Component resolved diagnosis of egg yolk is an indispensable part of egg allergy

Introduction and objectives: It was urgent to explain the role of egg yolk allergen sensitization to the egg allergic population and we would evaluate the diagnostic value of allergen components in whole eggs, including egg white and egg yolk.Materials and methods: Firstly, we collected 99 positive and 21 negative sera against egg allergy. Then we used modified enzyme linked immunosorbent assay (ELISA) to survey specific IgE (sIgE) to all-proven and single component in eggs, Ovomucoid (Gal d 1), Ovalbumin (Gal d 2), Ovotransferrin (Gal d 3), Lysozyme C (Gal d 4), Serum Albumin (Gal d 5), and YGP42(Gal d 6) in allergic and non-allergic populations. Last but not least, we studied the sIgE reactivities to egg allergen components by receiver operating characteristic (ROC) analysis.Results: Among egg-allergic individuals, nearly 10% were sensitized to five of six egg allergen components, and the cross-reaction frequency between two egg yolk allergens with Gal d 1 was about 30% in the groups diagnosed with egg allergy or non-allergy. The best component-combination diagnosis in egg allergy of Gal d 1+ Gal d 6 demonstrated the largest area under curve (AUC) of 0.994.Conclusions: Our results suggested that there were individual differences in allergenicity of different egg allergen components, especially in the samples negative to egg allergy diagnosed but sensitive to egg yolk components. It was indicated that component resolved diagnosis of egg yolk improved the value for egg allergy management indispensably.

Hazelnut Allergy

Background and Objectives: Hazelnuts are frequently involved in IgE-mediated reactions and represent the main culprit of nut allergy in Europe. The clinical presentation varies from mild symptoms limited to the oropharynx [oral allergy syndrome (OAS)], due to the cross-reaction with homologues in pollen allergens and more severe events caused by the primary sensitization to highly stable molecules contained in hazelnuts. The aim of this review is to summarize the most relevant concepts in the field of hazelnut allergy and to provide a practical approach useful in the clinical practice Materials and Methods: References were identified by PubMed searches dating from January 2000 up to November 2020 using the search terms: “component resolved diagnosis” and “Hazelnut allergy. Results: The storage proteins Cor a 9 and Cor a 14 resulted highly specific for primary hazelnut allergy and strongly associated with severe reactions, while the cross reactive Cor a 1, an homolog of the birch Bet v1, were related to OAS. Any cut-off has shown a specificity and sensitivity pattern as high as to replace the oral food challenge (OFC), which still remains the gold standard in the diagnosis of hazelnut allergy. To date there is still no definitive treatment. Hazelnut free-diet and treatment of symptoms with emergency management, including the prescription of auto-injective epinephrine, still represent the main approach. Oral allergen immunotherapy (AIT) appears a promising therapeutic strategy and the definition of individual clinical threshold would be useful for sensitized individuals, caregivers, and physicians to reduce social limitation, anxiety, and better manage food allergy. Conclusions: An accurate diagnostic work-up including clinical history, in vivo and in vitro test including component resolved diagnosis and OFC are essential to confirm the diagnosis, to assess the risk of a severe reaction, and to prescribe an adequate diet and treatment.

Oral allergy syndrome and angioedema in patients with birch allergen sensitization: are there any high risks?

Aim: to study the sensitization profile in patients with sensitivity to Bet v1 allergen who have clinically significant respiratory symptoms of pollinosis during the birch flowering season, oral allergy syndrome (OAS), and angioedema to nuts and stone fruits. Patients and Methods: a prospective open-label study included 40 children (average age 7.52±0.64), 26 (65%) boys and 14 (35%) girls. All children had sensitization to the birch major allergen (Bet v1), symptoms of respiratory allergy during the birch flowering season, manifestations of OAS with angioedema in combination with hives or without it after eating fruits of Rosaceae family/nuts/peanuts. Children underwent general clinical and allergy researches, determination of total IgE and eosinophil cationic protein. By the method of component-resolved diagnosis of allergy (ISAC-112, ImmunoCAP), a comprehensive allergology examination for 112 allergen molecules was performed for each child. Results: the children of the study group were found to have increased values of total IgE (256.66±40.45 IU/mL) and eosinophil cationic protein (67.22±8.67 ng/mL). It was found that 57.5% of children were sensitized to tree nut storage proteins (rJug r1, rJug r2, NCoR a9, rAna o2, rBer e1), and some patients (27.5%) had increased specific IgE to non-specific lipid-transfer proteins (npLTPs) (rPru p3, NCoR a8, rAra h9, rJug r3). Antibodies to peanut storage proteins (rAra h1, rAra h2, rAra h3, rAra h6) were in 22.5% of children in the study group. Conclusion: the component-resolved diagnosis of allergy allows to determine the sensitization profile of patients. Sensitization detection to storage proteins and/or nsLTPs of nuts, peanuts and fruits is a predictor of possible severe allergic reactions. The exclusion of these products, both raw and heat-treated, reduces the number of severe acute allergic reactions in patients and prevents possible fatal outcomes. KEYWORDS: oral allergy syndrome, angioedema, children, birch, sensitization to Bet v1 allergen, storage proteins, nsLTPs. FOR CITATION: Lepeshkova T.S., Beltyukov E.K., Tsarkova S.A., Naumova V.V. Oral allergy syndrome and angioedema in patients with birch allergen sensitization: are there any high risks? Russian Medical Inquiry. 2021;5(1):21–24. DOI: 10.32364/2587-6821-2021-5-1-21-24.

