11/52. Type III hyperlipoproteinemia with xanthomas and multiple myeloma. BACKGROUND: Type III hyperlipoproteinemia usually results from an inherited defect in the composition of apolipoprotein E and is associated with atherosclerosis. An acquired form of the type III phenotype may rarely be associated with myeloma and immunoglobulin-lipoprotein complexes. observation: We present the case of a 72-year-old man with a history of well-controlled, unclassified hypercholesterolemia and hypertriglyceridemia, without evidence of atherosclerotic disease. He subsequently developed refractory dyslipidemia, palmar crease, and tuberous xanthomas. Type III hyperlipoproteinemia was confirmed, and nonclassic defective apolipoprotein E. Common secondary causes of hyperlipidemia were ruled out. A workup for malignancy revealed monoclonal IgA gammopathy. Immunostaining confirmed IgA antibodies complexed to the patient's very low-density lipoprotein (VLDL) fraction, causing gross impairment of VLDL metabolism. Conventional therapy for type III hyperlipoproteinemia was attempted but ineffective. Thus, chemotherapy was initiated for his myeloma, with subsequent lowering of his IgA, cholesterol, and triglyceride levels, and improvement of his xanthomas. CONCLUSION: There are several unusual features to this case. Planar xanthomas can be associated with myelomas, but usually in the setting of normal lipids. Type III hyperlipoproteinemias are not usually refractory to standard therapy and are only rarely associated with IgA myeloma. IgA antibodies complexed to the patient's VLDL caused gross impairment of VLDL metabolism. The patient's apolipoprotein E genotype (heterozygote E2/E3) is not typical for expression of the heritable type III phenotype (homozygote E2/E2). These features support a causal relationship between this patient's multiple myeloma and type III hyperlipoproteinemia rather than two independent, coexistent conditions. ( info) |
12/52. Unmasking of type III hyperlipoproteinemia by hypothyroidism: a dramatic illustration of altered lipoprotein metabolism in a postpartum woman. OBJECTIVE: To illustrate the potential abnormalities in lipoprotein metabolism associated with type III hyper-lipoproteinemia and the modulation of their clinical expression by thyroid hormone and estrogenic status. methods: An illustrative case, with associated clinical and laboratory data, is presented, and relevant clinical and pathophysiologic studies from the literature are reviewed. RESULTS: A 35-year-old woman, at 7 months after delivery of her first child, presented to her family physician with a complaint of painful eruptions on the palms of her hands. On evaluation, she was found to have new hypothyroidism and severe hypertriglyceridemia (>1,569 mg/dL). thyroxine replacement was initiated, and she was referred to the lipid clinic. When seen in the lipid clinic shortly thereafter, her triglyceride level had normalized, but her low-density lipoprotein (LDL) fraction was strikingly elevated (representing a combination of elevated intermediate-density lipoprotein and LDL cholesterol). On physical examination, palmar xanthomas were noted, suggestive of type III hyperlipoproteinemia. This diagnosis was further supported by homozygosity at the apolipoprotein E (apo E) gene locus for the apo E2 allele implicated in this condition. Ultimately, with attainment of euthyroidism in the subsequent weeks, the lipid profile normalized, with the LDL cholesterol concentration particularly reduced at 55 mg/dL. CONCLUSION: Clinical expression of type III hyperlipoproteinemia necessitates interaction between an underlying genetic defect of lipoprotein metabolism (apo E2 homozygosity) and a secondary metabolic insult such as, in the current case, hypothyroidism and possibly breast-feeding-mediated hypoestrogenemia. As such, in patients with type III hyperlipoproteinemia, it is essential to search for exacerbating factors, particularly because the amelioration of such factors may rectify the effects of the underlying dyslipidemia. ( info) |
