Use of a rat basophil leukemia (RBL) cell-based immunological assay for allergen identification, clinical diagnosis of allergy, and identification of anti-allergy agents for use in immunotherapy.

Food allergy is an important public health problem that affects an estimated 8% of young children and 2% of adults. With an increasing interest in genetically-engineered foods, there is a growing need for development of sensitive and specific tests to evaluate potential allergenicity of foods and novel proteins as well as to determine allergic responses to ensure consumer safety. This review covers progress made in the field of development of cell models, specifically that involving a rat basophil leukemia (RBL) cell-based immunoassay, for use in allergen identification, diagnosis, and immunotherapy. The RBL assay has been extensively employed for determining biologically relevant cross-reactivities of food proteins, assessing the effect of processing on the allergenicity of food proteins, diagnosing allergic responses to whole-food products, and identifying anti-allergy food compounds. From the review of the literature, one might conclude the RBL cell-based assay is a better test system when compared to wild-type mast cell and basophil model systems for use in allergen identification, diagnosis, and analyses of potential immunotherapeutics. However, it is important to emphasize that this assay will only be able to identify those allergens to which the human has already been exposed, but will not identify a truly novel allergen, i.e. one that has never been encountered as in its preferred (humanized) configuration.