Predictive biomarkers in allergen specific immunotherapy

Mast Cell Desensitization in Allergen Immunotherapy

Allergen immunotherapy (AIT) is the only treatment with disease-transforming potential for allergic disorders. The immunological mechanisms associated with AIT can be divided along time in two phases: short-term, involving mast cell (MC) desensitization; and long-term, with a regulatory T cell (Treg) response with significant reduction of eosinophilia. This regulatory response is induced in about 70% of patients and lasts up to 3 years after AIT cessation. MC desensitization is characteristic of the initial phase of AIT and it is often related to its success. Yet, the molecular mechanisms involved in allergen-specific MC desensitization, or the connection between MC desensitization and the development of a Treg arm, are poorly understood. The major AIT challenges are its long duration, the development of allergic reactions during AIT, and the lack of efficacy in a considerable proportion of patients. Therefore, reaching a better understanding of the immunology of AIT will help to tackle these short-comings and, particularly, to predict responder-patients. In this regard, omics strategies are empowering the identification of predictive and follow-up biomarkers in AIT. Here, we review the immunological mechanisms underlying AIT with a focus on MC desensitization and AIT-induced adverse reactions. Also, we discuss the identification of novel biomarkers with predictive potential that could improve the rational use of AIT.

Nasal Nitric Oxide and Nasal Cytology as Predictive Markers of Short-Term Sublingual Allergen-Specific Immunotherapy Efficacy in Children with Allergic Rhinitis

BACKGROUND

Few studies have been conducted on the short-term response to sublingual immunotherapy (SLIT).

OBJECTIVE

The purpose of our experimental trial was to evaluate if two markers such as nasal nitric oxide (nNO) and nasal cytology could be useful to identify a precocious clinical efficacy of SLIT treatment.

METHODS

We enrolled 34 children aged 6 to 14 years old with diagnosis of allergic rhinitis (AR) and documented sensitization towards house dust mites. We started allergoid-monomeric tablets immunotherapy along with any conventional therapy for AR and we evaluated at baseline (T0), after one (T1), two (T2), three (T3), and six months (T6) the effects of the treatment through the study of: i) a visual analogue scale (VAS 1-10); ii) measurement of nNO; iii) measurement of FeNO; iv) nasal cytology; v) spirometry; and vi) evaluation of any conventional therapy.

RESULTS

We observed an improvement in symptoms evaluated by global VAS (T0 vs. T6: 47.13 vs. 17.57; p < .05) and a statistically significant reduction of nNO (1035.2 ± 956.08 vs. 139.2 ± 59.01; p < .05). In this case, significance was reached when the patients completed the 6 months of treatment. Cytological evaluation revealed significant reduction in nasal eosinophils (T0 vs. T6: 87% vs. 16%; p < .01). Moreover, at T0, 56% of patients had also neutrophils that were reduced up to the 8% at T6 (p < .05).

CONCLUSIONS

Our data confirm the effectiveness of SLIT treatment from a clinical perspective and identifies two biomarkers, such as nNO and nasal cytology, as predictive of treatment efficacy in the short term.

GRAZAX®: a sublingual immunotherapy vaccine for Hay fever treatment: from concept to commercialization

Allergen immunotherapy has been used for more than 100 y, but only recently underlying immunological mechanisms have started to be understood. New Allergy vaccines are now considered to be full pharmaceutical products, that should comply with general as well as specific pharmaceutical legal framework. GRAZAX® is the first global allergy vaccine developed in compliance with the new legal environment and is thus a reference for developing new allergy vaccines. Here, we provide a rationale description of GRAZAX®, providing a sequential description of its pharmaceutical and clinical development. With more than 25 clinical trials, involving more than 8000 patients, including as well three 5-y prospective clinical trials, GRAZAX® is a key product to understand the unique position of allergen-specific immunotherapy as a disease-modifying intervention.