Contribution of the Leukocyte Adherence Inhibition Test to the Evaluation of Cellular Immunoreactivity against Latex Extracts for Non—IgE-Mediated Latex-Fruit-Pollen Syndrome in Allergic Candidates to Exclusion Diets and Allergic Desensitization

Abstract

Background: Due to the lack of standardized laboratory procedures able to demonstrate specific non—IgE-mediated immune responses against latex allergens, these conditions are diagnosed mostly by clinical criteria based on empiric exclusion prescriptions monitored by in vivo challenge tests.
 Objective: To evaluate the opportunity of an ex vivo challenge immunoassay, the Leukocyte Adherence Inhibition (LAI) Test (LAIT), to discriminate non—IgE-mediated latex-specific immunoreactivity.
 Methods: Ex vivo challenge tests performed with Hevea Brasiliense’s latex extract, monitored by LAIT, were assayed in an asymptomatic control group and a group of patients with diverse respiratory and cutaneous non—IgE-mediated allergic conditions, clinically diagnosed by a certified allergologist.
 Results: The mean LAI of the control group was 8.3%. The mean LAI of the complete patients’ group was 41.1%. The non-parametric Wilcoxon-Mann-Whitney U (WMWU) test comparing the control group with the whole patient’s group showed significance with a p-value < 0.00001. The WMWU test comparing the control group with each other patient’s group showed significance with a p-value < α = 0.05 for all comparisons. The WMWU test comparing the patients’ groups between each other did not show any significant p-value.
 Conclusion: Several patients from the diverse non—IgE-mediated allergic phenotypes presented variable immunoreactivity against the latex extract, as demonstrated by the LAIT, which proved to be an easy, quick, and inexpensive ex vivo immunoassay with the potential to predict individual immunoreactivity against Hevea brasiliensis latex allergens in real-world patients with non—IgE-mediated allergies.