D3.477 - IgE Sialylation as a Potential Biomarker of Allergy: Evidence from Patients with Diverse Allergic Conditions
Background
It has been proposed that sialylation of IgE controls the pathogenicity of this immunoglobulin in allergic disease. However, to date, this relationship is mainly supported by proof-of-principle studies and lacks clinical evidence. This study aimed to assess IgE sialylation levels in large patient cohorts through an ELISA assay, with the goal of elucidating the contribution of this IgE characteristic to allergic disease.
Method
A specific lectin-based ELISA developed in our laboratory to determine IgE sialylation in serum was applied to analyse samples from allergic patients (n=405), categorized into: (i) adults with respiratory allergy, (ii) children (<18 years) with respiratory allergy, and (iii) adults with Hymenoptera venom allergy. Additionally, a fourth group (iv) consisting of thirty sera from non-allergic subjects was included as a control. Total IgE levels in all samples were quantified using ImmunoCAP™. Statistical analyses were performed with GraphPad Prism, version 10.5.
Results
IgE sialylation levels were significantly higher in allergic patients compared to controls (p < 0.0001). All three clinical groups (i), (ii), and (iii) maintained significant differences relative to the control group. Moreover, respiratory allergy groups (i and ii) were further subdivided by condition: rhinitis, asthma, or both. Differences in IgE sialylation levels between all allergic subgroups and controls remained significant after stratification. Finally, correlation analysis of the total of allergic samples revealed only a weak association between the lectin-based ELISA signal and total IgE concentration, suggesting that sialylation levels are not dependent on IgE quantity.
Conclusion
Our findings reveal a strong association between elevated IgE sialylation and allergy across different allergic conditions. Based on this evidence, we propose IgE sialylation as a potential biomarker of allergy, distinguishing it from mere sensitization detected by specific IgE.
