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Exhaled nitric oxide helps discriminating asthmatic children with and without positive specific IgE to aeroallergens
Li-Ching Fang1, Shyh-Dar Shyur1,2, Jen-Yu Wang3
1Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan.
Insights
Fractional exhaled nitric oxide (FeNO) levels are higher in sensitized asthmatic children. Age-specific FeNO cut-off values can distinguish between children with and without aeroallergen sensitization.
Area of Science:
- Pediatric Allergy and Immunology
- Respiratory Medicine
- Clinical Diagnostics
Background:
- Aeroallergen sensitization is linked to elevated fractional exhaled nitric oxide (FeNO) levels.
- Understanding FeNO's role in allergic respiratory diseases is crucial for diagnosis and management.
Purpose of the Study:
- To determine age-specific fractional exhaled nitric oxide (FeNO) cut-off values for differentiating aeroallergen sensitization in asthmatic children.
- To evaluate the predictive performance of these FeNO cut-offs in children with allergic rhinitis (AR).
Main Methods:
- A study involving 564 asthmatic children (5-18 years) with allergic rhinitis (AR).
- Patients were categorized into sensitized (positive specific immunoglobulin E [IgE] to common aeroallergens) and non-sensitized groups.
- Pulmonary function, FeNO, eosinophil counts, and IgE levels were analyzed across age groups: preschool, elementary, and adolescent.
Main Results:
- Preschoolers: FeNO ≥15.5 ppb (AUC 0.72) differentiated sensitization.
- Elementary students: FeNO ≥19.5 ppb (AUC 0.81) showed optimal discrimination.
- Adolescents: FeNO ≥27.5 ppb (AUC 0.76) was identified as the key cut-off for sensitization.
Conclusions:
- Aeroallergen sensitization significantly elevates FeNO levels in asthmatic children.
- Age-specific FeNO cut-off values are essential for accurately identifying sensitization in pediatric asthma.
- These findings support FeNO as a valuable biomarker in managing pediatric allergic respiratory conditions.
Background:
Aeroallergen sensitization may predict higher fractional exhaled nitric oxide (FeNO) levels.
Objective:
We evaluate cut-off values of FeNO in asthmatic children with and without positive specific immunoglobulin E (IgE) to at least one of 5 aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, and cockroach).
Methods:
564 patients with asthma and allergic rhinitis (AR) aged 5 to 18 years were enrolled into two groups. Sensitized group included 378 children with positive IgE to at least one of 5 inhaled allergens. Non-sensitized group included 186 children. Pulmonary function tests, FeNO, eosinophil counts, and IgE levels were examined. Patients were divided into preschool age (5~6 years old), elementary school children (7~11 years old) and adolescents (12~18 years old).
Results:
In preschool children, FeNO≥15.5 ppb differentiates between non-sensitized and sensitized groups. (sensitivity 54.3%; specificity 87.5%; positive predictive value (PPV) 86.2%; negative predictive value (NPV) 57.1%; area under receiver operating characteristic curve (AUC) 0.72) Among elementary school children, the cut-off value of FeNO≥19.5 ppb showed sensitivity 66.4%; specificity 85.8%; PPV 90.5%; NPV 55.7%; AUC 0.81. In adolescents, FeNO≥27.5 ppb showed sensitivity 60.2%; specificity 85.4%; PPV 91.2%; NPV 46.1%; AUC 0.76.
Conclusion:
In asthmatic children, aeroallergen sensitization appears to contribute to higher FeNO levels than those not sensitized. Cut-off values of FeNO which well discriminate asthmatic children with and without aeroallergen sensitization should be chose according to different ages.
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