title: Immunophenotyping of the cellular infiltrate in the early elicitation phase of contact dermatitis in the skin of presensitized atopic individuals.
abstract: Little is known about the composition of the cellular infiltrate in the early elicitation phase of contact allergy in atopic individuals. Therefore, we rechallenged ten presensitized disease-free atopic volunteers with their known contact allergen and performed biopsies at time 0 and after 6 and 24 h. Ten patients with acute exacerbated atopic dermatitis in the early stage were chosen as a control group. Skin biopsy specimens were processed for immunohistochemistry (APAAP) and evaluated by computer-assisted morphometry. CD4+ and CD45R0+ cells were found to be significantly increased after 6 (t6) and 24 h (t24), and this was accompanied by an enhanced TCR alpha/beta receptor expression at t6-CD45O+ cells showed a marked influx into the epidermis at t24. CD8+ cells infiltrated the basal layer of the epidermis, thus changing the CD4/CD8 ratio from 4.6:1 at t0 to 2.2:1 at t6. CD1a+ epidermal dendritic cells increased significantly from 811 +/- 240/mm2 at t0, to 1210 +/- 333/mm2 at t24 (P < 0.01). At t6 and t24, a so-called 'epitope CD1a+ shedding' was observed into the intercellular spaces of keratinocytes as well as an elongation and enlargement of the dendrites of CD1a+ cells. In the upper dermis, the number of CD1a+ cells increased from 1098 +/- 485/mm2 at t0 to 2388 +/- 740/mm2 at t24 (P < 0.01). In 7/10 volunteers, IgE+ dendritic cells increased significantly in number at t6 (P < 0.02). The activation markers HLA-DR and CD25 were expressed most distinctly at t24. Interestingly, expression of ICAM-1 on keratinocytes occurred only in four of the ten atopic volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Dermatology, University Medical Center Steglitz, Free University of Berlin, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Garmann
authors.forename: H P
authors.initials: HP
authors.lastname: Gollnick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000032:analysis*; D001706:Biopsy; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000473:pathology; D003877:Dermatitis, Contact / Q000276:immunology* / Q000473:pathology; D004890:Erythema; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D016130:Immunophenotyping; D008214:Lymphocytes / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D012867:Skin / Q000276:immunology* / Q000473:pathology; D012882:Skin Tests; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D007073:Immunoglobulin E