma occurs, AHR remains positive for a long time even after the disappearance of asthma-related symptoms.

Tacrolimus inhibits cytokine production and chemical mediator release following antigen stimulation of passively sensitized human lung tissues

BACKGROUND The immunosuppressive effects of tacrolimus are mediated by inhibition of cytokine production by inflammatory cells. The role of tacrolimus on cytokine production and release of chemical mediators in asthma is not known at present. OBJECTIVES We compared the effects of tacrolimus on interleukin (IL)-5 and tumor necrosis factor-alpha (TNF-alpha) production and chemical mediator release from excised human lung tissue with those of steroids. METHODS Human lung tissue was passively sensitized with serum from atopic patients then preincubated with tacrolimus (10(-6), 10(-7), 10(-8) M) or dexamethasone (10(-6) M) for 2 hours. The lung tissue was then exposed to 1.5 microg/mL of mite antigen and then cultured for 48 hours. Culture supernatants were collected and IL-5 and TNF-alpha levels were measured by ELISA. IL-5 and TNF-alpha messenger ribonucleic acid (mRNA) expression was also investigated by reverse transcriptase-polymerase chain reaction. The level of histamine and leukotriene E4 was also measured in the culture supernatant. In addition, tryptase staining was performed to compare degranulation of mast cells. RESULTS Antigen stimulation increased histamine and leukotriene release in the supernatant. Tacrolimus significantly and dose-dependently inhibited the release of histamine and leukotriene; dexamethasone did not. The results of tryptase staining demonstrated that tacrolimus dose-dependently inhibited degranulation of mast cells, whereas dexamethasone did not. Antigen stimulation increased TNF-alpha and IL-5 protein production and mRNA expression. Tacrolimus and dexamethasone significantly inhibited TNF-alpha and IL-5 protein production and mRNA expression. CONCLUSIONS Our results indicated that tacrolimus is more powerful in inhibition of cytokine production and release of chemical mediators than steroids, and suggested that this immunosuppressor drug might be useful for the treatment of asthma.

Effects of sodium cromoglycate on cytokine production following antigen stimulation of a passively sensitized human lung model.

BACKGROUND Interleukin-5 (IL-5) and tumor necrosis factor-alpha (TNF-alpha) play key roles in bronchial asthma. Sodium cromoglycate (DSCG) and dexamethasone (Dex) are used in the treatment of asthma as anti-inflammatory agents. OBJECTIVE We investigated whether DSCG inhibited the expression of IL-5 and TNF-alpha mRNA and proteins from isolated human lungs, and compared these findings with those of Dex. METHODS Human lung specimens were passively sensitized with sera from atopic patients, then preincubated in the presence of DSCG (10(-3), 10(-4), 10(-5) M) or Dex (10(-6) M) for 2 hours. The specimens were stimulated with Dermatophagoides antigen, then cultured for 48 hours. The supernatant was collected 1, 2, 4, 8, 24, and 48 hours to measure IL-5 and TNF-alpha by enzyme-linked immunosorbent assay. mRNA expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS Tumor necrosis factor-alpha protein reached a peak level at 4 hours (156.57 +/- 18.29 pg/mL). Dex decreased TNF-alpha protein to 31.86 +/- 4.67 pg/mL (P < .001). There was also a decrease of TNF-alpha protein to 107.43 +/- 14.25 pg/mL by 10(-4) MD SCG (P < .001). Antigenic stimulation also increased the release of IL-5 protein at 4 hours and the peak level was observed at 24 hours (150.29 +/- 19.12 pg/mL). Dex decreased IL-5 protein to 28.57 +/- 5.27 pg/mL (P < .0001), 10(-4) M DSCG also decreased to 111.57 +/- 15.28 pg/mL (P < .05). RT-PCR analysis showed persistence of IL-5 and TNF-alpha mRNA expression from 1 to 24 hour after antigen stimulation. Dex but not DSCG inhibited IL-5 and TNF-alpha mRNA levels. CONCLUSION Our results showed that DSCG significantly inhibited IL-5 and TNF-alpha production by human lung specimens, suggesting that it acts as an anti-inflammatory agent.

