Microcytic Anemia Flashcards Preview

SBM > Microcytic Anemia > Flashcards

Flashcards in Microcytic Anemia Deck (33):
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

treatment sideroblastic anemia

figure out cause
try pyrdoxine or folic acid
iron chelators/PRBC transfusions`

31

neurological findings with lead poisioning

motor neuropathy
autonomic neuropathy--> abdominal pain and lead colic
insomnia, irritability, psychosisw

32

what does lead do to your body

inhibits both heme and globin synthesis, interefers with RNA breakdown which causes accumulaton of denatured RNA in blood cells--> basophlic stippling

33

treatment lead poisioning

chelators
remove agent