0
selected
-
1.
Ara h 7 isoforms share many linear epitopes: Are 3D epitopes crucial to elucidate divergent abilities?
Ehlers, AM, Klinge, M, Suer, W, Weimann, Y, Knulst, AC, Besa, F, Le, TM, Otten, HG
Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology. 2019;(11):1512-1519
-
-
Free full text
-
Abstract
BACKGROUND The peanut allergens Ara h 2, h 6, and h 7 are potent allergens and can trigger severe reactions. Ara h 7 consists of three isoforms differing in their ability to induce basophil degranulation, whereas the ability of Ara h 7.0201 is comparable to Ara h 2 and 6 as shown in previous literature. OBJECTIVE To identify linear epitopes of Ara h 7.0101, Ara h 7.0201 and Ara h 7.0301 recognized by IgE and IgG4 from patients sensitized to Ara h 7 and to investigate their potential to elucidate divergent abilities of the Ara h 7 isoforms in inducing basophil activation. METHODS Linear epitopes recognized by IgE and IgG4 were mapped by peptide microarray analysis containing 15-mer peptides of Ara h 2.0201, 6, 7.0101, 7.0201 and 7.0301 and 39 peanut allergic patients sensitized to Ara h 7 (discovery). For validation, 20-mer peptides containing the minimal epitope and surrounding amino acids were incubated with 25 sensitized patients and 10 controls (validation). RESULTS Three out of 14 linear epitopes were unique for each isoform (Ara h 7.0101: aa 97-109; Ara h 7.0201: aa 122-133; Ara h 7.0301: aa 65-74) but scarcely recognized by IgE. The main linear IgE epitope (aa 51-57) located in the long flexible loop of all Ara h 7 isoforms was bound by antibodies from 31% of the patients (discovery and validation cohort). Regarding IgG4, 55% of the patients recognized an epitope present on all isoforms (aa 55-65), whereas epitope aa 129-137, only present on Ara h 7.0101/0.0301, was recognized by 38% of the patients. Recognition was highly individual, although 20% of the patients recognized any linear epitope neither by IgE nor by IgG4 despite a low mean z-score of ≥ 1.7. Remarkably, only 50% of the patients recognized one or more epitopes by IgE. CONCLUSION & CLINICAL RELEVANCE Ara h 7 isoforms share many linear epitopes being easily accessible for antibody binding. Unique epitopes, essential to elucidate divergent potencies, were scarcely recognized, suggesting a crucial involvement of conformational epitopes.
-
2.
Eosinophilic Esophagitis: Personalized Treatment With an Elimination Diet Based on IgE Levels in Children Aged <16 Years.
Gómez Torrijos, E, Moreno Lozano, L, Extremera Ortega, AM, González Jimenez, OM, Mur Gimeno, P, Borja Segade, JM, Alfaya Arias, T, García Rodríguez, R
Journal of investigational allergology & clinical immunology. 2019;(2):155-157
-
3.
Epigenetic features of FoxP3 in children with cow's milk allergy.
Paparo, L, Nocerino, R, Cosenza, L, Aitoro, R, D'Argenio, V, Del Monaco, V, Di Scala, C, Amoroso, A, Di Costanzo, M, Salvatore, F, et al
Clinical epigenetics. 2016;:86
Abstract
BACKGROUND DNA methylation of the Th1 and Th2 cytokine genes is altered during cow's milk allergy (CMA). Forkhead box transcription factor 3 (FoxP3) is essential for the development and function of regulatory T cells (Tregs) and is involved in oral tolerance acquisition. We assessed whether tolerance acquisition in children with IgE-mediated CMA is associated with DNA demethylation of the Treg-specific demethylated region (TSDR) of FoxP3. RESULTS Forty children (aged 3-18 months) were enrolled: 10 children with active IgE-mediated CMA (group 1), 10 children who outgrew CMA after dietary treatment with an extensively hydrolyzed casein formula containing the probiotic Lactobacillus rhamnosus GG (group 2), 10 children who outgrew CMA after treatment with other formulas (group 3), and 10 healthy controls (group 4). FoxP3 TSDR demethylation and expression were measured in mononuclear cells purified from peripheral blood of the four groups of children. FoxP3 TSDR demethylation was significantly lower in children with active IgE-mediated CMA than in either children who outgrew CMA or in healthy children. Formula selection influenced the FoxP3 TSDR demethylation profile. The FoxP3 TSDR demethylation rate and expression level were correlated. CONCLUSIONS Tolerance acquisition in children with IgE-mediated CMA involves epigenetic regulation of the FoxP3 gene. This feature could be a new target for preventive and therapeutic strategies against CMA.
-
4.
