Birch Pollen Immunotherapy Research Articles

A double‐blind placebo‐controlled birch allergy vaccination study II: correlation between inhibition of IgE binding, histamine release and facilitated allergen presentation

The pathogenesis of IgE-mediated allergic disease is closely related to the production of T-helper type 2 (Th2) cytokines, which lead to IgE production pivotal for activation of mast cells and basophils. Proliferating T cells along with eosinophils expanded and attracted by Th2 cytokines are major contributors to the late-phase reaction. The activation of these Th2 cells is strongly enhanced by CD23-mediated IgE facilitated allergen presentation (FAP). The present study aims to investigate the effect of specific immunotherapy (SIT)-induced allergen-specific non-IgE antibodies (blocking antibodies) on IgE binding to allergen, histamine release (HR) and CD23-mediated allergen uptake in antigen-presenting cells. Competition between IgE and non-IgE for allergen binding was studied by Advia Centaur antibody measurements, passively sensitized basophils were used to study HR and IgE-facilitated binding of allergen to B cells (FAP) was studied by flow cytometry. FAP measurements were performed both with and without the addition of a reference IgE serum, which was included to obtain optimal complex formation. The serum samples were obtained from birch pollen immunotherapy (n=21) or placebo control patients (n=21) before and after 1 and 2 years of treatment. Statistically significant reduction of all parameters investigated was observed after 1 year of treatment and the effect was maintained during the second year of treatment. There was a clear correlation between the two FAP measurements and between each of them and the level of T cell activation reported upon previously. Moreover, strong correlations were found between changes in FAP, IgE binding and HR. The present study clearly demonstrates that SIT induces changes in the composition of serum antibodies that inhibit IgE binding, HR and FAP to a similar extent. This suggests that these measurements, individually or in combination, may be used to monitor the immunological effect of SIT, even though direct correlations to changes in clinical parameters could not be demonstrated.

Assessment of birch pollen immunotherapy effect on pollen-food allergy syndrome to apple with in vitro passive sensitization assay

Assessment of birch pollen immunotherapy effect on pollen-food allergy syndrome to apple with in vitro passive sensitization assay

Correspondence re commercially available allergoid products for birch pollen immunotherapy

Clinical & Experimental AllergyVolume 37, Issue 10 p. 1576-1577 Correspondence re commercially available allergoid products for birch pollen immunotherapy M. Casanovas, M. Casanovas Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this authorJ. Carnés, J. Carnés Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this authorR. K. Gieseler, R. K. Gieseler Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this author M. Casanovas, M. Casanovas Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this authorJ. Carnés, J. Carnés Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this authorR. K. Gieseler, R. K. Gieseler Laboratorios LETI, Research and Development Tres Cantos (Madrid), Spain. E-mail: mcasanovas@leti.comSearch for more papers by this author First published: 10 September 2007 https://doi.org/10.1111/j.1365-2222.2007.02825.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume37, Issue10October 2007Pages 1576-1577 RelatedInformation

Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy

Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens. The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine. Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose. IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice. While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid concept.

Comparison of Allergenicity and Immunogenicity of an Intact Allergen Extract (Alutard SQ®) and 4 Commercially Available Allergoid Products for Birch Pollen Immunotherapy

RATIONALE: Specific immunotherapy with intact allergens is a well documented treatment for allergy. In Europe, several vaccine formulations are currently commercially available, the active ingredient being either intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However statistics from the German health authorities based on adverse events reporting over a 10 year period did not indicate increased safety of allergoids over intact allergens.

Mutational Analysis of Amino Acid Positions Crucial for IgE-Binding Epitopes of the Major Apple (Malus domestica) Allergen, Mal d 1

Background: Individual amino acid residues of the major birch pollen allergen, Bet v 1, have been identified to be crucial for IgE recognition. The objective of the present study was to evaluate whether this concept was applicable for the Bet v 1-homologous apple allergen, Mal d 1. Methods: A Mal d 1 five-point mutant was produced by PCR techniques, cloned into pMW 172 and expressed in Escherichia coli BL21(DE3) cells. To evaluate the allergenic properties of the engineered protein compared to Mal d 1 wild-type IgE immunoblotting, ELISA, peripheral blood monocytes proliferation assays, and skin prick tests were performed. Results: The Mal d 1 mutant showed reduced capacity to bind specific IgE as compared to wild-ype Mal d 1 in in vitro assays in the majority of the sera tested. In ELISA, 10 out of 14 serum samples displayed an 88–30% decrease in IgE binding to Mal d 1 mutant compared to wild-type Mal d 1. Skin prick tests in apple-allergic patients (n = 2) confirmed the markedly decreased ability of the Mal d 1 mutant to induce allergic reactions in vivo. However, the relevant T cell epitopes were present in the mutated molecule according to peripheral blood mononuclear cell proliferation assays. Conclusions: Our findings suggest that it is possible to modulate the IgE-binding properties of allergens by single amino acid substitutions at crucial positions which might be useful for future immunotherapy of birch-pollen-associated food allergies which are not ameliorated by birch pollen immunotherapy.

