BACKGROUND: Lipoprotein glomerulopathy (LPG) is a apolipoprotein E (ApoE)-related glomerular disease and has been associated with type III hyperlipidemia. Without appropriate treatment, chronic kidney disease (CKD) caused by LPG progresses, and approximately half of the patients develop end-stage kidney disease within 1-27 years of disease onset. However, few studies have highlighted the clinical course of cardiovascular diseases (CVDs) in patients with LPG. Herein, we report the first case of LPG in which the CVD risk was assessed using arterial stiffness.
METHODS: A 32-year-old Japanese man was referred to our hospital due to persistent proteinuria. Kidney biopsy showed markedly dilated capillary lumens containing pale-stained thrombi, which stained positively with Oil Red O. Electron microscopy revealed the presence of thrombi in the capillary lumen with low electron density and vacuoles of various sizes in part of the thrombi. Toluidine blue and Sudan IV stains were used to stain the thin sections of Epon-embedded tissue samples for electron microscopy. Sudan IV-positive droplets were observed in the capillary lumens, vascular walls, and cytoplasm of tubular cells. Increased serum ApoE concentration was observed. Liquid chromatography-tandem mass spectrometry of laser-microdissected glomeruli from paraffin sections revealed an increase in ApoE. Direct deoxyribonucleic acid sequencing of ApoE revealed a heterozygous ApoE Sendai mutation (Arg145Pro). The patient was finally diagnosed with LPG with heterozygosity for ApoE-Sendai mutation (Arg145Pro). Notably, at the time of diagnosis, he had markedly increased arterial stiffness for his age. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV), which was equivalent to that of a 56-year-old man. After three months of treatment with fenofibrate and losartan, a significant reduction in proteinuria was achieved along with an improvement in baPWV. Furthermore, these effects were maintained despite the lack of decrease in serum ApoE levels.
CONCLUSIONS: Herein, we report the case of a patient with LPG with markedly increased arterial stiffness at the time of diagnosis, in whom combination therapy with fenofibrate and losartan successfully improved proteinuria and arterial stiffness. To the best of our knowledge, this is the first case report of LPG in which CVD risk was assessed using arterial stiffness.

Xanthomas are papulonodular skin lesions present in lipoprotein metabolism disorders, which result in cholesterol deposits in subcutaneous tissue, tendons, ligaments, periosteum, etc. A 11-year-old male presented with multiple soft tissue swellings, prominently over joints. Fine-needle aspiration (FNA) from multiple sites had similar appearance with foamy histocytes and giant cells. Oil Red O and polarized microscopy were also positive for fat. We describe an unusual case of tendinous and tuberous xanthoma diagnosed by cytology. Acquaintance with fine-needle aspiration cytology findings in xanthomas can help to avoid the need of surgical biopsy, as xanthomas can regress on medical therapy alone.