RBC Profiles Flashcards
Spherocytes
Immune-Mediated Damage
Appearance: Macrocytic No disc shape or central pallorUsually hyperchromic, Very circular
Causes: Immune-mediated hemolytic anemia Can be hereditary
Formation:Macrophages remove membranes with surface antibodies.
Agglutionation
Immune-Mediated Damage
Appearance:Clumps of erythrocytes Can be seen macroscopically
Causes:Immune-mediated hemolytic anemia Transfusion of non-matched blood Many immune-related conditions
Formation: Surface-antibodies link to each other, causing many erythrocytes to clump together
Ghost Cells
Immune-Mediated Damage
Appearance: Very pale Sometimes microcytic
Causes: Intravascular hemolysisImmune-mediated damage
Formation: Autoantibody response causes a rupture of the cell membrane where the antibodies are located. The cell lyses and leaves an empty ‘shell’ behind.
Heinz Body
Oxidative Injury
Appearance: Protuberance at the borders of the RBCWill stain differently with NMB
Causes:Ingestion of garlic, onions, or Tylenol Ingestion of thiosulfate Oxidative injuries Lymphosarcoma Hyperthyroidism Diabetes mellitus
Formation:An unwanted electron reaction causes the premature lysis of the cell as well as the denaturation of hemoglobin. The hemoglobin is ‘pushed’ towards the end of the cell membrane. The spleen can remove the Heinz body, resulting in a ‘bite’ cell.
Eccentrocyte
Oxidative Injury
Appearance:Clear and often crescent structure at the ends of the RBC
Causes:Ingestion of garlic, onions, or Tylenol Ingestion of thiosulfate Oxidative injuries Lymphosarcoma Hyperthyroidism Diabetes mellitus
Formation:The inner membranes on one side of the RBC adheres to each other, forming a ‘pinched’ appearance. This area that is stuck together is the clear area as it is poorly saturated with hemoglobin.
Schistocyte
Mechanical Fragmentation
Appearance: Fragmented pieces of RBCs No true shape
Causes: Intravascular damage/traumaDisseminated intravascular coagulation ThromboembolismsFormation:
Any condition that can mechanically damage an RBC can cause the shredded appearance. Schistocytes can be formed when an RBC forces its way through a mesh-like clot due to blood pressure; moving through the clot can damage the cell itself.
Dacryocyte
Mechanical Fragmentation
Appearance: Teardrop shaped
Causes: Myelofibrosis Mechanical artifact due to slide spreading
Formation: Not fully understood within medicine. One theory is that RBCs are squeezed out of bone marrow due to myelofibrosis; this may cause the tear-shaped formation. Can also be formed when the blood cell is pulled in one direction when sliding a blood smear.
Echinocyte
Membrane/Metabolic Disorders
Appearance: Spiky with small, evenly-spaced projectionsT rue echinocytes are typically slightly oval in shape.
Causes: True echinocytes: Renal disease, uremia, liver disease, lymphosarcoma, snake venom, post-transfusions Crenated cells: Excess EDTA, slide drying slowly, humidity, alkaline glass on slide
Formation:Many factors can cause the spiky appearance. Removal of water from the RBC will cause shrinkage while leaving portions of the membrane intact (spiky.) Excess lipids with liver failure can also bind to the membrane cholesterol, forming the spiky appearance.
Acanthocyte (spur cells)
Membrane/Metabolic Disorders
Appearance: Long, thorn-like, not-evenly spaced projections Projections not as numerous as echinocytes
Causes:Liver failure Hemangiosarcoma Lipid abnormalities secondary to renal disease
Formation:Like echinocytes, many factors involving the cell membrane can cause the thorny appearance. Excess lipids from liver and renal failure can integrate into the cell membrane, forcing the long projections.
Keratocyte
(blister cell, bite cell, helmet cell)
Membrane/Metabolic Disorders
Appearance: Horn-like membrane projections
Causes: Hemangiosarcoma Neoplasia Glomerulonephritis Liver disease
Formation: A keratocyte can have several forms which involve different processes: A blister cell is formed when a vacuole migrates to the cell membrane, forming a ‘bubble’ pushing towards the end. If the blister ruptures, the sides of the blister remains which has the appearance of horns (commonly referred as a keratocyte or a helmet cell) A bite cell is formed when the macrophages of the spleen removes a damaged section of the RBC membrane, thus forming a ‘bite’ into the cell. This can also be seen as horns instead of a bite. For simplicity, the term ‘keratocyte’ is broadly used to describe everything previously mentioned.
Hypochromasia
Membrane/Metabolic Disorders
Appearance: Large central pallor Cells stain lighter
Causes: Iron deficiency Thalassemia Lead poisoning
Formation: Hypochromic cells have less hemoglobin than normal. The cells become lighter in color and the central pallor appears larger due to the lighter contrast.
Elliptocyte/Ovalocyte
Membrane/Metabolic Disorders
Appearance: Oval-shaped RBC Central pallor not as visible
Causes: Normal in camelidsLymphoblastic leukemia Hepatic lipidosis Portosystemic shunts Glomerulonephritis Thalassemia
Formation: Several illnesses can cause disruption to the RBC cytoskeleton and membrane proteins. This weakens the cell membrane and causes the cell to elongate within
Codocyte (Leptocyte category)
Membrane/Metabolic Disorders
Appearance: Target-shaped Darked central area that is normally somewhat clear
Causes:Liver failure Regenerative anemia (with polychromatophils)
Formation:These cells have increased membrane-surface area with no changes in cell volume. This thins the membrane and allows the cell to assume a different shape. In this case, it creates a bell shape. This bell shape appears as a ‘target’ when placed on a slide and stained.
Torocyte
Membrane/Metabolic Disorders
Appearance: Increased central pallor size but smaller than hypochromic cells Cells stain the normal color
Causes:Preparation artifact
Formation:It is thought that prolonged exposure to EDTA can induce the thickened-hemoglobin edge and the accentuated central pallor characteristic with torocytes. Membrane/Metabolic Disorders
Knizocyte (bar cell-falls under leptocyte category)
Membrane/Metabolic Disorders
Appearance: Darkened ‘bar’ running across the diameter of the cell
Causes: Liver failure Regenerative anemia (with polychromatophils) *Similar to codocytes
Formation:These cells have increased membrane-surface area with no changes in cell volume. This thins the membrane and allows the cell to assume a different shape. In this case, the cell has a ‘pinched’ section along the middle of the cell. This pinched area forms the distinctive ‘bar’.
