162 research outputs found

    Inhibition of CD203c membrane up-regulation in human basophils by high dilutions of histamine: a controlled replication study

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    none5noPrevious research suggests that human basophil activation may be inhibited by histamine even at extremely low doses (high dilutions). In our experiment, membrane up-regulation of CD203c, which proved to be a more consistent activation marker than CD63, was significantly inhibited in samples treated with histamine at the dilutions of 2C, 12C, 14C, 15C and 16C. Control water dilutions/succussions did not show any significant effect. Therefore, using a strictly standardized flow cytometry protocol and a new dilution/succussion procedure, we have shown that low and high dilution of histamine do inhibit CD203c up-regulation in anti-IgE stimulated basophils.mixedS. Chirumbolo; M. Brizzi; R. Ortolani; A. Vella; P. BellaviteS. Chirumbolo; M. Brizzi; R. Ortolani; A. Vella; P. Bellavit

    Nonsteroidal anti-inflammatory drug hypersensitivity syndrome. A multicenter study I. clinical findings and in vitro diagnosis

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    ackground: We present the results obtained from the largest series of in vitro diagnostic tests ever reported in patients with clinically validated hypersensitivity to acetylsalicylic acid (ASA)/nonsteroidal anti-infl ammatory drugs (NSAID) compared with various categories of controls tolerating ASA/NSAIDs. This multicenter study, which was performed within the framework of the European Network for Drug Allergy (ENDA) group, showed that the basophil activation test (BAT), particularly when used with the 3 NSAIDs aspirin (ASA), diclofenac (DIC), and naproxen (NAP), allows us to confi rm the diagnosis of NSAID hypersensitivity syndrome. The results of the cellular allergen stimulation test (CAST) frequently correlate with those of the BAT, although not always. An unexpected fi nding was that basophil activation by NSAIDs is not an all-or-nothing phenomenon restricted to clinically hypersensitive patients, but that it also occurs in a dose-related manner in some NSAID-tolerant control individuals. Therefore, NSAID hypersensitivity appears as a shift in the normal pharmacological response to NSAIDs. These fi ndings allow us to formulate a new rational hypothesis about the mechanism of NSAID hypersensitivity syndrome, a mechanism that most authors continue to describe as “unknown.” Methods: We enrolled 152 patients with a history of hypersensitivity to NSAIDs and 136 control participants in 11 different centers between spring 2003 and spring 2006. Flowcytometric BAT was performed. Results: The most noteworthy results of our study were that 57% of 140 patients presented very clear-cut positive BAT results to multiple NSAIDs, and 16% were entirely negative. In about 27% of cases, positive results were obtained with 1 or 2 concentrations of a single NSAID. There is clearly a correlation between the results of BAT and CAST. Conclusions: BAT seems particularly indicated in patients with a clinical history of NSAID intolerance, and in whom a provocation test is not advisable for ethical, clinical, or other reasons

    Using Time-Resolved Fluorescence to Measure Serum Venom-Specific IgE and IgG

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    We adapted DELFIA™ (dissociation-enhanced lanthanide fluoroimmunoassay), a time resolved fluorescence method, to quantitate whole venom specific and allergenic peptide-specific IgE (sIgE), sIgG1 and sIgG4 in serum from people clinically allergic to Australian native ant venoms, of which the predominant cause of allergy is jack jumper ant venom (JJAV). Intra-assay CV was 6.3% and inter-assay CV was 13.7% for JJAV sIgE. DELFIA and Phadia CAP JJAV sIgE results correlated well and had similar sensitivity and specificity for the detection of JJAV sIgE against intradermal skin testing as the gold standard. DELFIA was easily adapted for detecting sIgE to a panel of other native ant venoms

    Differential response of human basophil activation markers: a multi-parameter flow cytometry approach

