Guest guest Posted May 29, 2005 Report Share Posted May 29, 2005 Googling Tony's term for your red blood cells I found this: this site, which has some rather exquisite pictures and diagrams of these cells. Is this what your cells look like? It suggests you may want to get checked further for the underlying cause of this, as it's not only due to bacterial toxin. Jim http://www.vet.uga.edu/vpp/clerk/Gunter/ The term acanthocyte is derived from the Greek word " acantha " meaning " thorn. " Acanthocytes are cells with five to ten irregular, blunt, finger-like projections (Fig. 1). The projections vary in width, length, and surface distribution (Fig. 2). They are not to be confused with echinocytes, another morphologic variation of the erythrocyte that occurs in an alkaline pH or with certain diseases or disorders (please see clerkship manuscript titled " Significance of Echinocytosis in Blood Smears " ).4 Echinocytes have multiple, small, delicate regular-shaped spines distributed evenly around the cell membrane and are indistinguishable from artifactually crenated cells (Fig. 3).2, 8 Figure 1. Acanthocytes with prominent, irregularly shaped, blunt, finger-like projections in the blood of a dog with hemangiosarcoma. Polychromatophilic erythrocytes also are present (blood, dog, -Leishman stain). Figure 2. Scanning electron micrographs demonstrating successive stages of acanthocyte formation in the blood. Membrane spicules are irregular in number, length, and spacing (modified from Bessis M: Blood Smears Reinterpreted, Springer-Verlag, 1977, p. 67). Figure 3. Echinocytes with evenly spaced, short projections from the cell membrane that have formed as an artifact of blood smear preparation (blood, cat, -Leishman stain). Review of Erythrocyte Membrane Structure To understand the pathophysiology of acanthocyte formation, basic knowledge of erythrocyte membrane structure is essential (Fig. 4). The erythrocyte membrane consists of two domains, the lipid bilayer and the cytoskeleton.3 Figure 4. Schematic diagram of the erythrocyte cell membrane (courtesy of Dr. Guillaume Lenormand, Harvard School of Public Health, Boston, MA, 02115-6021). Phospholipids and cholesterol compose most of the lipid bilayer. The membrane phospholipids are aphipathic; each leaflet has a hydrophilic domain (on the exterior cytoplasmic and extracellular surfaces) and a hydrophobic domain (between the two leaflets of the bilayer). The phospholipids are asymmetrically dispersed in the bilayer. The outer half of the bilayer contains sphingomyelin, glycolipids, and phosphatidylcholine, while the inner half (facing the cytoplasm) is composed of phosphatidylinositols, phospatidylserine, and phosphatidylethanolamine.3,7 Cholesterol is distributed evenly throughout the lipid domain.3 The cholesterol allows flexibility and provides stability to the membrane.8 The cell membrane also contains proteins and glycoproteins embedded in or attached to the lipid bilayer. Proteins in the lipid domain are asymmetrically organized and usually extend through the entire bilayer, forming integral proteins. Carbohydrates are located on the hydrophilic, external portion of these proteins, forming red cell antigens and receptors or transport proteins.3,7 The cytoskeleton is the other domain of the erythrocyte membrane. It is composed of several proteins including spectrin, ankyrin, actin, and protein 4.1, forming a meshwork under the lipid bilayer. The aforementioned proteins interact with the integral proteins and lipid of the bilayer to preserve membrane integrity. The cytoskeleton is essential for maintaining shape, allowing flexibility, and organizing lipids in the erythrocyte.3,7 Pathophysiology of Acanthocyte Formation Most research describing the pathophysiology of acanthocyte formation has been performed in human medicine. In humans, acanthocytes result from abnormalities of the lipid region in the red blood cell membrane. When observed in human blood smears, acanthocytosis is a serious finding that often is associated with severe liver disease, anorexia nervosa, cystic fibrosis, hypothyroidism, post-splenectomy, and myelodysplasia.4,5,6 It also is linked with at least three hereditary neurological disorders that are generally referred to as neuroacanthocytosis. These associated neurological diseases in humans are abetalipoproteinemia, chorea-acanthocytosis, and McLeod syndrome.5 Although the