Table 2.

Examples of factors that can influence the diagnostic cut-offs for BAT in food allergy [4, 14, 39, 40, 41]

Study population	Prevalence of the food allergy in the population
	Origin of the study population (e.g. recruited from a specialized Allergy clinic or from the general population)
	Geographical location
	Associated respiratory and food allergies
Study design	Inclusion criteria (e.g. whether sensitized as well as non-sensitized patients were included in the study)
	Gold-standard used as a comparator to determine the diagnostic cut-offs
	Criteria for performing OFC (e.g. whether patients with a history of anaphylaxis or other risk factors for a severe reaction or with high levels of IgE or large wheals on skin prick test were included)
	OFC protocol (e.g. criteria for stopping the OFC, criteria for a positive OFC, intervals between doses and duration of OFC)
Laboratory procedure	Interval between blood collection and the performance of BAT
	Allergen extracts or purified/recombinant allergens used
	Concentration of the allergens
	Pre-incubation with IL-3
	Markers and antibodies (e.g. clones, fluorochromes) used to identify the basophils and to detect basophil activation
Flow cytometry data analyses	Adopted gating strategy
	Parameters used as the outcomes of the test [e.g. CD63 or CD203c, % or SI, CD-sens, area under the dose–response curve]
	Definition of negative gate
	Whether results were corrected for the background
	Cytometer used and application settings