Lipoprotein Glomerulopathy, First Case Report from Canada

Abstract

Julie Anne Ting,1 Susanna A McRae,1,2 Daniel Schwartz,1 Sean J Barbour,1 Maziar Riazy1,2 1Division of Nephrology, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada; 2Department of Pathology, University of British Columbia, Vancouver, BC, V6Z 1Y6, CanadaCorrespondence: Maziar Riazy, Department of Pathology, St. Paul’s Hospital, 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada, Tel [phone], extension 62228 or 62225, Fax [phone], Email [email protected]: Lipoprotein glomerulopathy (LPG) is caused by a mutation in the apolipoprotein E gene (APOE) gene and is characterized by lipoprotein thrombi in glomerular capillaries. Here, we describe a case of LPG, the first to be reported from Canada and the first case of LPG in North America to be associated with the APOE Tokyo/Maebashi mutation (p.Leu162_Lys164del, traditional nomenclature 142_144del). A 49-year-old man of Chinese descent with a previous diagnosis of dyslipidemia and a new diagnosis of hypertension was found to have proteinuria on routine urinalysis. Renal biopsy showed markedly dilated glomerular capillaries filled with pale staining mesh-like material that stained positive for Oil-Red-O, consistent with lipoprotein thrombi. APOE gene sequencing confirmed the diagnosis of LPG. The patient was treated with fenofibrate and perindopril. His lipid profile normalized and proteinuria dropped to minimal levels. Repeat renal biopsy 2 years after the first showed resolution of lipoprotein thrombi but with rare residual granular densities by electron microscopy consistent with lipoprotein in the subendothelial space, supporting the hypothesis that this subendothelial material contains precursors to lipoprotein thrombi.Keywords: apolipoprotein E, apoE Tokyo/Maebashi, proteinuria, dyslipidemia, fibrate, lipoprotein glomerulopathy

Keywords

• apolipoprotein e
• apoe tokyo/maebashi
• proteinuria
• dyslipidemia
• fibrate
• lipoprotein glomerulopathy