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