Lecture 138

Question 1

What is erythropoiesis?

Answer 1

Production of RBCs in bone marrow

Question 2

What triggers the release of erythropoietin (EPO)?

Answer 2

Secreted in response to low oxygen

Question 3

What type of RBC appear more basophilic due to residual rRNA?

Answer 3

Reticulocytes

Question 4

What are the effects of one unit of packed RBCs transfusion?

Answer 4

Increase Hgb by 1g/dL and increase hematocrit by 3%

Question 5

Hemoglobin values represent:

Answer 5

Oxygen-carrying capacity

Question 6

Hematocrit values represent:

Answer 6

Percentage of RBC volume

Question 7

What do RDW values represent?

Answer 7

Red cell distribution width, variability in RBC size

Question 7

What is the structure of hemoglobin?

Answer 7

Heme (iron + protoporphyrin) + globin (4 protein chains)

Question 8

What do MCH/MCHC values represent?

Answer 8

Amount/concentration of hemoglobin in RBCs

Question 9

What does serum iron represent?

Answer 9

Amount of circulating iron

Question 10

What does serum ferritin represent?

Answer 10

Reflects storage iron in macrophages and liver

Question 11

What does TIBC represent?

Answer 11

Transferrin level, total iron binding capacity

Question 12

What does % saturation represent?

Answer 12

% of transferrin occupied by iron

Question 13

What is the major site of iron absorption?

Answer 13

Duodenum

Question 14

What are the typical lab findings for iron deficiency anemia?

Answer 14

Decreased serum iron, decreased ferritin, increased TBIC, decreased % saturation

Question 15

What does a peripheral smear in iron deficient anemia look like?

Answer 15

Microcytic, hypochromatic RBCs with increased central pallor

Question 16

Pica, koilonychia (spoon nails), alopecia, angular cheilitis, and restless legs are unique features of what type of anemia?

Answer 16

Iron-deficient anemia

Question 17

Iron deficiency anemia, esophageal webs, and strophic glossitis can indicate what syndrome?

Answer 17

Plummer-Vinson syndrome

Question 18

What is the underlying mechanism of anemia of chronic disease?

Answer 18

Inflammatory medaitors such as IL-6 lead to an increase in hepcidin production which decreases iron release from storage and decreases EPO release

Question 19

What are the typical lab findings for anemia of chronic disease?

Answer 19

Decreased serum iron, increased ferritin, decreased TIBC, and decreased % saturation

Question 20

What is the underlying mechanism of sideroblastic anemia?

Answer 20

Defect in protoporphyrin synthesis so iron can’t be incorporated into heme

Question 21

What is the mechanism behind congenital sideroblastic anemia?

Answer 21

X-linked defect in ALAS

Question 22

What is the mechanism behind alcoholism-induced sideroblastic anemia?

Answer 22

Mitochondrial toxin

Question 23

What is the mechanism behind lead posioning and sideroblastic anemia?

Answer 23

Lead inhibits ferrochelatase and ALAD

Question 24

What is the mechanism behind B6 deficiency sideroblastic anemia?

Answer 24

B6 is needed by ALAS

Question 25

What effect of lead poisoning leads to basophilic stippling in RBCs?

Answer 25

Inhibition of rRNA degradation

Question 26

Abnormalities on gingiva or metaphyses of long bones, encephalopathy, abdominal pain, and wrist/foot drop are signs of:

Answer 26

Lead poisoning

Question 27

What are the typical lab findings for sideroblastic anemia?

Answer 27

Increase serum iron, increased ferritin, decreased TIBC, increased saturation %

Question 28

What characteristics are observed in the bone marrow of a patient with sieroblastic anemia?

Answer 28

"Ringed sideroblasts" (iron-laden mitochondria around nucleus)

Question 29

Basophilic stippling (aggregates of residual ribosomes) on peripheral smear is a sign of:

Answer 29

Sideroblastic anemia

Question 30

Decreased synthesis of alpha or beta globin chains describes:

Answer 30

Thalassemia

Question 31

Thalassemia is protective against what parasite?

Answer 31

Malaria

Question 32

What is seen in a peripheral smear in a patient with thalassemia?

Answer 32

Target cells

Question 33

Gene deletions on chromosome 16 results in:

Answer 33

alpha thalassemia --> reduced alpha-globin

Question 34

Cis alpha-thalassemia minor is seen in what population?

Answer 34

Asians

Question 35

Trans alpha-thalassemia minor is seen in what population?

Answer 35

Africans

Question 36

3 deletions in alpha-thalassemia results in:

Answer 36

Hemoglobin H disease (HbH)

Question 37

4 deletions in alpha-thalassemia results in:

Answer 37

Hemoglobin barts, hydrops fetalis, fatal in utero

Question 38

Point mutations on chromosome 11 result is what type of thalassemia?

Answer 38

Beta-thalassemia

Question 39

Electrophoresis in beta-thalassemia minor shows what type of hemoglobin?

Answer 39

Increased HbA2

Question 40

When does beta-thalassemia major typically present?

Answer 40

After 6 months of age

Question 41

What does an excess of alpha-chains cause in beta-thalassemia mjor?

Answer 41

Alpha-chains precipitate and cause hemolysis and ineffective erythropoiesis

Question 42

What X-ray finding is common in beta-thalassemia major?

Answer 42

"crew cut" appearance caused by marrow expansion

Question 43

Hepatosplenomegaly and chipmunk facies are signs of what anemia?

Answer 43

Beta-thalassemia

Question 44

What electrophoresis findings are seen in beta-thalassemia?

Answer 44

Increased HbF and increased HbA2