[Clinical significance of fractional exhaled nitric oxide combined with in vitro allergen test in identifying children at a high risk of asthma among those with recurrent wheezing].

Objective: To investigate the clinical value of combined determination of in vitro allergens and fractional exhaled nitric oxide (FeNO) in indentifying children at a high risk of asthma among those with recurrent wheezing.

Methods: A total of 148 children with recurrent wheezing (0.5-6 years old) were enrolled as study subjects, and 80 healthy children who underwent physical examination were enrolled as the control group. Pharmacia UniCAP immunoassay analyzer was used to measure specific immunoglobulin E (sIgE). Nano Coulomb Nitric Oxide Analyzer was used to measure FeNO. The asthma predictive index (API) was evaluated.

Results: The recurrent wheezing group had a significantly higher proportion of children with positive sIgE than the control group [68.9% (102/148) vs 11.3% (9/80); P<0.05]. The recurrent wheezing group also had significantly higher levels and positive rate of FeNO than the control group (P<0.05). The overall positive rate of API in children with wheezing was 32.4%, and the API-positive children had a significantly higher FeNO value than the API-negative children (51±6 ppb vs 13±5 ppb; P<0.05). The detection rate of API was 40.2% (41/102) in positive-sIgE children and 50.1% (38/73) in FeNO-positive children, and there was no significant difference between these two groups. The children with positive sIgE and FeNO had a significantly higher detection rate of API (81.4%) than those with positive sIgE or FeNO (P<0.05).

Conclusions: Combined determination of FeNO and in vitro allergens is more sensitive in detecting children at a high risk of asthma than FeNO or in vitro allergens determination alone and provides a good method for early identification, diagnosis, and intervention of asthma in children.