Immunohistological Analysis of CD34-Positive Dermal Dendritic Cells and Microvessel Density in the Genital and Extragenital Lichen Sclerosus.

BACKGROUND: Lichen sclerosus (LiS) is a chronic scleroatrophic condition that usually affects the anogenital area and occasionally the extragenital sites. CD34-positive dermal dendritic cells (DDCs) contribute to the maintenance of the dermal microarchitecture and modulation of the immune response. p53 is a tumor suppressor gene important for the regulation of the cell cycle and apoptosis. Similar to morphea (a LiS-closely related scleroatrophic condition), dermal sclerosis, alterations of DDCs, and dermal microvasculature may be important underlying pathogenetic mechanisms in LiS.

OBJECTIVES: To examine the profile of CD34-positive DDCs, microvessel density (MVD), and p53 protein in LiS.

MATERIALS AND METHODS: The immunohistological profiles of DDCs, MVD, and p53 were examined in 19 cases of LiS and their age- and sex-matched normal skin (10 specimens), using antibodies against CD34 and p53.

RESULTS: There was a markedly decreased counts (1.7 ± 0.5/mm2 ) or complete loss of CD34-positive DDCs in LiS against their abundance in the normal skin (23.4 ± 2.1/mm2 , p = 0.000). MVD was markedly increased in LiS lesions (20 ± 0.47) as compared to normal skin (5.50 ± 0.20, p = 0.000). Discontinuous single-cell p53 weakly positive nuclear staining was seen in the epidermal basal cell keratinocytes in normal skin and LiS lesions.

CONCLUSIONS: To the best of this author's knowledge, this is the first study analyzing DDCs, MVD, and p53 profiles together in LiS. The findings suggest that alterations of DDCs and MVD have roles in the pathogenesis of LiS.