Alterations of basement membrane zone and cutaneous microvasculature in morphea and extragenital lichen sclerosus.

The aim of this study was to compare alterations of the basement membrane zone (BMZ) and to visualize changes within the skin vascular network in morphea and extragenital lichen sclerosus with the use of laser scanning confocal microscopy. This work was performed in eight plaques of morphea (three active and five inactive) and eight of lichen sclerosus (three of short duration and five long-lasting). Biopsy specimens from six healthy individuals served as controls. The biopsies were cut into 40-microm-thick sections, labeled with antibodies against beta4-intergin (a lamina lucida marker), collagen IV, and the N-terminal end of collagen VII (lamina densa markers) and C-terminal end of collagen VII (a sublamina densa marker) and studied using laser scanning confocal microscopy. Three-dimensional reconstruction of various regions of the BMZ showed a decreased number and size of the dermal papillae both in morphea and lichen sclerosus compared with normal skin. In morphea, the continuity of the BMZ at the level of lamina lucida, lamina densa, and sublamina densa was preserved whereas in LS numerous invaginations and holes were present in the BMZ at the level of the lamina lucida and lamina densa. Thus the alterations of the BMZ in morphea differ from those in lichen sclerosus. Three-dimensional reconstruction of the skin vascular network showed increased angiogenesis only in the early inflammatory stage of morphea, whereas in inactive morphea and lichen sclerosus various numbers of enlarged vessels were visible. The changes in the vascular network in morphea appear to be related to the activity of the disease.