Evaluating Non-IgE-Mediated Allergens’ Immunoreactivity in Patients Formerly Classified as “Intrinsic” Asthmatics with Help of the Leukocyte Adherence Inhibition Test

Abstract

Background: The ancient concept of “intrinsic” and “extrinsic” asthma has evolved in line with growing scientific knowledge and the use of new clinical diagnostic tools. Objective: The present study aims to evaluate the non-IgE-mediated immunoreactivity against common allergens, in asthmatic patients without evidence of IgE-mediated hypersensitivity against these allergens. Methods: A group of 127 “intrinsic” asthmatic outpatients, were submitted to ex vivo Leukocyte Adherence Inhibition Tests (LAIT) with extracts of Dermatophagoides pteronyssinus, Hevea brasiliensis latex, dog dander, cat dander, cow’s milk proteins, beekeeping pollen and a mixture of fungal extracts. Results: Cascade graphs were assembled according to the distribution of the LAIT results among the range of results of Leukocyte Adherence Inhibition (LAI) inside each group. A column graph was plotted with the mean LAI results for each antigen. The non-parametric Wilcoxon-Mann-Whitney U-test performed between the results of each test was significant only between the results of the LAIT performed with the dog extract and the mixed fungal extract (U = 1,179.5; the z-score was -2.64109; the p-value was 0.0083). All other Wilcoxon-Mann-Whitney U-test calculations between LAIT performed with the other allergens were not significant at p < 0.01. Conclusion: The evidence of non-IgE-mediated immunoreactivity in allergic patients has been reported in the medical literature since the beginning of the 19th century and has been increasing since then. This descriptive article presents the contribution of the LAIT as a tool to quantify the overall non-IgE-mediated cellular/humoral immunoreactivity against common allergens in patients formerly classified inside the “intrinsic” asthma endotype.