Immunological Parameters As Biomarkers of Response to MicroCrystalline Tyrosine-adjuvanted Mite Immunotherapy

Background: Despite the effectiveness of allergen immunotherapy (AIT), some patients are unresponsive for reasons still unknown; yet validated response biomarkers remain unavailable. Objective: To analyze immunological parameters as biomarkers to monitor and predict clinical response to a MicroCrystalline Tyrosine-adjuvanted house dust mite (HDM) AIT in patients with allergic rhinitis (AR). Methods: Observational, prospective, multicenter study including adult patients (aged 18-65 years) with AR, with and without asthma, sensitized to the HDM Dermatophagoides pteronyssinus (DP) and prescribed Acarovac Plus (R) DP 100% in the routine practice. Serum concentrations of total IgE, specific IgE, specific IgG4, IL-4, IL-5, IL-10, IL-13, and IFN-g were compared between baseline and 12 months after AIT. The relationship between patients' baseline immunological profiles and classification as low, high, and non-responders and between their sensitization profile to DP allergens and effectiveness were analyzed. Results: Of 141 patients recruited, 118 (mean [SD] age of 33.6 [9.5] years) were evaluable. One year after treatment, Der p 1-specific IgE, DP-specific IgG4, and IL-10 increased by a mean (SD) of 3.4 (13.6) kU/L (p 1/4 0.016), 0.43 (0.55) mg/L (p < 0.0001), and 1.35 (7.56) pg/mL (p <1/4> 0.033), respectively. Non-responders showed increased baseline levels of IL-13 compared to high responders (p 1/4 0.037). Changes in effectiveness variables between baseline and after AIT were similar regardless of the sensitization profile. Conclusion: Non-responsive patients to AIT showed increased baseline IL-13 concentrations, suggesting its value as prognostic biomarker. DP-specific AIT increased Der p 1-specific IgE, DPspecific IgG4, and IL-10 concentrations in patients with AR. All patients benefited from treatment regardless of their sensitization profile to major DP allergens.