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 > or =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 microg/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.