Red Blood Cell anomalies (1)

Question 1

Increased number of red cells with variation in size

Answer 1

Anisocytosis

Question 2

Size of normal RBCs (normocytes)

Answer 2

6-8 um in diameter

Question 3

Normal MCV value

Answer 3

80-100 fL

Question 4

Larger than normal RBCs (>8.0 um), MCV > 100 fL, impaired DNA synthesis

Answer 4

Macrocytes

Question 5

Smaller than normal RBCs (diameter < 6.0 um), seen when MCV is < 80 fL, defective hemoglobin formation

Answer 5

Microcytes

Question 6

Four ways to detect anisocytosis

Answer 6

1) Using the nucleus of a small lymphocyte in a peripheral blood smear (PBS), 2) Using the MCV value, 3) Using the RBC histogram, 4) Using the RDW value

Question 7

Average volume of individual RBCs

Answer 7

MCV

Question 8

Visual display of cell size (X-axis) and cell frequency (Y-axis), provided by high-volume instruments

Answer 8

RBC histogram

Question 9

Two parameters calculated from RBC histogram

Answer 9

MCV and RDW

Question 10

RBC histogram range for RBCs

Answer 10

36 fL to 360 fL

Question 11

MCV formula

Answer 11

MCV = HCT * 10 / RBC count

Question 12

Decreased MCV value

Answer 12

Microcytic < 80 fL, RDW > 14.5%

Question 13

Normocytic MCV

Answer 13

80-100 fL, RDW 11.5 - 14.5%

Question 14

Macrocytic MCV

Answer 14

> 100 fL, RDW > 14.5%

Question 15

RDW in macrocytic and microcytic

Answer 15

Increased regardless of size

Question 16

RBC histogram measurement range

Answer 16

Can measure cells as small as 24 fL

Question 17

Effect of elevated leukocyte count on RBC histogram

Answer 17

Affects the RBC histogram

Question 18

Shift to the right in RBC histogram indicates

Answer 18

macrocytic RBCs

Question 19

Shift to the left in RBC histogram

Answer 19

Indicates microcytic RBCs

Question 20

Bimodal RBC histogram curve

Answer 20

Indicates two populations of RBCs, such as in blood transfusion, cold agglutinin disease, or hemolytic anemia with schistocytes

Question 21

Wider or flattened RBC histogram curve

Answer 21

Indicates more variation in cell size, the population is not homogeneous

Question 22

Methods to calculate RDW

Answer 22

RDW-CV (coefficient of variation), RDW-SD (standard deviation)

Question 23

RDW-CV based on

Answer 23

Width of the RBC distribution curve and mean RBC size

Question 24

RDW-SD based on

Answer 24

Measurement of the width of the RBC distribution curve at 20% above the baseline

Question 25

RDW-CV reference range

Answer 25

11.5 - 14.5%

Question 26

RDW-SD reference range

Answer 26

39 - 46 fL

Question 27

RDW-CV measurement method

Answer 27

Depends on the width of the distribution curve and MCV

Question 28

RDW-SD advantage

Answer 28

Not influenced by MCV, better measure of erythrocyte variability, especially in abnormal conditions

Question 29

Methods to evaluate RBC size

Answer 29

PBS, MCV, RBC Histogram

Question 30

Methods to detect anisocytosis

Answer 30

RDW, PBS, MCV, RBC Histogram

Question 31

Reference range for RDW in newborns

Answer 31

14.2 to 19.9%

Question 32

RDW in newborns

Answer 32

Markedly increased, decreases to adult levels by 6 months of age

Question 33

Abnormal RDW indication

Answer 33

Wider-than-normal RBC histogram

Question 34

# Anemia type Normal, little or no anisocytosis, Decreased MCV (microcytic)

Answer 34

Anemia of chronic inflammation (ACI)

Question 35

Normal, little or no anisocytosis, Normal MCV (normocytic)

Answer 35

G6PD deficiency

Question 36

Increased MCV (macrocytic), Normal, little or no anisocytosis

Answer 36

Liver disease

Question 37

# Anemia Increased anisocytosis, Decreased MCV

Answer 37

Iron deficiency anemia (IDA)

Question 38

# Anemia Increased anisocytosis, Normal MCV

Answer 38

Sickle cell anemia

Question 39

# Anemia Increased anisocytosis, Increased MCV

Answer 39

Megaloblastic anemia

Question 40

Variation in normal coloration of RBCs, may involve hypochromic and normochromic cells in the same smear

Answer 40

Anisochromia

Question 41

Normal RBC coloration

Answer 41

Central pallor is approximately 1/3 the diameter

Question 42

Conditions associated with Anisochromia

Answer 42

Sideroblastic anemias, hypochromic anemia after transfusion or iron therapy

Question 43

Hypochromic cells appearance

Answer 43

Central pallor >1/3 of diameter, usually microcytic

Question 44

Grading of hypochromia 1+

Answer 44

Area of central pallor = 1/2 diameter

Question 45

Grading of hypochromia 2+

Answer 45

Area of central pallor = 2/3 diameter

Question 46

Grading of hypochromia 3+

Answer 46

Area of central pallor = 3/4 of diameter

Question 47

Grading of hypochromia 4+

Answer 47

Thin rim of hemoglobin

Question 48

A.k.a. Pessary cell, Ghost cell; RBC with a thin rim of hemoglobin and a large, clear center; observed in iron deficiency anemia

Answer 48

Anulocyte

Question 49

Hyperchromic cells appearance

Answer 49

RBCs that lack central pallor, caused by shape change (e.g., spherocytes); true hyperchromia occurs when MCHC is high

Question 50

Only disease where MCHC is high above reference range

Answer 50

Hereditary Spherocytosis

Question 51

Key clinical manifestations of symptomatic HS

Answer 51

Splenomegaly, Anemia, Jaundice

Question 52

DAT (direct antiglobulin test) in HS

Answer 52

Negative

Question 53

MCV in HS

Answer 53

Normal to low

Question 54

MCH in HS

Answer 54

Normal

Question 55

MCHC in HS

Answer 55

Slightly increased

Question 56

Immune disorders with spherocytes

Answer 56

Usually characterized by a positive DAT result

Question 57

Autohemolysis test in HS

Answer 57

Greatly increased (can be corrected with glucose or ATP)

Question 58

OFT (Osmotic Fragility Test) in HS

Answer 58

Increased osmotic fragility, not diagnostic of HS

Question 59

EMA binding test in HS

Answer 59

Decreased fluorescence (flow cytometry)

Question 60

Polychromatophilic erythrocytes

Answer 60

Larger than normal red cells with bluish tinge caused by residual RNA (Wright’s stain)

Question 61

Polychromasias are associated with

Answer 61

Decreased RBC survival, hemorrhage, erythroid hyperplastic marrow

Question 62

Grading of Polychromasia - Slight

Answer 62

1% of Polychromatophilic RBCs

Question 63

Grading of Polychromasia - 1+

Answer 63

3% of Polychromatophilic RBCs

Question 64

Grading of Polychromasia - 2+

Answer 64

5% of Polychromatophilic RBCs

Question 65

Grading of Polychromasia - 3+

Answer 65

10% of Polychromatophilic RBCs

Question 66

Grading of Polychromasia - 4+

Answer 66

>11% of Polychromatophilic RBCs