13/52. Tuberous xanthomas associated with olanzapine therapy and hypertriglyceridemia in the setting of a rare apolipoprotein E mutation. OBJECTIVE: To describe a patient with tuberous xanthomas and high levels of cholesterol and triglycerides, who was found to have type III hyperlipoproteinemia (HLP) and a rare apolipoprotein E (apoE) mutation. methods: We present a case report with extensive clinical, laboratory, and genetic documentation. RESULTS: A 33-year-old African American man presented for evaluation of hypertriglyceridemia. His medical history was remarkable for schizophrenia necessitating ongoing olanzapine therapy for the past 6 years. A few months after olanzapine treatment was begun, he noted the development of nontender, firm, papular skin lesions on his elbows and knees. His family history was negative for lipid disorders or premature vascular disease. physical examination revealed the presence of prominent tuberous xanthomas on both elbows and knees. Results of a lipid panel demonstrated a total cholesterol level of 374 mg/dL (9.7 mmol/L) and triglycerides of 828 mg/dL (9.3 mmol/L). A work-up for causes of secondary hyper-triglyceridemia was negative. Results of apoE genotyping by a commercial laboratory showed the E3/E3 genotype, based on gene sequencing at codons 112 and 158. Because the skin lesions were typical for type III HLP, his entire apoE gene was sequenced. This analysis revealed an apoE2/E2 (arginine 145 to cysteine) mutation, previously reported to be a rare cause of type III HLP in 5 patients of African descent. Triglyceride-lowering therapy with gem-fibrozil was initiated, in addition to lifestyle modification. At follow-up several months later, total cholesterol was 276 mg/dL (7.14 mmol/L) and triglycerides were 479 mg/dL (5.41 mmol/L). CONCLUSION: We speculate that olanzapine therapy, with its known metabolic side effects, exacerbated this patient's underlying lipoprotein metabolic abnormality. To our knowledge, this is the first report of an association between olanzapine therapy and tuberous xanthomas and the sixth report of this rare apoE2/E2 (arginine 145 to cysteine) mutation in the literature. ( info) |
14/52. Apolipoprotein E-4Philadelphia (Glu13 Lys,Arg145 Cys). Homozygosity for two rare point mutations in the apolipoprotein E gene combined with severe type III hyperlipoproteinemia. The molecular defect in a 24-year-old white female with severe type III hyperlipoproteinemia has been elucidated. The patient's apolipoprotein (apo) E migrated in the apoE-4 position on isoelectric focusing gels. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the apoE-4 variant had a smaller apparent molecular weight than apoE-4(Cys112 Arg). sequence analysis of dna amplified with the polymerase chain reaction revealed two nucleotide substitutions in the proband's apoE gene. A C to T mutation converted arginine (CGT) at position 145 of the mature protein to cysteine (TGT) thus creating the apoE-2 variant. A second G to A substitution at amino acid 13 led to the exchange of lysine (AAG) for glutamic acid (GAG), thereby adding 2 positive charge units to the protein and producing the apoE-5 variant. Computer analysis of the apoE-4Philadelphia gene revealed that the G to A mutation in exon 3 resulted in the loss of an AvaI restriction enzyme site. The second mutation, a C to T substitution in the fourth exon of the apoE gene, eliminated a cleavage site for the enzyme BbvI. Using these restriction fragment length polymorphisms as well as dna sequence analysis we have demonstrated that the patient is homozygous for both point mutations in the apoE gene. ( info) |
15/52. Effects of atorvastatin and apoA-I/phosphatidylcholine discs on triglyceride-rich lipoprotein subfractions as characterized by capillary isotachophoresis. BACKGROUND: The present study examined the effects of atorvastatin and the in vitro effect of apolipoprotein (apo) A-I/phosphatidylcholine (POPC) discs on charge-based triglyceride-rich lipoprotein (TRL) subfractions in a patient with type III hyperlipoproteinemia (HLP) and the apoE2/2 phenotype. methods: Charge-based lipoprotein subfractions were characterized by capillary isotachophoresis (cITP). cITP analysis was performed using plasma that had been prestained with a lipophilic dye on a Beckman P/ACE MDQ system. RESULTS: Treatment with atorvastatin for 4 weeks markedly decreased the slow (s)-migrating TRL subfraction and both fast- and slow-migrating low-density lipoprotein (LDL) subfractions, but did not affect the fast (f)-migrating TRL subfraction in this patient. ApoA-I/POPC discs consisted of two major charge-based subfractions that had the mobility of cITP fTRL and sTRL. Incubation of plasma from this patient in the presence of apoA-I/POPC discs caused not only a reduction in cITP fast- and intermediate-migrating HDL and an increase in cITP sHDL but also a reduction in fTRL and sTRL and an increase in sLDL. CONCLUSION: Atorvastatin and apoA-I/POPC discs decreased cITP TRL subfractions in a complementary manner, suggesting that the combination of apoA-I/POPC discs and atorvastatin could be a promising therapeutic approach for hypertriglyceridemia. ( info) |
