Exploring novel systemic biomarker approaches in grass-pollen sublingual immunotherapy using omics.

BACKGROUND: Sublingual allergen-specific immunotherapy (SLIT) intervention improves the control of grass pollen allergy by maintaining allergen tolerance after cessation. Despite its widespread use, little is known about systemic effects and kinetics associated to SLIT, as well as the influence of the patient sensitization phenotype (Mono- or Poly-sensitized). In this quest, omics sciences could help to gain new insights to understand SLIT effects. METHODS: 47 grass-pollen-allergic patients were enrolled in a double-blind, placebo-controlled, multicenter trial using GRAZAX® during 2 years. Immunological assays (sIgE, sIgG4, and ISAC) were carried out to 31 patients who finished the trial. Additionally, serum and PBMCs samples were analyzed by metabolomics and transcriptomics, respectively. Based on their sensitization level, 22 patients were allocated in Mono- or Poly-sensitized groups, excluding patients allergic to epithelia. Individuals were compared based on their treatment (Active/Placebo) and sensitization level (Mono/Poly). RESULTS: Kinetics of serological changes agreed with those previously described. At two years of SLIT, there are scarce systemic changes that could be associated to improvement in systemic inflammation. Poly-sensitized patients presented a higher inflammation at inclusion, while Mono-sensitized patients presented a reduced activity of mast cells and phagocytes as an effect of the treatment. CONCLUSIONS: The most relevant systemic change detected after two years of SLIT was the desensitization of effector cells, which was only detected in Mono-sensitized patients. This change may be related to the clinical improvement, as previously reported, and, together with the other results, may explain why clinical effect is lost if SLIT is discontinued at this point.

Challenges for allergy diagnosis in regions with complex pollen exposures.

Over the past few decades, significant scientific progress has influenced clinical allergy practice. The biological standardization of extracts was followed by the massive identification and characterization of new allergens and their progressive use as diagnostic tools including allergen micro arrays that facilitate the simultaneous testing of more than 100 allergen components. Specific diagnosis is the basis of allergy practice and is always aiming to select the best therapeutic or avoidance intervention. As a consequence, redundant or irrelevant information might be adding unnecessary cost and complexity to daily clinical practice. A rational use of the different diagnostic alternatives would allow a significant improvement in the diagnosis and treatment of allergic patients, especially for those residing in complex pollen exposure areas.

Diagnosis and treatment of grass pollen-induced allergic rhinitis in specialized current clinical practice in Spain.

Allergic rhinitis (AR) is the leading cause of consultation at the allergy specialist's office, but detailed, reliable, and validated clinical data on this condition are limited. This study was designed to define the clinical features, diagnostic methods, and therapeutic approaches of patients with AR induced by grass pollen in Spain. Two hundred twelve specialists participated in a multicenter, observational, epidemiologic, questionnaire-based study. Each investigator had to recruit at least two patients consulting for the first time and with a diagnosis of AR induced by grass pollen. Five hundred twenty-four patients (52% men; mean age, 29.3 years) with grass pollen-induced rhinitis (mean disease duration, 8.7 years) were recruited. Just 18.4% of patients reported that their symptom status had improved since the beginning of the condition, 89.4% had moderate-severe rhinitis (Allergic Rhinitis and Its Impact on Asthma classification) and 35.1% had concomitant bronchial asthma. For 52.1% of patients, control of symptoms with previous drug treatment was poor. Most of the patients were polysensitized to other pollens (sensitization to olive tree pollen, 57.1%). Oral antihistamines (97.3%) and nasal corticosteroids (82.3%) were the most frequently prescribed drugs and 43.1% of patients received specific immunotherapy. The clinical profile for the majority of Spanish patients consulting an allergy specialist for AR induced by grass pollen corresponds to a young adult with a lengthy moderate-severe rhinitis, often accompanied by bronchial asthma. Their symptoms progressively worsen and rhinitis is poorly controlled by symptomatic treatment. Oral antihistamines and nasal corticosteroids are the most frequently used therapeutic approaches and less than one-half receive specific immunotherapy.