Nasal epithelium injury by chlorination products and other stressors predicts persistent sensitization to aeroallergens in young schoolchildren.

BACKGROUND: Allergic sensitization during childhood is a dynamic process with a substantial rate of remission. Factors influencing this process are largely unknown. METHODS: We conducted a two-year prospective study among 121 schoolchildren (mean age, 5.8 years; 64 boys). We measured urea, club cell protein (CC16), ß2-microglobulin and albumin in nasal lavage fluid (NALF) and IgE to cat, pollen or house dust mite (HDM) in nasal mucosa fluid. RESULTS: Odds of persistent sensitization to any aeroallergen increased across baseline ascending tertiles of urea-adjusted ß2-microglobulin or albumin and descending tertiles of albumin- or ß2-microglobulin-adjusted CC16 (P-trend = 0.006, 0.02, 0.044 and 0.006, respectively). Persistent HDM sensitization also increased with baseline descending tertiles of raw or urea-adjusted CC16 (both P-trend = 0.007). Such strong associations were not observed with new-onset or remitted sensitization to any aeroallergen or with raw NALF concentrations of urea, albumin or ß2-microglobulin. At baseline, house cleaning with bleach and chlorinated pool attendance emerged among the strongest and most consistent determinants of NALF biomarkers, being both associated with higher urea and lower CC16 in NALF. CONCLUSION: In young children, a defective nasal epithelium attributable to immaturity or stressors such as chlorination products is predictive of more persistent aeroallergen sensitization.