Thiamine can be assayed directly (eg, through Specialty Laboratories of Santa Monica, California). B1, Thiamine or thiamin . See our User Agreement and Privacy Policy. Lab tests indicate low RBC's and a urine test indicates the presence of free hemoglobin. Once produced, the shape change usually is irreversible. Leptocytes and target cells (codocytes) also may be observed in hepatic insufficiency, especially in dogs and cats with portocaval shunts. The MCV may be increased (macrocytosis) or decreased (microcytosis). This section aims to provide a reference list of abbreviations and acronyms that are frequently used within oncology. RBC morphology may provide important diagnostic information regarding the underlying cause of anemia and systemic disease. If you continue browsing the site, you agree to the use of cookies on this website. Vitamin B₂ (riboflavin) Characteristics. A high percentage of polychromatophilic cells (reticulocytes) may result in an increased MCV and decreased MCH or MCHC. Most shape changes result from alteration of the red cell membrane. Acanthocyte membranes are enriched with cholesterol by 50% to 70%. A well-nourished physician of Mediterranean heritage is suffering fatigue while doing missionary work in Africa. Abnormal lipid metabolism alters the lipid composition of RBC membranes and reduces RBC deformability. The cytoskeleton delimits membrane deformability and confers the physical properties necessary for normal shape changes during circulation. Animals with portocaval shunts and other hepatic diseases may develop "functional iron deficiency" with similar RBC morphologic changes. Shortly after receiving an anti-malarial drug, symptoms started to appear. Meaning of Pentose Phosphate Pathway. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Abnormal RBC Morphology Caused by Iron Deficiency. Changes in the distribution of the phospholipids may have profound effects on red cell shape and other cell properties. Now customize the name of a clipboard to store your clips. Target cells also may form because of decreased hemoglobin concentration secondary to altered iron metabolism, which may occur in hepatic insufficiency. The principal proteins--spectrin, actin, protein 4.1, and ankyrin--form a hexagonal lattice that underlies and attaches to the lipid bilayer via trans-membrane proteins (band 3 and glycophorins). If both macrocytes and microcytes are present, the MCV may be normal. Echinocytosis has been linked to total body cation depletion in horses with colitis or with furosemide administration, and is associated with. Eccentrocytes that have become spherical with only a small tag of cytoplasm remaining are called pyknocytes. In addition to spherocytosis, RBC agglutination commonly occurs in IMHA. In immune-mediated hemolytic anemia (IMHA), spherocytes are the sole or primary type of poikilocyte observed. Splenic hemangiosarcoma is a disease that best characterizes microangiopathic fragmentation in dogs. [MN Chatterjea]Textbook of Medical Biochemistry (8th Ed.) In this presentation, I will discuss the pathophysiologic mechanisms of RBC morphologic alterations in dogs and cats (with an emphasis on shape changes) and their significance in the diagnosis of disease. Cholesterol is in the free, unesterified form; phospholipids are a mixture of lecithin (phosphatidylcholine), phosphatidylethanolamine, sphingomyelin, phosphatidylserine, and phosphatidylinositol. Polychromasia is the most important indicator of responsiveness to anemia, and may be further quantitated by counting reticulocytes. Glucose 6-phosphate for the production of NADPH (by the reduction of coenzyme NADP) and a Pentose sugar.. Increased RDW may be a sensitive means of detecting early iron deficiency, especially in cats. RBCs in uremic patients have decreased transketolase activity, increased susceptibility to oxidants, and decreased Na/K ATPase activity leading to altered shape, increased rigidity, and susceptibility to mechanical fragmentation. More than 50% of cats with liver disease have poikilocytosis (usually acanthocytes), and serum cholesterol concentrations are higher in cats with more severe poikilocytosis. Pentose phosphate pathway is defined as the metabolic pathway that occurs in all living organisms, and it utilizes the first intermediate product of glycolysis, i.e. Vitamin B1 deficiency causes B er 1B er 1. Spherocytes are primarily identified in dogs; they are difficult, if not impossible, to identify in cats. Oxidative damage to hemoglobin results in Heinz body formation (oxidation of globin chains) and/or methemoglobinemia (oxidation of iron). Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Evaluation and interpretation of red blood cell (RBC) morphology is an important component of a complete blood count (CBC). RBC distribution abnormalities include rouleaux and agglutination. erythrocyte [ĕ-rith´ro-sīt] one of the formed elements in the peripheral blood, constituting the great majority of the cells in the blood. 