Introduction to Anemia Flashcards
What is anemia?
condition in which there is reduced oxygen delivery to tissues, impaired production of RBCs (hypoxia)
Anemias may result from what things?
Increased RBC loss
RBC destruction (Hemolysis)
excessive blood loss
Decreased production of rbcs
What two things help you classifiy anemias?
Morphology (MCV and MCHC)
Pathophysiology
Describe an anemia with an absolute retic count that is high
short RBCs survival
hemolysis and blood loss
Describe an anemia with an absolute retic count that is low, how to you classify them?
decreased RBc production
classified via MCV
low (micro) - hgb issues
Norm (norm) - hemolysis/intrinsic
High (macro) - megaloblastic
How much iron is found hgb?
recycling?
diet?
2/3rd of total body iron is found in hgb,
it is repeatedly recycled and small amounts are lost but replaced by diet
What are some ways daily iron is effected?
menstruation, pregnancy, growth/additional blood loss
Describe Iron metabolism, absorption and the function of DCYTB
how does dietary iron look
dietary iron is in the ferric state +3, and is converted to ferrous by reductase enzymes like Duodenal Cytochrome for optimal absorption
T/F optimal pH for absorption is <3.0 (duodenum) and is good for reducing substances like ascorbic acid
false. optimal pH is <4.0 and is good for reducing substances like ascorbic acid
What is the function of Divalent metal transport 1? (DMT1)
hint: place…ent
Fe+2 carried into enterocyte
What transports iron around the body if it is not stored as ferratin?
Ferroportin 1 (FPN1)
What changes iron from the ferrous form back into the ferric form?
Hephaestin
What is apoferratin?
Intracellular storage form of iron
What is ferroportin 1? (FPN1)
protein transports iron across the membrane , carries iron from enterocytes, macrophages and hepatocytes
What is ferroportin regulated by? What does this do?
Regulated by Hepcidin
binds to ferroportin and inactivates it
adequate iron - liver creates hepcidin
decreased iron absorption and release
T/F when iron storages drop, hepcidin increases, and iron absorption decreases and release decreases
false, when iron storage drops, hepcidin is decreased and iron absorption increases and releases
How is hepcidin regulated? what is the simplified version?
regulation is complex/not understood
simplified - involves Hemochromatosis gene (HFE)
Increased iron = HFE allows prod of hepcidin blocking release of iron
T/F there is no genetic component to HFE
False, mutations in HFE cause hereditary hemochromatosis
What does EPO do?
stimulates rbc production and enhances hormone production by rubriblasts that suppress hepcidin
What hormone is produced by rubriblasts that surpasses hepcidin?
Erythroferrone (ERFE)
Transport: what picks up Fe+3 in circulation? what happens after it is picked up? Is it soluble?
Picked up via transferrin/apotransferrin and is transported to BM for Rbc production and storage
It remains soluble
How much iron can a molecule of Transferrin carry?
it can carry 2 atoms of Fe+3
What allows the transferrin bound iron (Fe+3) to move into nrbcs and retics?
What happens to the complex after this?
Transferrin receptor 1
after this, the complex is internalized and acidified/reduced to Fe+2 and carried into the cytoplasm by DMT1
What does Ferrocchelatase do?
it is the final step in heme synthesis by insertion of Fe+2 into protoprphyin ring
T/F TR1 (transferrin receptor 1) decreases when iron is low
false, transferrin receptor 1 increases when iron is low
Where is iron stored?
BM, liver and spleen
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
T
F, free iron is toxic and needs to be sequestered by a protein
What does Apoferritin do? Solubility?
protein that binds to Fe+3 to form ferritin, storage form of iron in tissues
Water soluble/easily used
T/F there is an equilibrium between intracellular stored ferritin and serum ferritin
true
T/F as cellular iron levels fall, levels of ferritin increase and transferrin receptors on cells decrease
false, as cellular iron levels fall, levels of ferritin decrease and transferrin receptors on cells increase
T/F when cellular irons increase, ferritin increases and transferrin receptor 1 decreases
true
Briefly describe Hemosiderin
breakdown product of what?
found in what cells?
solubility?
what kind of aggregates are found/where/stains?
availability?
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
What is serum iron? what is special about its testing?
measure of transferrin bound iron and it fluncuates so you need to use along w other testing
What is TIBC? Total iron binding capacity?
bound to what?
binding capacity?
increased/decreased in?
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
What is transferrin saturation?
% saturation of transferrin measured as max amount of iron bound to serum or plasma
describe serum ferritin
better measurement than what?
APR?
directly proportional to amount of iron stored
better measurement of body storage iron than Serum iron/TIBC
APR
Describe soluble transferrin receptors? (STfRs)
inverse..
sloughed from what?
increases?
inversely proportional to body iron
sloughed from cells and measured in serum
increases when cellular iron stores are depleted
Describe Hepcidin levels
increases with what
decreases when
used in complex with?
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
Describe Free erythrocyte protoporphyrin (FEP) or Zinc proto..
inverse to ?
FEP is heme w/o Iron inserted
ZPP is heme w/ zinc in place of iron
inverse to ferritin level
Describe retic count and retic corpuscular hgb (CHr)
indicates?
retic # decreased/ineffective EPO
Early indicator of iron deficiency
good indicator of pt response to iron therapy
Describe BM Iron
