Flow CAST®
Basophil Activation Test (BAT) - A Safer Alternative for Your Patients
Basophil Activation is a biomarker of in vivo allergic reaction that offers a different approach to traditional allergy tests by creating the allergic response in a test tube. The Basophil Activation Test (BAT) can be used for the in vitro detection of immediate type allergic reactions and hypersensitivities to suspected allergens.
BAT is able to detect both IgE and non-IgE mediated allergies, making it suitable for the diagnosis of a range of different types of allergy, including food and drug allergies.
The Flow CAST® is intended for the determination of basophil activation in patient whole blood samples by flow cytometry.
Thanks to its easy protocol and smart marker combination the first results can be obtained within one hour - perfect conditions for
routine laboratories.
Applications
The Flow CAST® system represents a significant step forward in in vitro allergy testing, allowing the simple detection of Basophil Activation on whole blood samples. It uses a dual labelling system to identify basophils in whole blood samples, negating the requirement for lengthy and labour intensive leukocyte isolation steps.
Using a flow cytometer, basophils are identified in the sample by a specific marker (CCR3) and then the level of CD63 is analysed on this sub-population to give a read out of the response to a purified allergen which is added to the sample.
The Flow CAST system, together with the CAST ELISA, is particularly suited for the following types of allergies:
Drug hyper-sensitivites (e.g. anaesthetics, antibiotics, NSAIDs)
Food allergies
Bee and wasp stings
Benefits
The BÜHLMANN CAST® assays detect immediate type allergic reactions and hypersensitivities to suspected allergens.
In some cases, specific IgE fails to demonstrate absolute diagnostic reliability. This happens mainly in more complex reactions such as drug, venom or food allergies. The CAST® (Cellular Allergen Stimulation Test) allergy assays will identify both IgE and non-IgE allergies.
Patient Safety
Oral food challenges can be unpleasant and stressful for patients and their families, as well as posing a danger to the patient. Patients undergoing oral food challenges are often young children; food allergy is estimated to affect 5-8% of toddlers, compared with only 1-2% of adults1 .
BAT is a much safer alternative to an oral food challenge for your patients. Offering BAT before an oral food challenge test will significantly reduce the number of patients having to undertake an oral food challenge.
A peanut study undertaken by Santos et al. in 2014 has shown a 67% reduction in the need for oral food challenges3 .
Improved Workflow for the Flow CAST® Basophil Activation Test
The Flow CAST kit wash buffer, used to reconstitute the cell pellet immediately after red blood cell lysis, now includes a stabiliser. This allows for the cells to be fixed, with an additional thirty-minute incubation of the samples at room temperature.
Previously, the samples needed to be analysed using flow cytometry immediately following completion of the Flow CAST protocol, but the added stabiliser now means the samples can be analysed up to five days after completion of the protocol, if stored at 2-8C and protected from light.
This change significantly improves workflow in laboratories, allowing for samples to be reliably fixed, stored and then analysed on subsequent days, in case instrumentation is overwhelmed. This gives the laboratory additional time to analyse these samples, making it easier for them to plan instrumentation and staffing resources.
Product Information
| Method | Flow Cytometry | ||
|---|---|---|---|
| Method | Flow Cytometry | Time to Result | 1 h (approx.) |
| Method | Flow Cytometry | Sample Type | 50 µl EDTA blood |
| Method | Flow Cytometry | Marker | CCR3-PE / CD63-FITC |
| Method | Flow Cytometry | Flow CAST is CE Marked | |
Videos
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Webinar: Clinical Applications of the Basophil Activation Test in Food Allergy
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Watch a quick overview of the BÜHLMANN Flow Cast Basophil Activation Test Procedure
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Basophils as Biomarker for Potency and Efficacy of Drugs in Development Flow CAST®
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The Application of Data Driven Approaches to Flow Cytometric Analysis of Basophil A
Publications
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1. Food Allergy: Flow CAST® Citation List
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2. Diagnosis of Immediate-Type ß-Lactam Allergy In Vitro by Flow-Cytometric Basophil Activation Test and Sulfi doleukotriene Production: A Multicenter Study
De Week at al. J Investig Allergol Clin Immunol;Volume 19, Issue 2, 2009, Pages 91-109 -
3. Basophil activation test discriminates between allergy and tolerance in peanut-sensitized children.
Santos at al. Journal of Allergy and Clinical Immunology;Volume 134, Issue 3, September 2014, Pages 645–652 -
4. Road map for the clinical application of the basophil activation test in food allergy.
Santos, A.F. and Shreffler, W.G. Clin. & Exp. Allergy Volume 47, Issue 9, September 2017, Pages 1115–1124
Kinase Inhibition Assays for Drug Development
Measuring the activation of basophils has also become a useful tool as an in vitro surrogate for drug discovery for agents active in inhibiting allergic reactions and agents active in moderating other disease types that work through these common signaling pathways.
Several drug development projects are focusing on inhibition of the signaling pathways found in immune cells targeting key kinases to slow or prevent progression of diseases caused or modulated through the dysregulated activation of several immune cell types.
Any functional assay to detect the bioactivity of these kinases in a whole cell system is extremely helpful to screen and evaluate the potency of inhibitor compounds.
A basophil activation test perfectly matches the requirements of scientists:
Key kinase targets like SYK, BTK, PI3K δ and γ are also main components in basophil activation signaling pathways
The surface expression of CD63 is an extremely easy and clear parameter to quantify. BAT is a fully standardised assay with years of use in allergy labs. Therefore, basophil activation offers a powerful tool, measuring the inhibition of basophil activation by drug treatment