PLASMA-LEVELS OF LEUKOTRIENE E(4) DURING CLINICAL COURSE OF BRONCHIAL-ASTHMA AND THE EFFECT OF ORAL PREDNISOLONE

To investigate the relationship between circulating leukotriene E(4) and bronchial asthma, we tried to measure the concentration of leukotriene E(4) during the clinical course of bronchial asthma with or without oral prednisolone treatment. Additionally, we investigated the relationship between the LTE(4) levels and FEV(1) (percent predicted) and PaCO2 (mm Hg) concomitantly. Two milliliters of blood were drawn from the femoral artery of eight patients on three occasions: (1) during remission; (2) during an attack treated without prednisolone; and (3) during an attack treated with prednisolone. Leukotriene E(4) was detected by high-pressure liquid chromatography and radioimmunoassay. In eight asthmatic patients, mean (SD) leukotriene E(4) levels on the three occasions were 11.8 (2.61), 48.4 (18.2), and 32.6 (8.28) pg/ml, respectively. In contrast, the mean leukotriene E(4) level of ten normal control subjects was 11.8 (4.49) pg/ml. Leukotriene E(4) levels differed significantly between remission and attack treated without prednisolone, and between attacks treated with and without prednisolone. Mean FEV(1) values were 85.5 (3.07), 50.5 (9.58), and 65.9 (7.44) on the three occasions, respectively; corresponding mean PaCO2 values were 31.7 (2.74), 55.5 (5.81), 48.9 (2.56), respectively. Leukotriene E(4) was significantly correlated with FEV(1) and relatively with PaCO2 during an attack without prednisolone. We suggest that leukotriene E(4) levels in arterial blood reflect the severity of asthmatic attacks and orally administered prednisolone may affect the leukotriene E(4) levels.