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

To validate the prevalence rate of symptoms of asthma produced by the phase I ISAAC (International Study of Asthma and Allergies in Childhood) study, hypertonic saline challenge test was carried out during the phase II study at a year after the phase I study. For the phase II study, six middle schools from three cities in the phase I study were selected. Finally, 499 children who responded to both studies were analyzed. All subjects were asked to complete the written questionnaire (WQ) first, followed by a video questionnaire (AVQ 3.0) during the phase I study. Of the 499 children, only 19 (3.8%) were positive to the hypertonic saline bronchial challenge test. The degree of agreement between responses to the two corresponding questions "wheezing at rest" and "nocturnal wheeze" in the AVQ 3.0 and WQ were moderate and weak with a Kappa indices of 0.45 and 0.23, respectively. The question on "severe wheeze" in the AVQ 3.0 had the highest Youden's index among the five questions related to asthma symptoms in the previous 12 months, but its specificity was low whereas it 's sensitivity was 1.0. There was no consistency of priority between the two questionnaires in predicting bronchial hyperreactivity in a group of Korean schoolchildren. Therefore we need to develop more appropriate WQ or AVQ to compare the prevalences of asthma to other countries.
Adolescent ; Asthma/diagnosis* ; Asthma/epidemiology ; Asthma/etiology ; Bronchial Hyperreactivity/complications ; Bronchial Hyperreactivity/diagnosis* ; Bronchial Hyperreactivity/epidemiology ; Bronchial Provocation Tests ; Comparative Study ; Female ; Human ; Korea/epidemiology ; Language ; Male ; Prevalence ; Questionnaires* ; Random Allocation ; Respiratory Sounds ; Saline Solution, Hypertonic/diagnostic use ; Sampling Studies ; Videotape Recording ; Writing