Influence of bee venom immunotherapy on degranulation and leukotriene generation in human blood basophils.
ABSTRACT Rapid clinical tolerance can be induced over several hours by very fast bee venom immunotherapy (VIT) protocols.
To investigate the mechanisms underlying VIT we examined the changes of blood basophil responsiveness during VIT.
Seven bee venom allergic patients with a history of severe systemic reactions after a bee sting were investigated. A cumulative dose of 111.1 micrograms bee venom (BV) was administered sc over 3.5 h under intensive care conditions according to an ultra-rush protocol. The release of histamine and the formation of leukotrienes in response to BV, major BV allergen Phospholipase A2 (PLA), IgE receptor cross-linking with the use of monoclonal antibodies against IgE and IgE receptor, as well as IgE independent activation in response to C5a were determined in vitro before and after ultra-rush VIT.
We demonstrated a decrease of total histamine in peripheral blood leucocytes just after VIT. Histamine release in response to all the stimuli used is not affected by ultra-rush VIT, if expressed as per cent release of total histamine. However, the absolute amount product released in response to stimulation was decreased, particularly with allergen (BV, PLA). We also found a significant reduction of LTC4 formation after VIT in samples stimulated with specific allergen (BV, PLA).
Blood basophils are a target for VIT, which induces impaired release of both preformed and newly generated mediators. However, we believe the basic mechanisms of rapid clinical tolerance induced by ultra-rush VIT remain to be investigated.
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ABSTRACT: BACKGROUND: Despite the efficiency of venom immunotherapy, the effects on basophils and mast cells remain incompletely understood and probably vary according to the treatment phase. OBJECTIVES: To study the effect of build-up and maintenance venom immunotherapy on individual basophils. METHODS: Intracellular histamine and its release was analyzed flow cytometrically by a new enzyme-affinity method using diamine oxidase conjugated to laser-excitable fluorochromes. Phenotyping of cells included flow cytometric quantification of CD63 and CD203c. Analyses of basophil activation experiments were performed before the start of treatment, after build-up therapy and during maintenance therapy. RESULTS: Before the start of therapy, patients demonstrated significantly higher numbers of basophils when compared with stung control individuals. At the end of build-up therapy a decrease of basophil numbers was observed, whereas during maintenance therapy basophil counts returned to pretreatment values. Before the start of therapy, the intracellular histamine content per cell in patients was significantly higher when compared with stung control individuals. During maintenance therapy intracellular histamine content decreased to values observed in stung control individuals. In addition, maintenance therapy lowered the net release of histamine per cell in response to optimal stimulation with wasp venom. CONCLUSIONS: We introduce a novel technique that enables to assess the effects of venom immunotherapy on basophils. This new technique may help to monitor treatment effects in individual patients and could aid in the development of more efficient and better tolerated immunotherapy protocols. © 2013 International Clinical Cytometry Society.Cytometry Part B Clinical Cytometry 02/2013; · 2.23 Impact Factor
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ABSTRACT: Background Basophils are important effectors cells in allergic rhinitis (AR) since they are involved in immunoglobulin (Ig) E – mediated inflammation and in the release of pro-inflammatory mediators. Specific subcutaneous immunotherapy (SCIT) provides clear immunologic modulation in some immune cells, however its systemic effects on basophils are not well known. Methods Peripheral blood (PB) samples from 43 patients with allergic rhinitis mono-sensitized to Dermatophagoides pteronyssinus (Dpt) [33 of them under SCIT with allergoid Dpt extract, in maintenance dose (SCIT), with evaluation just before SCIT injection (SCIT-T0) and 4 hours later (SCIT-T4) and the other 10 Dpt allergic patients never having, in the past, undergone specific immunotherapy treatment (NSIT)], and 15 healthy age- and gender-matched controls (HG), were analyzed. For each sample, the total (t-IgE) and specific IgE (s-IgE) was performed, as well as, the relative frequency and absolute number of PB basophils and receptor-bound IgE and IgG expression were evaluated by flow cytometry and the Histamine N-methyltransferase (HNMT) and tryptase α/β1 (TPSAB1) gene expression was assessed by real-time PCR. Results Higher levels of receptor-bound IgE were observed in SCIT patients, which are correlated with the levels of serum t-IgE and s-IgE, whereas no significant differences were observed for receptor-bound IgG. Regarding HNMT mRNA expression, significantly lower expression levels were detected in AR patients compared to HG, independently of type of therapy. Moreover a negative correlation was found between HNMT gene expression and time under SCIT. Conversely, tryptase gene expression was significantly up-regulated in NSIT when compared to HG; however in SCIT patients, tryptase gene expression was significantly decreased than in NSIT patients. No differences were found for any parameter between SCIT-T0 and SCIT-T4 with exception of a transient increased expression of tryptase in SCIT-T4. Conclusion PB basophils from patients with AR show altered functional features, which seems to be influenced by SCIT, suggesting that these cells could be useful to clarify the SCIT triggered mechanisms at a systemic level.Allergy Asthma and Clinical Immunology 10/2013; 9(1).
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ABSTRACT: Immunotherapies with T-cell epitope peptides have shown a promising impact over allergic diseases as a potential therapeutic tool in in vitro and in vivo conditions. It is recognized as an effective treatment with long lasting clinical effects and subsequent reduction of the allergic inflammatory reactions. In this review, we have summarized the role of peptide based immunotherapy and emphasis has also been given to the recent advancement in pollen, cat, hymenoptera venom, and food allergy.International Immunopharmacology 01/2014; · 2.42 Impact Factor