OBJECTIVE: To determine the extent to which thin-section and volumetric three-dimensional CT can depict airway reactivity to bronchostimulator, and to assess the effect of different airway sizes on the degree of reactivity. MATERIALS AND METHODS: In eight dogs, thin-section CT scans were obtained before and after the administration of methacholine and ventolin. Cross-sectional areas of bronchi at multiple levels, as shown by axial CT, proximal airway volume as revealed by three-dimensional imaging, and peak airway pressure were mea-sured. The significance of airway change induced by methacholine and ventolin, expressed by percentage changes in cross-sectional area, proximal airway volume, and peak airway pressure was statistically evaluated, as was correlation between the degree of airway reactivity and the area of airways. RESULTS: Cross-sectional areas of the bronchi decreased significantly after the administration of methacholine, and scans obtained after a delay of 5 minutes showed that normalization was insufficient. Ventolin induced a significant increase in cross-sectional areas and an increase in proximal airway volume, while the effect of methacholine on the latter was the opposite. Peak airway pres-sure increased after the administration of methacholine, and after a 5-minute delay its level was near that of the control state. Ventolin, however, induced no significant decrease. The degree of airway reactivity did not correlate with airway size. CONCLUSION: Thin-section and volumetric spiral CT with three-dimensional reconstruction can demonstrate airway reactivity to bronchostimulator. The degree of reactivity did not correlate with airway size.
Albuterol/pharmacology ; Animal ; Bronchoconstriction/*physiology ; Bronchoconstrictor Agents/*pharmacology ; Bronchodilator Agents/*pharmacology ; Dogs ; *Imaging, Three-Dimensional ; Methacholine Chloride/pharmacology ; Tomography, X-Ray Computed/*methods

BACKGROUND: Cysteinyl leukotrienes are important inflammatory mediators in bronchial asthma because they enhance microvascular permeability, increase nonspecific bronchial hyperresponsiveness, and are potent bronchoconstrictor agents. Leukotriene E4 is a major metabolite of cysteinyl leukotriene excreted in urine and its concentration of urine can be a reliable marker of the overall leukotriene production in the body. OBJECTIVE: To determine whether clinical parameters of bronchial asthma are associated with production of cysteinyl leukotrienes, expressed by urinary leukotriene E4. METHOD: We measured the urinary concentration of leukotriene E4 in bronchial asthma(127 patients) and normal control(15 persons) group by ELISA method. Pulmonary function test, allergic skin test, measurement of peripheral eosinophil count and eosinophil cationic protein were undertaken in bronchial asthma patients. RESULTS: The concentrations of urinary leukotriene E4 were significantly higher in bronchial asthma patients than normal controls (p<0.05). The increased concentrations of leukotriene E4 had a significant correlation with FEV1/FVC or methacholine PC20(p<0.05). However, the concentration of leukotriene E4 did not have any correlation with the presence of atopy, peripheral blood eosinophil count, and eosinophil cationic protein level. CONCLUSION: The concentration of urinary leukotriene E4 that represents the overall leukotriene production in the body is correlated with the degree of airway obstruction and airway hyperresponsiveness. So, the concentration of urinary leukotriene E4 may be used as an adjunctive parameter of airway obstruction and hyperresponsiveness in bronchial asthma.
Airway Obstruction ; Asthma* ; Bronchoconstrictor Agents ; Capillary Permeability ; Enzyme-Linked Immunosorbent Assay ; Eosinophil Cationic Protein ; Eosinophils ; Humans ; Leukotriene E4* ; Leukotrienes ; Methacholine Chloride ; Respiratory Function Tests ; Skin Tests

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: The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS: One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent bronchoprovocation tests to both histamine and methacholine after determining their blood eosinophil counts, serum total IgE levels and skin test reactivity to 10 common aeroallergens. RESULTS: The responsiveness to histamine was significantly related to that to methacholine (r=0.609, p<0.001), but many individuals with a negative methacholine test response showed a positive response to histamine. The histamine-bronchial reactivity index (BRindex) was significantly higher than the methacholine-BRindex in subjects with a positive response to none (n=69, p<0.01) or only one (n=42, p<0.001) of histamine and methacholine, while there was no significant difference in the subjects with positive responses to both of them (n=57). The histamine-BRindex was significantly higher than the methacholine-BRindex in the subjects with mild histamine hyperresponsiveness (n=58, 1.28+/-0.01 vs. 1.20+/-0.02, respectively, p<0.001). Both histamine and methacholine responsiveness was significantly related to the atopy markers. However, the histamine-BRindex/methacholine-BRindex ratio of the atopics was not significantly different from that of the non-atopics. CONCLUSIONS: The airway responsiveness to histamine is comparable to that of methacholine in the subjects with positive responses to both histamine and methacholine, but the airway responsiveness to histamine is greater than that to methacholine in those subjects with mild airway hyperresponsiveness, regardless of atopy.
Adult ; Asthma/*physiopathology ; Bronchi/drug effects ; Bronchial Hyperreactivity/*diagnosis ; Bronchial Provocation Tests ; Bronchoconstrictor Agents/*pharmacology ; Eosinophils ; Female ; Histamine/*pharmacology ; Humans ; Immunoglobulin E/blood ; Male ; Methacholine Chloride/*pharmacology ; Severity of Illness Index ; Skin Tests

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