Introduction to Anemia

Question 1

What is anemia?

Answer 1

condition in which there is reduced oxygen delivery to tissues, impaired production of RBCs (hypoxia)

Question 2

Anemias may result from what things?

Answer 2

Increased RBC loss
RBC destruction (Hemolysis)
excessive blood loss
Decreased production of rbcs

Question 3

What two things help you classifiy anemias?

Answer 3

Morphology (MCV and MCHC)
Pathophysiology

Question 4

Describe an anemia with an absolute retic count that is high

Answer 4

short RBCs survival
hemolysis and blood loss

Question 5

Describe an anemia with an absolute retic count that is low, how to you classify them?

Answer 5

decreased RBc production
classified via MCV
low (micro) - hgb issues
Norm (norm) - hemolysis/intrinsic
High (macro) - megaloblastic

Question 6

How much iron is found hgb?
recycling?
diet?

Answer 6

2/3rd of total body iron is found in hgb,
it is repeatedly recycled and small amounts are lost but replaced by diet

Question 7

What are some ways daily iron is effected?

Answer 7

menstruation, pregnancy, growth/additional blood loss

Question 8

Describe Iron metabolism, absorption and the function of DCYTB
how does dietary iron look

Answer 8

dietary iron is in the ferric state +3, and is converted to ferrous by reductase enzymes like Duodenal Cytochrome for optimal absorption

Question 9

T/F optimal pH for absorption is <3.0 (duodenum) and is good for reducing substances like ascorbic acid

Answer 9

false. optimal pH is <4.0 and is good for reducing substances like ascorbic acid

Question 10

What is the function of Divalent metal transport 1? (DMT1)
hint: place…ent

Answer 10

Fe+2 carried into enterocyte

Question 11

What transports iron around the body if it is not stored as ferratin?

Answer 11

Ferroportin 1 (FPN1)

Question 12

What changes iron from the ferrous form back into the ferric form?

Answer 12

Hephaestin

Question 13

What is apoferratin?

Answer 13

Intracellular storage form of iron

Question 14

What is ferroportin 1? (FPN1)

Answer 14

protein transports iron across the membrane , carries iron from enterocytes, macrophages and hepatocytes

Question 15

What is ferroportin regulated by? What does this do?

Answer 15

Regulated by Hepcidin
binds to ferroportin and inactivates it
adequate iron - liver creates hepcidin
decreased iron absorption and release

Question 16

T/F when iron storages drop, hepcidin increases, and iron absorption decreases and release decreases

Answer 16

false, when iron storage drops, hepcidin is decreased and iron absorption increases and releases

Question 17

How is hepcidin regulated? what is the simplified version?

Answer 17

regulation is complex/not understood
simplified - involves Hemochromatosis gene (HFE)
Increased iron = HFE allows prod of hepcidin blocking release of iron

Question 18

T/F there is no genetic component to HFE

Answer 18

False, mutations in HFE cause hereditary hemochromatosis

Question 19

What does EPO do?

Answer 19

stimulates rbc production and enhances hormone production by rubriblasts that suppress hepcidin

Question 20

What hormone is produced by rubriblasts that surpasses hepcidin?

Answer 20

Erythroferrone (ERFE)

Question 21

Transport: what picks up Fe+3 in circulation? what happens after it is picked up? Is it soluble?

Answer 21

Picked up via transferrin/apotransferrin and is transported to BM for Rbc production and storage
It remains soluble

Question 22

How much iron can a molecule of Transferrin carry?

Answer 22

it can carry 2 atoms of Fe+3

Question 23

What allows the transferrin bound iron (Fe+3) to move into nrbcs and retics?
What happens to the complex after this?

Answer 23

Transferrin receptor 1
after this, the complex is internalized and acidified/reduced to Fe+2 and carried into the cytoplasm by DMT1

Question 24

What does Ferrocchelatase do?

Answer 24

it is the final step in heme synthesis by insertion of Fe+2 into protoprphyin ring

Question 25

T/F TR1 (transferrin receptor 1) decreases when iron is low

Answer 25

false, transferrin receptor 1 increases when iron is low

Question 26

Where is iron stored?

Answer 26

BM, liver and spleen

Question 27

T/F Senescent rbcs - iron recycled by macrophages t/f free iron is not toxic and doesn't need to be sequestered by a protein

Answer 27

T F, free iron is toxic and needs to be sequestered by a protein

Question 28

What does Apoferritin do? Solubility?

Answer 28

protein that binds to Fe+3 to form ferritin, storage form of iron in tissues Water soluble/easily used

Question 29

T/F there is an equilibrium between intracellular stored ferritin and serum ferritin

Answer 29

true

Question 30

T/F as cellular iron levels fall, levels of ferritin increase and transferrin receptors on cells decrease

Answer 30

false, as cellular iron levels fall, levels of ferritin decrease and transferrin receptors on cells increase

Question 31

T/F when cellular irons increase, ferritin increases and transferrin receptor 1 decreases

Answer 31

true

Question 32

Briefly describe Hemosiderin breakdown product of what? found in what cells? solubility? what kind of aggregates are found/where/stains? availability?

Answer 32

breakdown product of ferritin found principally in RES cells of liver/spleen/BM Not water soluble granules/aggreg of iron can be visualized in tissues (stain w Prussian blue) less readily available than ferritin

Question 33

What is serum iron? what is special about its testing?

Answer 33

measure of transferrin bound iron and it fluncuates so you need to use along w other testing

Question 34

What is TIBC? Total iron binding capacity? bound to what? binding capacity? increased/decreased in?

Answer 34

total amount of iron that can be bound to transferrin in serum or plasma binding capacity is usually 1/3rd saturated Increased in iron def anemia and dec in iron overload

Question 35

What is transferrin saturation?

Answer 35

% saturation of transferrin measured as max amount of iron bound to serum or plasma

Question 36

describe serum ferritin better measurement than what? APR?

Answer 36

directly proportional to amount of iron stored better measurement of body storage iron than Serum iron/TIBC APR

Question 37

Describe soluble transferrin receptors? (STfRs) inverse.. sloughed from what? increases?

Answer 37

inversely proportional to body iron sloughed from cells and measured in serum increases when cellular iron stores are depleted

Question 38

Describe Hepcidin levels increases with what decreases when used in complex with?

Answer 38

adequate iron storages, liver increases production of hepcidin (which inactivates ferroportin) decrease iron absorption Iron storage decreased, hepcidin decrease, more iron absorbed/released used in complex with IDA AOI

Question 39

Describe Free erythrocyte protoporphyrin (FEP) or Zinc proto.. inverse to ?

Answer 39

FEP is heme w/o Iron inserted ZPP is heme w/ zinc in place of iron inverse to ferritin level

Question 40

Describe retic count and retic corpuscular hgb (CHr) indicates?

Answer 40

retic # decreased/ineffective EPO Early indicator of iron deficiency good indicator of pt response to iron therapy

Question 41

Describe BM Iron