The development of manifest psoriatic lesions is linked with the appearance of ICAM-1 positivity on keratinocytes.
The development of psoriatic lesions was studied in 36 psoriatic patients using the Koebner reaction induced by tape stripping. Two biopsies per patient were taken from non-lesional psoriatic skin before, and 6 h, 2 days, 7 days, 14 days and 21 days after tape stripping. Alterations in HLA-DR, ICAM-1, Ki-67 and FXIIIa positivities in both the dermis and the epidermis were estimated using immunohistochemical methods. A double staining for CD4+ and CD8+ T cells was also carried out to show their possible Ki-67 positivity. Results were compared with those from lesional (mature plaque) and non-lesional psoriatic skin, and control skin. Of the 36 patients, 9 were Koebner-positive. The most important finding in Koebner-positive psoriatic skin was the appearance of ICAM-1 positivity on epidermal keratinocytes simultaneously with the clinically observed lesion on day 7. The number of FXIIIa+ dendrocytes in the dermis was quite constant, and increased in mature psoriatic lesions only. The number of active HLA-DR+ immunocompetent cells increased in developing psoriatic lesions, being highest in mature lesions, but no Ki-67 positivity was detected in epidermal or dermal T cells in the psoriatic specimens. Based on these results, it is concluded that T cells divide and are activated extracutaneously in psoriasis, and also that ICAM-1/LFA-1 interactions are important in the recruitment of inflammatory cells and in controlling the effector cell functions.
Paukkonen
K
K
Department of Dermatology, Kuopio University Hospital, Finland.
Naukkarinen
A
A
Horsmanheimo
M
M
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D016022:Case-Control Studies; D000078404:Epidermal Cells; D004817:Epidermis / Q000276:immunology / Q000473:pathology; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis*; D015603:Keratinocytes / Q000166:cytology / Q000276:immunology / Q000473:pathology*; D019394:Ki-67 Antigen; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D009687:Nuclear Proteins / Q000032:analysis; D011565:Psoriasis / Q000276:immunology / Q000473:pathology*; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D011503:Transglutaminases / Q000032:analysis
D015415:Biomarkers; D006684:HLA-DR Antigens; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D018799:Intercellular Adhesion Molecule-1; D011503:Transglutaminases