BACKGROUND: Airway hyperresponsiveness (AHR) to direct stimuli, such as methacholine (MCh), is observed not only in asthma but other diseases. AHR to indirect stimuli is suggested to be more specific for asthma. The purpose of this study was to determine whether asthmatic airway inflammation is more closely related to AHR to hypertonic saline (HS), an indirect stimulus, than to MCh. METHODS: Sixty-four consecutive adult patients with suspected asthma (45 asthma and 19 non-asthma) performed a combined bronchial challenge and sputum induction with 4.5% saline, and MCh challenge on the next day. RESULTS: Both HS-PD15 and MCh-PC20 were significantly lower in asthma patients than in non-asthma patients. However, the sensitivity/ specificity for asthma was 48.9%/100%, respectively, in the HS test and 82.2%/ 84.2%, respectively, in the MCh test. There was a significant relationship between HS-PD15 and MCh-PC20 and only 52.9% of patients with MCh-PC20 < or= 4 mg/mL showed HS-AHR, but 4 patients with HS-AHR showed MCh-PC20 > 4 mg/mL. There were significant correlations between both HS-PD15 and MCh-PC20 and FEV1, or sputum eosinophils, but FEV1 was more closely related to MCh-PC20 (r=0.478, p < 0.01) than to HS-PD15 (r=0.278, p < 0.05), and sputum eosinophils were more closely related to HS-PD15 (r=-0.324, p < 0.01) than to MCh-PC20 (r=-0.317, p < 0.05). Moreover, the IL-5 level (r=-0.285, p < 0.05) and IFN-gamma/IL-5 ratio (r=0.293, p < 0.05) in sputum were significantly related to HS-PD15, but not to MCh-PC20. CONCLUSION: HS-AHR may reflect allergic asthmatic airway inflammation more closely than MCh-AHR.
Asthma/*physiopathology ; Bronchial Hyperreactivity/*physiopathology ; Bronchial Provocation Tests ; Bronchoconstrictor Agents/*diagnostic use ; Comparative Study ; Female ; Human ; Male ; Methacholine Chloride/*diagnostic use ; Saline Solution, Hypertonic/*diagnostic use ; Support, Non-U.S. Gov't

BACKGROUND: Changes in airway mucosal osmolarity are an underlying mechanism of bronchoconstrictive responses to exercise and hypertonic saline (HS). The purpose of this study was to examine whether an osmotic challenge test using HS can predict exercise-induced bronchospasm (EIB) in asthma patients. METHODS: Thirty-six young male asthmatic patients underwent bronchial challenge tests based on 4.5% HS, exercise (> 24h later), and methacholine (MCh) at the Chonnam National University Hospital. The relationships between responses to HS and exercise, and between MCh and exercise were evaluated. RESULTS: The maximal fall in forced expiratory volume in one second following exercise was significantly higher in the HS-responders (n=19) than in the HS-nonresponders (n=17, 35.9+/-4.1% vs. 17.9+/-2.7%, p< 0.001), and there was a significant correlation between the severity of EIB and HS-airway hyperresponsiveness (AHR). When compared with the MCh-AHR test in terms of predicting EIB, the HS-AHR test showed higher specificity (71.4% vs. 42.9%), but a lower sensitivity (58.6% vs. 89.7%) and negative predictive value (29.4% vs. 50.0%). At the moderate AHR cutoff value, the MCh-AHR test had a specificity that was comparable with and predictive values that were higher than those of the HS-AHR test. CONCLUSIONS: The HS-AHR test was more specific than the MCh-AHR test, but was less sensitive and had a poorer negative predictive value, which in combination preclude the use of the HS-AHR test as a screening tool for EIB. The MCh-AHR test had a cutoff value for moderate AHR that may be more useful for predicting EIB in asthmatic patients.
Saline Solution, Hypertonic/*diagnostic use ; Predictive Value of Tests ; Methacholine Chloride/diagnostic use ; Male ; Humans ; Bronchoconstrictor Agents/diagnostic use ; Bronchial Provocation Tests/*methods ; Bronchial Hyperreactivity/*diagnosis ; Asthma, Exercise-Induced/*diagnosis ; Adult ; Adolescent

The aim of this study was to investigate the possible adverse effects of Asian dust events on respiratory health in asthmatic children. Fifty-two children with mild asthma were studied for eight consecutive weeks in the spring of 2004 (March 8 to May 2). During the study period, five Asian dust days were identified; we included a lag period of two days following each of the events. Subjects recorded their respiratory symptom diaries and peak expiratory flow (PEF) twice daily during the study period; and they underwent methacholine bronchial challenge tests. The subjects reported a significantly higher frequency of respiratory symptoms during the Asian dust days than during the control days. They showed significantly more reduced morning and evening PEF values, and more increased PEF variability (10.1%+/-3.5% vs. 5.5%+/-2.2%) during the Asian dust days than during the control days. Methacholine PC20 was not significantly different between before and after the study period (geometric mean: 2.82 mg/mL vs. 3.16 mg/mL). These results suggest that the short-term Asian dust events might be associated with increased acute respiratory symptoms and changes in PEF outcomes. However, there might be little long-term influence on airway hyperresponsiveness in children with mild asthma.
Adolescent ; Asthma/*physiopathology ; Bronchial Hyperreactivity/physiopathology ; Child ; *Dust ; Female ; Humans ; Male ; Methacholine Chloride/diagnostic use ; *Peak Expiratory Flow Rate ; Respiration Disorders/*etiology/physiopathology

