Assessment of the relationship between the levels of exhaled eicosanoids, FEV1, and FeNO with steroid responsiveness
To assess whether the levels of exhaled eicosanoids varied during exacerbation and after convalescence, the levels of the exhaled eicosanoids, FeNO and FEV1 in asthmatic children (N=75; Supplementary Table S1) at acute exacerbation and convalescence stages were measured. As shown in Fig. 2, while the level of FeNO was not at variance between these two stages (Fig. 2A), there was a significant enhancement in the level of FEV1 (Fig. 2B; p <0.001), and 15-HETE (Fig. 2C, p<0.001), and a significant reduction in the TXB2 (Fig. 2D, p<0.05) level, while, as a group, the levels of LTB4, LTE4, LXA4 and PGE2 did not reveal significant difference (Supplemental Fig. S2) before and after prednisone treatment. Furthermore, when the respective levels of each eicosanoid species were stratified into those at the 30th percentile, significant changes were particularly noted for those with higher initial levels of both 15-HETE and TXB2 at the exacerbation phase (Fig. 3); also, significant decreases for exhaled LTB4, LTE4, LXA4, and PGE2were noted (all with p<0.001; Supplemental Fig. S3) for those at the top 30 percentile.