pathophysiology of acanthocytosis in domestic animals has not been studied extensively, it is believed to be similar to the acanthocytosis associated with severe liver disease in humans. With hepatocellular injury in humans, acanthocyte formation is due to a marked increase in cholesterol concentration and, subsequently, the cholesterol to phospholipid ratio of the erythrocyte cell membranes. In cirrhotic liver disease, the liver produces abnormal lipoproteins with a high cholesterol content. This excess cholesterol is readily transferred to the outer hemileaflet of the erythrocyte cell membrane, resulting in formation of flat scalloped cells.4,7 This occurs because there is a dramatic increase in the surface area of the outer portion of the lipid bilayer in comparison to the inner portion of the bilayer.4 Once in the spleen, these abnormal red cells are structurally modified, resulting in membrane fragmentation. The surface projections are remodeled and become longer and less regular, resembling spurs.4,7 The surface area is decreased, and these cholesterol-enriched erythrocytes become less deformable.4,7,8 Deformability is essential for erythrocyte passage through small capillary beds. It also is beneficial to prevent phagocytosis by macrophages, to allow exit from bone marrow, and to reduce bulk viscosity in larger vessels.3 This decrease in cellular deformability ultimately leads to destruction of acanthocytes by the spleen and, consequently, an extravascular hemolytic anemia. Acanthocytes are red blood cells that show many spicules when viewed on a wet film. They occur in abetalipoproteinaemia. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted May 29, 2005 Report Share Posted May 29, 2005 Jim look at this, it also mentions finding echinocytes from a cat with peritonitis-- 'Echinocytosis is a common observation in blood smears from a variety of animal species. It is often overlooked as an artifact of preparation. However, several disease processes and toxins have been found to alter the red blood cell membrane, leading to the formation of echinocytes. Therefore, the presence of echinoctyosis on blood smear examination or on hematology reports may have diagnostic significance.' I would tend to err on the suide of bacterial toxins rather than artifacts, after all it's bacterial toxins that have bought us all here. If our bacteria where producing healthy enzymes this list wouldn't exist. tony > Googling Tony's term for your red blood cells I found > this: > this site, which has some rather exquisite pictures > and diagrams of these cells. Is this what your cells > look like? > It suggests you may want to get checked further for > the underlying cause of this, as it's not only due to > bacterial toxin. > Jim > > http://www.vet.uga.edu/vpp/clerk/Gunter/ > > The term acanthocyte is derived from the Greek word > " acantha " meaning " thorn. " Acanthocytes are cells with > five to ten irregular, blunt, finger-like projections > (Fig. 1). The projections vary in width, length, and > surface distribution (Fig. 2). They are not to be > confused with echinocytes, another morphologic > variation of the erythrocyte that occurs in an > alkaline pH or with certain diseases or disorders > (please see clerkship manuscript titled " Significance > of Echinocytosis in Blood Smears " ).4 Echinocytes have > multiple, small, delicate regular-shaped spines > distributed evenly around the cell membrane and are > indistinguishable from artifactually crenated cells > (Fig. 3).2, 8 > > > Figure 1. Acanthocytes with prominent, irregularly > shaped, blunt, finger-like projections in the blood of > a dog with hemangiosarcoma. Polychromatophilic > erythrocytes also are present (blood, dog, > -Leishman stain). > > > > > Figure 2. Scanning electron micrographs demonstrating > successive stages of acanthocyte formation in the > blood. Membrane spicules are irregular in number, > length, and spacing (modified from Bessis M: Blood > Smears Reinterpreted, Springer-Verlag, 1977, p. 67). > > > > Figure 3. Echinocytes with evenly spaced, short > projections from the cell membrane that have formed as > an artifact of blood smear preparation (blood, cat, > -Leishman stain). > Review of Erythrocyte Membrane Structure > > To understand the pathophysiology of acanthocyte > formation, basic knowledge of erythrocyte membrane > structure is essential (Fig. 4). The erythrocyte > membrane