Microcytic anemia Flashcards
Anemia
Reduction of hgb and/or hct
Anemia is classified how?
Pathophysiologic mechanism
- Reduced production RBC
- Accelerated loss/destruction of RBCs
Low iron
Low TIBC
high ferritin
High cytokine levels
Anemia of chronic dz
Anemia of chronic dz expected lab values
Low iron
Low TIBC
high ferritin
Low iron High soluble transferrin recep High TIBC Low ferritin Transferrin saturation low Hypochromic RBCs
IDA
IDA expected lab values
Low iron High soluble transferrin recep High TIBC Low ferritin Transferrin saturation low Hypochromic RBCs
High iron
Low tibc
High ferritin
Suspect thalassemia
Must reflec w/ hgb electrophoresis
Thalassemia expected labs
High iron
Low tibc
High ferritin
—- must get hgb electrophoresis
High iron
NL TIBC
High ferritin
Sideroblastic anemia
As long as BM iron:
>10% Ringed sideroblast
Review RBC morphology
Sideroblastic anemis expected lab values
High iron
NL TIBC
High ferritin
BM - >10% ringed sideroblasts
RBC morphology
Anemia eval steps
- Determine MCV
- Hx/PE
- Determine MOA
MC cause of anemia (MC pop)
IDA - females (menses/preg)
Ferritin purpose
Amount of iron stored
Storage protein w/in cells
Transferrin purpose
Protein that transports iron
TIBC - total iron-binding capacity purpose
Measures bloods capability to bind iron w/ transferrin
Hepcidin is?
Hormone that assists regulation of iron storage
Where is Hepcidin produced?
Liver
Inflam/infection or increased iron levels changes iron metabolism how?
Hepcidin increases > decreases intestinal iron absorption
Insoluble form of iron is called?
Hemosidirin
When is hemosidirin formed?
Excess iron in the body/circulation
What intestinal cells absorb iron?
Duodenal enterocytes
Most iron is incorporated into? Where else
RBC 1800mg Liver parenchyma 1000mg Spleen 600mg BM 300mg Muscle 300mg Plasma transferrin 3mg
Iron content NL, in/out?
NL - 3-4mg
In/out - 1-2mg
IDA mechanisms of cause
Increased loss
Inadequate absorption
Inadequate intake
IDA development stages
1 - ferritin decreases
2 - RBCs hypochromic
3 - hgb drops
4 - MCV drops
Anema S/S
F- fatigue
L- light headed/dizzy
A- angina
P- palpitations
T- tachy-C/Poe
H- HOTN
P- pallor
S- syncope
Other unusual S/S of IDA
Glossitis - swollen, inflam, smooth tongue
Cheilosis - scaling, cracking, fissuring of lips (b12 issue usually)
Koilonychia - spoon nails
Nail dystrophy
Pica - craves non-nutritious substances >1mo
Plummer-vinson syndrome
Triad
1- Dysphagia
2- Esophageal webs (causes the dysphagia)
3- IDA
Plummer-vinson syndrome MC affects who
Post menopausal females
TIBC represents
Ability of transferrin to bind more iron
Transferrin saturation represents?
Ratio between serum iron:transferrin
IDA due to decreased absorption suspect?
Celiac sprue
Bariatric procedures
PPI therapy
H. Pylori inf
New onset IDA in a male >50 or postmenopausal female is what?
GI malig until R/O
New onset IDA in a male >50 or postmenopausal female W/U
Eval GI blood loss w/
- EGD
- Colonscopy
IDA 1st line TXT
(PO) replacement
-ferrous sulfate 325mg
SE of iron replacement?
Constipation
ABD pain
Dark stools
How long should iron replacement go for?
3-6mo to replenish stores
Until ferritin returns to NL
H/H return to NL 6-8wks
IV iron therapy is reserved for? Req?
Cant tolerate or Refrac
Req internal med/hematology consukt
Thalassemias are?
Hereditary dz w/ defects in the synth of globin chains in hgb.
Alpha thalassemia is a genetic issue of
Deletion of the alpha chain allele
Beta thalassemia is a genetic issue of
Mutation of beta chain allele
MC genetic pop?
Mediterranean
Africa
Asian
Hard sign of thalassemia
Microcytosis out of proportion to the degree of the anemia
Alpha thalassemia mutation causes what to happen?
Unstable - Relative beta chain excess w/ no chance for alpha substitution
Alpha thal minima
1 mutated chain - asymp
Alpha thal Minor
2 mutations
Mild anemia
Clinically normal
Hgb H disease (intermedia)
3 mutations
Severe chronic hemolytic anemia
Hgb Barts-hydrops fetalis
4 mutations - no alpha chains
Death
Beta thalassemia is
Impaired production of beta chains that leads to a relative excess alpha chains but can be substituted
Beta chain reduction can be substituted w/
Delta chains - hgbA2
Gamma chains - hgbF
Excess alpha globin chains are
Unstable, incapable of forming soluble tetramers leading RBC membrane damage
What determines severity of beta thalassemia?
Degree of alpha globin chain excess
Homozygous impaired beta globin synthesis results in?
Profound clinical manifestations
Keys to thalassemia dx?
-Microcytosis out of proportion to anemia
-positive fam hx/lifelong microcytic anemia
-RBC morphology
—microcytes
—acanthocytes
—target cells
Thalassemia trait is described as
Lab features w/out significant clinical impact
Thalassemia intermedia is described as
Req RBC transfusions
Moderate clinical impact
Thalassemia major is described as
Life threat
Thalassemia Dx
R/o IDA
Iron shows overload
Elevated ferritin
Low TIBC
Method of thalassemia detection
Hgb Electrophoresis
Or genetic testing
Hgb electrophoresis resulta A/B thal
Alpha thal trait - NL
—-alpha still made
Beta thal - ABNL
—-gamma/delta high
Mild Thalassemia txt
Avoid unnecessary iron
Avoid some Rx
-sulfa drugs (oxidative stress > hemolysis
Severe thalassemia txt
Req freq transfusions
Folate supplement
Splenectomy
BM transplant
Freq Transfusions can lead to?
Iatrogenic iron overload syndrome
Anemia of chronic disease is
Ass/w chronic comorbidities like
- chronic infectious processes
- autoimmune d/o
- malig
- liver disease
- chronic kidney disease
Anemia of chronic disease labs
Normocytic or microcytic
Low serum, transferrin, TIBC
Nl - ^ ferritin
Anemia of chronic disease txt
Txt underlying condition
Siderobladtic anemia is
Mishandling of serum iron by mitochondria leading to ABNL RBC precursor processing of iron.
W/ sideroblastic anemia bone marrow produces what?
Ringed sideroblast rather than NL RBCs
Bone marrow composition w/ sideroblastic anemia?
> 10% bone marrow sideroblast in aspirate
Sideroblast is?
RBCs >1 iron containing granule in Cytoplasm
-iron poorly incorporated into heme of RBC
Sideroblastic anemia causes
- Inherited
2. Acquired (MC) (Rx/toxins)
Rx causing sideroblastic anemia?
Ethanol Isoniazid INH Cycloserine Chloramphenicol Busulfan
Copper chelators causing sideroblastic anemia
Penicillsmine
Triethylene tetramine dihydrochloride
Toxins causing sideroblastic anemia
Lead
Zinc
Auto-antibodies
Sideroblastic anemia txt
D/C offending agent
Supportive
pRBC if hgb <7.0
(PO) pyridoxine B6