Differential Airway Inflammatory Responses in Asthma Exacerbations Induced by Respiratory Syncytial Virus and Influenza Virus A

Background: Although respiratory viral infections cause acute exacerbations of asthma, the inflammatory responses vary depending on the causative virus. The purpose of this study was to compare the inflammatory responses in the airways of acute exacerbations of asthma induced by respiratory syncytial virus (RSV) and influenza A virus. Methods: Sputum induction was performed in asthmatic patients with acute exacerbations induced by RSV (n = 6), influenza A (n = 7), and non-upper respiratory infection (URI)-related factors (n = 8). Sputum concentrations of cysteinyl leukotrienes (cysLTs), TNF-α and IFN-γ were measured. Results: Sputum cysLTs were significantly higher in RSV-induced exacerbations than in influenza A- and non-URI-induced exacerbations. Sputum TNF-α was significantly higher in influenza A-induced exacerbations than in RSV- and non-URI-induced exacerbations. Sputum IFN-γ was significantly lower in RSV-induced exacerbations than in the others. Conclusions: RSV and influenza A cause acute exacerbations and have different effects on airway inflammation in asthmatic patients. RSV significantly increased cysLTs, while influenza A significantly increased TNF-α in the airway. The underlying mechanism in virus-induced asthma might depend on the viral species.

The Position of Pranlukast, a Cysteinyl Leukotriene Receptor Antagonist, in the Long-Term Treatment of Asthma

Background: Adverse effects, tachyphylaxis, and the position of pranlukast, a cysteinyl leukotriene receptor antagonist, in asthma treatment have not been fully established. Objectives and Methods: To address these questions, adverse effects and long-term efficacy of pranlukast were evaluated in 82 patients [28 patients with moderate asthma (group I), 27 with severe persistent asthma not on oral corticosteroid (OCS; group II) and 27 with severe persistent asthma on OCS (group III)] at 4 and 16 weeks. In the following, pranlukast was either withdrawn 1 year after the start of therapy, or if that was not possible due to reappearance of symptoms, the dose of OCS or inhaled corticosteroid (ICS) was reduced. The efficacy of pranlukast was evaluated during 5 years by peak expiratory flow rate (PEFR), and symptom and treatment scores. Results: Adverse reactions appeared in 4 patients (4.9%; diarrhea, dizziness and leg edema). The mean improvement in PEFR on week 16 was 18.5 ± 2.3, 18.8 ± 3.2, and 15.2 ± 3.8% in groups I–III, respectively (p < 0.01, for all groups). However, increases in PEFR in 29 of 72 patients (40.3%) were less than 15%. Pranlukast could not be withdrawn in 28 of 42 responders (66.7%), but their dose of ICS was reduced by 363 ± 97 µg/day (group II) and that of OCS by 3.4 ± 0.7 mg/day (group III). Tachyphylaxis was not recognized during the 5-year period. Conclusion: Pranlukast is safe when taken for up to 5 years, and is effective irrespective of asthma severity. In the majority of patients with persistent asthma, pranlukast may help to control the disease in the long term.

Effects of amphotericin B gargles on oral colonization of Candida albicans in asthmatic patients on steroid inhalation therapy.

Background: Early use of inhaled steroids is recommended for bronchial asthma. The side effects are rare, but oral discomfort and candidiasis are clinically important complications. Most previous studies reported that the use of spacer and water gargling was necessary to prevent oral complications. However, in some patients, this may fail to prevent such complications. Objective: To compare the effects of water gargling with those of amphotericin B, in the prevention of oral complications in asthmatics using inhaled steroids. Methods: Pharyngeal swab samples were obtained aseptically from the posterior pharyngeal wall of 128 asthmatics who have been using inhaled steroids (beclomethasone dipropionate) for more than 1 year. The amount of Candida albicans in cultured swabs was evaluated based on the following criteria: oral symptoms, method of gargling, dose of inhaled steroids, type of spacer and serum cortisol level. Results: The number of isolated C. albicans was significantly higher in asthmatics with oral symptoms than in those free of symptoms. It was also significantly higher in patients who gargled with water or 1,000 times dilution than in those who gargled with 100 or 50 times dilutions of amphotericin B. Moreover, it was significantly higher in patients with low levels of serum cortisol than in those with normal serum cortisol. Conclusion: We demonstrated that at least in a subgroup of asthmatics using steroid inhalers, gargling with water or even weak concentrations of amphotericin B does not prevent colonization of the throat with C. albicans. This group at high risk of developing oral candidiasis should gargle with amphotericin B at concentrations higher than 100 times dilution that can prevent clinically detectable oral candidiasis.

