Fibrogenic cytokines in vulvar lichen sclerosus. An immunohistochemical study.

OBJECTIVE

To evaluate the expression of fibrogenic cytokines in lichen sclerosus (LS) infiltrate as compared with lichen planus (LP) infiltrate.

METHODS

Eight cases of vulvar LS (early stage, n = 3; well developed or old, n = 5) and 4 of vulvar LP were studied. Monoclonal antibodies directed against some of the major fibrogenic cytokines (IL-4, TGF-beta, IL-6) and against IFN-gamma, which inhibits collagen synthesis, were used per the alkaline phosphatase/anti-alkaline phosphatase technique on frozen sections.

RESULTS

Staining for IL-4 revealed higher expression of fibrogenic cytokines (more than 50% infiltrating cells) in the LS infiltrate, mainly in early lesions, than in LP. Conversely, staining for IFN-gamma in LS was poor (less than 10% infiltrating cells), while strong positivity (more than 60% infiltrating cells) was found in LP. Staining for TGF-beta, a mediator of fibrosis in scleroderma, was similar in both LS and LP dermis.

CONCLUSIONS

This study showed the immunohistochemical expression of fibrogenic cytokines in vulvar LS, with a different pattern as compared to that of LP. It is conceivable that dermal infiltrating cells actively participate, via cytokine production, in the pathogenesis of fibrosis in LS.