RBC MORPHOLOGY AND PHYSIOLOGY Flashcards
aka Red Blood Cells (RBC)
ERYTHROCYTES
Average Life Span of erythrocytes
120 days
RBC Reference values for males
4.0 – 5.2 x 10^12/L
RBC Reference values for females
3.6 – 5.6 x 10^12/L
RBC Reference values for newborns
5.0 – 6.5 x 10^12/L
Functions of erythrocytes
- Oxygen transport
- Removal of metabolic wastes
Size of RBC
6-8 um
T/F: RBC is nucleated
F (anucleated)
Thickness of RBC
1.5-2.5 um
Shape of RBC
Biconcave disc
Describe the cytoplasm of RBC
Salmon pink with central pallor area
Average volume of RBC
80-100 fL (90 fL)
Surface area of RBC
140 um^2
Ratio of RBC
Increased surface-to-volume ratio
During their intravascular lifespan, erythrocytes require _____ to maintain a number of _________
energy, vital cell functions
State the 7 energy-dependent RBC metabolism
(1) maintenance of glycolysis
(2) maintenance of the electrolyte gradient between plasma and red cell cytoplasm through the activity of adenosine triphosphate (ATP)-driven membrane pumps
(3) synthesis of glutathione and other metabolites
(4) purine and pyrimidine metabolism
(5) maintenance of hemoglobin’s iron in its functional, reduced, ferrous state
(6) protection of metabolic enzymes, hemoglobin, and membrane proteins from oxidative denaturation
(7) preservation of membrane phospholipid asymmetry.
What are the 4 pathways in RBC metabolism
- Embden-Meyerhof Pathway
- Hexose Monophosphate Shunt
- Methemoglobin Reductase Pathway
- Rapoport-Luebering Pathway
Anaerobic pathway of glucose metabolism
Embden-Meyerhof Pathway
- Source of 90-95% of RBC requirement
Embden-Meyerhof Pathway
Embden-Meyerhof Pathway requires _____________ to produce ATP
glucose
Product of Embden-Meyerhof Pathway
o Lactate
o Pyruvate
o ATP
Hexose-Monophosphate Shunt is aka as what?
aka Pentose Phosphate Pathway, phosphogluconate pathway
- Aerobic and oxidative pathway
Hexose-Monophosphate Shunt
- Functionally dependent on Glucose-6-phosphate dehydrogenase pathway (G-6-PD)
Hexose-Monophosphate Shunt
- Detoxifies accumulated peroxides
Hexose-Monophosphate Shunt
Hexose-Monophosphate Shunt produces _______________
reduced glutathione
reduced glutathione prevents ______
Prevents oxidative denaturation of hemoglobin
Maintains iron in the hemoglobin molecule in the Ferrous (Fe2+) state by the action of Methemoglobin reductase (cytob5r).
Methemoglobin-Reductase Pathway
what is (cytob5r)
Methemoglobin reductase
Action involved in Methemoglobin-Reductase Pathway
Methemoglobin reductase (cytob5r)
- Third metabolic shunt
Rapoport-Luebering Pathway
- Generates 2,3-bishosphoglycerate (2,3-BPG,2,3-DPG)
Rapoport-Luebering Pathway
- Regulates affinity of hemoglobin to oxygen
Rapoport-Luebering Pathway
Rapoport-Luebering Pathway regulates ___________________________
affinity of hemoglobin to oxygen
- A curve produced when pO2 and hemoglobin affinity to oxygen are plotted on a graph
OXYGEN DISSOCIATION CURVE
increased hemoglobin affinity to oxygen
- Shift to the left
decreased hemoglobin affinity to oxygen
Shift to the right
4 FUNCTIONS OF RBC MEMBRANE
- It gives the RBC its shape
- It provides skeletal system for RBC
- It maintains Osmotic balance
- It facilitates transportation of gases
- The increased surface-to-volume ratio allows RBC to stretch undamaged 2.5 times their resting diameter.