54 55. First Aid for the USMLE Step 1 2018. Several commercial laboratories can perform this assay. Hypercholesterolemia usually is associated with severe cholestatic disease, and is accompanied in dogs and humans by increased serum levels of lipoprotein X as well as other abnormal lipoproteins. Macrocytic red cells resembling reticulocytes may result that have abnormally high membrane cholesterol content. Echinocytes (crenation) and torocytes may result from prolonged storage of blood in EDTA; target cells and stomatocytes may result from slow drying of the blood smear. Cholesterol enrichment of the membrane expands the outer leaflet of the lipid bilayer, distorts cell contours, disturbs cell functions and accelerates cell destruction. Some new hematology analyzers determine the percentage and number of hypochromic (and hyperchromic) cells of different sizes. 16 Full PDFs related to this paper. Evaluation and interpretation of red blood cell (RBC) morphology is an important component of a complete blood count (CBC). Abnormal RBC Morphology Caused by Mechanical Fragmentation. MCH and MCHC indicate hemoglobin concentration; decreased values indicate hypochromasia. Thiamin(e), vitamin B1, is spelled with and without an ‘e’. Anemia is variably regenerative and characterized by microcytosis, hypochromasia (not always in cats), and increased RDW. Mukhammed Seidaly. Animals fed sunflower oil had more target cells and animals fed fish oil had more echinocytes compared with animals fed olive oil. Diagnostics: vitamin B 1 administration → ↑ RBC transketolase activity; In malnourished or alcohol-dependent patients, always administer thiamine before giving dextrose to decrease the risk of precipitating or exacerbating Wernicke encephalopathy. IMHA may be primary, secondary to neoplasia or other diseases, or may result from RBC organisms such as Mycoplasma Haemophilus. Echinocytes and echinocytic elliptocytes (burr cells) have been reported in dogs with renal disease (glomerulonephritis) and in humans with uremia, where they are thought to reflect changes in the metabolic environment and are associated with decreased red cell lifespan. Anisocytosis is a qualitative measure of variability in RBC size. (For immature forms see erythrocytic series.) Agglutination can falsely increase the MCV. RBCs passing through microangiopathic vessels are prone to mechanical fragmentation. Glucose breakdown and synthesis are essential processes in the human body. Agglutination may be the only RBC morphologic abnormality in IMHA in cats, and must be differentiated from rouleaux. Polychromasia refers to the light blue color of immature RBCs (caused by residual RNA). Contents Introduction List of Abbreviations List of Acronyms of Cancer Organisations The Female Reproductive Organs Combined List of Abbreviations and Acronyms Introduction. Because mature RBCs cannot synthesize lipids, they rely on a continuous exchange of lipids between their membranes and plasma lipoproteins for homeostasis. Rouleaux also may form normally in feline blood and as an artifact due to slow drying of the blood smear. Download. When low numbers of spherocytes are seen with other types of poikilocytes, diseases causing RBC fragmentation are more likely. The combination of turbulent blood flow through sinuous and rough, neoplastic vessels yields a unique mix of schistocytes, acanthocytes, keratocytes, dacryocytes, blister cells, and a few spherocytes. Phospholipids are asymmetrically distributed within the bilayer, with hydrophobic long chain fatty acids oriented towards the inner core of the membrane. Microangiopathy is the deposition of fibrin strands or microthrombi in small blood vessels. Fragmentation may result in schistocytes and acanthocytes; acanthocytes also may be seen in conjunction with renal disease-induced lipid abnormalities. Echinocytes also have been described in dogs with neoplasia (lymphoma, hemangiosarcoma, mast cell tumor, carcinoma) and in people with sepsis. The cytoskeleton helps determine and maintain the shape of red cells through the arrangement and interactions of cytoskeletal proteins. Anemia is variable in severity, and can be mild or even absent. Feline acanthocytes have few blunt projections and may appear to be misshapen RBCs. Movement of free cholesterol between plasma and lipid bilayer is rapid and dynamic; membrane phospholipid turnover with plasma is a passive process that occurs very slowly. Glucose provides the required substrates for aerobic and anaerobic metabolism. NADPH is required for the reduction of glutathione, an antioxidant preventing excess hydrogen peroxide and free radicals from damaging RBC membranes. Glycolysis versus gluconeogenesis. Looks like you’ve clipped this slide to already. Abnormalities are graded as slight, moderate or marked (or 1+ to 4+). Thiamine Deficiency • The transketolase activity is measured in RBCs is an index of the thiamine status of an individual. It is catalysed by the enzyme transketolase and the coenzyme is Thaimine pyrophosphate (TPP). Agglutination refers to small groups or clumps of RBCs that result from the interaction between bound antibodies on the surface of RBCs. Download PDF Feline RBCs with Heinz bodies, especially those caused by oxidant drugs, also can undergo hemolysis, such that "ghost cells" are seen on blood smears. Other, more reliable lab markers include erythrocyte transketolase activity and RBC (red blood cells) thiamine diphosphate, but these tests are more expensive and don’t give quick results [64, 29]. Other