Background & Objective: Non-IgE (Type IV) hypersensitivity is a complex issue for allergic patients with no proper diagnosis and treatment. The Leukocyte Adherence Inhibition Test (LAIT) measures antigen-specific, cell-mediated immune responses by detecting the inhibition of leukocyte adherence to glass surfaces upon exposure to an antigen. This process is mediated by the release of lymphokines such as Leukocyte Migration Inhibition Factor (LIF). This makes it a functional assay for non-IgE hypersensitivity detection. This study aimed to use LAIT in detection of non-IgE-mediated immunoreactivity to potassium sorbate.
 Materials & Methods: This retrospective study involved a review of 50 patients’ medical history with diagnosis of various allergic phenotypes; including allergic bronchitis, sinus headache, and urticaria and who were suspected of having non-IgE-mediated hypersensitivity to potassium sorbate. An ex vivo challenge test was done by incubating the patients’ leukocytes with potassium sorbate, and the resultant immunoreactivity was measured by LAIT, with major readout of the extent of leukocyte adherence inhibition (LAI).
Results:  The findings indicated that the values of LAI were very much varied with a minimum and maximum of 0 and 98, respectively, and the mean, median, and standard deviation of 52.2, 51.6, and 18.9, respectively. The distribution of LAI results as a cascade revealed patients with mild, moderate, or severe non-IgE-mediated immunoreactivity to potassium sorbate. Others did not show any immunoreactivity. These preliminary results indicate LAIT that worked with potassium sorbate can possibly select different levels of ex vivo immunoreactivity of patients with various allergic phenotypes.
Conclusion:  This research offers information about the potential usefulness of LAIT in measuring non-IgE-based immunoreactivity against potassium sorbate. The findings may be priceless in knowing the reason behind non-IgE-mediated allergic reactions mechanisms and possibly guiding the potential creation of more individualized treatment methods for these patients.