RBC MEMBRANE DEFORMABILITY
- Increased cytoplasmic viscosity compromised its _______________
deformability
- RBC membrane lipid component maintains its _______
strength and deformability
RBC Membrane consist of:
lipids, proteins, carbohydrates
percent of lipids in RBC membrane
40%
percent of proteins in RBC membrane
52%
percent of carbohydrates in RBC membrane
8%
Transmembrane
Integral Proteins
Cytoskeletal/skeletal
Peripheral Proteins
- Responsible for the semi- permeability of the cell
RBC Membrane Lipids
2 Lipid Bilayer:
o Hydrophilic polar head group
o Hydrophobic nonpolar tail
o Hydrophilic polar head group includes what
Phosphatidylcholine
Sphingomyelin
o Hydrophobic nonpolar tail includes what
Phosphatidylserine
Phosphatidylethanolamine
Phosphatidylinositol
confers tensile strength to the lipid bilayer.
- Cholesterol
forms the glycocalyx with the integral proteins
Glycolipids
- Penetrates the lipid bilayer
Integral Proteins
- Has high sialic acid residue (zeta potential)
Integral Proteins
sialic acid residue (___________)
zeta potential
Functions of Integral Proteins
o Transport site
o Adhesion site
o Signaling receptors
- Supports carbohydrate-defined blood group antigen
Integral Proteins
- Located adjacent to the cytoplasmic membrane lipid layer
Peripheral Proteins
- Provides lateral or horizontal membrane stability
Peripheral Proteins
Peripheral Proteins provides _____________ or ________ membrane stability
lateral or horizontal
principal proteins (25-30%)
- Spectrin (α, ß)
o Responsible for the elasticity of the cell (with actin and protein 4.1)
- Spectrin (α, ß)
percent of actin in peripheral proteins
(4.5%)
5 RBC anomalies
- Variation in size
- Variation in shape
- Color variation
- RBC inclusions
- Alteration in the RBC distribution on a peripheral blood smear
- Variation in size
ANISOCYTOSIS
Anisocytosis with
>8 um
MCV: >100 fL
Seen in: Pernicious anemia, Liver cirrhosis, Aplastic anemia
- Macrocyte
Anisocytosis with
MCV of >120 fL
Seen in: Pernicious anemia, Vitamin B12 and folic acid deficiency
- Megalocyte
Anisocytosis with
<6 um
MCV: <60 fL
Seen in: IDA, Thalassemia, Hemolytic anemia, Sideroblastic anemia
- Microcyte:
Mean Cell Volume (MCV):
80-100 fL
Ways to detect anisocytosis
- Using the nucleus of small lymphocyte in a peripheral blood
- Mean Cell Volume (MCV) value
- Red Cell Distribution Width (RDW) value
Red Cell Distribution Width (RDW) value:
o Index of anisocytosis
o Coefficient of variation of RBC volume
o Reference value (CV): 11.5-14.5%
- Variation in color
ANISOCHROMIA
- Reflects the hemoglobin content of RBC
ANISOCHROMIA
Describe normal RBC (Normochromia)
salmon-pink with central pallor area approx. 1/3 of the diameter.
