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

Abstract

Background: Several publications report that tartrazine is responsible for IgE-mediated and non–IgE-mediated hypersensitivity reactions. There is no standardized lab exam to endotype non–IgE-mediated immunoreactivity against tartrazine besides in vivo provocation tests. 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 tartrazine in patients clinically diagnosed with non–IgE-mediated allergic phenotypes associated with various non-IgE-mediated allergic conditions. Study Design: We retrospectively examined the medical charts of two cohorts of patients diagnosed with the aforementioned allergic phenotypes with clinical suspicion of tartrazine hypersensitivity, who were investigated with the help of TTP (first cohort) or ex vivo challenge tests monitored by LAIT (second cohort) against tartrazine. Methodology: The registered results of the semi-quantitative serum TTP against 1 mg/mL tartrazine 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 tartrazine solution were distributed in ranges through a cascade distribution chart to outline the variability of results inside the second cohort. The statistical characteristics of these cohorts were calculated. Results: Most positive TTP results concentrated on the higher dilutions. The mean was estimated at 1:290; the standard deviation was estimated at 1:200. The LAI ranged from 0% to 88%. The mean was 35.4%; the standard deviation was 24,7%. The cascade distribution graph demonstrates that the LAIT distribution is mainly over the negative and weaker results. Conclusion: Our preliminary results support that the TTP and LAIT performed with 1 mg/mL tartrazine solution may discriminate diverse humoral and cellular immunoreactivity degrees in patients suffering from several non–IgE-mediated allergic conditions, encouraging further prospective studies and validation.