causes of spherocytosis are coral snake envenomation and zinc toxicity. Dietary lipid also can affect RBC membrane lipid composition and morphology. K. Thornton, E. Villamor, in Encyclopedia of Food and Health, 2016 Nutritional Epidemiology. Elliptocytes result from abnormalities in spectrin and other membrane proteins and their interaction with the lipid bilayer. Membrane enzymes depend on the integrity of phospholipids for normal function. URONIC ACID … These cells form when erythrocyte membranes contain excess cholesterol compared to phospholipids (increased cholesterol:phospholipid ratio), due to hypercholesterolemia or abnormal lipoprotein composition. Abnormal RBC Morphology Caused by Oxidative Damage. University of California-Davis, School of Veterinary MedicineDavis, CA, Interpretation of Red Blood Cell Morphology (Advanced Level), World Small Animal Veterinary Association World Congress Proceedings, 2004, Mary M. Christopher, DVM, PhD, DACVP, DECVCP, University of California Davis, Department of Pathology, Microbiology, and Immunology School of Veterinary Medicine. Hypochromasia refers to pale RBCs with a wide central pallor. These tumors are essentially giant masses of thrombotic blood vessels and sinuses. Transfer of 2-carbon moiety i.e., active glycelaldehyde is known as transketolation. Your doctor may also perform a physical exam and look for deficiency symptoms. The RDW is a quantitative index of variability in RBC size, and is increased in regenerative anemia and iron deficiency anemia. GANDHAM RAJEEV-BIOCHEMISTRY IMPORTANT QUESTIONS-RGUHS-2017, No public clipboards found for this slide. Nursing animals also are susceptible to iron deficiency. Altered lipoprotein metabolism also can inhibit the maturation of erythrocytes in the bone marrow, at the time at which they are discarding their nuclei and organelles and assuming a flexible biconcave shape. Abnormal RBC Morphology Caused by Immune-Mediated Disease. In cats, an increased percentage of Heinz bodies with no history of drug toxicity may reflect diet (e.g., onions, fish) or underlying disease, especially ketoacidotic diabetes mellitus, lymphoma, and hyperthyroidism. The most common red cell shape abnormalities in dogs and cats with liver disease are echinocytes and/or acanthocytes (spur cells). READ PAPER. Target cells result from excess membrane relative to low intracellular hemoglobin concentration. Abnormal RBC Morphology Caused by Hepatic Disease. • The occurrence & manifestation of Wernickes korsakoffs syndrome (encephalopathy) which is seen in alcoholics & those with thiamine deficiency is due to a genetic defect in the enzyme transketolase. Fusiform cells may be found in birds. Olive oil is rich in monounsaturated fatty acids, whereas, sunflower oil is rich in linoleic and arachidonic acids (n-6 PUFAs), and fish oil is rich in n-3 PUFAs. Other poikilocytes result from membrane lipid and protein abnormalities that decrease deformability and make RBCs more fragile and susceptible to fragmentation and to oxidative stress. RBC morphology is assessed qualitatively on a well-made blood smear and includes RBC distribution, anisocytosis, poikilocytosis, polychromasia/hypochromasia, and inclusions or organisms. Other disorders that cause microangiopathy and RBC fragmentation are chronic disseminated intravascular coagulation, heartworm disease, valvular vegetative endocarditis, and glomerulonephritis. In cats with many large Heinz bodies, evaluation for ketosis is recommended. Poikilocytes seen most often in iron deficiency are target cells, leptocytes, schistocytes, elliptocytes, and dacryocytes. RDW increases when microcytes and fragments form, and then normalizes. Nutritional epidemiology is the application of epidemiological methods to the study of how diet is related to health and disease in humans at the population level. Role: B1 is a coenzyme that helps the body produce energy, is involved in glucose, amino acid, lipid, and alcohol metabolism, and is required for the proper functioning of the nervous system, heart, and muscles. Transaldolation reaction: The Merck Manual of Diagnosis and Therapy 19th Edition - Copy. Both hypochromasia and microcytosis may be difficult to assess visually, but usually are detectable with changes in RBC indices. RBC inclusions include basophilic stippling, Heinz bodies, Howell-Jolly bodies and RBC organisms, such as Mycoplasma hemophilus, Babesia canis, and Eperythrozoon spp. First Aid for the USMLE Step 1 2018 The type of shape abnormality must be specified. The biochemical cause of echinocytosis in renal disease is unknown. RBC indices are quantitative indicators of RBC morphology. