Matrix metalloproteinase 9 (MMP-9) is differently expressed in cutaneous lichen planus and lichen sclerosus

Abstract

Lichen planus is a mucocutaneous inflammatory disease of unknown etiology. Hyperkeratosis, focal hypergranulosis, damage to the basal cell layer, and bandlike infiltrate are hallmarks of LP skin. Lichen sclerosus is a lymphocyte-mediated dermatosis that has a predilection for the genital skin in both sexes. Both pathologies are sharing a number of common characteristics. Previous studies have reported on involvement of matrix metalloproteinases and their capability of digesting extracellular matrix and basement membrane components. We report on the clinical examination of 11 lichen planus patients and 5 lichen sclerosus patients and the morphological evaluation of their skin biopsy samples. Clinical and routine light microscopy findings correlate with the literature data. By contrast, the expression of MMP-9 was greatly varying among clinical types of cutaneous lichen ruber planus. There was similarity in the MMP-9 expression observed between lichen planus pemphigoides and lichen sclerosus.