Leukocyte Adherence Inhibition Test to the assessment of Immunoreactivity Against Cow’s Milk Proteins in Non—IgE-Mediated Gastrointestinal Food Allergy

Background:  The non—IgE-mediated food allergy syndromes are a group of conditions diagnosed mostly by clinical criteria and Oral Food Challenge tests (OFC). Objective:  To evaluate the feasibility of the Leukocyte Adherence Inhibition Test (LAIT) to discriminate antigen-specific immunoreactivity in a group of patients with non—IgE-mediated cow’s milk allergy diagnosed by OFC and clinical criteria. Methods:  Ex vivo challenge tests performed with cow’s milk proteins extracts were monitored by LAIT in two groups: A) the active group consisting of 38 patients presenting non—IgE-mediated gastrointestinal lactose-free cow’s milk hypersensitivity; B) the control group consisting of 29 cow’s milk tolerant individuals Results:  The mean Leukocyte Adherence Inhibition (LAI) of the control group was 5.48%, and the mean LAI of the active group was 54.18%.  The non-parametric Wilcoxon-Mann-Whitney U test showed p < α = 0.05. Conclusion:  The Leukocyte Adherence Inhibition Test is an ex vivo immunoassay able to predict individual non—IgE-mediated immunoreactivity against cow’s milk allergens and to act as a triage test to select food allergens to be prescribed in exclusion diets to perform OFC in patients with suspected non—IgE-mediated food allergies.