Nephrogenic systemic fibrosis

Abstract

Nephrogenic systemic fibrosis (NSF) is a relatively new fibrosing disorder which has caught the attention of various specialities in the past decade. NSF is an extremely disabling and often painful condition, affecting up to 13% of the individuals with chronic kidney disease. The administration of a gadolinium chelate contrast agent has been reported to induce the development of NSF, particularly in patients who have acute or chronic renal disease with a glomerular filtration rate (GFR) lower than 30-mL/min/1.73 m2 and in those with acute renal insufficiency. Mass spectroscopy studies have demonstrated particles of gadolinium in the lesional tissue. The exact pathogenesis of this curious sclerosing condition is unknown. The role of the aberrant targeting of ‘circulating fibrocytes’ to the peripheral tissues and viscera has been hypothesized. NSF has distinct clinicopathological features in the setting of renal failure and needs to be looked upon as a new entity on the block. The condition is characterized by irregular indurated plaques, with amoeba-like projections and islands of sparing, chiefly on the trunk and extremities. Flexion contractures of fingers, knees, and elbow joints are known to occur in advanced cases of NSF. The course is frequently associated with painful episodes and loss of ambulation. Histopathology shows haphazard arrangement of thickened bundles of collagen, varying amount of mucin, and increased population of fibroblast-like cells in the dermis. Immunohistochemistry shows increased deposition of type-I procollagen and CD 34+ cells having fibroblastic activity. The condition is refractory to treatment with corticosteroids and immunosuppressive agents. Various modalities of therapy such as UVA1 phototherapy, imatinib mesylate, photodynamic therapy, plasmapheresis, extracorporeal photochemotherapy, and high-dose intravenous immunoglobulin have shown a moderate degree of improvement in skin thickness scores. A prudent option is restoration of renal function to normalcy via renal transplantation but to date the outcome of renal transplantation is unknown.