Predictivity of clinical efficacy of sublingual immunotherapy (SLIT) based on sensitisation pattern to molecular allergens in children with allergic rhinoconjunctivitis

Abstract BACKGROUND: The diagnostic and therapeutic approach to grass pollen allergy is now possible by detecting specific IgE (sIgE) to its allergenic components. AIM: To evaluate the correlation between the sensitisation to different molecular Phleum pratense (Phl p) allergens and clinical efficacy of SLIT. METHODS: The pilot study included 36 patients affected by allergic rhinoconjunctivitis, all treated with SLIT actively. We performed serum analysis of sIgE to Phl p 1, 2, 4, 5, 6, 7, 11 and 12. The Average Rhinoconjunctivitis Total Symptom Score (ARTSS) and the Average Combined Score (ACS) were evaluated before and after one year of immunotherapy. RESULTS: Three different groups of sensitisation were defined based on the range of IgE reactivity to Phleum pratense allergens at baseline: group I (sIgE reactive to 1-3 allergens); group II (sIgE reactive to 4-5 allergens); and group III (sIgE reactive to 6-8 allergens). At T0 ACS was 1.79±0.18 in group I; 1.81±0.23 in group II; and 1.95±0.34 in group III. At T1 ACS was 0.85±0.55 in group I; 1.01±0.31 in group II; and 1.44±0.39 in group III. At T1 there was a significant improvement of ARTSS and ACS for group I (p=0.001). CONCLUSIONS: Sublingual immunotherapy with a grass pollen is efficacious irrespective of the patients' baseline sensitisation to either single or multiple grass pollen molecular allergens. We found that patients with few sensitisations have a greater improvement in combined symptom and medication score. SLIT improves the clinical course of allergic patients although new sensitisations may appear.