CYTOKINE EXPRESSION IS DOWN-REGULATED BY COLLAGEN-POLYVINYLPYRROLIDONE IN HYPERTROPHIC SCARS

We evaluated the in situ expression of adhesion molecules (E-selectin and vascular cell-adhesion molecule) and proinflammatory/fibrogenic cy tokines (IL-1 beta, TNF-alpha, TGF-beta 1, and PDGF) in sections of no rmal skin, hypertrophic scar, and hypertrophic scar previously treated with an irradiated mixture of collagen-polyvinylpyrrolidone and compl etely resolved. Expression of these proteins was detected by indirect immunoperoxidase staining. The hypertrophic scar group displayed an in creased amount of IL-1 beta, TNF-alpha, TGF-beta 1, and PDGF compared with the normal skin and treated scar groups. Values were statisticall y significant when cytokines in hypertrophic scar and hypertrophic tre ated sections were compared. Surprisingly, no differences were detecte d between normal skin and treated scars. On the other hand, difference s in levels of E-selectin and vascular cell-adhesion molecule were not statistically significant between the groups, except for vascular cel l-adhesion molecule, which decreased in treated scars. Also, supernata nts from fibroblast cultures derived from treated hypertrophic scar, s howed a reduction in TGF-beta 1 and PDGF expression, although apparent ly collagen synthesis was not affected. Based on previous data from cl inical studies in human dermal fibrosis remodeling, and the results pr esented here, we suggest that collagen-polyvinylpyrrolidone modulates extracellular matrix turnover, mainly of collagen, because expression levels of IL-1 beta, TNF-alpha, TGF-beta 1, and PDGF were diminished. We infer that collagen-polyvinylpyrrolidone participation could also m odify the inflammatory process observed in hypertrophic scarring, by d iminishing the expression of adhesion molecules, as a consequence of l ower levels of proinflammatory cytokines, mainly IL-1 beta and TNF-alp ha.