Investigation of intercellular matrix macromolecules involved in lichen sclerosus.

Dermal changes of the vulva in lichen sclerosus were compared with control vulvar samples using ultrastructural and immunofluorescence techniques. Collagen degeneration and regeneration were observed ultrastructurally in the superficial dermis of lichen sclerosus with increased amounts of ground substance. These processes appeared to alter the affinity of collagen fibres for the anticollagen antisera types I, III, IV. A decrease in elastin content was observed by electron microscopy. A loss of fibronectin was discovered at the dermo-epidermal junction, which looked normal ultrastructurally. The linear laminin pattern at the dermo-epidermal junction was also altered. These results suggested an enzymatic process in the pathogenesis of lichen sclerosus. Amidase activity could be determined in 6 normal and 6 pathological biopsies, though higher in the pathological samples (p less than 0.01).