Effect of lidocaine on histamine release and Ca2+ mobilization from mast cells and basophils

Background : Various anesthetic drags have been known to induce allergic reactions, which have been caused by histamine release from mast cells/basophils. Although lidocaine is reported to suppress allergic reactions, there have been no reports about lidocaine's direct effects to inhibit histamine release from mast cells/basophils. Methods : We examined the effect of lidocaine on histamine release in vitro from freshly extracted as well as cultured mast cells and basophils. Additionally, the effects of lidocaine on intracellular calcium concentration were monitored by assessing Fura-2 signals in cultured cells. Results : Lidocaine (10^?3～10^?2 M: approximately 234～2340 μg/ ml) inhibited both the IgE-dependent and IgE-independent histamine release from all mast cells/basophils in a dose-dependent manner. However, lidocaine inhibited the IgE-dependent response more than the IgE-independent response (P<0.01). Lidocaine also inhibited increases in intracellular Ca²⁺ to a greater extent after IgE-dependent stimulation as compared with IgE-independent stimulation. The degree of the inhibition of histamine release by lidocaine appeared to parallel decreases in Ca²⁺ mobilization. Conclusions : Our results indicate that lidocaine directly inhibits histamine release from both rodent mast cells and human basophils in vitro at concentrations from 10^?3 to 10^?2 M (234 to 2340 μg/ml). That may be influenced by Ca²⁺ mobilization. Although these results are not immediately relevant to clinical practice, allergic reaction caused by direct effect of lidocaine seems to be impossible.     

Chemokines and the allergic response

Abstract The β subfamily of chemokines contains-cytokine-like factors which are chemotactic for human basophils and eosinophils. They also stimulate these cells to secrete pro-inflammatory substances such as histamine or eosinophil cationic protein. MCAF/MCP-1, MCP-2, MCP-3, RANTES and MIP-lα all attract and stimulate basophils; MCP-I and MCP-3 are the most potent. RANTES, MCP-3 and to a lesser degree MIP-Ia are chemotactic factors and activators of eosinophils. Cytokines such as IL3, IL5 and GM CSF can augment the responses of these cells to the various chemokines and function as primers. These substances may have particular importance as mediators of allergic inflammation, particularly the late phase component of the response.     

Tryptase and histamine release due to a sting challenge in bee venom allergic patients treated successfully or unsuccessfully with hyposensitization *

Background: Hyposensitization with bee venom leads to full protection in most, but not all patients with IgE-mediated systemic reactions to bee stings. Objective: To determine the relationship of clinical reactivity to the release of mediators and to changes of antibody concentrations in the peripheral circulation at a bee sting challenge test. Methods: Blood was sampled before (0 min) and at 15, 60 and 180 min after a sting challenge from 19 patients on hyposensitization. Of these, six still reacted and 13 were protected. Histamine, mast cell tryptase, bee venom-specific IgE and IgG in the serum, and histamine release from peripheral blood leucocytes (PBL) upon exposure to bee venom were determined. Results: Tryptase above the detection level was found only at 15 (60)min in 4/6 (1/6) patients who reacted. After the sting challenge there was a significant increase of the histamine levels in patients who reacted at 15 min (P < 0.05) and in patients who did react at 60 and 180 min (P < 0.01). The total histamine content of PBL was significantly decreased after 15 and 60 min in patients who reacted (P < 0.01) and in those that did not (P < 0.05). Bee venom-induced histamine release was significantly reduced in patients reacting and those that did not at 15 min (P / 0.05), and was significantly decreased in reactors also at 60 and 180 min (P < 0.05/0.01). Specific IgG antibodies showed a minor decrease (P < 0.05) after the sting challenge in both groups, whereas specific IgE did not change significantly. Conclusion: These results indicate that bee venom anaphylaxis is associated with the release of mediators from both mast cells as well as basophils. Successful hyposensitization does not induce a state of immunological non-reactivity, but rather alters the magnitude and the pattern of mediator release.     

