LOWER LEUKOTRIENE C-4 LEVELS IN BRONCHOALVEOLAR LAVAGE FLUID OF ASTHMATIC SUBJECTS AFTER 2.5 YEARS OF INHALED CORTICOSTEROID-THERAPY

LONG-TERM treatment with inhaled corticosteroids has been shown to res ult in improvement of symptoms and lung function in subjects with asth ma. Arachidonic acid (AA) metabolites are thought to play a role in th e pathophysiology of asthma. It was assessed whether differences could be found in bronchoalveolar lavage (BAL) AA metabolite levels between subjects with asthma who were treated for 2.5 years with inhaled bron chodilators alone or in combination with Prostaglandin (PG)D-2, PGF(2 alpha), 6-keto-PGF(1 alpha), thromboxane B-2, leukotriene (LT)C-4 and LTB(4) levels and cell numbers were assessed in BAL fluid from 22 non- smoking asthmatic subjects. They were participating in a randomized, d ouble-blind multicentre drug trial over a period of 2.5 years. Results of the group treated with inhaled corticosteroids (CS+: beclomethason e 200 mu g four times daily) were compared with the other group (CS-) which was treated with either ipratropium bromide (40 mu g four times daily) or placebo. BAL LTC(4) levels of asthmatic subjects were signif icantly lower after 2.5 years inhaled corticosteroid therapy (CS+ 9(1- 17)pg/ml vs. CS-, 16(6-53)pg/ml; p = 0.01). The same trend was observe d for the PGD(2) levels. The results suggest that inhaled corticostero ids may exert their beneficial effect on lung function via a mechanism in which inhibition of LTC(4) synthesis in the airways is involved.