A prospective study of the Koebner reaction and T lymphocytes in uninvolved psoriatic skin.
T lymphocyte and dendritic cell subpopulations were counted in untraumatized, uninvolved skin of 27 patients with psoriasis. Eight of the patients proved to be Koebner-positive, as determined by tape stripping and punch biopsy, and 19 Koebner-negative. In the epidermis the CD4/CD8 T cell ratio was significantly higher in the Koebner-positive vis-à-vis Koebner-negative patients (median CD4/CD8 = 1.68 and 0.75, respectively: p less than 0.05). This resulted from a small increase in CD4 and a larger decrease in CD8 epidermal T cells in the Koebner-positive group. However, numbers of epidermal dendritic cells did not differ significantly between the two groups. In the dermis the CD4/CD8 T cell ratio was also higher in the Koebner-positive than in Koebner-negative patients (median of 3.56 and 2.57, respectively). These findings demonstrate that the tendency of uninvolved skin of psoriatic individuals to become lesional after trauma is associated with a predominance of CD4 over CD8 T cells in the epidermis.
Baker
B S
BS
Department of Immunology, St. Mary's Hospital Medical School, London, England.
Powles
A V
AV
Lambert
S
S
Valdimarsson
H
H
Fry
L
L
D003713:Dendritic Cells / Q000473:pathology; D006801:Humans; D011446:Prospective Studies; D011565:Psoriasis / Q000473:pathology*; D012867:Skin / Q000473:pathology*; D013601:T-Lymphocytes / Q000145:classification* / Q000473:pathology; D014945:Wound Healing