Background: The impact of allergen-specific and total IgE serum levels before and during the pollen season on symptom severity as well as efficacy of treatment with anti-IgE requires further delineation.
Methods: Birch and grass pollen allergic patients aged 6–17 years with seasonal allergic rhinitis (SAR) were analyzed for the association of IgE serum concentration with symptom severity and rescue medication use (combination: symptom load, SL) during the grass pollen season. Reference group A (n = 53) received placebo, while group B (n = 54) received Omalizumab (anti-IgE) monotherapy before and during the grass pollen season.
Results: Patients on placebo with high baseline specific grass pollen IgE (>50 kU/l) had a significantly higher SL compared with those with low IgE levels (≤50 kU/l): SL 1.28 vs 0.61, P = 0.015. This association was nonexistent in patients treated with anti-IgE. In contrast, baseline total IgE levels did not correlate with SL in any group. Patients with anti-IgE treatment and high free total IgE levels (>16.7 ng/ml) had a significantly higher SL compared with those with low free total IgE levels (≤16.7 ng/ml): SL 0.63 vs 0.23, P = 0.031.
Conclusions: Baseline specific IgE, but not total IgE, is associated with symptom severity during the pollen season in children with SAR. Likewise, the symptom load in SAR patients with anti-IgE correlates with free total IgE levels. Although further research in larger populations is needed to confirm our findings, our data suggest that specific IgE can be used as a parameter for patient selection for this kind of treatment.