consists of two domains, the lipid bilayer > and the cytoskeleton.3 > > > Figure 4. Schematic diagram of the erythrocyte cell > membrane (courtesy of Dr. Guillaume Lenormand, Harvard > School of Public Health, Boston, MA, 02115-6021). > Phospholipids and cholesterol compose most of the > lipid bilayer. The membrane phospholipids are > aphipathic; each leaflet has a hydrophilic domain (on > the exterior cytoplasmic and extracellular surfaces) > and a hydrophobic domain (between the two leaflets of > the bilayer). The phospholipids are asymmetrically > dispersed in the bilayer. The outer half of the > bilayer contains sphingomyelin, glycolipids, and > phosphatidylcholine, while the inner half (facing the > cytoplasm) is composed of phosphatidylinositols, > phospatidylserine, and phosphatidylethanolamine.3,7 > Cholesterol is distributed evenly throughout the lipid > domain.3 The cholesterol allows flexibility and > provides stability to the membrane.8 The cell membrane > also contains proteins and glycoproteins embedded in > or attached to the lipid bilayer. > > Proteins in the lipid domain are asymmetrically > organized and usually extend through the entire > bilayer, forming integral proteins. Carbohydrates are > located on the hydrophilic, external portion of these > proteins, forming red cell antigens and receptors or > transport proteins.3,7 > > The cytoskeleton is the other domain of the > erythrocyte membrane. It is composed of several > proteins including spectrin, ankyrin, actin, and > protein 4.1, forming a meshwork under the lipid > bilayer. The aforementioned proteins interact with the > integral proteins and lipid of the bilayer to preserve > membrane integrity. The cytoskeleton is essential for > maintaining shape, allowing flexibility, and > organizing lipids in the erythrocyte.3,7 > > Pathophysiology of Acanthocyte Formation > > Most research describing the pathophysiology of > acanthocyte formation has been performed in human > medicine. In humans, acanthocytes result from > abnormalities of the lipid region in the red blood > cell membrane. When observed in human blood smears, > acanthocytosis is a serious finding that often is > associated with severe liver disease, anorexia > nervosa, cystic fibrosis, hypothyroidism, > post-splenectomy, and myelodysplasia.4,5,6 It also is > linked with at least three hereditary neurological > disorders that are generally referred to as > neuroacanthocytosis. These associated neurological > diseases in humans are abetalipoproteinemia, > chorea-acanthocytosis, and McLeod syndrome.5 > > Although the pathophysiology of acanthocytosis in > domestic animals has not been studied extensively, it > is believed to be similar to the acanthocytosis > associated with severe liver disease in humans. With > hepatocellular injury in humans, acanthocyte formation > is due to a marked increase in cholesterol > concentration and, subsequently, the cholesterol to > phospholipid ratio of the erythrocyte cell membranes. > In cirrhotic liver disease, the liver produces > abnormal lipoproteins with a high cholesterol content. > This excess cholesterol is readily transferred to the > outer hemileaflet of the erythrocyte cell membrane, > resulting in formation of flat scalloped cells.4,7 > This occurs because there is a dramatic increase in > the surface area of the outer portion of the lipid > bilayer in comparison to the inner portion of the > bilayer.4 Once in the spleen, these abnormal red cells > are structurally modified, resulting in membrane > fragmentation. The surface projections are remodeled > and become longer and less regular, resembling > spurs.4,7 The surface area is decreased, and these > cholesterol-enriched erythrocytes become less > deformable.4,7,8 Deformability is essential for > erythrocyte passage through small capillary beds. It > also is beneficial to prevent phagocytosis by > macrophages, to allow exit from bone marrow, and to > reduce bulk viscosity in larger vessels.3 This > decrease in cellular deformability ultimately leads to > destruction of acanthocytes by the spleen and, > consequently, an extravascular hemolytic anemia. > > > > > > > Acanthocytes are red blood cells that show many > spicules when viewed on a wet film. > > They occur in abetalipoproteinaemia. > > Quote Link to comment Share on other sites More sharing options...
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