Enhanced cough response has been frequently observed in chronic cough. Recently, extrathoracic airway constriction to inhaled histamine was demonstrated in some chronic cough patients. However, relation between extrathoracic airway hyperresponsiveness (EAHR) and cough sensitivity determined by capsaicin inhalation is unclear in each etiological entity of chronic cough. Seventy-seven patients, with dry cough persisting for 3 or more weeks, normal spirometry and chest radiography, and 15 controls, underwent methacholine bronchial provocation test and capsaicin cough provocation test. Elicited cough number and flow-volume curve was examined after inhalation of capsaicin to evaluate cough sensitivity and EAHR. Thirty-three patients, with postnasal drip, showed normal extrathoracic airway responsiveness, and 27 of them showed normal cough sensitivity to capsaicin. Cough sensitivity was enhanced in 14 patients with cough variant asthma (CVA) who showed bronchial hyperresponsiveness; EAHR to inhaled capsaicin was present in 12 of them. The remaining 30 patients were tentatively diagnosed as idiopathic chronic cough (ICC). Eleven ICC patients showed enhanced cough sensitivity and EAHR to inhaled capsaicin while 19 patients showed normal values. These results indicate that cough sensitivity is closely related with extrathoracic airway responsiveness during capsaicin provocation in some chronic cough patients. EAHR and enhanced cough sensitivity to inhaled capsaicin may be a part of mechanism developing chronic cough.
Administration, Inhalation ; Adult ; Bronchial Hyperreactivity/*etiology/physiopathology ; Bronchial Provocation Tests ; Capsaicin/*administration & dosage ; Case-Control Studies ; Chronic Disease ; Cough/*etiology/physiopathology ; Female ; Humans ; Male ; Methacholine Chloride/diagnostic use ; Middle Aged

Current asthma is often diagnostically excluded by the presence of normal bronchial responsiveness. We report on a TDI-induced occupational asthma patient with normal bronchial responsiveness. He had suffered from shortness of breath during and after TDI exposure for several months. His initial methacholine bronchial challenge test showed a negative response. The bronchoprovacation test with TDI showed an isolated immediate bronchoconstriction. The following methacholine bronchial challenge tests revealed that the bronchial hyperresponsiveness developed seven hours after the TDI challenge (methacholine PC20:5.1 mg/ml), progressed up until 24 hours, and returned to normal on the seventh day. This case provides evidence that the response of the airway to TDI may not always be accompanied by bronchial hyperresponsiveness to methacholine. Screening programs utilizing methacholine challenges may not always identify TDI-sensitized asthmatic workers.
Adult ; Asthma/*chemically induced/diagnosis ; Bronchial Provocation Tests ; Bronchoconstriction/*drug effects ; Humans ; Male ; Methacholine Chloride/*diagnostic use ; Occupational Diseases/*chemically induced ; Skin Tests ; Time Factors ; Toluene 2,4-Diisocyanate/*adverse effects

To investigate the pathogenic mechanism of late asthmatic response in comparison to early asthmatic response, changes of serum neutrophil chemotactic activity (NCA) using the Boyden chamber method and histamine level using the automated fluorometric analyzer were observed in 13 aspirin (ASA)-sensitive asthma subjects (group I: 7 early responders and group II: 6 dual responders) during lysine aspirin bronch-oprovocation test (L-ASA BPT). Sera were collected before, and 30 min and 240 min after L-ASA BPT. Serum NCA increased significantly after 30 min (p=0.02) and decreased significantly at 240 min (p=0.02) in group I, while serum NCA of group II increased significantly at 30 min (p=0.04), tending to increase further up to 240 min with no statistical significance. NCA at 240 min in group II subjects was significantly higher than baseline NCA (p=0.02). The serum NCAs collected before and 240 min were significantly higher in group II than in group I (p<0.05, respectively). There were no significant changes in serum histamine levels during L-ASA BPT in both groups. NCA derived from mast cell may contribute to the development of early asthmatic response induced by L-ASA inhalation. There may be a possible involvement of NCA derived from mononuclear cells during late asthmatic response.
Adult ; Aged ; Aspirin/adverse effects ; Aspirin/diagnostic use* ; Asthma/blood* ; Asthma/chemically induced ; Bronchial Provocation Tests* ; Chemotactic Factors/blood* ; Chemotactic Factors/secretion ; Chemotaxis/drug effects* ; Comparative Study ; Female ; Histamine/blood ; Human ; Interleukin-8/antagonists & inhibitors ; Interleukin-8/physiology ; Lysine/diagnostic use* ; Male ; Mast Cells/secretion ; Methacholine Chloride/diagnostic use ; Middle Aged ; Monocytes/secretion ; Neutrophils/drug effects* ; Time Factors