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    <p>Abstract</p> <p>Background</p> <p>Basophils are circulating cells involved in hypersensitivity reactions and allergy but many aspects of their activation, including the sensitivity to external triggering factors and the molecular aspects of cell responses, are still to be focused. In this context, polychromatic flow cytometry (PFC) is a proper tool to investigate basophil function, as it allows to distinguish the expression of several membrane markers upon activation in multiple experimental conditions. </p> <p>Methods</p> <p>Cell suspensions were prepared from leukocyte buffy coat of K2-EDTA anticoagulated blood specimens; about 1500-2500 cellular events for each tested sample, gated in the lymphocyte CD45dim area and then electronically purified as HLADRnon expressing/CD123bright, were identified as basophilic cells. Basophil activation with fMLP, anti-IgE and calcium ionophore A23187 was evaluated by studying up-regulation of the indicated membrane markers with a two-laser six-color PFC protocol.</p> <p>Results</p> <p>Following stimulation, CD63, CD13, CD45 and the ectoenzyme CD203c up-regulated their membrane expression, while CD69 did not; CD63 expression occurred immediately (within 60 sec) but only in a minority of basophils, even at optimal agonist doses (in 33% and 14% of basophils, following fMLP and anti-IgE stimulation respectively). CD203c up-regulation occurred in the whole basophil population, even in CD63non expressing cells. Dose-dependence curves revealed CD203c as a more sensitive marker than CD63, in response to fMLP but not in response to anti-IgE and to calcium ionophore.</p> <p>Conclusion</p> <p>Use of polychromatic flow cytometry allowed efficient basophil electronic purification and identification of different behaviors of the major activation markers. The simultaneous use of two markers of activation and careful choice of activator are essential steps for reliable assessment of human basophil functions.</p

    Diversité des rejets de station d'épuration : leçons d'un petit bassin versant rural

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    Extrait de documentThese results confirm that treated wastewaters are variable from one site to another and according to time. However, self-monitoring data are now more and more available and will help us understanding this variability. Relationships between these parameters and those used in the frame of water quality models (such as biodegradable carbon) were found and will be used for the data bases of the programme.The treated wastewaters were found to contribute significantly to the deposition of particulate organic matter in the Grand Morin.Les résultats exposés dans le rapport confirment le fait que les rejets de station d'épuration sont non seulement très divers selon les installations mais aussi très variables dans le temps. Les raisons de cette variabilité temporelle sont encore obscures mais la généralisation des pratiques d'auto-surveillance permettra certainement dans un avenir proche de mieux l'appréhender. Afin de pouvoir exploiter ces données, nous nous sommes attachés à chercher des relations entre les paramètres" classiques " qui seront mesurés en routine dans ce cadre, et les variables utilisées par le PIREN Seine (en particulier le carbone organique biodégradable). Ces relations, très significatives, sont pour certaines différentes de celles qui avaient été observées sur les stations parisiennes et vont être utilisées pour une mise à jour des bases de données de rejets de STEP du programme. D'autre part, le travail conjoint avec le thème transversal modélisation a permis de mettre en évidence le rôle potentiel des dépôts en MES dans le Grand Morin. Les rejets de station d'épuration contribuent de façon significative à ces dépôts et c'est justement la fraction particulaire des rejets qui porte l'essentiel de leur variabilité. Ces hypothèses concernant le fonctionnement de la rivière seront donc mises à l'épreuve de nouvelles campagnes l'année prochaine

    IgE-mediated anaphylaxis after first intravenous infusion of cyclosporine.

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    BACKGROUND: Intravenous administration of cyclosporine, which contains Cremophor EL (a polyethoxylated castor oil; BASF, Berlin, Germany), has occasionally resulted in an anaphylactic reaction. An apparent hypersensitivity reaction (bronchospasm and decrease in blood pressure) had occurred during heart transplantation in a 59-year-old woman after intravenous infusion of cyclosporine. Subsequent oral administration of cyclosporine precipitated no reaction. OBJECTIVE: The purpose of this study was to attempt to ascertain the mechanism responsible for the anaphylactic reaction. METHODS: Hypersensitivity investigations, including total serum IgE and allergen-specific IgE quantifications, skin testing, and basophil activation tests by flow cytometric determination of CD63 upregulation were undertaken in the study patient and in two healthy control subjects who were free of medication. RESULTS: The results of intradermal testing with Cremophor EL were positive after 15 minutes in the study patient only. Both cyclosporine and Cremophor EL induced considerable activation of the basophils from our study patient, with an upregulation of CD63 expression from 1% to 39% and 55%, respectively. In contrast, the expression of CD63 on basophils from the two control subjects remained essentially unchanged. CONCLUSIONS: The negative investigative findings in the control subjects, the patient's clinical manifestations in temporal relationship to the infusion, her positive results on intradermal testing with Cremophor, the basophil activation test results, and her uneventful course after oral administration of cyclosporine strongly support the presence of IgE antibodies to Cremophor EL in our patient
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