Abstract: TH-PO527
A Unique Case of Lipoprotein Glomerulopathy
Session Information
- Trainee Case Reports - I
October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Patcha, Kishore, University of Utah Hospital, Salt Lake, Utah, United States
- Abraham, Josephine, University of Utah Hospital, Salt Lake, Utah, United States
- Aljuaid, Mossab, University of Utah Hospital, Salt Lake, Utah, United States
- Gilligan, Sarah, University of Utah Hospital, Salt Lake, Utah, United States
- Raghavan, Divya, University of Utah Hospital, Salt Lake, Utah, United States
- Al-Rabadi, Laith, University of Utah Hospital, Salt Lake, Utah, United States
Introduction
Lipoprotein Glomerulopathy has recently been recognized as a unique type of glomerular injury characterized by lipid accumulation in the glomerular capillaries. It has been mainly reported in Asian patients, and linked with rare APOE gene mutations resulting in a structurally abnormal Apolipoprotein E (ApoE).
Case Description
A 47-year-old Filipino male presented to the renal clinic with nephrotic-range proteinuria. Past Medical history was significant for hypertension treated with irbesartan and carvedilol. Physical exam was unremarkable. Labs showed serum creatinine of 1.47mg/dl (unclear baseline). Urine microscopy revealed several red blood cells. Urine protein to creatinine ratio was 5.1 g/g with a urine albumin to creatinine ratio of 3.7 g/g. Renal Ultrasound was unremarkable. Further workup, including ANA, ANCA, HIV, Anti-GBM antibody, serum and urine protein electrophoresis, was negative. Hemoglobin A1C was 5.1. Total cholesterol was 221mg/dL with triglycerides of 180 mg/dL, HDL cholesterol of 55mg/dL, VLDL cholesterol of 36mg/dL and LDL cholesterol of 142mg/dL. Patient underwent kidney biopsy for definitive diagnosis. Light microscopy showed 32 glomeruli, many with dilated capillary lumina filled with very pale, mesh-like lipoprotein “thrombi”. Five glomeruli were globally sclerosed. Oil red O stain highlighted glomerular capillary lumina thrombi. There was evidence of focal areas of interstitial fibrosis and mononuclear inflammatory infiltration. Immunofluorescence did not reveal any immune-complex deposits. Electron microscopy showed remodeling of the glomerular basement membranes and capillary loops were distended and occluded by lipid-like material containing vacuoles of different sizes and with lamellation. His genetic testing showed both APOE alleles to be E3.
Discussion
Approximately 95% of individuals with type III hyperlipoproteinemia have the E2/E2 genotype. The remainder have rare mutations in one copy of the APOE gene some of which are not detectable by the APOE genotype test.
Lipoprotein thrombi in the glomerulus should prompt consideration for Lipoprotein glomerulopathy. Based on clinical information and renal biopsy results, this patient has lipoprotein glomerulopathy in the absence of APOE E2/E2 genotype.