[The role of the T-lymphocyte in atopic dermatitis].

Atopic dermatitis (AD) comprises a wide spectrum of clinical symptoms, among which dermatitis is the most prominent feature. Recent finding that Langerhans cells bind IgE molecules via Fc receptors brought new insight into the pathogenesis of dermatitis lesions in AD. Langerhans cells from AD patients can present environmental allergens to T cells, both in vivo and in vitro, because they can bind allergens through IgE. Alternatively, Langerhans cells from normal individuals do not bind IgE molecules and are ineffective in stimulation of allergen specific T cells. Thus, the dermatitis lesion in AD seem to be due to an IgE-mediated delayed type hypersensitivity mechanism.