Renal failure with intracapillary thrombi. Lipoprotein glomerulopathy

Lipoprotein Glomerulopathy, First Case Report from Canada

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.

Lipoprotein Glomerulopathy in a Hispanic Female: A Case Report and Literature Review

Rationale:

Lipoprotein glomerulopathy (LPG) is a rare renal disorder that features glomerular capillary lipoprotein thrombi, proteinuria, and progressive renal failure. Although most reported cases describe involvement in Asian patients, occurrence in Caucasian and other ethnicities has also been reported.

Presenting concern:

A 28-year-old Hispanic female with a past medical history of hypertension, high cholesterol, gastritis, and a strong family history of renal disease presented with abdominal pain. On admission, her blood pressure was elevated. A computed tomography scan was unremarkable. Her laboratory studies showed proteinuria, high creatinine level, and an abnormal lipid profile.

Diagnosis:

The kidney biopsy showed glomerular capillary lipoprotein thrombi that stained positively for Oil-Red-O, confirming the lipid nature of the material consistent with LPG.

Intervention:

After stabilizing her blood pressure, the patient was started on fenofibrate to treat her high cholesterol and improve her renal function.

Outcome:

Her lipid profile and renal function were initially improved. However, after one year of treatment, her renal function started to decline and the patient was referred to a transplant center for further management.

Novel finding:

To the best of our knowledge, this the first reported incidence of LPG in a Hispanic female.