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Flashcards in Microcytic Anemias Deck (33):
1

What is the cause of microcytic anemias?

Decreased production of hemoglobin

2

Why is microcytosis seen in the presence of decreased hemoglobin?

RBCs must divide an extra time in order to try and maintain hemoglobin concentration, causing microcytic anemia

3

What is the composition of heme?

Iron and protoporphyrin

4

What are the 4 microcytic anemias?

1) iron deficiency anemia
2) anemia of chronic disease
3) sideroblastic anemia
4) thalassemia

5

Anemia due to decreased levels of iron…

Iron deficiency anemia

6

Where does the absorption of iron occur?

Duodenum

7

How is iron transported across the cell membrane into the blood?

Enterocytes transport iron using ferroportin

8

What substance is responsible for the transport of iron in the blood?

Transferrin

9

Where does transferrin transport iron for storage?

To the liver and bone marrow macrophages

10

What is stored intracellular iron bound to?

Ferritin

11

What does the storage of iron bound ferritin prevent?

Free radical formation via the Fenton reaction

12

What are the 4 laboratory measurements used to evaluate iron status in patients?

1) serum iron
2) Total iron-binding capacity (TIBC)
3) % saturation
4) Serum Ferritin

13

What serum iron measuring?

Measure of iron in the blood

14

What is total iron-binding capacity (TIBC) measuring?

Measure of transferrin molecules in the blood

15

What is % saturation of iron measuring?

% of transferrin molecules that are bound by iron (normal is 33%)

16

What is serum ferritin measuring?

Iron stores in macrophages and the liver

17

What is the most common cause of microcytic anemia seen in infants?

Breast-feeding—human milk is low in iron

18

What is the most common cause of microcytic anemia in children?

Poor diet

19

What is the most common cause of microcytic anemia in male adults ages 20-50?

Peptic ulcer disease

20

What is the most common cause(s) of microcytic anemia in female adults ages 20-50?

Menorrhagia
Pregnancy

21

What is the most common cause(s) of microcytic anemia in the elderly?

Colon polyps/carcinoma in Western world

Hookworm in developing world

22

Malnutrition, malabsorption and gastrectomy are all causes of why type of anemia?

Microcytic anemia

23

What is the first stage of iron deficiency?

Storage iron is depleted

24

What are the laboratory values, with respect to ferritin and TIBC, in the first stage of iron deficiency?

Ferritin: decreased
TIBC: increased

NOTE: If ferritin is decreased then TIBC will be increased, ALWAYS

25

What is the second stage of iron deficiency?

Serum iron is depleted

26

What are the laboratory values, with respect to serum iron and % saturation of iron, in the second stage of iron deficiency?

Serum iron: decreased
% Saturation: decreased

27

What is the third stage of iron deficiency?

Normocytic anemia

28

Why is normocytic anemia seen in the third stage of iron deficiency?

The bone marrow is making fewer, but normal sized RBCs

29

What is the fourth stage of iron deficiency?

Microcytic, hypochromic anemia—bone marrow is making smaller and fewer RBCs

30

What are the clinical features of iron deficiency?

Anemia
Koilonychia
Pica

31

What are the laboratory findings seen with iron deficiency anemia with respect to the following: RBCs, Ferritin, TIBC, serum iron, % saturation, and free erythrocyte protoporphyrin (FEP)?

RBCs: microcytic and hypochromic with increased red cell distribution width
Ferritin: decreased
TIBC: increased
Serum iron: decreased
% Saturation: decreased
FEP: increased

32

What is the treatment for iron deficiency microcytic anemia?

Supplemental iron—ferrous sulfate

33

Iron deficiency anemia with esophageal web and atrophic glossitis that presents as anemia, dysphagia, and beefy-red tongue…

Plummer-Vinson syndrome