Mediator concentrations in bronchoalveolar lavage fluid of patients with mild asymptomatic bronchial asthma.

Bronchoalveolar lavage (BAL) was performed on 11 atopic patients with mild asymptomatic bronchial asthma and 11 healthy nonasthmatic volunteers. All asthmatic subjects had evidence of bronchial hyperresponsiveness to inhaled carbachol. The concentrations of leukotriene (LT) C4, LTD4, LTE4, LTB4, prostaglandin D2 (PGD2), platelet-activating factor (PAF) and histamine in BAL fluid measured. The leukotrienes were measured by radioimmunoassay following reverse phase high performance liquid chromatography. PGD2 concentrations were determined by radio immunoassay after Amprep C2 extraction. PAF was quantitated by means of in vitro aggregation of rabbit platelets and histamine content was measured using a single isotope radio-enzymatic assay. There was an increase in the levels of PGD2 and a decrease in the concentration of LTB4 in asthmatic lavage samples. There were no significant differences in the lavage concentrations of LTC4/D4/E4 and histamine between the two groups of individuals. PAF was undetectable.