Eosinophil activation and preschool viral wheeze

Background: A study was undertaken to ascertain whether systemic eosinophil activation is associated with preschool viral wheeze (PVW). Methods: Urinary eosinophil protein X (uEPX) and serum total IgE ( IgE) levels were measured in children admitted to hospital with PVW, and uEPX was measured 6 weeks after discharge. Two years after admission, current wheeze in children aged > 5 years was determined by questionnaire. Controls were recruited from children undergoing elective surgery ( normal controls) and from those with skin prick test reactivity to foods ( atopic controls). Results: There was no difference in uEPX levels between normal controls ( n = 15) and atopic controls ( n = 8). uEPX levels were increased in children with acute PVW ( n = 84; p< 0.001 v normal controls, p< 0.01 v atopic controls) and fell on convalescence ( n = 20, 95% CI - 217 to - 31 mug/mmol creatinine, p< 0.05). In children with acute PVW there was no association between uEPX and serum IgE levels or markers of clinical severity. Respiratory questionnaires were returned for 25/55 eligible children. There was no difference in uEPX level during acute PVW when stratified by "current wheeze'' ( n = 18) or "no wheeze'' ( n = 7) 2 years later. Conclusions: Systemic eosinophil activation is associated with PVW but is not associated with serum IgE, clinical severity, or persistence of wheeze into the early school age period.