[The role of gamma-interferon in blister formation of bullous pemphigoid].

Recently it has been reported that cell-mediated immune (CMI) reaction is related to the blister formation as well as the reaction of autoantibody against the basement membrane zone (BMZ-Ab) in bullous pemphigoid (BP). Previously we reported that T-cells infiltrated were producing gamma-interferon (IFN-gamma) and that high levels of IFN-gamma were detected in the blister fluids of BP. In the present study, in order to find the effect of IFN-gamma on the skin, we have done the organ culture of normal skin explants with IFN-gamma. The dermal-epidermal separation (DES) was histologically observed in skin explants which were incubated with high level of IFN-gamma after 24 hours. The DES was found to be located between the basal layer and the site of laminin and type IV collagen. It is considered that IFN-gamma alters the antigenicity and mediates to release some other cytokines in CMI reaction. In addition to these, IFN-gamma seems to directly work on the DES in normal skin. Around the DES of the skin explants, plasminogen activator was accelerated immunohistologically. The results suggest that IFN-gamma mediated by CMI response also plays an important role as well as the autoantibody in the blister formation of BP.