[Significance of leukotrienes in chronic respiratory tract diseases in childhood].

The role of lipoxygenase products was studied in children suffering from chronic diseases of the lung. Leukotrienes C4, D4, E4 and B4 were measured by high performance liquid chromatography (HPLC) and a specific radioimmunoassay (RIA) for C4. Elevated levels (up to 40 ng/ml), especially for leukotriene E4, were found in plasma of asthmatic and bronchitic patients (leukotriene C4 concentrations varied between 0.05 and 40 ng/ml, mean 4.9 +/- 7.8 ng/ml). In healthy donors the concentrations were below the detection limits of HPLC, leukotriene C4 ranging between 5 +/- 4 ng/ml (RIA data). The conversion of leukotriene C4 to D4 and E4 was observed by incubating the samples with synthetic leukotriene C4. The half-life of leukotriene C4 in plasma varied greatly, ranging from less than 12 min to 72 min (mean 39 +/- 16 min). Bronchial lavages yielded leukotriene C4 concentrations of 0.2 to 7 ng. Leukotriene E4 was detected in 10 of 41 cases. Conversion of leukotriene C4 did not occur in 50% of all cases, but was regularly observed in putrid lavages. These data suggest that leukotrienes play an important role in allergic and infectious lung diseases.