The immunome of soy bean allergy: Comprehensive identification and characterization of epitopes.

BACKGROUND: The precise mapping of multiple antibody epitopes recognized by patients' sera allows a more detailed and differentiated understanding of immunological diseases. It may lead to the development of novel therapies and diagnostic tools. OBJECTIVE: Mapping soy bean specific epitopes relevant for soy bean allergy patients and persons sensitized to soy bean, and analysis of their IgE/IgG binding spectrum. METHODS: Identification of epitopes using sera, applying an optimized peptide phage display library followed by next-generation sequencing, specially designed in silico data analysis and subsequent peptide microarray analysis. RESULTS: We were able to identify more than 400 potential epitope motifs in soy bean proteins. More than 60% of them have not yet been described as potential epitopes. Eighty-three peptides, representing the 42 most frequently found epitope candidates, were validated by microarray analysis using 50 sera from people who have been tested positive in skin prick test (SPT). Of these peptides, 56 were bound by antibodies, 55 by serum IgE, 43 by serum IgG and 30 by both. Person-specific epitope patterns were found for each individual and protein. CONCLUSIONS: For individuals with clinical symptoms, epitope resolved analyses reveal a high prevalence of IgE binding to a few soy bean specific epitopes. Evaluation of individual immune profiles of patients with soy bean sensitization allows the identification of peptides that do facilitate studying individual IgE/IgG epitope binding patterns. This enables discrimination of sensitization from disease, such assay test has the potential to replace SPT assays.

Component-resolved diagnosis in adult patients with food-dependent anaphylaxis.

Food anaphylaxis is a severe, potentially life-threatening, systemic hypersensitivity reaction. Within a retrospective study we applied ImmunoCAP-ISAC in a heterogenous cohort of 54 food anaphylactic patients and compared its performance to conventional in vitro (ELISA, ImmunoCAP) and in vivo (skin prick test, oral food challenge) diagnosis. Comparing clinical diagnosis with results obtained by ImmunoCAP-ISAC we obtained moderate agreement (kappa 0.524, p < 0.05). The comparison between SPT and ImmunoCAP vs ImmunoCAP-ISAC indicates a good sensitivity of microarray testing. Among the 54 tested sera, 36 and 41 were in substantial agreement with results obtained by SPT (69%, kappa 0.667, p < 0.05) and ImmunoCAP-ISAC (76%, kappa 0.759, p < 0.05), respectively. Within this adult anaphylaxis cohort, plant food allergens were identified as the predominant IgE-binding proteins, with PR10 proteins, ω-5-gliadin and nsLTPs as the most frequent ones. In summary, microarray based IgE testing may help to unravel the elicitating food in anaphylaxis in particular when the elicitor is so far unknown.

Anaphylaxis in Elderly Patients-Data From the European Anaphylaxis Registry.

Background: Elicitors and symptoms of anaphylaxis are age dependent. However, little is known about typical features of anaphylaxis in patients aged 65 years or more. Methods: The data from the Network for Online Registration of Anaphylaxis (NORA) considering patients aged ≥65 (elderly) in comparison to data from adults (18-64 years) regarding elicitors, symptoms, comorbidities, and treatment measures were analyzed. Results: We identified 1,123 elderly anaphylactic patients. Insect venoms were the most frequent elicitor in this group (p < 0.001), followed by drugs like analgesics and antibiotics. Food allergens elicited less frequently anaphylaxis (p < 0.001). Skin symptoms occurred less frequently in elderly patients (77%, p < 0.001). The clinical symptoms were more severe in the elderly (51% experiencing grade III/IV reactions), in particular when skin symptoms (p < 0.001) were absent. Most strikingly, a loss of consciousness (33%, p < 0.001) and preexisting cardiovascular comorbidity (59%, p < 0.001) were more prevalent in the elderly. Finally, adrenaline was used in 30% of the elderly (vs. 26% in the comparator group, p < 0.001) and hospitalization was more often required (60 vs. 50%, p < 0.001). Discussion and Conclusion: Anaphylaxis in the elderly is often caused by insect venoms and drugs. These patients suffer more often from cardiovascular symptoms, receive more frequently adrenaline and require more often hospitalization. The data indicate that anaphylaxis in the elderly tends to be more frequently life threatening and patients require intensified medical intervention. The data support the need to recognize anaphylaxis in this patient group, which is prone to be at a higher risk for a fatal outcome.

A Case of Anaphylaxis to Intramuscular but Not to Oral Application of Thiamine (Vitamin B1).

We report a 78 year-old non-atopic female with polyneuropathy who started to receive monthly intramuscular injections of thiamine hydrochloride. She had an anaphylaxis after the fourth injection. Skin prick test (SPT) with pure commercially available aqueous preparations was positive for thiamine hydrochloride. A titrated, single blinded, placebo-controlled oral provocation test with thiamine hydrochloride was well tolerated. The patient was then diagnosed as compartment allergy with hypersensitivity to parenteral but not to oral thiamine. Because in our patient, oral intake of thiamine has never been reported to lead to any adverse reaction. Oral tolerability might be due to the uptake mechanism of thiamine in the gastrointestinal system.

A Case of Anaphylaxis to Patent Blue in a Patient with Sentinel Lymph Node Excision.

In medicine, patent blue violet (PBV) is utilized for staining lymphatic vessels in sentinel lymph node (SLN) surgery. Moreover, PBV (also called E131 ) is used as food additive. We report on a 51-year-old non-atopic female with early breast cancer, who was scheduled for SLN excision and experienced an intra-operative anaphylactic reaction. In diagnostics the skin prick test (SPT) was positive to PBV. Hypersensitivity reactions to PBV can arise after the first exposure in surgery as sensitization may arise from either PBV (E131) in foods (i.e. in sweets or blue curacao) or from other structurally closely related triarylmethane dyes in objects of everyday life like textiles, detergents, paints, cold remedies and cosmetics. This article supports the necessity of an increased awareness of the possibility of anaphylactic reactions to PBV during SLN surgery, even if the patient never had contact to PBV before.