Flashcards in Microcytic Anemia Deck (33)
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1
reasons for microcytosis
decreased globin production
decreased heme productio
reduced Fe availabilty
2
2 reasons for reduced globin producton
thalassemia
hemoglobinopathies
3
2 reasons for reduced heme synthesis
lead poisioning
sideroblastic anemias
4
2 reasons for reduced Fe availability
absolute Fe deficiency
functional Fe deficency (chronic illness/inflammation
5
prevalence of Fe from most to least
hemoglobin
ferritin in MO, spleen, bone marrow, liver
myoglobin
bound to transferrin (in plasma)
6
iron excretion
no physiologcial way exept 1-2 mg/day lost through desquamation (shedding skin)
7
hepcidin
how Fe absorption is regulated at level of duodenum
8
heme
iron complexed to protoporphyn IX
9
enhances Fe absorption
ascorbic acid
10
reduced Fe absorption
Ca, antacids, phyates (in brans and oats), polyphenols (in tea and some veggies)
11
TS
how much of the transferrin is bound to Fe
decrease= decreased Fe
increase= iron overload
12
best test to show if Fe deficiency is present
ferritin
13
ferritin can be elevated by
inflammation
14
causes of Fe deficiency
inadequate oral intake
inadequate absorption (messed up duodenum)
increased loss (bleeding)
intravascular hemolysis
depletion of epo
15
clinical signs Fe deficiency
pica
restless leg syndrome
plummer-vinson syndrome
16
thalaseemias
autosomal recessive quantitative disorder with insufficient production of alpha and beta-globin chains
17
normal adults hb types
95-98% HgbA1 (a2b2)
2-3% HgbA2 (a2d2)
1-2% HgbF (a2,g2)
18
where does B thalasemia occur?
SE asia (burma, thailand, cambodia, vietname, china, malaysia, indonesia, phillipines)
19
B thalasemia produces no
HbA1- agg of alpha chans therefore decrease in RBC lifespan
20
compensatory mech of B thala
increase in fetal Hb
21
alpha thal found in
se asia
africa
india
22
what happens in a thal
impaired production of alpha globin chans wth resultant excess beta globin chains that are toxc to RBC membrane skeleton
23
treatment thal a
does not require much; sometmes splenectomy
genetc counseling can be helpful to reduce rsk of H dsease and hydrops fetalis
24
comp mech of thal a
relative excess of other chains
25
diagnoss thal a
dna analysis
26
sideroblastic anemia
decrease in heme synthesis; erythroblasts accumulate Fe in mitochondra without being able to produce adequate heme
27
primary sideroblastic disease
myelodysplasia with ringed sideroblasts
28
secondary sideroblastic disease
nutritional: B6 or Cu deficiency
Drugs- isoniazid, chloramphenicol, phenacetin, alkylating agents
alcohol
toxins: lead, zinc poisioning
29
labs sideroblasts
serum Fe- INC
ferritin- INC
Transferrin (total Fe)- normal/dec
TS- INC
30