The diagnostic value of component-resolved diagnostics in peanut allergy in children attending a Regional Paediatric Allergology Clinic.
van Veen, LN, Heron, M, Batstra, M, van Haard, PMM, de Groot, H
BMC pediatrics. 2016;:74
Abstract
BACKGROUND To date, diagnosing food allergies in children still presents a diagnostic dilemma, leading to uncertainty concerning the definite diagnosis of peanut allergy, as well as to the need for strict diets and the potential need for adrenalin auto-injectors. This uncertainty in particular is thought to contribute to a lower quality of life. In the diagnostic process double-blind food challenges are considered the gold standard, but they are time-consuming as well as potentially hazardous. Other diagnostic tests have been extensively studied and among these component-resolved diagnostics appeared to present a promising alternative: Ara h2, a peanut storage protein in previous studies showed to have a significant predictive value. METHODS Sixty-two out of 72 children, with suspected peanut allergy were analyzed using serum specific IgE and/or skin prick tests and specific IgE to several components of peanut (Ara h 1, 2, 3, 6, 8, 9). Subsequently, double-blind food challenges were performed. The correlation between the various diagnostic tests and the overall outcome of the double-blind food challenges were studied, in particular the severity of the reaction and the eliciting dose. RESULTS The double-blind provocation with peanut was positive in 33 children (53 %). There was no relationship between the eliciting dose and the severity of the reaction. A statistically significant relationship was found between the skin prick test, specific IgE directed to peanut, Ara h 1, Ara h 2 or Ara h 6, and the outcome of the food challenge test, in terms of positive or negative (P < .001). However, we did not find any relationship between sensitisation to peanut extract or the different allergen components and the severity of the reaction or the eliciting dose. There was no correlation between IgE directed to Ara h 3, Ara h 8, Ara h 9 and the clinical outcome of the food challenge. CONCLUSIONS This study shows that component-resolved diagnostics is not superior to specific IgE to peanut extract or to skin prick testing. At present, it cannot replace double-blind placebo-controlled food challenges for determination of the eliciting dose or the severity of the peanut allergy in our patient group.
-
5.
Preliminary human study for possible alteration of serum immunoglobulin E production in perennial allergic rhinitis with fermented milk prepared with Lactobacillus gasseri TMC0356.
Morita, H, He, F, Kawase, M, Kubota, A, Hiramatsu, M, Kurisaki, J, Salminen, S
Microbiology and immunology. 2006;(9):701-6
Abstract
The fermented milk prepared with Lactobacillus gasseri TMC0356 was administered at 200 ml per day for 4 weeks to 15 subjects with high serum IgE levels and perennial allergic rhinitis. The serum total IgE concentration was significantly reduced after 28 days' exposure to the fermented milk (P <0.05) compared to that before the intervention. The serum IgE specific to Acari and those to Japanese cedar pollen also significantly declined (P <0.05). T helper 1 (Th1) cells in the composition of their peripheral blood mononuclear cells (PBMCs) significantly increased after 14 days (P <0.01) and after 28 days (P <0.05). These results suggest that the fermented milk prepared with L. gasseri TMC0356 may alter serum IgE concentration, at least partly by enhancement of Th1 immune responses of the subjects with high concentration of serum IgE. However, further studies are still necessary to know the underlying mechanisms by which the tested fermented milk could influence the host immunity.
-
6.
Anaphylactic reactions to aprotinin reexposure in cardiac surgery: relation to antiaprotinin immunoglobulin G and E antibodies.
Dietrich, W, Späth, P, Zühlsdorf, M, Dalichau, H, Kirchhoff, PG, Kuppe, H, Preiss, DU, Mayer, G
Anesthesiology. 2001;(1):64-71; discussion 5A-6A
-
-
Free full text
-
Abstract
BACKGROUND Aprotinin, a serine proteinase inhibitor, reduces bleeding during cardiac surgery. As aprotinin is derived from bovine lung, it has antigenic properties. This investigation examined the incidence of anaphylactic reactions in patients reexposed to aprotinin and the relation to preformed antiaprotinin immunoglobulin (Ig)G and IgE antibodies. METHODS This prospective observational study conducted at five centers in Germany evaluated patients undergoing repeat cardiac surgery reexposed to aprotinin between 1995 and 1996. Antiaprotinin IgG and IgE antibody measurements, using a noncommercial enzyme-linked immunosorbent assay and an immunofluorescence assay, respectively, were performed preoperatively and postoperatively. An anaphylactic reaction was defined as major changes from baseline within 10 min of aprotinin administration of systolic pressure 20% or greater, heart rate 20% or greater, inspiratory pressure greater than 5 cm H2O, or a skin reaction. RESULTS In 121 cases (71 adults, 46 children), a mean aprotinin reexposure interval of 1,654 days (range, 16-7,136 days) was observed. Preoperative antiaprotinin IgG (optical density ratio > 3) and IgE antibodies (radioallergosorbent test [RAST] score < 3) were detected in 18 and 9 patients, respectively. High concentrations of each (IgG, optical density ratio > 10; IgE, RAST score > or = 3) were detected in five patients. Three patients (2.5%; 95% confidence interval, 0.51-7.1%) experienced an anaphylactic reaction after aprotinin exposure, followed by full recovery; these patients had reexposure intervals less than 6 months (22, 25, and 25 days) and the highest preoperative IgG concentrations of all patients (P < 0.05). Assay sensitivity was 100%, as no anaphylactic reactions occurred in IgG-negative patients (95% confidence interval, 0.0-3.1%); assay specificity was 98%. Preoperative IgE measurements were quantifiable in two of three reactive patients and in three nonreacting patients. CONCLUSIONS Quantitative detection of antiaprotinin IgE and IgG lacks specificity for predictive purposes; however, quantitation of antiaprotinin IgG may identify patients at risk for developing an anaphylactic reaction to aprotinin reexposure.