Multiple cerebral lesions as the unique complication of idiopathic retroperitoneal fibrosis.

We present a case of idiopathic retroperitoneal fibrosis (IRF) complicated by severe renal failure and multiple intracranial lesions, which are probable results of cerebral vasculitis. IRF is an idiopathic hyperplasia of the retroperitoneal tissue that often entraps the ureters and causes post-renal failure. While the etiology of IRF is unclear, researchers consider IRF a systemic autoimmune disease complicated by immune-mediated vasculitides. The chief complaints of the patient were cognitive disorders, and brain MRI findings revealed multiple intracranial lesions with accompanying central degeneration. Given that vasogenic cerebral edemas derive from uremia, we speculated that the lesions in our case were related to more destructive changes such as aortic and periaortic inflammation. Details on this case manifesting rare cerebrovascular complications may help elucidate the pathogenesis of IRF.

Proliferative glomerulonephritis with monoclonal immunoglobulin G3κ deposits in association with parvovirus B19 infection.

Proliferative glomerulonephritis with monoclonal immunoglobulin G deposits is a recently described disease entity, characterized by nonorganized electron-dense deposits in glomeruli and immunofluorescence findings indicating monoclonal immunoglobulin G deposits. The pathogenesis of many cases of proliferative glomerulonephritis with monoclonal immunoglobulin G deposits remains unknown. We herein report 2 patients with parvovirus B19 infection who developed acute nephritic syndrome with hypocomplementemia (patient 1) or persistent proteinuria and congestive heart failure (patient 2); however, neither patient had detectable levels of serum monoclonal immunoglobulin G. Renal biopsy in both patients showed diffuse endocapillary proliferative glomerulonephritis with monoclonal immunoglobulin G3κ deposits, and electron microscopy showed nonorganized electron-dense deposits mainly in the subendothelial and mesangial areas. Clinical symptoms, abnormal laboratory findings, and urinary abnormalities recovered spontaneously in both cases within 4 weeks. Our 2 cases may be the first reported patients with proliferative glomerulonephritis with monoclonal immunoglobulin G deposits possibly associated with parvovirus B19 infection. Virus infection-associated immune disorders could be implicated in the pathogenesis of proliferative glomerulonephritis with monoclonal immunoglobulin G deposits.