Cellular in vitro Assays in the Diagnosis of Hymenoptera Venom Allergy

Abstract

Background: The current diagnostic procedures of anaphylactic reactions to hymenoptera stings include intradermal tests, venom-specific IgE (sIgE) and possibly sting challenge tests. Sometimes, the culprit insect remains unidentified. The usefulness of the cellular assays CAST®-ELISA and Flow-CAST® in the management of hymenoptera venom allergy was investigated. Methods: 134 patients with systemic reactions after a yellow jacket wasp and/or honey bee sting and 44 healthy controls underwent skin tests, as well as determination of sIgE (CAP-FEIA), leukocyte sulfidoleukotriene release (CAST-ELISA) and basophil CD63 expression (Flow-CAST) upon insect venom stimulation. The clinical diagnosis based on the history alone served as reference. Sensitivity, specificity, and positive and negative predictive value of all methods were compared. Concordance and correlations among methods were calculated. Results: Sensitivity and specificity of all in vitro tests were consistently high. The combination of all tests (skin tests, sIgE, combined cellular assays) yielded a positive predictive value of 100% for both venoms, if all 3 were positive, and a negative predictive value of 100%, if at least 1 test was positive. Relative specificities were considerably higher for the cellular assays (honey bee: CAST 91.1%, Flow-CAST 85.7%; yellow jacket wasp: CAST 98.4%, Flow-CAST 92.1%) and allow the detection of the culprit insect in patients with reactivity to both insects. The concordance between methods was good. There is no correlation between severity of clinical reaction and cellular assays. Conclusion: CAST-ELISA and Flow-CAST are valuable additional diagnostic tools for establishing the true culprit insect in patients with unclear clinical history or sensitization to both insects.

Diagnostic Tests Based on Human Basophils: More Potentials and Perspectives than Pitfalls

“…The utility of BAT in hymenoptera venom hypersensitivity [34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56]has been confirmed hitherto by many more than the two studies quoted by Kleine-Tebbe et al [1] (table 2). The main benefit of BAT in that indication is that it may confirm clinical history in the absence of positive skin tests or positive allergen-specific IgE.…”

“…Many of these studies have been reviewed recently [8,9,10]. Herewith, tables 1, 2, 3, 4, 5, 6, 7summarize the results of validated clinical studies performed with various allergens such as inhalant allergens [25,26,27,28,29,30,31,32,33] (table 1), hymenoptera venoms [34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56] (table 2), latex [57,58,59,60,61,62,63] (table 3), food [64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80] (table 4) and drugs [81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,…”

“…The main benefit of BAT in that indication is that it may confirm clinical history in the absence of positive skin tests or positive allergen-specific IgE. In addition, by using BAT, the insect responsible for clinical sensitivity may be detected leading to a more specific indication for immunotherapy [43, 45]. There is no reason to cast doubt on the results, as possibly due to aggregated platelets [1], since specific investigations on that point [54, 126] have been negative.…”

“…There is no reason to cast doubt on the results, as possibly due to aggregated platelets [1], since specific investigations on that point [54, 126] have been negative. In the largest series reported so far [44, 45], correlation of BAT with skin tests and specific IgE ranged from 0.71 to 0.82. In a recent large series of 118 patients, a definite diagnosis of venom anaphylaxis [history + unequivocal single positive specific IgE (sIgE) and skin test] was observed in only about 55% of the patients.…”

Zelluläre In-vitro-Allergiediagnostik

“…Verschiedene Arbeiten [11] [33]. Bei Insektengiftallergikern (40 min Stimulation mit 10 ng/ml Gift, ALK abello) wurde beispielsweise für Bienengift eine Sensitivität von 94%, Spezifität 93% ("cut-off " 266 pg/ml SLT) und für Wespengift eine Sensitivität von 89%, Spezifität 96% gezeigt [41]. Andere Autoren zeigten Sensitivitäten zwischen 68 und 100% und Spezifitäten zwischen 67 und 100% (Details s. [41]).…”