Evaluation of molecular basis of cross reactivity between rye and Bermuda grass pollen allergens

A robust method for the estimation and visualization of IgE cross-reactivity likelihood between allergens belonging to the same protein family

Among the vast number of identified protein families, allergens emanate from relatively few families which translates to only a small fraction of identified protein families. In allergy diagnostics and immunotherapy, interactions between immunoglobulin E and allergens are crucial because the formation of an allergen-antibody complex is necessary for triggering an allergic reaction. In allergic diseases, there is a phenomenon known as cross-reactivity. Cross-reactivity describes a situation where an individual has produced antibodies against a particular allergenic protein, but said antibodies fail to discriminate between the original sensitizer and other similar proteins that usually belong to the same family. To expound the concept of cross-reactivity, this study examines ten protein families that include allergens selected specifically for the analysis of cross-reactivity. The selected allergen families had at least 13 representative proteins, overall folds that differ significantly between families, and include relevant allergens with various potencies. The selected allergens were analyzed using information on sequence similarities and identities between members of the families as well as reports on clinically relevant cross-reactivities. Based on our analysis, we propose to introduce a new A-RISC index (Allergens’–Relative Identity, Similarity and Cross-reactivity) which describes homology between two allergens belonging to the same protein family and is used to predict the likelihood of cross-reactivity between them. Information on sequence similarities and identities, as well as on the values of the proposed A-RISC index is used to introduce four categories describing a risk of a cross-reactive reaction, namely: high, medium-high, medium-low and low. The proposed approach can facilitate analysis in component-resolved allergy diagnostics, generation of avoidance guidelines for allergic individuals, and help with the design of immunotherapy.

Molecular biomarkers for grass pollen immunotherapy

Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.

Practical guide to skin prick tests in allergy to aeroallergens

This pocket guide is the result of a consensus reached between members of the Global Allergy and Asthma European Network (GA(2) LEN) and Allergic Rhinitis and its Impact on Asthma (ARIA). The aim of the current pocket guide is to offer a comprehensive set of recommendations on the use of skin prick tests in allergic rhinitis-conjunctivitis and asthma in daily practice. This pocket guide is meant to give simple answers to the most frequent questions raised by practitioners in Europe, including 'practicing allergists', general practitioners and any other physicians with special interest in the management of allergic diseases. It is not a long or detailed scientific review of the topic. However, the recommendations in this pocket guide were compiled following an in-depth review of existing guidelines and publications, including the 1993 European Academy of Allergy and Clinical Immunology position paper, the 2001 ARIA document and the ARIA update 2008 (prepared in collaboration with GA(2) LEN). The recommendations cover skin test methodology and interpretation, allergen extracts to be used, as well as indications in a variety of settings including paediatrics and developing countries.