A case report of palmar xanthoma with xanthomatous neuropathy

Xanthomas are plaques or nodules consisting of an accumulation of excess lipids, resulting in the formation of foam cells in the skin or tendons. Typically, xanthomas are not accompanied by other symptoms. Here, we report a patient with a presentation of painful palmar xanthomas and subsequent diagnosis of metabolic and cardiovascular morbidities. A 44-year-old man presented with multiple yellowish, firm, and painful nodules on his right palm and fingers. Lipid panel and medical examination revealed a diagnosis of type III hyperlipoproteinemia and diabetes mellitus type II. Histopathological examination of the lesions revealed numerous lipid-laden foamy cells surrounding the nerve bundles through the dermis. This unique presentation of painful xanthomas prior to the manifestation of more significant underlying conditions suggested that xanthomas might be used as early diagnostic indicators. Based on this case, we propose more thorough examinations of palmar xanthomas in patients for earlier detection of potentially lethal diseases.

Pathogenesis, histopathologic findings and treatment modalities of lipoprotein glomerulopathy: A review

Lipoprotein glomerulopathy (LPG) is an uncommon cause of nephrotic syndrome and/or kidney failure. At microscopy, LPG is characterized by the presence of lipoprotein thrombi in dilated glomerular capillaries due to different ApoE mutations. ApoE gene is located on chromosome 19q13.2, and can be identified in almost all serum lipoproteins. ApoE works as a protective factor in atherosclerosis due its interaction with receptor-mediated lipoprotein clearance and cholesterol receptor. Most common polymorphisms include ApoE2/2, ApoE3/2, ApoE3/3, ApoE4/2, ApoE4/3, and ApoE4/4. All age-groups can be affected by LPG, with a discrete male predominance. Compromised patients typically reveal dyslipidemia, type III hyperlipoproteinemia, and proteinuria. LPG treatment includes fenofibrate, antilipidemic drugs, steroids, LDL aphaeresis, plasma exchange, antiplatelet drugs, anticoagulants, urokinase, and renal transplantation. Recurrence in kidney graft suggests a pathogenic component(s) of extraglomerular humoral complex resulting from abnormal lipoprotein metabolism and presumably associated to ApoE.

Development of a Novel Homogeneous Assay for Remnant Lipoprotein Particle Cholesterol

Background Quantification of remnant lipoprotein particle cholesterol (RLP-C) by automated assay is useful in routine clinical laboratories to assess coronary artery disease risk and diagnose type III hyperlipoproteinemia. Methods Enzymes and surfactants were screened to establish a homogeneous RLP-C assay using the chylomicron-VLDL, LDL, and HDL fractions isolated by ultracentrifugation, along with the RLP fraction isolated by immunoaffinity gel. All data were generated using a Hitachi analyzer. Results A specific cholesterol esterase with a polyoxyethelene styrenated phenyl ether derivative (surfactant) was used for the establishment of a homogeneous RLP-C assay. This cholesterol esterase with subunits of >40 kDa (H-CE) was found to react with lipoproteins other than RLP, whereas this enzyme with subunits of <40 kDa (L-CE) reacted with RLP. H-CE was applied for the first reaction step with the specific surfactant to decompose non-RLP lipoproteins, degrading non-RLP cholesterol into water and oxygen in the presence of cholesterol oxidase and catalase. For the second step, L-CE was applied to release cholesterol from RLP, and then the released RLP-C was determined in a standard cholesterol oxidase and peroxidase system. This new homogeneous assay exhibited good correlation with the RLP-C immunoseparation method. Conclusions We established a simple, rapid, automated homogeneous assay for RLP-C. The assay can determine RLP-C levels in 10 min in a fully automated manner, processing a large number of samples in routine clinical laboratories.