MOD 3 lectures: Nutritional/hyperproliferative anemias, Hemolytic anemias, & Transfusion medicine Flashcards
What is hemoglobin?
The oxygen carrying molecule on a RBC
What is MCV? (mean corpuscular volume)
Measures size of RBC
What is MCHC
measures hb conc per RBC
What is RDW
measures how variable/uniform the cell size is
What is anisocytosis
degree of variation between RBCs
reticulocyte count
measures bone marrow response to anemia
TBIC
total iron binding capacity, measures TRANSFERRIN molecs in blood
Ferritin
storage form of iron
Hepcidin
regulates iron absorption
normal hb and hcrt?
Hb 12-16 g/dL
Hcrt 35-50%
Normal MCV, microcytic, macrocytic
microcytic <80
Normal: 80-100
Macro >100
what blood disorders are assoc with microcytic anemia <80
iron def, thalassemia, anemia of chronic disease
What should normal RBCs on slides look like
mature lympho nucleus same size as RBC
area of central pallor 1/3 diameter, lil platelets
What IS anemia?
Decreased number of RBCs in blood, OR decreased oxygen-carrying capacity of blood due to reduced RBC mass etc
can cause fatigue etc
3 main causes of anemia
Blood loss
Increased DESTRUCTION of RBC
impaired PRODUCTION of RBCs
What are 3 main nutritional anemias
Iron, B12, and folate def
Iron def
impaired heme synthesis, microcytic anemia
B12 and folate def
imparied DNA synthesis (nucl need B12 and folate to make DNA), causing macrocytic anemia (present similarly but B12 involves neuro sx)
Where is iron absorbed?
proximal duodenum!
What forms is iron abs and stored>
absorbed in ferrous Fe2+ form (two-inTO), stored in Fe3+ ferric form (while bound to ferritin), recticuloendothelial sys
What is hepcidin
rel by the liver and regulates iron absorption.
incr iron presence in liver stimulates hepcidin synth so it can absorb more (?) by sequestering iron in storage sites
what level is hepcidin at in adequate iron levels?
High hepcidin
What stain can visualize iron?
PRUSSIA BLUE (more blue= more iron stored)
What does serum ferritin represent?
Iron stored in macros and liver
high serum ferritin means increased iron storage
What does TBIC measure
measures transferrin molecules in blood! (eg number of iron transport proteins in blood)
What does high TBIC correlate with?
Low iron in blood (lots of unoccupied transferrin circulating)
(% saturation is percent of transferrin molecs bound by iron, normal is 1/3)
How does iron def lead to micro anemia?
Decreased iron means decreased heme which means decreased hemoglobin which means micorcytic anemia
What will iron def look like in terms of lvls and cells?
Low hb, RBC, hcrt, MHCH, microcytosis with MCV<80, Hypochromic/pale, incr RDW (central pallor>1/3 RBC)
DECREASED serum iron so INCREASED TIBC
-elliptocytes (pencil cells) and Target cells
Which anemia/deficiency may pencil cells and target cells indicate?
Iron deficiency anemia!
Anemia of Chronic disease
1 in US hospitalized pts
(iron is common in world?)
Assoc with chronic infxn/inflam/malig, IL-6 inflam mediator incr -> incr hepcidin -> decr EPO
(hepcidin tries to prevent bacteria from accessing iron which they use for survival, by sequestering it in storage)
Anemia of chronic disease iron issues?
Impaired iron utilization (low serum iron, low TIBC reflects incr storage of iron in tissue macros, so less storage in blood)
Iron deficiency anemia: TIBC, serum iron, marrow stores (increased or decreased)?
Iron def anemia: INCREASED TIBC transferrin (bc not enough iron to bind up the transferrin, and liver senses low iron and produces more transferrin to pick up iron), decreased serum ferritin bc not enough iron to get stored in cells. Decreased marrow stores.
Anemia of chronic disease: TIBC, serum iron, marrow stores (increased or decreased)?
-Anemia of chronic disease: DECREASED TIBC bc iron stored in places other than blood, and INCREASED serium ferritin bc iron being stored in cells and not in blood. INCREASED marrow stores bc hepcidin drives iron into storage
Macrocytosis can be caused by…
Reticulocytosis (prolif of immature RBCs, which are bigger), caused by EPO prod
and Megaloblastic anemia (vit b12 and folate def, alcoholism, liver dis, MDS, hypothy, drugs etc)
What does periph blood smear show in macrocytosis
pancyto
large oval RBCs hyperchormic
NUCLEATED RBCs!
LARGE HYPERSEGMENTED NEUTROS!
Bone marrow in macro anemia?
hypercellular (bc ineffective hematopoeisis), marrow responds to low cell counts by incr cell prod but eventually leads to pancytopenia bc ineffective dna synth as they mature
(normal cellularity is 100-age)
more (next)
What is megaloblastic change in macro anemia?
nuclear/cytoplasmic asynchrony of all cells, mature cytoplasm but chromatin looks like cut salami (nucl remains immautre), hyperseg neutros, or bands, large hyperlobated megakaryocytes
What are B12 and folate needed for? Why does this cause macro anemia?
coenzymes for thymidine synth in dna syth
If cant make dna, can grow but not divide causing amcro (nucleus remains immature)
pancyto
What chemicals buildup due to B12 def?
HOMOCYSTINE cannot be conv to methionine
and METHYLMALONIC ACID incr bc cant be conv to succinyl coa for krebs
Where is vitamin B12 absorbed?
Terminal ileum!
What does b12 due in absorption?
pepsin frees it from food, then b12 copmlexes with IF from parietal cells in stomach and is abs in terminal iluem