In vitro allergy diagnosis: should we follow the flow?

Abstract

During the last 5 years, an increasing number of studies have demonstrated that flow cytometric quantification of in vitro basophil activation can be a quite performant and reliable tool to measure IgE-dependent allergen-specific responses in allergic patients. So far, most assays have used CD63 as a basophil activation marker and native allergen extracts for stimulation. However, other basophil markers and recombinant allergens have recently been introduced. The technique has been applied for the diagnosis of allergy to pollen, house dust mite, food, natural rubber latex, hymenoptera venom and drugs. In addition, the technique has proven to be useful in non-IgE-mediated reactions such as hypersensitivity to drugs as well as detection of auto-antibodies in chronic urticaria. This review will focus on some specific issues: (1) principles of flow cytometric analysis of in vitro-activated basophils, (2) general technical aspects of the technique (including passive sensitization), (3) clinical applications and (4) recommendations for further development and evaluation of the technique.

In vitro Analysis of Birch-Pollen-Associated Food Allergy by Use of Recombinant Allergens in the Basophil Activation Test

“…The CD63 glycoprotein is present on the membrane of cytoplasmic granules and expressed only to an extent of less than 5% on the outside membrane of resting basophils, but with high density on activated basophils after the fusion of these granules with the cytoplasmic membrane [1]. Flowcytometric detection of basophil activation by CD63 expression has been studied in diagnosing immediate-type allergy to various allergens such as natural rubber latex, foods, hymenoptera venoms, aeroallergens (cypress pollen, house dust mites) and drugs [1, 2, 3, 4, 5]. This new in vitro method has been commonly referred to as basophil activation test (BAT) [2]or test of basophil altered surface immunofluorescence detected by cytometry [3].…”

A Cytologic Assay for Diagnosis of Food Hypersensitivity in Patients With Irritable Bowel Syndrome

“…6 More recently, the flow cytometric basophil activation test, based on the demonstration of altered membrane phenotypes on allergen-activated basophils, with up-regulation, surface expression, and cytofluorometric detection of CD63 protein, has been applied to allergy diagnosis. 7 However, no studies have evaluated the diagnostic accuracy of the test in FH diagnosis in patients with IBS-like clinical symptoms.…”

CD 63 Cell Expression Detected by Flow-Cytometric Determination and Basophil Activation in Allergic Patients

“…As the technique closely resembles the in vivo pathway leading to symptoms, it is theoretically justified to anticipate that the technique might further be adopted for other objectives such as differentiation between clinically relevant and irrelevant ematochemical exams, quantitative evaluation of residual allergenicity, componentresolved diagnosis, and last but not least, to select and monitor specific immunotherapy (11).…”