o Central pallor area >1/3 of RBC diameter
o Usually microcytic
- Hypochromia
- Hyperchromia aka __
Spherocytes
aka Spherocytes
Lacks central pallor area
- Hyperchromia
GRADING OF HYPOCHROMIA
What is the central pallor area of +1
1/2 of RBC diameter
GRADING OF HYPOCHROMIA
What is the central pallor area of +2
2/3 of RBC diameter
GRADING OF HYPOCHROMIA
What is the central pallor area of +3
3/4 of RBC diameter
GRADING OF HYPOCHROMIA
What is the central pallor area of +4
Thin rim of hemoglobin
Three parameters of Anisochromia
- Central Pallor Area
- Mean Cell Hemoglobin (MCH)
- Mean Cell Hemoglobin Concentration (MCHC)
o Average weight of hemoglobin in an individual RBC
- Mean Cell Hemoglobin (MCH)
o Reference range (Normochromia) in Mean Cell Hemoglobin (MCH)
26-32 pg
MCH
<26 pg
Hypochromia
MCH
> 32 pg
Hyperchromia
o Average concentration of hemoglobin in each individual RBC
- Mean Cell Hemoglobin Concentration (MCHC)
o Reference range (Normochromia) in * Mean Cell Hemoglobin Concentration (MCHC)
32-36 g/dL or %
MCHC
<32 g/dL
Hypochromia:
MCHC
> 36 g/dL
Hyperchromia
RBC with different degrees of staining affinity
POLYCHROMASIA
- Slightly larger RBC with bluish tinge (Wright stain)
POLYCHROMASIA
POLYCHROMASIA indicates:
reticulocytosis
GRADING OF POLYCHROMASIA
Grading: Slight
Percentage of Polychromatophilic RBCs: ?
1%
GRADING OF POLYCHROMASIA
Grading: 1+
Percentage of Polychromatophilic RBCs: ?
3%
GRADING OF POLYCHROMASIA
Grading: 2+
Percentage of Polychromatophilic RBCs: ?
5%
GRADING OF POLYCHROMASIA
Grading: 3+
Percentage of Polychromatophilic RBCs: ?
10%
GRADING OF POLYCHROMASIA
Grading: 4+
Percentage of Polychromatophilic RBCs: ?
> 11%
- Variation is shape
POIKILOCYTOSIS
- Normal (Discocyte)
round biconcave shape
What are the 17 examples of Poikilocytes
o Spherocytes
o Stomatocytes
o Acanthocytes
o Echinocytes
o Burr cells
o Ovalocytes
o Dacryocytes
o Knizocytes
o Keratocytes
o Schistocytes
o Blister cells
o Drepanocytes
o Degmacyte
o Leptocytes
o Biscuit cells
o Bronze elliptocytes
o Semilunar bodies
- Spherical RBC
- No central pallor area
- Decreased surface-to-volume ratio
Spherocytes
- Seen in:
o Hereditary spherocytosis
o Hemolytic anemia
o Burns (microspherocytes)
Spherocytes
- aka Mouth cells
Stomatocytes
- Elongated RBCs with a slit-lit central pallor
Stomatocytes
Stomatocytes is seen in:
o Rh null Syndrome
o Alcoholism
o Hereditary Stomatocytosis
o Electrolyte imbalance
o Severe liver disease
o Thalassemia minor
o Glutathione deficiency
o Infectious mononucleosis
- aka Thorn cells, Spur cells
Acanthocytes
- RBC with irregular spiculated surface (spike-like)
Acanthocytes
- Seen in:
o Abetalipoproteinemia
o Spur cell anemia
o McLeod Syndrome
o Liver cirrhosis
o Hemangioma
o Post-heparin administration
o Neonatal hepatitis
o Post-splenectomy
Acanthocytes
- RBCs with regularly spiculated surface
Echinocytes
- Seen in:
o Artifactual drying of blood smear
o Effects of salicylates or barbiturates
o Bile acid abnormalities
o Osmotic imbalance
