T lymphocyte phenotype of contact‐allergic patients: experience with nickel and p‐phenylenediamine

• Published in: Contact dermatitis Vol. 81; no. 1; pp. 43 - 53
• Main Authors: Wicks, Kate, Stretton, Clare, Popple, Amy, Beresford, Lorna, Williams, Jason, Maxwell, Gavin, Gosling, John Paul, Kimber, Ian, Dearman, Rebecca J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2019; Wiley Subscription Services, Inc
• Subjects: Allergens; Allergies; Buffy coat; Case-Control Studies; CD4; CD4 antigen; CD4-CD8 Ratio; CD8; Cell Proliferation; Coloring Agents - adverse effects; Contact dermatitis; Dermatitis, Allergic Contact - etiology; Dermatitis, Allergic Contact - immunology; Disinfectants - adverse effects; Flow cytometry; Genotype & phenotype; Humans; Immunologic Memory - immunology; inverted CD4/CD8, skin‐homing CLA; Lymphocyte Activation; lymphocyte transformation test; Lymphocytes; Lymphocytes T; Nickel; Nickel - adverse effects; Oligosaccharides - immunology; Patch Tests; Peripheral blood; Phenotype; Phenotypes; Phenylenediamine; Phenylenediamines - adverse effects; Risk assessment; RRID:SCR_001905; Sialyl Lewis X Antigen - analogs & derivatives; Sialyl Lewis X Antigen - immunology; Skin; T cell phenotype; T-Lymphocytes - immunology; T-Lymphocytes, Regulatory - immunology; Thiazoles - adverse effects; Thymidine; CD4; inverted CD4/CD8, skin-homing CLA; RRID:SCR_001905; T cell phenotype; CD8; lymphocyte transformation test
• ISSN: 0105-1873; 1600-0536
• DOI: 10.1111/cod.13246

Background There is considerable interest in understanding the immunological variables that have the greatest influence on the effectiveness of sensitization by contact allergens, particularly in the context of developing new paradigms for risk assessment of novel compounds. Objectives To examine the relationship between patch test score for three different contact allergens and the characteristics of T cell responses. Methods A total of 192 patients with confirmed nickel, p‐phenylenediamine (PPD) or methylisothiazolinone (MI) allergy were recruited from the Contact Dermatitis Investigation Unit at Salford Royal Hospital. Severity of allergy was scored by the use of patch testing, peripheral blood lymphocytes were characterized for T cell phenotype by flow cytometry, and proliferative activity was characterized by radiolabelled thymidine incorporation. Comparisons were drawn with buffy coat samples from healthy volunteers. Results Patch test positivity for nickel, PPD and MI was associated with changes in the phenotype of peripheral blood T cells: increases in naïve cells, decreases in regulatory T cell frequency and the CD4+/CD8hi ratio, and increased expression of the skin‐homing marker cutaneous lymphocyte antigen (CLA), particularly for those patients with a +++ patch test score. Conclusions This increased understanding of the characteristics of the T cell responses to contact allergens may provide parameters with which to better measure health risks associated with skin sensitization.