BRONCHODILATOR S-NITROSOTHIOL DEFICIENCY IN ASTHMATIC RESPIRATORY-FAILURE

Background Nitric oxide (NO) gas concentrations are high in the expire d air of individuals with asthma, but not consistently so in the expir ed air of people with pneumonia. S-nitrosothiols are naturally occurri ng bronchodilators, the concentrations of which are raised in the airw ays of patients with pneumonia. Airway S-nitrosothiols have not been s tudied in asthma. Methods Tracheal S-nitrosothiol concentrations from eight asthmatic children in respiratory failure were compared with tho se of 21 children undergoing elective surgery. Results Mean S-nitrosot hiol concentrations in asthmatic children were lower than in normal ch ildren (65 [SD 45] nmol/L vs 502 [SD 429] nmol/L) and did not vary wit h inspired oxygen concentration or airway thiol concentration. Interpr etation Severe asthma is associated with low concentrations of airway S-nitrosothiols. This is the first reported deficiency of an endogenou s bronchodilator in the human asthmatic airway lining fluid, We sugges t that S-nitrosothiol metabolism may be a target for the development o f new asthma therapies.