Chylomicrons are tiny fatty droplets that are covered up with a beta-lipoprotein and execute an important function in fat transport in the bloodstream, and therefore have a part in the metabolic processes of fat. The lack of VLDL and chylomicrons interfere with the function of fat and leads to abnormal fat excretion. This is known as steatorrhea.
Other problems and issues of Acanthocytosis include: abnormal red blood cells (acanthocytes), an eye disease, retinitis pigmentosa, and diminished muscle coordination, commonly referred to as ataxia.
Factors of Acanthocytosis
The explanations of acanthocyte pathology differ depending on the underlying illnesses involved. Acanthocytes can be a result of modified quantities of membrane lipids (lipids on the edges of cells) or by tissue layer protein or membrane skeleton irregularities. In membrane lipid irregularities, previously unharmed red blood cell precursors acquire the acanthocytic characteristics and come from the plasma.
Modified membranes may contain diminished phosphatidylcholine levels, but with elevated levels of cholesterol. The abnormality in membrane lipids makes cells really stiff and crinkly. In membranous protein or membrane skeleton irregularities, the defect is internal. This creates imbalances in inner versus outer surface areas of the cell and hampers the interactions between the membraneous skeleton of the cells and certain tissues of the body.
The abnormality in autosomal recessive a-beta-lipo-proteinemia (acanthocytosis) when brought about by the absence of beta-apolipoprotein, is better described in detail. Specifically, the lipids apoprotein B (ApoB) 48 and ApoB 100 are lacking as a result of abnormal cell assembly or faulty secretion of these lipids, leading to absent cell secretion from liver cells or intestinal cells.
Acanthocytosis and Fat
Acanthocytosis also leads to serious malabsorption of fat . In addition to lipid irregularities and altered membrane structure, red cells have secondary vitamin E–deficiency and acquire increased oxidant sensitivity, which basically means cells get destroyed more easily.
Acanthocytes in the homozygous form of familial hypo-beta-lipoproteinemia are believed to have a similar pathology.
Severe liver illness of various causes could also induce altered plasma lipid composition and acanthocytes (generally called spur cells in this instance) as a result of irregular red cell lipid structure. The liver dysfunction causes aggregation of an abnormal, apolipoprotein A-II type of lipid in plasma. Red blood cells are loaded with cholesterol by this lipoprotein and get an increased cholesterol- to- phospholipid ratio and a cell surface area.
A different group of individuals with liver illness may have normal red blood cell membrane lipids, and the pathology in these instances is unknown. This condition is seen more frequently in children with serious liver cell disease.
Acanthocytes are also found in myxedema (decreased thyroid activity, dry skin and mental deterioration) and in 20-65% of hypothyroidism cases. Serum lipid abnormalities are common in acanthocytosis.
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References:
Hegele, RA; Miskie, BA. "Acanthocytosis in a patient...." Clinical Genetics; V. 61 (2) Feb. 2002: 101-103
Rodriguez-Oquendo A, et al. "Inborn metabolic diseases: diagnosis and treatment." Springer: 2006: 400-401. Germany.
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