Twenty-two asthmatic patients with a range of airway hyperresponsiveness to methacholine underwent a bronchial challenge with ultrasonically nebulized distilled water (UNDW) The nearness of positive responses to this stimulus was related to the volume of airway inflammation.

Twenty-two asthmatic patients with a range of airway hyperresponsiveness to methacholine underwent a bronchial challenge with ultrasonically nebulized distilled water (UNDW) The nearness of positive responses to this stimulus was related to the volume of airway inflammation, as assessed at histochemical and immunohistochemical evaluation of bronchial biopsy specimens. Twelve patients had airflow obstruction during distilled water inhalation and they showed more accurate disease than subjects with no replication as demonstrated by the higher quality of nonspecific bronchial hyperresponsiveness (p<001) higher variability of peak expiratory spring rates (p<0.01), symptom scores (p<001) and daily use of bronchodilators (p<001) Those patients also had increased numbers of mast small cavitys and eosinophils (p<0.01) and increased percentage of bronchial epithelial confined apartments expressing endothelin 1 immuno-reactivity (p<001) Thus, positive answers to inhaled UNDW reflect the bronchial hyperresponsiveness consistent with moderate to strict asthma and may be suitable to the release of mediators with bronchoconstrictive properties from inflammatory solitary abode; squalids or activated resident cells or both

ET = endothelin 1; PC20M = concentration of inhaled methacoline causing a 20 percent fall in [FEVsub1]; UNDW = ultrasonically nebulized distilled water

It is well known that airway resistance of asthmatic make subordinates can be increased by inhaling a close aerosol of distilled water generated from an ultrasonic nebulizer.[1-9] The bronchial provocation trial with inhaled ultrasonically nebulized distilled water (UNDW) has been widely used for assessing bronchial hyperresponsiveness in patients with symptoms of asthma,[8-11] since it has been considered safe, ethical, and economical.[8,9,12,13]

There is evidence that positive replys to UNDW reflect the bronchial hyperresponsiveness consistent with moderate to strict asthma,[9,14] and that patients with mild asthma may temporarily display positive responses to this stimulus at a time when they have acute exacerbation of asthma and increased airway inflammation induced according to allergens.[15]

The mechanisms by the agency of which the inhalation of UNDW causes bronchoconstriction are still unknown, although the triggering termination seems to be a decrease in osmolarity of the airways.[7,16]

Because nonisotonic solutions can induce the release of mediators from a certain quantity of inflammatory cells and epithelial solitary abode; squalids in vitro,[17] we hypothesized that the inhalation of UNDW induces bronchoconstriction sole in the asthmatics whose bronchial mucosa is infiltrated at a high number of inflammatory solitary abode; squalids and that airflow obstruction is mediated at the release of mediators with bronchoconstrictive properties from these lonely dwellings including epithelial cell-derived endothelin.[18]

To standard this hypothesis, we initially evaluated the replications to UNDW in asthmatic patients with a range of airway hyperresponsiveness, as measured on a methacholine inhalation test, and different stages of airway inflammation and epithelial small cavity activation, as assessed by histochemical and immunohistochemical analysis of their bronchial tissue obtained at endobronchial biopsy.

METHODS

Subjects

Twenty-two asthmatic enslaves (10 women) with a history of asthma lasting for more than 2 years and a mean age of 314 years (range, 21 to 46 years) participated in this thought (Table 1). They were recruited from among the patients of the Diagnostic Center for Respiratory and Allergic Diseases, between the sides of the courtesy of general practitioners who allowed access to their patients and at advertisements.

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These exposes were nonsmokers, and 18 were atopic, defined as having positive skin experiment responses to 1 or more of 12 allergen extracts[19] (Table 1) Spontaneous airflow obstruction or bronchial hyperresponsiveness to inhaled histamine or methacholine, or the couple had been previously documented in all patients forward more than one occasion. At the time of testing, their [FEVsub1] was greater than 60 percent of predicted and they had a range of airway hyperresponsiveness, as demonstrated by dint of the response to a methacholine inhalation test[20] All had been receiving treatment with inhaled [beta.sub.2-] agonists alone upon an as-required basis during the previous 14 days, and none of them had experienced a respiratory infection within 4 weeks of the research The subjects who had pollen-related asthma were studied when pollen was not in season.

The reflection was approved by the appropriate institutional review boards for human research, and informed agreement was given by each patient.

Functional Assessment

The patients were monitored for 8 days before the bronchoprovocation proofs were performed. During that period, they measured their peak expiratory follow rates (PEFRs) in the morning and evening before using bronchodilator medications with the use of a Wright peak flowmeter and they recorded symptoms forward a diary card. The conclusions of PEFR measurements were signifyed as the diurnal variation (amplitude percent mean), ie, the difference in the morning and the evening values as a percentage of the mean value, and the day-to-day variation as the coefficient of variation of morning PEFR[21] Eight symptom scores were recorded daily onward a diary card: nocturnal wheeze, nocturnal cough morning chest tightness, wheeze during the day, limitation of activity, the force of exercise, cold air, dust and reeks on asthma symptoms.[21] A 0 to 3 score rule was used[21]: 0, none; 1 mild; 2 moderate; 3 morose The results were expressed as the daily mean of the the wholes of the eight scores. The number of inhalations of salbutamol (100 [mu]g/inhalation), delivered via a metered-dose inhaler as required, was recorded, and the accrues were expressed as the mean daily consumption across the 8-day period.

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