Today, in vivo allergy diagnosis and allergen-specific immunotherapy (AIT) are still based on allergen extracts obtained from natural allergen sources. Several studies analyzing the composition of natural allergen extracts have shown severe problems regarding their quality such as the presence of undefined nonallergenic materials, contaminants as well as high variabilities regarding contents and biological activity of individual allergens. Despite the increasing availability of sophisticated analytical technologies, these problems cannot be overcome because they are inherent to allergen sources and methods of extract production. For in vitro allergy diagnosis problems related to natural allergen extracts have been largely overcome by the implementation of recombinant allergen molecules that are defined regarding purity and biological activity. However, no such advances have been made for allergen preparations to be used in vivo for diagnosis and therapy. No clinical studies have been performed for allergen extracts available for in vivo allergy diagnosis that document safety, sensitivity, and specificity of the products. Only for very few therapeutic allergen extracts state-of-the-art clinical studies have been performed that provide evidence for safety and efficacy. In this article, we discuss problems related to the inconsistent quality of products based on natural allergen extracts and share our observations that most of the products available for in vivo diagnosis and AIT do not meet the international standards for medicinal products. We argue that a replacement of natural allergen extracts by defined recombinantly produced allergen molecules and/or mixtures thereof may be the only way to guarantee the supply of clinicians with state-of-the-art medicinal products for in vivo diagnosis and treatment of allergic patients in the future.

Cow’s milk is one of the most important and basic nutrients introduced early in life in our diet but can induce IgE-associated allergy. IgE-associated allergy to cow’s milk can cause severe allergic manifestations in the gut, skin and even in the respiratory tract and may lead to life-threatening anaphylactic shock due to the stability of certain cow’s milk allergens. Here, we provide an overview about the allergen molecules in cow’s milk and the advantages of the molecular diagnosis of IgE sensitization to cow’s milk by serology. In addition, we review current strategies for prevention and treatment of cow’s milk allergy and discuss how they could be improved in the future by innovative molecular approaches that are based on defined recombinant allergens, recombinant hypoallergenic allergen derivatives and synthetic peptides.

OBJECTIVES: Atopic dermatitis (AD) is an increasingly common, chronic, relapsing, inflammatory skin disease characterized by impaired epidermal barrier function and cutaneous inflammation. The prev...

Background: The analysis of longitudinal birth cohorts with micro‐arrayed allergen molecules has provided interesting information about the evolution of IgE sensitization in children. However, so far no cross‐sectional study has been performed comparing IgE sensitization profiles in children with and without symptoms of allergy. Furthermore, no data are available regarding molecular IgE sensitization profiles in children from Russia.Methods: We recruited two groups of age‐ and gender‐matched children, one (Group 1: n = 103; 12.24 ± 2.23 years; male/female: 58/45) with symptoms and a second (Group 2: n = 97; 12.78 ± 2.23 years; male/female: 53/44), without symptoms of allergy according to international ISAAC questionnaire. Children were further studied regarding symptoms of allergy (rhinitis, asthma, atopic dermatitis) according to international guidelines, and skin prick testing with a panel of aeroallergen extracts was performed before sera were analyzed in an investigator‐blinded manner for IgE specific to more than 160 micro‐arrayed allergen molecules using ImmunoCAP ISAC technology.Results: IgE sensitization = or >0.3 ISU to at least one of the micro‐arrayed allergen molecules was found in 100% of the symptomatic children and in 36% of the asymptomatic children. Symptomatic and asymptomatic children showed a comparable IgE sensitization profile; however, frequencies of IgE sensitization and IgE levels to the individual allergen molecules were higher in the symptomatic children. Aeroallergen sensitization was dominated by sensitization to major birch pollen allergen, Bet v 1, and major cat allergen, Fel d 1. Food allergen sensitization was due to cross‐sensitization to PR10 pollen and food allergens whereas genuine peanut sensitization was absent.Conclusion: This is the first study analyzing molecular IgE sensitization profiles to more than 160 allergen molecules in children with and without symptoms of allergy. It detects similar molecular IgE sensitization profiles in symptomatic and asymptomatic children and identifies Bet v 1 and Fel d 1 as the predominant respiratory allergen molecules and PR10 proteins as the major food allergens and absence of genuine peanut allergy in Moscow region (Russia).

Background: The nature of epitopes on Bet v 1 recognized by natural IgG antibodies of birch pollen allergic patients and birch pollen‐exposed but non‐sensitized subjects has not been studied in detail.Objective: To investigate IgE and IgG recognition of Bet v 1 and to study the effects of natural Bet v 1‐specific IgG antibodies on IgE recognition of Bet v 1 and Bet v 1‐induced basophil activation.Methods: Sera from birch pollen allergic patients (BPA, n = 76), allergic patients without birch pollen allergy (NBPA, n = 40) and non‐allergic individuals (NA, n = 48) were tested for IgE, IgG as well as IgG₁ and IgG₄ reactivity to folded recombinant Bet v 1, two unfolded recombinant Bet v 1 fragments comprising the N‐terminal (F1) and C‐terminal half of Bet v 1 (F2) and unfolded peptides spanning the corresponding sequences of Bet v 1 and the apple allergen Mal d 1 by ELISA or micro‐array analysis. The ability of Bet v 1‐specific serum antibodies from non‐allergic subjects to inhibit allergic patients IgE or IgG binding to rBet v 1 or to unfolded Bet v 1‐derivatives was assessed by competition ELISAs. Furthermore, the ability of serum antibodies from allergic and non‐allergic subjects to modulate Bet v 1‐induced basophil activation was investigated using rat basophilic leukaemia cells expressing the human FcεRI which had been loaded with IgE from BPA patients.Results: IgE antibodies from BPA patients react almost exclusively with conformational epitopes whereas IgG, IgG₁ and IgG₄ antibodies from BPA, NBPA and NA subjects recognize mainly unfolded and sequential epitopes. IgG competition studies show that IgG specific for unfolded/sequential Bet v 1 epitopes is not inhibited by folded Bet v 1 and hence the latter seem to represent cryptic epitopes. IgG reactivity to Bet v 1 peptides did not correlate with IgG reactivity to the corresponding Mal d 1 peptides and therefore does not seem to be a result of primary sensitization to PR10 allergen‐containing food. Natural Bet v 1‐specific IgG antibodies inhibited IgE binding to Bet v 1 only poorly and could even enhance Bet v 1‐specific basophil activation.Conclusion: IgE and IgG antibodies from BPA patients and birch pollen‐exposed non‐sensitized subjects recognize different epitopes. These findings explain why natural allergen‐specific IgG do not protect against allergic symptoms and suggest that allergen‐specific IgE and IgG have different clonal origin.