Multicentric Castleman's disease associated with glomerular microangiopathy and MPGN-like lesion: does vascular endothelial cell-derived growth factor play causative or protective roles in renal injury?

A 52-year-old Japanese man presented with fever spikes, generalized fatigue, anorexia, and anasarca. The patient was referred for the evaluation of fever of unknown origin in association with swelling of cervical, axillary, and inguinal lymph nodes. He also manifested nephrotic syndrome, acute renal failure, hepatosplenomegaly, massive pleural effusion, ascites, disseminated intravascular coagulation, and hypergammaglobulinemia. C-reactive protein was positive and plasma vascular endothelial cell-derived growth factor (VEGF) and serum interleukin-6 levels were markedly elevated. Lymph node biopsy results showed that findings were compatible with Castleman's disease of hyaline vascular type associated with interfollicular plasmacytosis. In conjunction with the clinical findings, a diagnosis of multicentric Castleman's disease was made. The patient underwent renal biopsy because of nephrotic syndrome, and the results showed proliferation of mesangial cells, lobulation of glomeruli, and tram track pattern of the capillary wall without immune complex deposition. Electron microscopy showed widening of the subendothelial space. No electron-dense deposits were present in both mesangial and subendothelial regions. Pathologic features were compatible with glomerular microangiopathy and membranoproliferative glomerulonephritis-like lesions. With corticosteroid therapy, systemic symptoms disappeared; both VEGF and interleukin-6 levels were normalized, and he went into complete remission of nephrotic syndrome. In this article, the role VEGF plays in the pathogenesis of nephrotic syndrome and glomerular microangiopathy is discussed.