Endotyping Cellular and Humoral Immunoreactivity against Aluminum in Allergic Patients: A Retrospective Study

Background: Several publications report that aluminum is responsible for hypersensitivity reactions. There is no standardized lab exam that can endotype (determine the pathophysiology responsible for the phenotype) hypersensitivity to aluminum.

Aim: To evaluate the potential of the Tube Titration of Precipitins (TTP) and the Leukocyte Adherence Inhibition Test (LAIT) to endotype humoral and cellular immunoreactivity against aluminum in patients clinically diagnosed with allergic contact dermatitis, intrinsic atopic dermatitis, and/or non–IgE-mediated urticaria.

Study Design: We retrospectively examined the medical charts of two cohorts of 100 patients each; range 6 to 87 years; diagnosed with allergic phenotipes, who were investigated with the help of TTP (first cohort) or ex vivo challenge tests monitored by LAIT (second cohort) against aluminum.

Methodology: The registered results of TTP against 1 mg/mL aluminum solution were distributed in ranges through a cascade distribution chart to outline the variability of the results inside the first cohort. The registered results of the Leukocyte Adherence Inhibition (LAI) percentage promoted by the ex vivo challenges with 1 mg/mL aluminum solution were distributed in ranges through a cascade distribution chart to outline the variability of results inside the second cohort.

Results: Most TTP results concentrated on higher dilutions. The mean was estimated at 1:301; the median was 1:256; the standard deviation was estimated at 1:204; the mode was 1:512 (appeared 46 times). The LAI ranged from 0% to 88%. The mean was 52%; the median was 49%; the standard deviation was 23.9%; the mode was 60% (appeared five times). The cascade graphs demonstrate a wide range of distribution of TTP and LAI results.

Conclusion: Our preliminary results support that the TTP and LAIT performed with 1 mg/mL aluminum solution may discriminate diverse humoral and cellular immunoreactivity degrees in patients suffering from allergic contact dermatitis, intrinsic atopic dermatitis, and/or non–IgE-mediated urticaria.