CCR3 as a single selection marker compared to CD123/HLADR to isolate basophils in flow cytometry: Some comments

Basophil Activation Tests (BAT): Wheat and Chaff

“…The Authors stressed on the commonly recognized role exerted by CD63 and CD203c markers in BAT, while existing further suggestions [2,3] but they never addressed the critical issue of basophil electronic capture in flow cytometry (FC), i.e. cell phenotyping protocols [4,5]. Advantages of BAT in allergy diagnosis are closely related to the simple fact that this assay is a cell based investigation procedure [6] and therefore, while its major value is the ability in diagnosing either an IgE-or non IgE-mediated allergy, immunotherapy and anaphylaxis and to prevent the ethical issue associated to skin tests [1], a main concern is represented by the interpretation of activation markers in a good phenotyping FC approach [7].…”

Immunotherapy in allergy and cellular tests

“…Some concern raises from BAT protocol in itself. Following CD63 membrane up-load should be reviewed and revised taking into account the fact that this marker is highly influenced by basophil ability to respond to any allergen or anti-IgE challenge 78,[189][190][191] : BAT CD63 sensitivity ranges from 17% to 94%, with a specificity of 79-100%, 40 while CD203c resulted in a higher performance 192 : this would suggest that CD203c should be a more reliable marker to uscertain allergy desensitization but it is highly influenced by IL-3 activity and is not always directly related to degranulation.…”

“…189,193 Phenotyping markers, likewise molecules tracing the activation mechanism of basophil, are restricted to very few molecules in available commercial kits. Each marker has its own analytical hallmark, which may affect the performance of the assay, 190,194 therefore a BAT made up within one's own laboratory might provide the researcher with more diagnostic advantages. Building up a CD45/CD123 gating protocol and investigating the expression of CD63 and CD203c, Subbarayal et al, showed that BAT was sensitive to IgG 4 blocking immunoglobulins produced by birch pollen allergens as well as other cross reactive ones, such as Mal d 1 (hazelnut) and Cor a 1 (apple) for food allergy.…”

“…CD164 was reported as a reliable marker to investigate pollen allergy diagnosis 206 but its evidence in immunotherapy is yet scanty. The 4-color flow cytometry protocol CD123/HLA-DR with CD63 and CD203c 189,190 was used in peanut-allergic children with encouraging results. 207 BAT protocol was built within the research laboratory and allowed to assess the hypothesis that effector cell anergy could contribute to clinical desensitization.…”

Opioid non-IgE mediated effects in a BAT assay on drug hypersensitivity to pholcodine

“…Actually, CD203c is a selective marker for basophil phenotyping, but some comments were recently raised about its reliability in flow cytometry protocol (3). The evaluation of % activated basophils may be perturbed therefore by preanalytical errors (4). Basophils preactivated by phenotyping anti-IgE, may down regulate surface FceRI so resulting in a poor anti-IgE response.…”