Basophil biomarkers as useful predictors for sublingual immunotherapy in allergic rhinitis

Prevalence of allergic diseases is increasing worldwide. Allergen-specific immunotherapy (ASIT) is potentially the only curative treatment for allergy, but there is a lack of reliable methods to monitor the immune responses to ASIT and to predict clinical efficacy. Recently, the definition of allergen sensitivity threshold (CD-Sens) by Basophil Activation Tests has been suggested as potential method in this context. The aim of this study was to compare trends of CD-Sens, measured by the markers CD63 and CD203c, and clinical symptoms in subjects with allergic rhinitis receiving Sublingual Immunotherapy (SLIT). 26 rhinitis patients allergic to Parietaria were selected and matched into two groups; a SLIT treated group (SG) and a reference group (RG) treated by traditional anti-allergic medications. Visual Analogue Scale (VAS) score for the four cardinal symptoms of rhinitis and peripheral blood was collected before the first dose of SLIT (T₀) and after 12 months (T₁₂) to define the severity of the symptoms and the sensitivity of basophils to Parietaria. The comparison between T0 and T12 in SG patients showed a significant decrease of symptom severity (VAS score) and an increased tolerability of basophils to Parietaria (CD-Sens) both by CD63 and CD203c. But, only CD203c seems to be correlated with the clinical symptoms. These data corroborate the hypothesis that SLIT could change the immunological course of allergic sensitization already in the first year, and that an immunological parameter as CD-Sens measured by CD63 and CD203c expression on stimulated basophils could be useful to monitor the changes in the immune system.