Echinocytes
- aka Sea-Urchin Cells
Burr Cells
- RBC with regularly spiculated surface
Burr Cells
Burr cells is seen in
o Uremia
o Acute Blood Loss
o Pyruvate Kinase deficiency
o Stomach Cancer
- Seen in:
o Uremia
o Acute Blood Loss
o Pyruvate Kinase deficiency
o Stomach Cancer
Burr Cells
- Oval-shaped RBC
Ovalocytes
rod-, sausage-, cigar-shaped RBC; More elongated than ovalocytes
- Elliptocytes
- Seen in Hereditary Elliptocytosis
Ovalocytes
Hereditary Elliptocytosis examples
o Hemoglobin C disease
o Hemolytic anemia
o IDA
o Pernicious anemia
o Sickle cell trait
o Thalassemia
- aka Teardrop cells
Dacryocytes
- Pear-shaped or tear-shaped RBCs
Dacryocytes
- Seen in:
o Primary myelofibrosis
o Pernicious anemia
o Homozygous Beta-thalassemia
o Hemolytic anemia
o Myelopthisic anemia
o Myeloid metaplasia
Dacryocytes
- Resembles a pinched bottle
Knizocytes
Knizocytes is seen in
o Hemolytic anemia
o Hereditary spherocytosis
- Partially deformed RBCs but not cut
Keratocytes
- Spiculated resembling two horns
Keratocytes
- Spindle-, half moon-shaped RBC
Keratocytes
Keratocytes is seen in
o Disseminated Intravascular Coagulation
- aka schizocytes, helmet cells
Schistocytes
- Fragmented RBCs
- Remains of ruptured blister cells
Schistocytes
- Seen in:
o Prosthetic implants (artificial heart valve)
o Uremia
o Infantile pyknocytosis
o Disseminated Intravascular Coagulation
o Severe burns
o Microangiopathic hemolytic anemia
o Renal transplant rejection
Schistocytes
- Erythrocyte containing one or more vacuoles that resemble skin blisters
Blister Cells
___ and ____ are produced in blister cells
Keratocytes and schistocytes
blister cells are seen in:
o Pulmonary embolism in sickle cell anemia
o Microangiopathic hemolytic anemia
- aka Meniscocyte, Sickle cell
Drepanocytes
- Sickle-cell or crescent-shaped RBCs
Drepanocytes
- Results from gelation of polymerized deoxygenated Hemoglobin S.
Drepanocytes
Two forms of Drepanocytes
o Oat-shape cells
o Irreversible Sickle Cell (ISC)
Crescent-shaped RBC with less pronounced projection
o Oat-shape cells
Crescent-shaped RBC with long projection
o Irreversible Sickle Cell (ISC)
- Seen in:
o Sickle cell anemia
o Hemoglobin SC disease
Drepanocytes
- aka Bite cells
Degmacyte
- RBC with one or more semicircular portions removed from the margin
Degmacyte
Degmacyte is seen in:
oxidative-related hemolysis in G6PD deficiency
- aka Target cells, Mexican Hat Cells, Codocytes
Leptocytes
- RBC with centrally stained area with a thin outer rim of hemoglobin
Leptocytes
- Seen in:
o Thalassemia
o Lecithin-Cholesterol Acyltransferase deficiency
o Hepatic disorder
o Iron deficiency anemia
o Hemoglobin C disease
o Post-splenectomy
Leptocytes
- Folded RBC
Biscuit Cells
- Bipolar or central distribution of hemoglobin
- Seen in Sickle cell anemia
Bronze Elliptocytes
WHAT ARE THE 9 RBC INCLUSION
- Basophilic stippling
- Pappenheimer bodies
- Howell-Jolly Bodies
- Cabot Rings
- Heinz Bodies
- Hemoglobin H
- Malarial stipplings
- Babesia spp.
- Bartonella spp.
