A young man with Propionibacterium acnes-induced shunt nephritis

Abstract

This case illustrates in a striking manner the potential renal complications associated with chronic, unrecognized VA shunt infection. The diagnosis of shunt nephritis is challenging and, as exemplified by this case, may be overlooked for several years, resulting in significant morbidity in the form of ongoing renal injury with proteinuria and renal failure. The finding of hematuria, proteinuria and even mild renal insufficiency in a patient with a VA shunt should prompt an aggressive microbiologic diagnostic evaluation to exclude subacute infection. Renal biopsy should be considered to document the pathognomonic membranoproliferative lesion and to assess the relative degrees of acute versus chronic injury. Further, this case highlights the critical importance of excluding secondary forms of disease in any patient with a nephritic presentation and biopsy findings demonstrating membranoproliferative features, as identification and treatment of the underlying condition may lead to remission of proteinuria and normalization of renal excretory function, even in patients with a baseline biopsy finding of significant sclerosis alongside ongoing active inflammation, as was the case in this patient. Finally, in this exciting era where the elucidation of entire microbial genome sequences has become possible, future studies correlating bacterial genomes and proteomes with specific mechanisms of disease may hold promise for identifying specific antigens involved in the pathogenesis of immune-mediated conditions, such as shunt nephritis. © 2008 International Society of Nephrology.