Flow cytometric analysis of in vitro activated basophils, specific IgE and skin tests in the diagnosis of pollen‐associated food allergy

• Published in: Cytometry. Part B, Clinical cytometry Clinical cytometry, 2005-03, Vol.64B (1), p.28-33
• Main Authors: Ebo, Didier G., Hagendorens, Margo M., Bridts, Chris H., Schuerwegh, Annemie J., De Clerck, Luc S., Stevens, Wim J.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Antigens, CD - metabolism; apple allergy; basophil; Basophils - immunology; Basophils - metabolism; Betula - immunology; birch; CD63; cross‐reactivity; Female; flow cytometry; Flow Cytometry - methods; Food Hypersensitivity - diagnosis; Food Hypersensitivity - immunology; Humans; immunoglobulin E; Immunoglobulin E - blood; Male; Malus; Malus - immunology; Middle Aged; oral allergy syndrome; Platelet Membrane Glycoproteins - metabolism; Pollen - immunology; ROC Curve; Sensitivity and Specificity; Skin Tests; Tetraspanin 30; Up-Regulation - immunology
• ISSN: 1552-4949; 1552-4957
• DOI: 10.1002/cyto.b.20042

Background Specific immunoglobulin E (IgE) and commercially available skin prick tests have been demonstrated to be unreliable methods to diagnose pollen‐associated food allergy. To evaluate the predictive value of the basophil activation test (BAT) in pollen‐associated food allergy, the apple‐mediated oral allergy syndrome (OAS) in patients with birch pollinosis was chosen as a representative model. Methods Patients with birch pollen allergy and a history of apple‐mediated OAS (OAS+, n = 29), patients with birch allergic without OAS (OAS−, n = 22), and healthy controls (HC, n = 10) without birch pollen allergy and OAS were included. Apple IgE was quantified by the CAP FEIA method. Skin prick tests were performed with a Jonagold apple extract. Flow cytometric analysis of basophils activated with the same Jonagold extract was based on double staining with anti‐IgE/anti‐CD63 monoclonal antibodies. Results Comparison between OAS+ subjects and HC showed sensitivities and specificities of 96% and 100% for apple IgE and 88% and 100% for the apple skin prick test, respectively. For the BAT, sensitivity and specificity were 100%. In contrast, when nonresponders on the BAT were considered, sensitivity decreased to 90%. In a separate analysis between OAS+ and OAS− subjects, specificities decreased to 30% for apple IgE and to 80% for the apple skin test, respectively. The BAT reached a sensitivity of 88% and a specificity of 75%. Conclusion Flow cytometry‐assisted quantification of in vitro basophil activation seems to be a reliable instrument in the diagnosis of this model of pollen‐associated food allergy. In addition, this study reemphasizes that the specificity of diagnostic allergy tests decreases considerably when, apart from HC, control individuals with cross‐reactive antibodies are included. © 2005 Wiley‐Liss, Inc.