- Punctuate stippling/punctuate basophilia
Basophilic Stippling
- Aggregated RNA
o Blueberry Bagel Appearance
Basophilic Stippling
- Seen in:
o Lead poisoning (Plumbism)
o Arsenic poisoning
o Pyrimidine-5’-nucleotidase deficiency
o Anemia with impaired hemoglobin synthesis
o Refractory anemias
o Alcoholism
o Megaloblastic anemia
Basophilic Stippling
- aka Siderotic granules (Supravital stain)
Pappenheimer Bodies
- Intraerythrocytic collections of iron
Pappenheimer Bodies
- Visualization in Pappenheimer Bodies
o Supravital stain
o Wright stain:
Visualization
Siderotic granules
e.g., Iron stain, Perl’s reagent, Prussian Blue, New methylene blue
Supravital stain
Visualization:
Pappenheimer bodies
Wright stain
- Seen in:
o Sideroblastic anemia
o Hemochromatosis
o Hemosiderosis
Pappenheimer Bodies
- Remnants of nuclear chromatin (DNA)
Howell-Jolly Bodies
- Round, solid-staining, dark-blue to purple inclusion (1-2 um)
Howell-Jolly Bodies
- Visualization in Howell-Jolly Bodies
o Wright stain (reddish-blue or purple)
o Supravital stain
o Feulgen
- Seen in:
o Megaloblastic anemia
o Post-splenectomy
Howell-Jolly Bodies
- Remnants of microtubules from mitotic spindle
Cabot Rings
- Ring-, figure-eight-, loop-shaped inclusion
Cabot Rings
- Visualized using Wright stain (reddish-violet)
Cabot Rings
cabot rings color in wright stain
reddish-violet
- Seen in:
o Abnormal erythropoiesis
o Pernicious anemia
o Lead poisoning
Cabot Rings
- Ehrlich bodies
Heinz Bodies
- Denatures and precipitated hemoglobin
Heinz Bodies
heinz bodies inclusions
0.2 to 2.0 um in size
Heinz bodies is visualized in ___ or ___
crystal violet or brilliant cresyl blue
- Seen in:
o Congenital hemolytic anemia
o G6PD Deficiency
o Drug-induced hemolytic anemia (phenacetin)
o Hemoglobinopathies
o Favism
Heinz Bodies
- Abnormal hemoglobin composed of 4 ß-globin chains
Hemoglobin H
Precipitated hemoglobin H appearance
o Pitted-golf ball/raspberry appearance
Hemoglobin H is visualized using
Supravital stain
- Seen in Hemoglobin H disease
Hemoglobin H
- Fine granular appearance in erythrocytes that harbor malarial parasites
Malarial Stippling
- Inclusion bodies resembling maltese cross
Babesia spp.
- Comma-shaped inclusion bodies
Bartonella spp.
RBC MORPHOLOGY GRADING CHART
MORPHOLOGY:
* Polychromatophilia
* Helmet cells
* Dacryocytes
* Acanthocytes
* Schistocytes
* Spherocytes
GRADING: ?
1+ = 1-5 per field
2+ = 6-10 per field
3+ = >10 per field
RBC MORPHOLOGY GRADING CHART
MORPHOLOGY:
* Poikolocytosis
* Ovalocytes
* Elliptocytes
* Burr cells
* Bizarre-shaped RBC
* Target cells
* Stomatocytes
GRADING: ?
1+ = 3-10 per field
2+ = 11-20 per field
3+ = >20 per field
RBC MORPHOLOGY GRADING CHART
MORPHOLOGY:
* Sickle cells
* Basophilic stipplings
* Pappenheimer bodies
* Howell-Jolly bodies
GRADING: ?
If present = “POSITIVE”
- Stacking or coining pattern of erythrocytes due to abnormal or increased plasma proteins
ROULEAUX
- Seen in: hyperproteinemia, multiple myeloma, Waldenstrom macroglobulinemia, increased fibrinogen
ROULEAUX
thicker area of blood smear
Artifactual (rouleaux)
seen in thinner area of blood smear
True (rouleaux)
GRADING
ROULEAUX
+1?
- aggregates of 3-4 RBC
GRADING
ROULEAUX
+2?
- aggregates of 5-10 RBC
GRADING
ROULEAUX
+3?
- many aggregates with only few free RBCs
Clumping of RBC with no pattern
AGGLUTINATION
- Occurs when RBC are coated with IgM antibodies and complement
AGGLUTINATION
AGGLUTINATION IS SEEN IN:
cold autoimmune hemolytic anemia (cold agglutinin disease)
