Symptom Severity and Allergen-specific IgE in Allergic Rhinitis

We read with great interest the article of Yadzir et al.1 We would like to underline some adjunctive topics in favor of serum allergen-specific IgE (sIgE) assessment in AR patients management. Component resolved diagnostics (CRD) is particularly useful in AR management to correctly define real allergy, so to prescribe the causal allergen for AIT. We would like to remark another important consideration: polysensitization should not be an obstacle for AIT prescription. There is a belief that AIT is contraindicated in polysensitized patients, but a series of studies evidenced that AIT (with 1-2 allergen extracts) may be effective in polysensitized patients.2 The reason is that thorough allergy work-up, including sIgE assay, usually allows the causal allergen(s) to be defined. Another important topic concerns the predictive value of sIgE in detecting AIT responders before AIT starting. As AIT is a prolonged and expensive treatment, a predictive biomarker of responsiveness could be useful. A first study, conducted by Di Lorenzo et al., demonstrated that the ratio of total IgE/sIgE could predict successful AIT.3 Later, two studies confirmed this hypothesis both in allergic children4 and adults.5 These studies defined a cut-off value of sIgE able to predict AIT responders.