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. Phospholipases in rattlesnake and coral snake venom result in dose-dependent echinocytosis. Target cells result from a balanced excess accumulation of both cholesterol and phospholipids and form later in the course of cholestatic disease (i.e., 1 week later than acanthocytes) because of the slower rate of phospholipid (vs cholesterol) exchange. Red cell morphology may be altered by alterations in lipid, iron and oxidative metabolism, immune-mediated disease, mechanical fragmentation, and by electrolyte or metabolic abnormalities. While methemoglobinemia does not alter RBC morphology, Heinz bodies are visible as spherical, slightly refractile spots on the RBC; they are much more easily seen on new methylene blue-stained smears. Heinz bodies in cats are often larger and usually single, compared with Heinz bodies in dogs. Phases. Iron deficiency, whatever the underlying cause, results in microcytic hypochromic anemia, often with mild to moderate poikilocytosis. You can change your ad preferences anytime. In dogs and cats, iron deficiency most commonly is caused by chronic blood loss from gastrointestinal bleeding (ulcers, neoplasia), severe flea infestation, hematuria (neoplasia) or coagulopathies. Like RDW, anisocytosis is increased when microcytic or macrocytic RBC (or both) are present, or when spherocytes are present (which have normal MCV but appear smaller on smears). This physician doesn't have a history of heavy alcohol consumption. Thiamine pyrophosphate is also a coenzyme of the transketolase system by which direct oxidation of glucose occurs in the cytoplasm of cells via the pentose phosphate pathway. Increased MCH or MCHC is an artifact secondary to Heinz bodies, lipemia, or hemoglobinemia. Hypercholesterolemia and cholesterol uptake into red cell membranes is further enhanced in hepatic insufficiency and obstructive liver disease by decreased activity of lecithin cholesterol acyltransferase (LCAT), the enzyme responsible for cholesterol esterification, resulting in decreased production of cholesterol esters and a subsequent increase in free cholesterol. Academia.edu is a platform for academics to share research papers. Liver disease is the most common causes of lipid-induced red cell shape changes because of its wide-ranging effects on phospholipid metabolism and plasma phospholipid concentrations. If you continue browsing the site, you agree to the use of cookies on this website. Heinz bodies in dogs result in hemolysis, with poikilocytosis (keratocytes, schistocytes, a few spherocytes). Mary M. Christopher, DVM, PhD, DACVP, DECVCP Quantitative Evaluation of RBC Morphology. Animals fed olive oil had the highest percentage of normal discocytes, suggesting yet another beneficial aspect of this dietary fat. Eccentrocytes are another important clue to oxidative damage in canine RBCs and are formed by the adhesion of opposing inner cytoplasmic membranes. Red cell fragmentation (schistocytes, keratocytes, and blister cells) may occur in hepatic insufficiency when microangiopathy develops secondary to decreased coagulation factor production and clearance. Hypochromic cells are almost always also microcytic. Spherocytes results from antibody binding to the RBC membrane, and subsequent removal of a portion of the membrane by a macrophage, usually in the spleen but also in liver and bone marrow. Erythrocyte (RBC) levels of metabolites of this system have been used to indicate thiamine status in experimental animals, including salmon and trout. Also known as: Vitamin F, Aneurin, Thiamine diphosphate (TDP) – physiologically active form. RBC morphology may provide important diagnostic information regarding the underlying cause of anemia and systemic disease. During erythropoiesis and during the 2-5 months spent in circulation, RBCs are exposed to the biochemical milieu of plasma and are reliant on the availability of biochemical precursors needed for membrane and hemoglobin synthesis. The lipid bilayer of the erythrocyte membrane is a permeability barrier composed of about equal amounts of cholesterol and phospholipids. See our Privacy Policy and User Agreement for details. Clinical Aspects • Wernicke-Korsakoff syndrome : - Genetic disorder - Alteration in transketolase activity - Symptoms : mental disorder, loss of memory, partial paralysis • Pernicious anemia : transketolase activity increases. With transfusion or iron treatment, the RDW again increases, as normocytic RBCs mix with microcytes. RBC fragmentation is not usually seen in feline Heinz body hemolytic anemia, because the spleen does not contribute to RBC lysis. Clipping is a handy way to collect important slides you want to go back to later. hyponatremia (<136 mmol/L) as well as hypochloremia, low TCO2, hypo-osmolality, and hypocalcemia. Abnormal RBC Morphology Caused by Electrolyte and Metabolic Abnormalities. Originally thought to be an amine, the ‘e’ was dropped when the formula became known, but the spelling using the ‘e’ is still used in many texts and across the internet. Poikilocytosis is a qualitative measure of RBC shape. Also, thiamine can be assayed indirectly by assaying RBC transketolase and reassaying after adding excess thiamine pyrophosphate to the test tubes. Cats with liver disease also often have elliptocytes or ovalocytes, which suggest uncoupling of cytoskeletal proteins from the lipid bilayer secondary to changes in phospholipid composition. Rouleau occurs with decreased negative charges on the RBC membrane caused by increased concentrations of positively-charged proteins in plasma (i.e., fibrinogen, immunoglobins), usually in association with chronic inflammatory disease. In thiamine deficiency (also in pernicious anemia) transketolase activity is decreased in blood. Red cell shape is a result of both the environment of the cell and its metabolic status.