Assessing Cellular and Humoral Immunoreactivity to Lanolin: A Retrospective Cohort Study in Atopic and Contact Dermatitis Patients

Background: Several publications report lanolin as responsible for hypersensitivity reactions in patients with atopic dermatitis and/or contact dermatitis, as diagnosed by in vivo provocation tests.There is no standardized lab exam that can endotype the mechanisms responsible for these phenotypes.Aim: To evaluate the potential of the Tube Titration of Precipitins (TTP) and the Leukocyte Adherence Inhibition Test (LAIT) to discriminate and endotype immunoreactivity against lanolin in patients with atopic dermatitis and/or contact dermatitis.Methods: We retrospectively examined the medical charts of two cohorts of patients diagnosed with atopic dermatitis and/or contact dermatitis with clinical suspicion of lanolin hypersensitivity, who were investigated with the help of TTP or ex vivo challenge tests monitored by LAIT against lanolin.The registered results were distributed in ranges through cascade distribution charts.The statistical characteristics of these cohorts were calculated. Results:The TTP results spread a distribution concentrated over the more diluted titrations (Fig. 1).There was no negative result.The mean was estimated at 1:343; the median was 1:512; the standard deviation was estimated at 1:187; the mode was 1:512 (appeared 53 times).The LAI ranged from 0% to 95%.The mean was 41.5%; the median was 41.5%; the standard deviation was 27.3%; the mode was 0% (appeared sixteen times).The cascade distribution demonstrates a widespread distribution of LAI results.Conclusion: TTP and LAIT performed with lanolin solution were able to discriminate diverse degrees of humoral and cellular immunoreactivity in patients suffering from atopic and/or contact dermatitis.It is worthwhile conducting more in-depth studies to evaluate the usefulness of TTP and LAIT in endotyping Non-IgE-mediated hypersensitivity to lanolin.