leukotriene-c4 and Insect-Bites-and-Stings

Potent allergens such as hymenoptera venoms are capable of inducing severe and life threatening clinical reactions. Percentage of false negative results obtained by the usual diagnostical methods is comprised between 10 and 25%.. Evaluation of the sensitivity and the specificity of cellular tests and particularly evaluation of a new flow cytometric method.. Forty-five allergic patients having experienced a local, a systemic reaction or an anaphylactic shock and 10 controls having undergone hymenoptera stings without clinical reactions were selected on the basis of the clinical history, skin tests and specific IgE. Three cellular tests were performed on the same cell suspensions and in the presence of 2 ng/mL of rIL3: histamine release (RIA), leukotriene C4 release (ELISA) and basophil activation test (flow cytometry after double anti-IgE FITC, anti-CD63 PE labelling).. As compared to the clinical history, sensitivities of skin tests, specific IgE, flow cytometry, histamine release and leukotriene release were, respectively; 85%, 88%, 100%, 89% and 100%. Flow cytometric analysis of basophil activation showed a significant decrease of the mean fluorescence density and number of IgE positive cells and a significant increase of the number of CD63 positive cells. The 10 controls tested by flow cytometry were negative.. As compared to the clinical history and to the other parameters tested here, flow cytometry showed a high sensitivity and a high specificity. The excellent correlation observed between this method and the other cellular tests such as histamine and leukotriene release are in favour of the specificity of flow cytomery and in favour of the use of this method for venom allergy diagnosis.

Topics: Adolescent; Adult; Allergy and Immunology; Animals; Antigens, CD; Arthropod Venoms; Basophils; Biomarkers; Child; Flow Cytometry; Histamine Release; Humans; Hymenoptera; Hypersensitivity; Immunoglobulin E; Insect Bites and Stings; Leukocytes; Leukotriene C4; Middle Aged; Platelet Membrane Glycoproteins; Sensitivity and Specificity; Skin Tests; Statistics as Topic; Tetraspanin 30

With regard to an observation of anaphylaxis after a mosquito bite, we have shown by new immunobiological parameters and clinical investigations: Skin tests, specific IgE, Tests of Activation of basophils by flow cytometry (on basophils and total blood) and measurement of Leucotriene LTC4, the objective reality of the mechanism of IgE-dependent hypersensitivity (HS). This observation is correlated with rare work in support of true IgE-mediated allergy to mosquito 9 authors having used skin tests, PK in 1984 and immunoblot.

Topics: Adult; Anaphylaxis; Animals; Basophils; Culicidae; Humans; Immunoglobulin E; Insect Bites and Stings; Leukotriene C4; Mice; Skin Tests

Mosquito bites are known to sensitize persons, and the most common cutaneous reactions are immediate wheals and delayed bite papules. Anti-saliva IgE and IgG4 antibodies are common in mosquito-sensitive subjects, but mediator release in bite reactions is not known.. We used the microdialysis technique to measure in vivo histamine and leukotriene C4 release after bite challenges in six mosquito-sensitive subjects. One individual who was not sensitive to bites volunteered as a control subject.. Three of the six mosquito-sensitive subjects had large wheals and showed clearly increased histamine concentrations 30 to 45 minutes after the bites. The histamine levels declined to baseline value within 2 hours; thereafter, one subject showed a second increase in histamine concentration. Four of the six mosquito-sensitive subjects showed increased leukotriene C4 concentrations, and this mediator seemed to be released somewhat later than histamine.. The increased histamine and leukotriene C4 release observed in this study suggests that both mediators are involved in the early allergic response caused by mosquito bites.

Topics: Adult; Aedes; Animals; Female; Histamine; Histamine Release; Humans; Insect Bites and Stings; Leukotriene C4; Male; Microdialysis; Middle Aged; Skin