Automated Measurement of Human Basophil Degranulation

Basophils disappear after challenge with specific antigen. A human basophil degranulation test has been carried out on a slide using an enriched cell suspension. On each slide, the same volume of cell suspension was deposited in wells with antigen diluted in buffer or with buffer only (control). The basophil count was made on an equal number of randomly distributed microscopic fields either by eye (optical) or by image analyser (automatic).
In 35 subjects, the correlation coefficient between the numbers of non-degranulated basophils counted by eye and by image-analyser on control wells was found to be r = 0.91, P < 10⁻⁸.
In 12 patients (6 with hydatidosis and 6 widi schistosomiasis), the percentage of degranulation with three antigen dilutions was measured. The correlation between the results obtained by eye and by image-analyser reached 0.76 (P < 10⁻⁷).
The authors now use the automated measurement of human basphil degranulation routinely.     

Relevance of Ara h1, Ara h2 and Ara h3 in peanut-allergic patients, as determined by immunoglobulin E Western blotting, basophil–histamine release and intracutaneous testing: Ara h2 is the most important peanut allergen

BACKGROUND: A number of allergenic proteins in peanut has been described and the relative importance of these allergens is yet to be determined. OBJECTIVES: We have investigated the relevance of previously identified peanut allergens in well-characterized peanut-allergic patients by in vitro, ex vivo and in vivo assays. METHODS: Thirty-two adult peanut-allergic patients were included based on careful and standardized patient history and the presence of peanut-specific IgE. The diagnosis peanut allergy was confirmed using double-blind placebo-controlled food challenges in 23 patients. Major peanut allergens Ara h1, Ara h2 and Ara h3 were purified from peanuts using ion-exchange chromatography. IgE immunoblotting was performed and IgE-cross-linking capacity was examined by measuring histamine release (HR) after incubating patient basophils as well as passively sensitized basophils with several dilutions of the allergens. Intracutaneous tests (ICTs) using 10-fold dilution steps of the purified allergens and crude peanut extract were performed. RESULTS: Ara h2 was recognized most frequently (26 out of 32) in all tests and induced both positive skin tests and basophil degranulation at low concentrations, whereas Ara h1 and Ara h3 were recognized less frequently and reacted only at 100-fold higher concentrations as analysed with HR and intracutaneous testing (ICT). Next to the three tested allergens, proteins with molecular weights of somewhat smaller than 15 kDa were identified as a IgE-binding proteins on immunoblot in the majority of the patients (20 out of 32). CONCLUSION: We conclude that Ara h2 is, for our patient group, the most important peanut allergen, and that previously unidentified peanut proteins with molecular weights of somewhat smaller than 15 kDa may be important allergens as well. ICT in combination with basophil-HR and IgE immunoblotting provides insight in the patient specificity towards the individual peanut allergens.     

Anti-IgE induces the opening of non selective cation channels on human basophils

Summary— Basophils play a major role in allergic reactions — particularly in late phase reactions — by releasing histamine and other mediators of inflammation. Although transmembrane ion fluxes are thought to play an important role in the modulation of histamine release, little is known about ion pathways through the basophil membrane. We thus studied human basophils from normal subjects ( n = 25 cells) with the patch-clamp method. We observed that IgE-dependent activation of human basophils led to the opening of non selective cation channels with a 20pS conductance. This was obtained when the patch pipette was applied onto the cell surface and sealed onto it in order to measure transmembrane currents on a small surface of intact basophils (cell-attached configuration). Non selective channels with the same 20pS conductance were also observed when a membrane patch was detached from basophil and its inner side placed in a Ca²⁺-containing medium (inside-out configuration). These data are a first contribution of the patch-clamp method in the understanding of ion movements in human basophils.     

Influenza A virus enhances allergic histamine release

Histamine release was examined in leukocyte suspensions from patients allergic to house dust mite, grass pollen, birch pollen or cat dander. Influenza A virus was found to enhance the antigen-induced mediator release, but did not cause release of histamine from the cells per se. Also histamine release induced by anti-IgE in cell suspensions from normal individuals was enhanced by virus. The potentiating effect of influenza A virus might be due to neuraminidase on the surface of virus, since a similar effect was caused by a purified neuraminidase obtained from Vibrio cholerae, and the effect of virus as well as the neuraminidase was completely abolished by a potent neuraminidase inhibitor. The synergistic enhancement in IgE-mediated histamine release by virus could be of significance for the conversion from latent to manifest asthma.