16/52. clomiphene-associated combined hyperlipidemia: a case report. BACKGROUND: Hyperlipidemia associated with clomiphene use is an uncommon but potentiallly serious complication of this therapy. clomiphene is structurally similar to other synthetic estrogen analogs, which are known to induce marked hypertriglyceridemia. There is a paucity of data regarding the effects of clomiphene on lipid metabolism in humans. CASE: A 33-year-old woman with obesity, polycystic ovary syndrome and a long history of amenorrhea was treated with clomiphene therapy to induce ovulation. Baseline lipids were suggestive of an underlying lipid disorder, but there was a marked deterioration in her lipid profile in association with the use of clomiphene. On cessation of the clomiphene therapy her lipid profile slowly improved, and specific lipid-lowering therapy was not used. Further investigation for the possibility of an underlying lipid disorder confirmed the diagnosis of familial dysbetalipoproteinemia. CONCLUSION: clomiphene should be used cautiously in women known to have dyslipidemia. We recommend that patients with predisposing risk factors have their lipids measured prior to ovulation induction with clomiphene. ( info) |
17/52. Expression of type III hyperlipoproteinaemia in a subject with secondary hypothyroidism bearing the apolipoprotein e2/2 phenotype. Post-surgical hypothyroidism developed in a now 43-year-old woman with complete insufficiency of the anterior pituitary gland who discontinued levothyroxine replacement therapy. serum cholesterol and serum triglyceride levels increased in parallel, and classical type III hyperlipoproteinaemia (HLP) with xanthoma striata palmaris developed. The patient is homozygous for apolipoprotein (apo) E2. The case reported here represents the first example of manifestation of type III hyperlipoproteinaemia in a subject with secondary hypothyroidism bearing the apo E2/2 phenotype. ( info) |
18/52. Potential role of insulin in the clearance of remnant lipoproteins in dysbetalipoproteinaemia. Dysbetalipoproteinaemia is a genetic disorder characterized by accumulation of lipoprotein remnant particles in the plasma, accelerated atherosclerosis, and the abnormal apoprotein E2. Uncontrolled diabetes mellitus can aggravate the hyperlipidaemia associated with this disorder, presumably by increasing triglyceride synthesis and reducing very low density lipoprotein catabolism by lipoprotein lipase. This report documents the gradual amelioration of dysbetalipoproteinaemia in uncontrolled diabetes mellitus following therapy with exogenous insulin alone. Although the beneficial effects of insulin therapy in this patient may include inhibition of triglyceride synthesis and improved triglyceride catabolism, we propose that insulin may also stimulate clearance of atherogenic remnant lipoprotein particles. ( info) |
19/52. Type III hyperlipoproteinemia in a patient with idiopathic hemochromatosis. A 60-year-old man is reported with idiopathic hemochromatosis and type III hyperlipoproteinemia. Regular phlebotomy therapy and fenofibrate treatment favorably influenced the disorder of iron metabolism and the lipid disease. Evidence is given that both errors of metabolism are independently inherited diseases, although the symptoms of the first (idiopathic hemochromatosis) may aggravate the expression of the second (type III hyperlipoproteinemia). ( info) |
20/52. Identification and characterization of a new variant of apolipoprotein E (apo E-Kochi). A new variant of apolipoprotein E (apo E), named apo E-Kochi, was identified in the sera of a 29-year-old male with hyperlipoproteinemia as characterized by a broad-beta band. The characteristic double bands of apo E were seen in the isoelectric focusing gel of very low density lipoprotein from the proband and three members of his family. Of the double bands from the probands, the more cationic component was identical to ordinary apo E3 and the other anionic band was located at approximately a distance of one-half charge to the anode side. This anionic band is a new electrophoretical isoform of apo E (apo E-Kochi), and the molecular weight by sodium dodecyl sulfate electrophoresis and its antigenicity against anti apo E serum are the same as apo E3. sequence analysis of lysyl endopeptidase fragments showed that apo E-Kochi differs from normal apo E3 at residue 145, where an arginine residue is substituted for histidine. ( info) |