Urinary leukotriene E4 in preschool children with acute clinical viral wheeze.

Cysteinyl leukotrienes (cystLTs) are important mediators of wheeze in atopic asthma, but the role of cystLTs in the pathogenesis of preschool viral wheeze (PVW) is unclear. Therefore, evidence for increased production of cystLTs in PVW was sought. Urinary leukotriene E4 (uLTE4) and serum total immunoglobulin (Ig)E were measured in children (1-5 yrs) with PVW during an acute attack (n=44) and in the convalescent phase (n=19), and compared with normal controls (n=15). The effect of atopic sensitisation was assessed in a separate group of atopic controls (n=6) in whom only uLTE4 was measured. The levels of uLTE4 were similar in normal and atopic controls and increased in acute PVW (median (interquartile range) 165 (101-285) versus 125 (82-163) ng x mM creatinine(-1)). Stratification by IgE showed that whereas uLTE4 was increased in 23 children with acute PVW and IgE > 95th percentile (median 211 (118-312) ng x mM creatinine(-1)), uLTE4 was not increased in the 21 children with acute PVW and IgE < or = 95th percentile. In the convalescent phase, uLTE4 fell in the subgroup with high IgE but not in the subgroup with low IgE. It is concluded that increased cysteinyl leukotriene production during acute preschool viral wheeze is associated with high serum immunoglobulin E.