Sensitization to fungal allergens in patients with respiratory allergy – accuracy in diagnostic process

Introduction. In Bulgaria, mold allergies are common, and sensitization to different fungal species is found in many patients with atopy.The objective of this study is to explore sensitization to the most widespread mold species in Bulgaria, and to determine the extent of sensitization to Alt a1, a major allergen of Alternaria alternata, by using component-resolved diagnosis.Materials and Methods. 21 patients (14 males and 7 females, age range 5-40 years), with respiratory allergy participated in the study. All patients are sensitized to mix of fungal allergens containing: Alternaria alternata, Aspergillus sp., Cladosporium herbarum, Penicillium notatum, proved by in vivo and in vitro methods. All patients underwent the ImmunoCAP test and were assessed for sIgE to individual fungal allergens: m1 Penicillium notatum, m2 Cladosporium herbarum, m3 Aspergillus fumigatus and m6 Alternaria alternata. The component-resolved diagnosis to Alt a1 was performed for 10 patients with increased sIgE to m6 Alternaria alternata.Results. All studied patients (100%) had elevated sIgE to Alternaria alternata. Eight (38%) patients were sensitized to Penicillium notatum. 11 (52%) and 10 (48%) patients were sensitized to Cladosporium herbarum and to Aspergillus fumigatus, respectively. Ten patients (48%) were monosensitized to Alternaria alternata. Nine (90%) patients with sensitization to Alternaria alternata demonstrated elevated levels of IgE to Alt a1.Conclusion. Alternaria alternata most often causes sensitization in patients with respiratory allergy. The component-resolved diagnosis using Alt a1 is a precision marker to prove species-specific sensitization to Alternaria alternata.

Utilization of Component-Resolved Diagnosis in Precision Allergology

It is very important to identify the causal allergen of each patient in the diagnosis and treatment of allergic diseases. An experimental method of specific IgE testing for single clinically meaningful antigens is called component resolved diagnosis (CRD). Since the introduction of CRD, many single antigens with clinical significance from animal and plant allergenic source have become known. Bet v 1, the major allergen of white birch pollen, can be an indication marker for allergen-specific immunotherapy if the patient is sensitized. Phl p 1, the group I allergen of timothy grass pollen, is an important marker that suggests that patients are truly sensitized to grass pollen. The major allergen of ragweed pollen, Amb a 1 and Art v 1, which is the major allergen of mugwort pollen, are clinically important to distinguish true sensitization. House dust mites have several clinically useful component allergens. Der p 1 and Der p 2 are the initiation molecules in the molecular spreading of allergic diseases caused by house dust mites. Among food allergens, Ara h 2 from peanut, which is closely related to anaphylaxis among several clinical manifestation of peanut allergy. Tri a 19, well known to omega-5 gliadin is important in patients with wheat-dependent exercise-induced anaphylaxis. It is conceivable that the molecular biological concept of CRD methods should lead to ‘patient-customized treatment’ beyond ‘diagnosis’ in the future. Primary prevention of the allergic diseases will apply, which will conceptually be called ‘allergen immunprophylaxis’. This is the right direction of future precision allergology.

Association between component-resolved diagnosis of house dust mite and efficacy of allergen immunotherapy in allergic rhinitis patients

Data regarding clinical relevance of house dust mite (HDM) components over allergen immunotherapy (AIT) for allergic rhinitis (AR) are lacking. 18 adult AR patients receiving HDM-AIT for 52 weeks were followed up to assess serum levels of sIgE and sIgG4 to HDM components. The study showed that Der p1, p2, p23, Der f1 and f2, are important sensitizing components of HDM, of which Der p1 appears to be the most clinically relevant allergenic component for effective AIT.