Nephrogenic systemic fibrosis: a clinicopathologic study of six cases.

BACKGROUND: Nephrogenic systemic fibrosis is a rare fibrosing condition that occurs in patients with renal insufficiency. While its histologic characteristics have been well described, the etiology and pathogenesis have not been fully characterized. Several recent studies support the theory that gadolinium-based contrast agents play a causative role in the development of the disease. Erythropoietin therapy and endothelial damage from surgical procedures have also been suggested as potential contributing factors. OBJECTIVE: This study attempts to help contribute to the understanding of this novel disorder. METHODS: We performed a retrospective chart review of 6 patients diagnosed with nephrogenic systemic fibrosis at our institution. Emphasis was placed on identification of potential putative etiologic agents including gadolinium, erythropoietin therapy, and previous surgical procedures. RESULTS: All patients had documented exposure to gadolinium-based contrast agents. Three of the 6 patients were treated with erythropoietin, and all patients underwent a previous surgical procedure. LIMITATIONS: This study is limited by its small size; therefore, the findings and results may not be applicable to all patients with this disorder. CONCLUSION: Our data suggest that gadolinium plays a primary role in nephrogenic systemic fibrosis and that prior surgery may be a contributory factor.

Case reports: nodular vasculitis responsive to mycophenolate mofetil.

Mycophenolate mofetil is commonly used as a steroid-sparing agent effective in the management of erythema nodosum, idiopathic nodular panniculitis (Pfiefer-Weber-Christian disease), bullous pemphigoid, pemphigus vulgaris, and psoriasis. We report a case of nodular vasculitis responsive to mycophenolate mofetil. The clinical presentation, etiology, and management options for nodular vasculitis are discussed.

Reovirus-induced alterations in gene expression related to cell cycle regulation.

Mammalian reovirus infection results in perturbation of host cell cycle progression. Since reovirus infection is known to activate cellular transcription factors, we investigated alterations in cell cycle-related gene expression following HEK293 cell infection by using the Affymetrix U95A microarray. Serotype 3 reovirus infection results in differential expression of 10 genes classified as encoding proteins that function at the G(1)-to-S transition, 11 genes classified as encoding proteins that function at G(2)-to-M transition, and 4 genes classified as encoding proteins that function at the mitotic spindle checkpoint. Serotype 1 reovirus infection results in differential expression of four genes classified as encoding proteins that function at the G(1)-to-S transition and three genes classified as encoding proteins that function at G(2)-to-M transition but does not alter any genes classified as encoding proteins that function at the mitotic spindle checkpoint. We have previously shown that serotype 3, but not serotype 1, reovirus infection induces a G(2)-to-M transition arrest resulting from an inhibition of cdc2 kinase activity. Of the differentially expressed genes encoding proteins regulating the G(2)-to-M transition, chk1, wee1, and GADD45 are known to inhibit cdc2 kinase activity. A hypothetical model describing serotype 3 reovirus-induced inhibition of cdc2 kinase is presented, and reovirus-induced perturbations of the G(1)-to-S, G(2)-to-M, and mitotic spindle checkpoints are discussed.