Leukaemia inhibitory factor: induction in the early phase of allergic contact dermatitis.

It has been suggested that leukaemia inhibitory factor (LIF), may be involved in the pathogenesis of cutaneous inflammation. In 5 patients with previously proven contact allergy to nickel, LIF mRNA and protein expression were assessed by reverse transcription-polymerase chain reaction and immunohistochemistry in 5% nickel sulfate patch test biopsies 24 h after application of the patch. Control specimens were obtained from non-tested and vehicle-tested skin from the same individuals. LIF mRNA expression was significantly increased in nickel-tested skin compared with both vehicle-tested (p = 0.045) and non-tested skin (p = 0.041). All biopsies showed similar patterns of LIF immunoreactivity, with no significant differences between nickel-tested, vehicle-tested and non-tested skin. Immunostaining was cytoplasmic and was present in the epidermis and hair follicles. No dermal staining was observed. This study suggests that LIF may play a role in the early phase of allergic contact dermatitis.