Contribution of the Leukocyte Adherence Inhibition Test to the Diagnosis of Non—IgE-Mediated Immunoreactivity against Cochineal Dye

Aims: To evaluate the potential of the Leukocyte Adherence Inhibition Test (LAIT) for evaluating immunoreactivity against cochineal dye (E120) in patients with clinical suspicion of symptomatic hypersensitivity to this food additive.

Study Design: We retrospectively examined the medical charts of a population of 82 patients diagnosed with Atopic Dermatitis and/or Urticaria with clinical suspicion of cochineal hypersensitivity investigated with an ex vivo challenge monitored by LAIT against a commercial preparation of cochineal dye provided for butcheries.

Place and Duration of Study: Instituto Alergoimuno de Americana – São Paulo – Brazil – between January 2018 and July 2023.

Methodology: The percentage of Leukocyte Adherence Inhibition (LAI) promoted by the ex vivo challenges with cochineal dye was distributed in ranges through a cascade distribution chart to outline the variability of the results.

Results: The LAI mean was 42.6%; SD 28.8%, ranging from 0% to 98%; mode = 0% (appeared 15 times). There was a wide range of distribution of LAI results, suggesting that some patients had immunoreactivity against the cochineal allergens while others did not.

Conclusion: Our preliminary results support that the LAIT performed with cochineal dye may differentiate diverse degrees of ex vivo immunoreactivity against this food colorant in allergic patients.