Pathomechanisms of nephrogenic systemic fibrosis: new insights.

Nephrogenic systemic fibrosis (NSF), previously known as nephrogenic fibrosing dermopathy, is a generalized fibrotic disorder occurring in people with renal failure, following exposure to gadolinium-based contrast agents used to enhance MRI. The cellular elements involved in pathology of NSF include bone-marrow-derived collagen-producing fibrocytes, myofibroblasts and activated macrophages. Mechanisms that have been hypothesized to play a role in the pathogenesis of NSF include upregulation of osteopontin, imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinase 1, and presence of transforming growth factor-β, nuclear factor κB, decorin and metallothioneins. Gadolinium (both free and chelated) is thought to be a bioactive trigger for NSF. Elucidation of these potential pathomechanisms would be useful for development of targeted therapies for NSF.