The Journal of experimental medicine. 2006;203(4):953-60.
We have examined whether psoriasis is associated with systemic effects on epidermal
Langerhans cell (LC) function and, specifically, the migration of LCs from the skin.
Compared with normal skin, the frequency and morphology of epidermal LCs in uninvolved
skin from patients with psoriasis was normal. However, mobilization of these cells
in response to stimuli that normally induce migration (chemical allergen, tumor necrosis
factor alpha [TNF-alpha], and interleukin-1beta [IL-1beta]) was largely absent, despite
the fact that treatment with TNF-alpha and IL-1beta was associated with comparable
inflammatory reactions in patients and controls. The failure of LC migration from
uninvolved skin was not attributable to altered expression of receptors for IL-1beta
or TNF-alpha that are required for mobilization, nor was there an association with
induced cutaneous cytokine expression. Although a role for altered dynamics of LC
migration/turnover has not been formally excluded, these data reveal a very consistent
decrement of LC function in psoriasis that may play a decisive role in disease pathogenesis.