FAQS on when to use Molecular Allergy Diagnosis (MD) in clinical practice

In the last decades there has been a great progress in the field of molecular biology allowing the study of the sensitization to individual allergenic components of an allergenic source, a practice that has been termed Molecular Allergy Diagnosis (MD) or Component Resolved Diagnosis (CRD). The purpose of the present review is to offer the clinician a practical approach to the use of MD by answering frequently asked questions among physicians on how MD can help us improve allergy diagnosis in our daily clinical practice. The article is divided in three sections. First, a brief review on the importance for the clinician to know the main allergens of the different allergenic sources, their structure and their in vitro cross-reactivity before approaching MD (section A). Secondly the core of the review on the usefulness of MD in clinical practice (section B) answering FAQS on the subject, and finally a section (C) on the interpretation and integration of MD with the rest of available tools for allergy diagnosis.

From Allergen Molecules to Molecular Immunotherapy of Nut Allergy: A Hard Nut to Crack

Peanuts and tree nuts are two of the most common elicitors of immunoglobulin E (IgE)-mediated food allergy. Nut allergy is frequently associated with systemic reactions and can lead to potentially life-threatening respiratory and circulatory symptoms. Furthermore, nut allergy usually persists throughout life. Whether sensitized patients exhibit severe and life-threatening reactions (e.g., anaphylaxis), mild and/or local reactions (e.g., pollen-food allergy syndrome) or no relevant symptoms depends much on IgE recognition of digestion-resistant class I food allergens, IgE cross-reactivity of class II food allergens with respiratory allergens and clinically not relevant plant-derived carbohydrate epitopes, respectively. Accordingly, molecular allergy diagnosis based on the measurement of allergen-specific IgE levels to allergen molecules provides important information in addition to provocation testing in the diagnosis of food allergy. Molecular allergy diagnosis helps identifying the genuinely sensitizing nuts, it determines IgE sensitization to class I and II food allergen molecules and hence provides a basis for personalized forms of treatment such as precise prescription of diet and allergen-specific immunotherapy (AIT). Currently available forms of nut-specific AIT are based only on allergen extracts, have been mainly developed for peanut but not for other nuts and, unlike AIT for respiratory allergies which utilize often subcutaneous administration, are given preferentially by the oral route. Here we review prevalence of allergy to peanut and tree nuts in different populations of the world, summarize knowledge regarding the involved nut allergen molecules and current AIT approaches for nut allergy. We argue that nut-specific AIT may benefit from molecular subcutaneous AIT (SCIT) approaches but identify also possible hurdles for such an approach and explain why molecular SCIT may be a hard nut to crack.

A Review of Honeybee Venom Allergens and Allergenicity

Honeybee venom is a source of proteins with allergenic properties which can result in in various symptoms, ranging from local reactions through to systematic life-threatening anaphylaxis, or even death. According to the World Allergy Organization (WAO), honeybee venom allergy is one of the most common causes of anaphylaxis. Among the proteins present in honeybee venom, 12 protein fractions were registered by the World Health Organization’s Allergen Nomenclature Sub-Committee (WHO/IUIS) as allergenic. Most of them are highly immunogenic glycoproteins that cross-react with IgE and, as a consequence, may give false positive results in allergy diagnosis. Allergenic fractions are different in terms of molecular weight and biological activity. Eight of these allergenic fractions have also been identified in honey. This explains frequent adverse reactions after consuming honey in people allergic to venom and sheds new light on the causes of allergic symptoms in some individuals after honey consumption. At the same time, it also indicates the possibility of using honey as a natural source of allergen in specific immunotherapy.

Integrative Analysis of Epidemiological Profile of Sensitization Clinical Laboratory Markers in Children: Cross-Sectional Study Results

Background. The prevalence of various allergic diseases has increased worldwide in recent decades. Allergy diagnosis in children should be economically optimal and as sparing as possible, while ensuring the high quality of medical care. Objective. The aim of the study is to develop optimal algorithms for analysis of sensitization profile in children with allergy family history, or suspected allergy, or atopy phenotype. Methods. Complete examination of 153 children aged from 1 to 17 years 11 months was performed. Children were divided in 4 groups according to the presence and characteristics of complaints, the presence of allergic disease. Sensitization was determined via the “gold standard” of allergy diagnosis — the ImmunoCap method (Phadia, Sweden), and the results of skin testing. Results. 97 (63.4%) children have shown sensitization to various allergens. We have revealed seasonal manifestation of allergy in children to various allergens: Fagales in 89-92% of cases, grasses in 68-72% of cases, weeds in 39-57% of cases. Complaints of all-year manifestations of allergic rhinitis were revealed in 24% of cases to cat dandruff, complaints of coughing and/or bronchospasm — in 100% of cases to birch pollen and in 35% of cases to house dust. The sensitization analysis has revealed strong correlations with confirmed statistical significance between pollen allergen sensitization classes in groups of different plants. Conclusion. Optimal algorithms for sensitization diagnosis in children living in Moscow agglomeration were developed according to the obtained results and revealed correlations.