Mast cell activation tests by flow cytometry: A new diagnostic asset?

Abstract

Since the late nineties, evidence has accumulated that flow-assisted basophil activation test (BAT) might be an accessible and reliable method to explore the mechanisms governing basophil degranulation and diagnostic allowing correct prediction of the clinical outcome following exposure to the offending allergen(s) and cross-reactive structures for different IgE-dependent allergies and particular forms of autoimmune urticaria. Although the BAT offers many advantages over mediator release tests, it is left with some weaknesses that hinder a wider application. It is preferable to perform the BAT analysis within 4 h of collection, and the technique does not advance diagnosis in patients with non-responsive cells. Besides, the BAT is difficult to standardize mainly because of the difficulty to perform large batch analyses that might span over several days. This article reviews the status of flow cytometric mast cell activation test (MAT) using passively sensitized mast cells (MCs) with patients' sera or plasma (henceforth indicated as passive MAT; pMAT) using both MC lines and cultured MCs in the diagnosis of IgE-dependent allergies. In addition, this paper provides guidance for generating human MCs from peripheral blood CD34 + progenitor cells (PBCMCs) and correct interpretation of flow cytometric analyses of activated and/or degranulating cells. With the recent recognition of the mas-related G protein-coupled receptor X2 (MRGPRX2) occupation as a putative mechanism of immediate drug hypersensitivity reactions (IDHRs), we also speculate how direct activation of MCs (dMAT)-that

Scientific Opinion on development needs for the allergenicity and protein safety assessment of food and feed products derived from biotechnology

“…hMAT also displayed a very high sensitivity which would be very useful in assessing the unintended presence of allergen during food production (Bahri et al, 2018 ). This technique may be superior to other MAT using other sources of MC or LAD‐2 cell lines (Elst et al, 2021 ), and its development will require collaboration and funding support.…”

The Asian wasp Vespa velutina nigrithorax: Entomological and allergological characteristics

“…72 Basophil reactivity is useful for confirming IgE-mediated activation, and basophil sensitivity is more sensitive for detecting changes over time, as could be the case for allergen immunotherapy. 72,73 In the study of new allergens, basophil activation tests (BATs) play a definitive role in confirming the allergic nature of the disease. 71,72 In a group of 10 patients who had experienced V. velutina anaphylaxis, Rodríguez et al demonstrated positive BAT reactivity against V. velutina whole venom (8/10) and its allergen components Vesp v 1 (5/10) and Vesp v 5 (7/10), all at very low concentrations.…”

“…Markers such as CD63 and CD203c can be used to identify activated basophils, 71–74 with CD63 the best clinically validated test 72 . Basophil reactivity is useful for confirming IgE‐mediated activation, and basophil sensitivity is more sensitive for detecting changes over time, as could be the case for allergen immunotherapy 72,73 . In the study of new allergens, basophil activation tests (BATs) play a definitive role in confirming the allergic nature of the disease 71,72 .…”

“…44,49 Thus, inhibition studies performed in patients with simultaneously positive sIgE to CCDs (MUXF3) and to Vesp v 1 showed extensive reduction (>90%) of sIgE reactivity to Vesp v 1. 49 and CD203c can be used to identify activated basophils, [71][72][73][74] with CD63 the best clinically validated test. 72 Basophil reactivity is useful for confirming IgE-mediated activation, and basophil sensitivity is more sensitive for detecting changes over time, as could be the case for allergen immunotherapy.…”

“…Basophils are often employed as target cells for ex vivo assays to detect the biologic activity of IgE sensitization. Markers such as CD63 and CD203c can be used to identify activated basophils, 71–74 with CD63 the best clinically validated test 72 . Basophil reactivity is useful for confirming IgE‐mediated activation, and basophil sensitivity is more sensitive for detecting changes over time, as could be the case for allergen immunotherapy 72,73 .…”