Observational study of the additive effects of pranlukast on inflammatory markers of clinically stable asthma with inhaled corticosteroids and long-acting beta 2 agonists.

Background: Little is understood about the additive effects of leukotriene receptor antagonists (LTRA) on asthmatics currently medicated with inhaled corticosteroids (ICS) and long-acting β2-agonists (LABA). Objectives: The present study examines the anti-inflammatory effects of the LTRA pranlukast in addition to ICS and LABA, among asthmatic patients with normal pulmonary function and unremarkable clinical symptoms. Methods: Fifteen adult asthmatics participated in a 2-month, open-label, uncontrolled, prospective, multicenter, observational trial. Patients stabilized (predicted forced expiratory volume in 1 s >80%) by medication with ICS and LABA were also given pranlukast (450 mg daily). Asthma-related symptoms, pulmonary function, blood eosinophil counts and several inflammatory markers in sputum were monitored at week 0, as well as at 4 and 8 weeks after starting therapy with pranlukast. Results: Adding pranlukast did not further improve blood eosinophil counts, pulmonary function and symptoms, but significantly attenuated sputum cysteinyl leukotrienes, tumor necrosis factor-α and interleukin-5 concentrations. Conclusions: Although the clinical relevance remains obscure, adding an LTRA attenuates allergic airway inflammation in some asthmatics undergoing treatment with ICS and LABA.

Effects of a Short Course of Pranlukast Combined with Systemic Corticosteroid on Acute Asthma Exacerbation Induced by Upper Respiratory Tract Infection

Background. Upper respiratory tract infections (URIs) represent the most frequent cause of acute asthma exacerbation. Systemic corticosteroid (CS) is presently recommended for URI-induced asthma exacerbation, although it might inhibit cellular immunity against respiratory virus infection. Objectives. To determine the effects of adding a short course (2 weeks) of a leukotriene receptor antagonist (LTRA) to systemic CS on URI-induced acute asthma exacerbation. Methods. Twenty-three adult asthmatics (mean age, 42.8 ± 9.8 y; Male:Female, 10:13) with URI-induced acute asthma exacerbation confirmed by a questionnaire and physical findings were randomly assigned to receive either oral prednisolone (PSL) alone or oral PSL plus the LTRA pranlukast (PRL) for 2 weeks (PSL + PRL). The cumulative doses of PSL and the amount of time required to clear asthma-related symptoms were determined. Levels of respiratory syncytial virus (RSV) RNA and influenza viral (IV) antigen in nasopharyngeal swabs were also determined. Results. Adding PRL significantly reduced the cumulative dose of PSL and tended to reduce the time required to clear asthma-related symptoms. Either RSV or IV was detected in about one-third of the patients. Conclusion. The combination of an LTRA and CS might be more useful than CS alone for treating URI-induced acute exacerbation of asthma and reducing the cumulative CS dose.

Sodium cromoglycate inhibits antigen-induced cytokine production by peripheral blood mononuclear cells from atopic asthmatics in vitro

BACKGROUND Several anti-allergic anti-inflammatory drugs are used for the treatment of asthma including glucocorticosteroids (GCS), sodium cromoglycate (SCG), leukotriene (LT) inhibitors, and LT receptor antagonists. The major mechanism of the anti-inflammatory action of GCS is inhibition of cytokine production by T-lymphocytes: however, the mechanisms of anti-inflammatory effects of SCG are still unclear. OBJECTIVE We elucidated the anti-inflammatory effects of SCG by investigating its effects on cytokine production by peripheral blood mononuclear cells (PBMCs) obtained from atopic asthmatics. METHODS Peripheral blood mononuclear cells were obtained from seven atopic asthmatics and sensitized with Dermatophagoides farinae (DJ) or concanavalin A (ConA). We compared the effects of SCG on interleukin (IL)-5 and interferon (IFN)-gamma production by sensitized PBMCs with that of dexamethasone (Dex). Based on their clinical concentrations, we compared the effects of 10(-6) to 10(-4) M of SCG to those of 10(-6) M Dex. RESULTS Stimulation with ConA increased the production of IL-5 and IFN-gamma. Dex significantly inhibited the production of both cytokines but SCG showed no inhibitory effects. On the other hand, Df stimulation increased IL-5 production only. Dermatophagoides farinae-induced overproduction of IL-5 was inhibited by SCG and Dex. CONCLUSIONS Our results suggested that SCG has antigen-specific anti-allergic inflammatory effects.