OBJECTIVE: To explore the use of β-lactoglobulin polymerized using microbial transglutaminase and heating to identify whether protein polymerization could reduce in vivo allergenicity and maintain in vitro and ex vivo immunoreactivity for use in tolerance-induction protocols. METHODS: Based on previous protocols applied in mice and children, we performed in vivo challenges (using a skin prick test) with native and polymerized β-lactoglobulin in adult patients with an IgE-mediated allergy to β-lactoglobulin. In vitro humoral immunoreactivity was analyzed using immunoblotting. Cell-mediated immunoreactivity was analyzed using ex vivo challenges with native and polymerized β-lactoglobulin and monitored by leukocyte adherence inhibition tests. RESULTS: The skin tests demonstrated that there was a significant reduction in immediate cutaneous reactivity after polymerization. Polymerization did not decrease the immunoblotting detection of s-IgE specific to β-lactoglobulin. Cell-mediated immunoreactivity, as assessed by ex vivo challenges and leukocyte adherence inhibition tests, did not exhibit significant differences between leukocytes challenged with native versus polymerized β-lactoglobulin. CONCLUSIONS: The polymerization of β-lactoglobulin decreased in vivo allergenicity and did not decrease in vitro humoral or ex vivo cell-mediated immunoreactivity. Therefore, we conclude that inducing polymerization using transglutaminase represents a promising technique to produce suitable molecules for the purpose of designing oral/sublingual tolerance induction protocols for the treatment of allergies.

Background:The Leukocyte Adherence Inhibition Test (LAIT) is an ex vivo challenge test used to testimony specific immunoreactivity. Despite numerous studies had been performed to elucidate the interactions involved in the assay, there are yet several questions about its mechanisms and how to translate its results into the medical practice.Objectives: To perform an experiment with an antibody disassembler: the papain, to demonstrate the participation of specific antibodies in the reconnaissance phase of the assay performed with protein antigens.Methods: Paired side-by-side ex vivo allergen-specific challenges monitored by the LAIT, were performed with the plasma of allergic patients, preincubated (or not) with papain. Results:The mean of the differences (26.66%) of the two arms was considered significative by the paired t-test (p-value < 0.05). Conclusion:Our results suggests that the leukocyte adherence inhibition phenomenon and its inhibition is possibly mediated by an interaction of cells and specific antibodies and deserves further studies as an ex vivo challenge test tool for research of Gell & Coombs type II hypersensitivity reactions.

Background: The Precision Medicine’s approach employs the endotype concept as a central feature to personalize medical treatment. Individual immunoreactivity, alongside characteristics such as genetics, environment, and diet, is one of the factors that differentiates the therapeutic-driven endotypes. Objective: To evaluate the opportunity of the Leukocyte Adherence Inhibition test to differentiate the immunoreactivity between two similar therapeutic agents employed on Allergen Immunotherapy. Methods: Side by side Leukocyte Adherence Inhibitions tests were performed with ovalbumin and carbamylated ovalbumin on a population of 33 self-reported egg-allergic individuals. Results: The results showed two endotypes inside the immune response of the studied groups: The first endotype was defined by the 16 individuals that presented a significant decrease in ovalbumin’s immunoreactivity after carbamylation (mean of differences = 35%; p = 0.002). The second endotype was defined by 17 individuals that presented a significant increase in ovalbumin’s immunoreactivity after carbamylation (mean of differences = 32%; p = 0.001). Conclusion: The Leukocyte Adherence Inhibition test was able to differentiate two distinct immunoreactivity patterns when comparing two similar therapeutic agents suggesting, as proof of concept, a potential role to be employed as a Precision Medicine tool.

Background: Asymptomatic sensitization is a frequent condition that must be considered before the indication of allergic-specific immunotherapy.Objective:

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