Lipoprotein-Associated Disorders

The pathogenic mechanisms responsible for the association of musculoskeletal abnormalities with hypercholesterolaemia remain obscure. However, it has been hypothesized that the deposition and modification of lipoprotein components within and around the joint of patients with hyperlipidaemia-associated arthropathy results in a pro-inflammatory response, giving rise to articular disorders (Prete et al., 1993). 

Lipoprotein pattern types I, III, IV, and V are associated with hypertriglyceridemia, and these primary lipoprotein disorders should be excluded prior to implementing therapy. 

Vitamin E may be indicated in some rare forms of anemia such as macrocytic, megaloblastic anemia observed in children with severe malnutrition and the hemolytic anemia seen in premature infants on a diet rich in polyunsaturated fatty acids. Also anemia s in malabsorption syndromes have shown to be responsive to vitamin E treatment. Finally, hemolysis in patients with the acanthocytosis syndrome, a rare genetic disorder where there is a lack of plasma jS-lipoprotein and consequently no circulating alpha tocopherol, responds to vitamin E treatment. In neonates requiring oxygen therapy vitamin E has been used for its antioxidant properties to prevent the development retrolental fibroplasia. It should be noted that high dose vitamin E supplements are associated with an increased risk in allcause mortality. 

Patients with HL deficiency present with hypercholesterolemia and hypertriglyceridemia, and accumulate VLDL remnants, triglyceride-rich LDL, and HDL [84]. These remnants mainly derive from a reduced catabolism of apoB-containing lipoproteins [82]. The disorder appears to be inherited in an autosomal recessive trait and is associated with an increased risk for coronary artery disease [8]. 

This familial disorder, which is associated with increased atherogenesis, is determined chiefly by alleles that dictate increased production of the Lp(a) lipoprotein. Niacin reduces levels of Lp(a) in... 

Although there are papers that discuss the relationships between cholesterol, lipid profiles, and major depression [34-39], there are few data that discuss the association between lipid profiles and depressive disorders with different phenotypes. Huang and Chen investigated the correlation between serum lipid, lipoprotein concentration, and major depressive disorder in patients evaluated for general health screening [41]. They found that analysis of covariance after age adjustment revealed significant differences in patients with melancholic feature and patients with atypical feature in serum concentrations of TG and VLDL in men and HDL in women [41]. However, there are still no reports that discuss the relationships between lipid profiles and major depression with postpartum onset or catatonic feature. In the future, large sample numbers will be needed to clarify the clinical differences in this field. 

Type I lipoproteinemia is generally caused by the inability of the organism to clear chylomicrons. The problem may be defective ApoC-II or a defective lipoprotein lipase. Very often, chylomicron clearance may be affected by injection of heparin, which apparently releases hepatic lipase from the liver into the circulation. ApoE disorders may be associated with type III lipoproteinemia, in which clearance of IDL is impeded. Increases in circulatory LDL are usually caused by a decrease in tissue receptors specific for ApoB-100. An extreme case of type Ha hyperlipoproteinemia is familial hypercholesterolemia, in which serum cholesterol levels may be as high as 1000 mg/dL and the subjects may die in adolescence from cardiovascular disease. There is total absence of ApoB-100 receptors. Mild type Ila and lib lipoproteinemias are the most commonly occurring primary lipoproteinemias in the general population. 

Three disorders of lipoprotein metabolism share these characteristics familial hypobetal-ipoproteinemia, chylomicron retention disease, and ABL (Table 27-2). The presence or absence of specific plasma apoB lipoproteins, as well as their mode of inheritance, can be useful when attempting to differentiate between these disorders. Symptoms associated with familial hypo-betalipoproteinemia are usually milder than for the other two and are inherited as dominant traits, that is, symptoms are observed in at least one parent of an affected offspring. Chylomicron retention disease is an autosomal recessive disorder with a severe phenotype commonly presenting soon after birth. Plasma lipoprotein analysis from affected individuals shows a specific absence of chylomicrons (apoB48) but normal amounts of VLDL and LDL (apoB 100). In our patient, evidence of recessive inheritance and absence of all apoB-containing lipoproteins implicates ABL as the most likely diagnosis. 

Recently, the CD/MRV hypothesis has received experimental support by the discovery of multiple rare variants in a few genes associated with several common disorders/quantity traits, including colorectal ademonas (Feamhead et al., 2004) and low plasma high-density lipoprotein levels (Cohen et al., 2004,... 

In addition to various plasma lipids and lipoprotein species, other markers of cardiovascular disease and atherosclerosis are now considered as potent screening tools to predict these diseases. These markers are mostly related to the discoveries that a low-level chronic inflammation and related disorders of the immune system are as much, and probably more, of a clinical predictor of cardiovascular pathology than dietary fat and associated lipoproteins (165). 

Exchangeable apolipoproteins are a class of functionally important proteins which play a key role in plasma lipoprotein metabolism. In this capacity they have been associated with several human disorders, including hyperlipidemia and cardiovascular disease (1,2). Apolipophorin-III (apoLp-III) is a model exchangeable apolipoprotein derived from the insect Manr/Mca sexta (166 residues, Mr 18,380). ApoLp-III is a major hemolymph protein in the adult life stage and... 

The clinical significance of lipids is primarily associated with coronary heart disease (CHD) and various lipoprotein disorders. 

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