Endotyping Cellular and Humoral Immunoreactivity against Formaldehyde in Patients with Atopic and/or Contact Dermatitis
Celso Eduardo Olivier *
Instituto Alergoimuno de Americana, Brazil.
Daiana Guedes Pinto
Instituto Alergoimuno de Americana, Brazil.
Ana Paula Monezzi Teixeira
Instituto Alergoimuno de Americana, Brazil.
Cibele Silva Miguel
Instituto Alergoimuno de Americana, Brazil.
Jhéssica Letícia Santos Santana
Instituto de Ensino e Pesquisa do Hospital de Amor de Barretos, Brazil.
Regiane Patussi Santos Lima
Lavoisier Laboratórios, São Paulo, Brazil.
Nicole Sartoreto Rocha
Faculdade de Americana, São Paulo, Brazil.
Raquel Acácia Pereira Gonçalves Santos
Instituto Alergoimuno de Americana, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Background: Several publications report that formaldehyde is responsible for hypersensitivity reactions in patients with 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 cellular and humoral immunoreactivity against formaldehyde in patients with contact dermatitis.
Methods: We retrospectively examined the medical charts of two cohorts (n = 100, each) of patients diagnosed with atopic dermatitis and/or contact dermatitis with clinical suspicion of formaldehyde hypersensitivity, who were investigated with the help of TTP or ex vivo challenge tests monitored by LAIT against formaldehyde. The registered results were distributed in ranges through cascade distribution charts. The statistical characteristics of these cohorts were calculated.
Results: TTP showed a distribution concentrated over the more diluted titrations with no negative result. The mean was estimated at 1:385; the median at 1:512; and the standard deviation at 1:166. The LAIT results demonstrated a wide range. The LAI ranged from 0% to 100%. The mean was 57.5%; the median was 65.5%; the standard deviation was 37.4%.
Conclusion: Our preliminary results support that the TTP and LAIT performed with formaldehyde solution may discriminate diverse degrees of humoral and cellular immunoreactivity in patients suffering from atopic and/or contact dermatitis. By evaluating the utility of TTP and LAIT as diagnostic tools, the study provides preliminary evidence for endotyping immunoreactivity, which could advance precision medicine in allergy management. The findings may guide clinicians in identifying hidden formaldehyde exposure in products and inform safer therapeutic strategies for sensitized patients. It is worthwhile conducting more in-depth studies to evaluate the usefulness of TTP and LAIT in endotyping non–IgE-mediated hypersensitivity to formaldehyde.
Keywords: Atopic dermatitis, contact dermatitis, endotype, hypersensitivity, formaldehyde, leukocyte adherence inhibition test, precipitins, precision medicine