Lecture 14 RBC Morphology Flashcards
1
Q
Rouleaux
A
- linear arrangement of at least four red cells
- must be in thin area
- seen in infections, inflammations, multiple myeloma (increased plasma proteins)
- plasma proteins (+ve) net negative charge from sialic acid -> no longer repel each other
- corresponds to elevated ESR
2
Q
RBC cold agglutinins
A
- interfering substance in automation
- caused by Pt’s autoantibody which reacts at cold temp -> RBCs agglutinate
- warm sample to 37 deg C
does not occur in circulation
3
Q
Normochromic
A
- diameter of pallor less than 1/3 of RBC diameter
- gradual increase of Hgb from interior towards outside
4
Q
Hypochromic
A
- Pallor greater than 1/3 of cell diameter
- decreased Hgb conc
- associated with microcytosis
- seen in iron deficiency anemia (IDA)
5
Q
Dimorphism
A
- two populations of cells
- histogram will show 2 peaks
- hypochromic and normochromic cells present
- seen in sideroblastic anemias, after blood transfusion treatment of IDA patients
6
Q
Normocytic
A
- normal diameter 6-8um (avg 7 um)
- avg volume 90 fL
- same size or slightly smaller than lymphocyte nucleus
7
Q
Macrocytic
A
- diameter exceeds 8.5-9 um
- MCV > 100 fL
- round macrocytes seen in neonates, alcoholism, liver disease, B12 and folate deficiency
- oval forms seen in B12, folate deficiency, and myelodysplastic syndromes
8
Q
Polychromatic Cells
A
- immature RBCs w/o nucleus, diffusely pale blue due to remnants of RNA
- can be stained with new methylene blue -> RNA precipitate -> reticulated appearance -> called reticulocytes
- small numbers normal
- increase from hemolysis
- decrease from metabolic of nutrient deficiency (B12 or folate)
9
Q
Microcytic Cells
A
- diameter less than 6um
- MCV less than 80 fL
- commonly associated with hypochromasia
- seen in IDA, hemiglobinopathies, inflammation, anisocytosis
- smaller than lymphocyte nucleus
10
Q
Anisocytosis
A
- mixture of normal, small, or large cells
- RDW will correspond, will be wide in histogram
11
Q
Poikilocytosis
A
- broad term for variation in shape and applied to many forms of RBC shapes (ex. spherocytes, sickle cells, schistocytes)
12
Q
Spherocytes
A
- lack central pallor, often microcytic
- commonly seen in hereditary spherocytosis, autoimmune hemolytic anemia, transfused cells, severe burns
- mcv would be low normal from loss of membrane
- know these four causes: fibrin strands, thermal injury, intrinsic abnormalities, immune hemolysis (ex.rheumatoid arthritis)
- mchc will be high (increased Hgb content for cell size) -> automatically perform pbs
- high mcv and mch -> cold agglutinin
- high mch and mchc -> lipemia
13
Q
Elliptocytes/Ovalocytes
A
- egg to slightly oval to sausage, rod, or pencil shape
- usually functionally normal
- seen in iron deficiencies, hemoglobinopathies (ex. thalassemia), hereditary elliptocytosis, megaloblastic anemias (B12, folate deficiency)
14
Q
Echinocytes/Burr Cells
A
- echinocyte: blunt, evenly spaced projections
- Burr cells: projections or spicules that are more uneven
- different from crenated cells which lack central pallor
- cause can be physiological environmental factors: increased pH , decreased albumin, metabolic state of cell, use of some chemicals,
- may be due to outer expansion of lipid bilayer compared to inner layer
- may be seen in severe renal disease, pyruvate kinase deficiency, burns, etc.
- occur in uremia, cancer of stomach, bleeding peptic ulcer, liver disease, heparin therapy, vit. E deficieny
15
Q
Acanthocytes
A
- have 2-20 uneven spicules or thornlike projections
- no central pallor
- caused by excess cholesterol with increased to phospholipid ratio resulting in increased area
- seen in liver disease, abetalipoproteinemia, post splenectomy, malabsorption, hypothyroidism, and vit E deficiency
