Erythrocyte Flashcards
Average MCV of RBC
90fL
Surface of RBC
140 um2
The narrowest capillary diameter that RBC can pass through?
2.5 times smaller of RBC’s diameter
How does viscosity change when MCHC increase?
MCHC increase: Viscosity increase (Deformability decrease)
The percentage of each composition of RBC Membrane?
Lipid: 40%
Protein: 50%
Carbohydrate: 10%
What determines ABO group?
Carbohydrates
The outer later of Phospholipid membrane
Phosphatidyl Choline and Sphingomyelin
Inner layer of Phospholipid Membrane
Phosphatidyl Serine 28%
Phosphatidyl Ethanolamine 14%
Where does Cholesterol locate in RBC?
Esterified Cholesterol locate between the phospholipid layer
Unesterified Cholesterol locate in the plasma (1:1 with membrane cholesterol)
Name key Integral Proteins
- Aquaporin 5%
- Band 3 (anion transporter) 25%
- Glycophorin
Function of Aquaporin
Allow water cross freely when osmotic changes
HCO3 and Cl - also across
Active transporters include?
Na+ pump keep the ration (1:12 in:out)
K+ pump keep the ration (25:1 in:out)
Ca+ pump keep Ca inside low
What controls function of Ca2+ pump?
Calmodulin and Cytoplasmic Ca2+ binding protein.
Function of band3 protein
- Anion transporter
- Interact with skeleton (Ankyrin, Protein 4.2 and secondarily Protein 4.1)
- Prevention of surface loss.
What makes RBC negative charge?
Sialic acid-rich glycophorins
Structure of Glycophorin
Single spanning alpha helix
Function of Glycophorin
- Glycophorin A & B: Carry blood group
2. Glycophorin C (protein 4.1 and p55): Maintain cell shape
Peripheral Protein
Skeleton
- Spectrin alpha, beta
- Ankyrin
- Protein 4.1
- Pallidin (band 4.2)
Spectrin structure
2 subunits: alpha and beta entwined to form a dimer
Flexible, rod-like, 100nm
Function of Spectrin
Make RBC biconcave shape
Bind Ankyrin at C terminus (connect to Band 3) and 4.1 Protein (connect to Glycophorin C)
Function of Ankyrin
Interacts with:
- Band 3
- Spectrin
- Protein 4.2
The cause of Target Cells
Incr RBC surface
Decr Hgb content
Decr Osmotic fragility (easy to break) due to the incre of S/V
What lead to Target cell?
Liver disease (incre Cholesterol/phopholipid)
Thalassemia
Hemoglobin C
The cause of Acanthocytes
No Apoprotein B
Cholesterol, Triglyceride decre + Sphingomyelin incre.
Affect of Acanthocytes
Decre of membrane fluidity
What is “Spur cell Anemia”?
Hemolytic anemia in Severe Chronic Liver Disease (CLD)
What happens in Spur Cell Anemia?
Free plasma cholesterol (increase) accumulate and equilibrate membrane cholesterol
—> Splenic remodeling of RBC:
spheroidal, longer projection, poorly deformable.
Treatment for Spur cell anemia
Resolve CLD and spenectomy (remove spleen)
The cause of Stomatocyte (uniconcave)
- Hereditary
- Dehydration (decre ions and cell volume)
- Overhydration (incre ions and cell volume) - Acquired
- Decre cell membrane
- Qualitative change in cell membrane composition
Can Stomatocytes be found in healthy people?
Yes, up to 3%
What is Spherocytosis and Elliptocytosis?
Disease caused by Membrane Protein Mutation.
What proteins mutated in Spherocytosis
Autosomal dominant mutations affect: Band 3 Ankyrin Protein 4.2 Spectrin —> Vertical anchorages Disruption.
What protein affected in Elliptocytosis?
Mutation to Spectrin + protein 4.1 complex
—> Horizontal disruption
Affect of Spherocytosis
Results in loss of lipid membrane support —> loss lipid membrane —> decrease ratio surface/volume
What is cation concentration in Spherocytes?
Abnormal permeability of cation:
Higher intra Na+
Lower intra K+
Eventually removed by Spleen.
Where Ellipcytosis has high prevalence?
West Africa and South East Asia
Where can Tear Drop cells be found?
Myelofibrosis
Pernicious Anemia
Myeloid Metaplasia
Hemolytic Anemia
What cause Tear drop cells
External disruption of membrane
Blister Cells and Bite cells
Oxidant induced hemolytic anemia
G6PD Deficiency
How Blister cells formed?
Spleen remove Heinz body (caused by denatured Hgb) and creating Blister cell.
