Normocholesterolemic tendon xanthomatosis with overproduction of apolipoprotein B.
This report describes a 46-yr-old man with normocholesterolemic tendon xanthomatosis. He had severe bilateral xanthomas of Achilles tendons and small lesions on patellar tendons; biopsy of the latter revealed a fibroxanthoma of high cholesterol content. He did not have clinical evidence of atherosclerotic disease. The patient's total cholesterol (TC) and triglycerides (TG) were 245 and 258 mg/dl, respectively. LDL-TC was 168 mg/dl and HDL-TC was 32 mg/dl. VLDL consisted mainly of small particles (SfO 20-100) which were unusually rich in apolipoproteins B and E (and low in apo Cs). Plasma LDL-apo B was not increased (85-120 mg/dl), but VLDL-apo B was distinctly elevated (58 mg/dl). The synthesis rate of apoLDL (29.9 mg/kg/d) was increased markedly compared to a matched control (13.9 mg/kg/d) and to a patient with familial hypercholestrolemia (15.9 mg/kg/d). The concentration of apoLDL in our patient was not increased; this was because of an associated high FCR (0.484 day-1). His HDL was relatively low in TC but high in TG, which caused an increase in HDL2b. The patient's xanthomata may have been the result of an overproduction of apo B possibly combined with a defect in HDL metabolism.
D001053:Apolipoproteins / Q000096:biosynthesis* / Q000097:blood; D001055:Apolipoproteins B; D002784:Cholesterol / Q000097:blood*; D006801:Humans; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D013261:Sterols / Q000378:metabolism; D013710:Tendons / Q000473:pathology; D014973:Xanthomatosis / Q000097:blood* / Q000473:pathology
D001053:Apolipoproteins; D001055:Apolipoproteins B; D008055:Lipids; D008074:Lipoproteins; D013261:Sterols; D002784:Cholesterol