Basophil anaphylaxis

There are also other immimological mechanisms, especially via IgG or IgM antibodies with immune complex formation, which can lead to similar clinical conditions [20, 34, 42] as has been shown in dextran anaphylaxis (table 1). Triggering of mast cells and basophils leads to release of various vasoactive mediators, among which histamine was the first recognized in 1908 (fig. 3,4) [6]. 

Our understanding of anaphylaxis has advanced substantially since the original description of this phenomenon in the scientific literature over 100 years ago. There is now little reasonable doubt that the IgE-dependent activation of mast cells and basophils is the key event underlying most examples of allergen-induced anaphylaxis in humans [3-5]. IgE binds to the high-affinity IgE receptor, FcsRI, expressed on the... 

This chapter highlights the mechanisms responsible for mast cell activation during anaphylactic responses to environmental substances. In addition to discussing in detail the activation of mast cells and basophils by IgE and antigen, we also will describe how mouse models have been used to analyze the importance of various proteins, cells, mediators and activation mechanisms in the expression of anaphylaxis in that species. 

It is generally accepted (based on clinical and in vitro studies) that mast cells (and basophils), IgE and FceRI are involved in most cases of allergen-induced anaphylaxis in humans. However, it is difficult to define the exact roles and relative importance of mast cells, basophils, and other potential effector cells (e.g monocytes/macrophages, dendritic cells) in either IgE-dependent or IgE-independent human anaphylaxis. Unlike in mice, we neither have access to mast cell- or basophil-deficient humans nor can we genetically manipulate human subjects to produce such phenotypes. 

In mice and humans, it is possible that mast cells and basophils contribute to the pathophysiology of anaphylaxis both via direct effects on end organ targets and also by indirect effects, including the ability of mast cells and basophils to influence the responsiveness of such target cells to mediators generated in subjects with anaphylaxis. 

The roles of potential effector cells other than mast cells and basophils (e.g. monocytes/ macrophages, dendritic cells) in IgE-dependent and IgE-independent anaphylaxis in mice and humans remain to be determined. 

There may be substantial variation both within and among species (e.g., in mice vs. humans) in the expression of various proteins, receptors and/or ligands that influence the activation of mast cells (or basophils or other potential effector cell types), or that can regulate the responsiveness of end organ target cells (e.g., bronchial or gastrointestinal smooth muscle cells, vascular endothelial cells) to potential mediators of anaphylaxis derived from mast cells. 

TsujimuraY, ObataK, Mukai K, Shindou H, Yoshida M, Nishikado H, Kawano Y, Minegishi Y, Shimizu X Karasuyama H Basophils play a pivotal role in SS immunoglobulin-G-mediated but not immuno-globulin-E-mediated systemic anaphylaxis. Immunity 2008 28 581-589. 

Fig. 2. IgG-mediated systemic versus local anaphylaxis, a IgG-mediated systemic anaphylaxis. When allergen-IgG immune complexes are formed in the circulation, basophils immediately capture them through IgG receptors on their surface and are activated to release PAF, that in turn act on vascular endothelial cells, leading to increased vascular permeability, b Passive cutaneous anaphylaxis. When allergen-IgG immune complexes are formed in the skin, they stimulate tissue-resident mast cells to release chemical mediators such as histamine, leading to local inflammation. 

Basophils Release Platelet-Activating Factor Instead of Histamine to Induce IgG-Mediated Systemic Anaphylaxis... 

If patients have experienced anaphylaxis, the identification of any possible elicitor is important to help avoid further episodes. With skin tests and specific IgE antibodies combined with history, a relevant allergy may be detected. Cellular tests monitoring basophil histamine release or basophil activation may be helpful in some patients who resist diagnosis by standard means [26,31]. 

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