Food allergy to apple and specific immunotherapy with birch pollen

Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen-allergic patients were included in a double-blind, double-dummy, and placebo-controlled comparison of sublingual-swallow (SLIT) and subcutaneous (SCIT) administration of a birch pollen extract. Sixty-nine percent of these patients reported allergy to apple. The clinical reactivity to apple was evaluated by open oral challenges with fresh apple and a questionnaire. The immunoglobulin E (IgE)-reactivity was assessed by skin prick test (SPT), specific IgE, and leukocyte histamine release (HR). Forty patients were included in the final evaluation of the effect of SIT. The challenges were positive in 9 (SCIT), 6 (SLIT), and 8 (placebo) patients after treatment compared to 10, 4, and 10 patients, respectively, before SIT. The symptom scores to apple during challenges decreased in all groups, but only significantly in the placebo group (p = 0.03). As evaluated by the questionnaire, the severity of food allergy in general did not change and there were no differences between the groups. In spite of a significant effect on seasonal hay fever symptoms and use of medication and decrease in IgE-reactivity, SIT was not accompanied by a significant decrease in the severity of allergy to apple compared to placebo. Therefore, oral allergy syndrome (OAS) to apple should not be considered as a main criterion for selecting patients for birch pollen immunotherapy at present.

Birch and ragweed pollen immunotherapy in the treatment of pollen-food allergy syndrome

Rationale Fruit/vegetable allergy affects up to 50% of pollen-allergic adults. Pollen sensitization is regarded as the primary event with subsequent development of allergy to cross-reactive fruits and vegetables. We sought to determine the effect of pollen immunotherapy on pollen-food allergy syndrome. Methods A randomized open trial of birch and ragweed pollen immunotherapy in patients with birch and ragweed allergic rhinitis and oral allergy to apple and/or cantaloupe Results Sixteen birch and ragweed allergic patients, median age 30 years (range; 11-47) with apple and/or cantaloupe allergy confirmed by double-blinded placebo-controlled oral challenge were randomized to receive birch and ragweed pollen immunotherapy (n=9) or to a control group that did not receive immunotherapy (n=7). Four immunotherapy patients underwent oral challenges at median 15 months (range; 12–16) and 5 control patients were challenged at median 12 months (range; 12–18). Following immunotherapy, blinded challenges revealed decreased symptom scores, mean 4.8 versus 1.0 (p<0.04). Open challenge symptom scores were also lower, median 3.0 vs 1.5 (p=0.3) and patients tolerated larger amount of an open challenge, median 16% vs 68% (p=0.03). Such significant changes were not seen in the control patients who at follow-up had not significantly different symptom scores on blinded challenge, median 4 versus 3 (p=0.06) and on open challenge, median 5.4 vs 4.6 (p=0.6). Control patients tolerated 100% of an open challenge at baseline and at follow-up. Conclusion Birch and ragweed pollen immunotherapy increases tolerance to fruits in subjects with pollen-food allergy syndrome.

Changes in Cytokine Production In Vitro during the Early Phase of Birch‐Pollen Immunotherapy

The kinetics of the immunological mechanisms during allergen-specific immunotherapy (IT) has not been thoroughly evaluated. In this investigation we study the changes in T-cell responses during the early phase of IT. Ten patients (IT group) with birch-pollen allergy were treated with conventional IT. Blood samples were collected at regular intervals for specific immunoglobulin (Ig)E measurements and preparation of peripheral blood mononuclear cells (PBMC). Seven allergic control patients (AC group) were included during the subsequent birch-pollen season. The PBMC were stimulated with birch-pollen extract or tetanus toxoid (TT) and mitogens. After a short decrease, probably owing to seasonal variation, the birch-pollen-specific proliferation and the interleukin (IL)-4, IL-5, and IL-10 production significantly increased when reaching the maintenance dose and during the subsequent pollen season. The increase in IL-4 correlated with a temporary increased serum level of birch-pollen-specific IgE. Interestingly, also the TT-specific response was affected by IT, resulting in weaker, but in time similar, changes in proliferation and cytokine production as in the birch-pollen-specific response. We speculate that the early phase of IT might lead to systemic changes in the capacity of Th2-like cytokine production, and that the early increase in allergen-specific IgE is a consequence of enhanced IL-4 production.

Cytokine production by peripheral blood mononuclear cells following birch-pollen immunotherapy

We studied the Th2/Th1 balance by short-term stimulation of peripheral blood mononuclear cells (PBMC) isolated during the pollen season from seven allergic patients treated with conventional birch-pollen immunotherapy (IT) for 18 months, eight matched allergic control patients and 10 non-atopic individuals. The PBMC were cultured for 7 days with birch-pollen extract (BPE) or tetanus toxoid (TT), and then restimulated with PHA and PMA to induce high IL-5, IL-10 and IFN-γ production. The serum levels of birch-pollen-specific IgG and IgG4 were significantly elevated after IT treatment. The proliferative response to BPE was significantly enhanced in the allergic control group, but not in the IT-treated group, compared to the non-atopic group ( P<0.05). Birch-pollen-specific IL-5 production was significantly enhanced in both the IT-treated group and the allergic control group ( P<0.01–0.05). Furthermore, both the IT-treated group and the allergic control group had a cytokine profile to BPE significantly more Th2 polarized (high IL-5/IFN-γ ratio) than to TT ( P<0.05 and P<0.01, respectively). No differences in IL-10 production between the three study groups were observed. The Th2/Th1 balance in vitro correlated with the serum concentrations of birch-pollen-specific IgE ( r=0.60, P<0.05), and in the IT-treated group, also with the IgG and IgG4 levels ( r=0.79, P<0.05 and r=0.86, P<0.05, respectively). We conclude that conventional birch-pollen IT does not lead to changes in the cytokine profile of the circulating pool of allergen-specific T cells during birch-pollen season. However, induction of peripheral T-cell tolerance and increased production of specific IgG and IgG4 might be part of the mechanisms of IT.