| Abstract: | The author investigated the basal lamina of cutaneous lesions in lupus erythematosus (LE) at the dermal-epidermal junction ultrastructurally, and discussed the differences between cutaneous LE (CLE) and systemic LE (SLE) and also among the types of cutaneous eruptions. The findings included micro-depression of the cytoplasm of basal cells, widening of the zona lucida, dissociation between anchoring filaments and the basal lamina, separation of the lamina from epidermal cells, focal defects and bifurcations of the basal lamina, and newly formed fine basal laminae at the original sites adjacent to the basal cells. The basal lamina deeply invaded the dermis with branching or multiplication which looked like loops or labyrinths and was thickened. These changes were all considered to be antecedents to the multiplication of the basal lamina. The basal lamina was multiple and sometimes more than five-layered. The laminae of the latter are thought to be specific to LE. The distances from the outer leaflet of the plasma membranes of basal cells to the deepest points of the multilayered basal laminae in the dermis were measured. They were regarded as an index of the degree of the multiplication of the lamina. Their mean value was significantly greater in CLE than in SLE. This fact indicated that the multiplication of the basal lamina in CLE was higher than in SLE. There were no significant differences among the types of cutaneous eruptions. The basal lamina is known to be formed beneath half-desmosomes without participation of the dermis. Thus multiplication is thought to be a secondary phenomenon following repeated damage to the epidermal cells. |
