11beta-hydroxysteroid dehydrogenase type 1 expression in periprosthetic osteolysis.

Periprosthetic membranes contain fibroblasts, macrophages and cytokines including interleukin 1Beta (IL-1Beta) and tumor necrosis factor alpha (TNF-alpha). Glucocorticoids may play an inhibitory role in osteolysis through the upregulation of 11Beta-hydroxysteroid dehydrogenase type 1 (11Beta-HSD1) in membrane fibroblasts by IL-1Beta and TNF-alpha. This study evaluated 15 periprosthetic membranes for the presence of 11Beta-HSD1 using immunochemistry. Also, fibroblast cell cultures were exposed to IL-1Beta and TNF-alpha, and 11Beta-HSD1 gene expression was evaluated. In all membranes, 11Beta-HSD1was present, and fibroblast 11Beta-HSD1 was upregulated significantly after the addition of IL-1Beta and TNF-alpha. These findings suggest increased 11Beta-HSD1 expression in fibroblasts may be a mechanism for increasing local cortisol levels in membranes, which could potentiate the osteolytic process through inhibition of osteoblastic function.