Allergy mediators

Parvalbumin was found to be a major fish allergen in approximately 70% of fish allergies, mediated by parvalbumin IgE antibodies, leading to respiratory and gastrointestinal symptoms. Parvalbumin also became of interest because of its potential use in gene therapy to correct cardiomyopathy. 

Allergy mediated by selective IgE to certain types of NSAIDs by which symptoms are caused exclusively by a specific group of NSAIDs and no cross-reactivity exists with the other groups of anti-inflammatories. In a study carried out with 26 methimazole-allergic patients with IgE-mediated reactions [33], 14 of which developed anaphylaxis, BAT showed a sensitivity of 42% with an optimum specificity of 100%. No other validated in vitro test exists to date for the diagnosis of this disorder and so it represents an essential aid to diagnosis. 

Cromolyn stabilizes the membranes of mast cells, stopping the release of allergy mediators and suppressing activation of eosinophiles, neutrophilis, thrombocytes, and macrophages, which take part in the formation of bronchospasms. 

Omalizumab is an anti-IgE recombinant humanized monoclonal antibody that is approved for the treatment of allergic asthma in adult and adolescent patients whose symptoms are refractory to inhaled corticosteroids (see Chapter 20). The antibody blocks the binding of IgE to the high-affinity Fes receptor on basophils and mast cells, which suppresses IgE-mediated release of type I allergy mediators such as histamine and leukotrienes. Total serum IgE levels may remain elevated in patients for up to 1 year after administration of this antibody. 

Figure 10.1 Effect of botanicals on allergy mediator release from stimulated cells.

Spanish needles have also been found to have anti-allergy action at the level of mast cells and other allergy mediators.4 Spanish needles contains quercetin and ethyl caffeate, both of which have previously been shown to possess in vitro anti-inflammatory or anti-allergic mediator action.23,24 Quercetin5 has also been shown to stabilize mast cells and basophils, decrease leukotriene formation, and reduce release of histamine and other mediators.24,25 Anti-inflammatory effects have been demonstrated in rats after receiving aqueous extracts of Spanish needles leaves and stems.26,27 A related species, Bidens parviflora, has been reported to inhibit histamine release from rat mast cells in vitro.6 Spanish needles have been shown to inhibit the inflammatory mediator nuclear transcription factor kappaB (NF-kappaB) and its downstream inflammatory mediators in vitro.23... 

A negative prick test usually rules out food allergy mediated by IgE mechanisms. The PST with a commercial food allergen extract has a high negative predictive value (>95%), whereas a positive PST has only a 30%-40% positive predictive value (Burks and Sampson, 1992 Sampson, 1999a Nowak-Wegrzyn and Sampson,... 

Life-threatening anaphylactic reactions that rarely occur during general anesthesia are mostly due to neuromuscular blockers. They may be due to cross-allergy mediated by drug-specific IgE antibodies to the quaternary ammonium moiety of the neuromuscular blocker molecule, perhaps with a contribution from IgE-independent mechanisms. Quaternary ammonium compounds, such as benzalkonium, in cosmetics and toiletries may play a role in sensitization (7). 

Narita S, Goldblum RM, Watson CS et al (2007) Environmental estrogens induce mast cell degranulation and enhance IgE-mediated release of allergie mediators. Environ Health Perspect 115(l) 48-52... 

Type I allergies are mediated by immunoglobulin E (IgE). Unlike the other immunoglobulins (G,M,A, and D), which are part of the essential defense... 

In addition to the proteins discussed above, a large number of reactive chemicals used in industry can cause asthma and rhinitis. Hypersensitivity pneumonias have also been described. Isocyanates and acid anhydrides are industrial chemicals that cause occupational asthma. Acid anhydrides, such as phthalic anhydride, seem to cause mainly type I reactions, whereas the IgE-mediated mechanism explains only a part of the sensitizations to isocyanates. Several mechanisms have been suggested, but despite intensive research no models have been generally accepted. The situation is even more obscure for other sensitizing chemicals therefore, the term specific chemical hypersensitivity is often used for chemical allergies. This term should not be confused with multiple chemical sensitivity (MCS) syndrome, which is a controversial term referring to hypersusceptibility to very low levels of environmental chemicals. ... 

In type III or immunocomplex-mediated allergy, IgG antibodies form complexes with antigen. At low exposures, the body is able to remove diese complexes, but if there is a severe exposure, immunocomplexes release a variety of proinflammatory cytokines. The involvement of this mechanism is clearest in serum sickness. This mechanism is also considered to be most important in the development of extrinsic allergic alveolitis (hypersensitivity pneumonitis, especially... 

Eclazolast (41) is an antiallergy compound which inhibits release of mediators of allergy. One reported synthesis involves the simple e.ster exchange of methyl 2-benzoxazolecarboxylate (40) with 2-ethoxyethanol catalyzed by sulfuric acid [13]. 

Allergy. Figure 1 Type I Anaphylactic Reaction IgE-bearing mast cells are activated by allergens to release mediators of acute allergic reactions. 

Allergy. Figure 5 Glucocorticoids regulate gene expression, resulting in a decrease of cytokine and mediator release. 

Allergy. Figure 6 Anti IgE antibodies prevent IgE from binding to their receptors on mast cells, and thus from releasing allergic mediators. 

Fujiwara M, Hirose K, Kagami S. Takatori H. Waka-shin H, Tamachi T, Watanabe N. Saito Y. Iwamoto I. Nakajima H T-bet inhibits both Th2 cell-mediated eosinophil recruitment and Th17 cell-mediated neutrophil recruitment into the airways. J Allergy Chn Immunol 2007 119 662-670. 

Liu YJ Thymic stromal lymphopoietin and 0X40 ligand pathway in the initiation of dendritic cell-mediated allergic inflammation. J Allergy Clin Immunol 2007 120 238-246. 

Shim JY, Kim BS, Cho SH, Min KU, Hong SJ Allergen-specific conventional immunotherapy decreases immunoglobulin E-mediated basophil histamine releasability. Clin Exp Allergy 2003 33 52-57. 

Stingl G. Maurer D IgE-mediated allergen presentation via FceRI on antigen-presenting cells. Int Arch Allergy Immunol 1997 113 24-29. 

Logan MR, Odemuyiwa SO, Moqbel R Understanding exocytosis in immune and inflammatory cells the molecular basis of mediator secretion. J Allergy Clin Immunol 2003 111 923-932. 

Stellato C, de Crescenzo G, Patella V, Mastronardi P. Mazzarella B, Marone G Human basophil/mast cell releasability. XL Heterogeneity of the effects of contrast media on mediator release. J Allergy Clin Immunol 1996 97 838. 

---