Effect of inhaled terbutaline on platelet activity in bronchial asthma.

Thirty five young subjects with long standing bronchial asthma were studied for the effects of terbutaline misthaler (500 micrograms) during acute asthma. Bronchodilators were omitted for a day before the test. Ten matched controls were also studied. In all subjects, basal IgE level (ELISA), pulmonary parameters (FVC, FEV, PEFR, FEF 25-75 and FEF 75-85) and platelet activity, (platelet clumping/150 WBC on smear, platelet adhesiveness, blood recalcification time and kaolin clotting time for platelet factor3) were compared. During acute asthma, the subjects displayed IgE levels > or = 500 IU/ml (n = 33), activation of clotting (n = 30) and eosinophilia > or = 450/cmm (n = 28). These changes were not seen in normal controls. Terbutaline resulted in a reversal of airway obstruction, mainly of small airways, while the platelet hyperactivity and blood hypercoagulability were rectified (P < 0.001). It is concluded that platelet activity increases in acute asthma and is corrected by inhaled terbutaline concomittant with the relief of bronchospasm.

Immunoglobulins and allergy mediators in bronchial asthma.

Seventy four young asthmatics were evaluated to establish the role of immunoglobulins and allergy mediators in clinical asthma. They were categorized into Group I (n = 38) or Group II (n = 36) when having mild or severe bronchospasm respectively. In some patients, reversibility of bronchospasm (n = 35), exercise challenge (n = 24) and intradermal allergy testing (n = 24) were also studied. Seventy subjects had raised IgE levels (greater than 100 KU/L) but these did not correlate with the severity of clinical or exercise induced asthma or with reversibility of bronchospasm. An IgE level greater than 1000 KU/L was associated with more number of positive skin tests. Group II subjects had a shorter blood recalcification time (p less than 0.01) and higher levels of IgG, histamine and serotonin (p less than 0.001). It appears that severe asthma is associated with activation of blood coagulation, and release of allergy mediators contributes to the evolution of bronchospasm. Total IgE predicts the utility of skin testing in asthma.