microcytic anemias Flashcards
definition of microcytic anemia
- MCV < 80
common microcytic anemias
- iron def anemia
- anemia of chronic disease
- thalassemia
- sideroblastic anemia
what is the most common cause of anemia
- iron deficiency anemia
what is the most common cause of iron def anemia
- GI bleeding
- menstrual bleeding
stages of iron def anemia
- depletion of iron stores without anemia
- anemia with normal RBC size
- anemia with reduced RBC size
clues in pts hx to think of iron def anemia
- diet
- PICA
- phagophagia
- glossitis
- mouth soreness
- angular cheilitis
- Koionychia
- dysphagia
where is iron absorbed
- acidic conditions
- stomach, duodenum, jejunum
- avg diet has 10-15 mg of iron, only absorb 1.5%
iron requirement in males and non-menstruating females
- 1 mg/d
iron requirements in menstruating females
- 3-4 mg/d
iron requirements in pregnant females
- 2-5 mg/d
what is the role of transferrin
- transports iron
what is the role of ferritin
- stores iron (simple)
what is the role of hemosiderin
- complex iron stores in macrophages
- helpful with insoluble Fe
iron deficiency categories
- deficient intake/ decreased absorption
- increased requirement
- blood loss
- other: hemoglobinuria, idiopathic, Fe sequestration
work up for iron def anemia
- low serum iron, transferrin, ferritin
- high TIBC
- usu low retic count
- low MCV and MCH
- peripheral smear: hypochromic and microcytic
si/sx of iron def anemia
- easily fatigued
- conjunctival pallor
- tachycardia, palpitations
- DOE
- pica
- severe: smooth tongue, brittle nails, koilonychia, chelosis
treatment for iron def anemia
- ferrous sulfate TID- tae with vit C/ OJ to increase absorption
- try cooking in cast iron skillet
- parenteral options
why give parenteral options in iron def anemia
- pt cant tolerate PO
- refractory to PO
- GI dz that limits absorption
- continued blood loss
side effect of iron supplementation
- constipation
- GI upset
- give colase
- titrate up to TID to mitigate
anemia of chronic disease
- usu MCV < 80 but can also be normocytic
- problem with iron utilization
- bone marrow unable to respond to EPO
causes of anemia of chronic disease
- inflammation
- endocrine disorders
- infection
- chronic liver dz
- CT disorders- SLE, RA
- endocarditis
- cancers- liquid and solid tumors
- *IS NOT the same as anemia of CKD
what disease states is anemia of chronic disease NOT seen in
- DM
- COPD
- CHF
- HTN
etiology of anemia of chronic disease
- “iron is there but vault is locked”
- lg amount of inflam cytokines released
- stim hpatocytes to make massive amounts of hepcidin
- prevents release of iron from macrophages and liver stores
lab findings for anemia of chronic disease
- microcytic or normocytic
- normochromic
- low retic count
- normal/ elevated serum ferritin
- decreased iron
- decreased-normal TIBC
- ferritin up or normal
- increased ESR and CPR
- bone marrow bx only in difficult cases
treatment of anemia of chronic disease
- treat underlying condition
- supplemental iron
- ok to use EPO - edu pt on risk
thalassemia
- defect in alpha or beta globin chains
- mild - severe depending on number of genes with mutations
- often confused with iron def d/t low MCV
alpha thalassemia
- gene deletion -> reduced alpha globin chain synthesis
- depends on how many genes deleted (1-4)
- common in Asia/ china
3 copies of alpha chain
- carrier
- no sx
2 copies of alpha chain
- minor
- mild sx
1 copy of alpha chain
- HbH disase
0 copies of alpha chain
- not compatible with life
si/sx of alpha thalassmia
- carriers have no sx
- fatigue, weakness
- pallor
- splenomegaly
lab findings for alpha thalassemia
- hypochromic, microcytic anemia
- smear: normal, target cells, heinz bodies
- get ferritin to r/o iron def
- Hgb electrophoresis*
treatment for alpha thalassemia carriers
- no treatment
- transfuse as needed
- can supplement with folic acid and iron
- offer genetic counseling
treatment for alpha thalassemia disease
- transfusion as needed
- consider iron chelation if overloaded
splenectomy and SCT in severe cases - off genetic counseling
beta thalassemia
- point mutation -> defective beta chains
- decreased production of normal Hgb, relative excess alpha
- more common in mediterranean
- major vs minor disease
major beta thalassemia
- homozygois
- two mutations -> no beta globin
minor beta thalassemia
- heterozygous
- one mutation -> less beta globin production
si/sx of minor beta thalassemia
- most asymptomatic
- hypochromic, microcytic
- may note target cells, dacrocytes, basophillic stippling
si/sx of major beta thalassemia
- severe anemia
- pallor, irritability, growth retardation, abd swelling
- hypochromic, microcytic
- smear: poikilocytosis, target cells, basophilic stippling
- RDW- normal
- ferritin- normal
treatment for major beta thalassemia
- transfusions as needed- esp periods of rapid growth
- consider splenectomy and SCT
- supplemental folic acid
- offer genetic couseling
sideroblastic anemia
- make ringed sideroblasts- iron cannot be incorporated
- assoc with copper def
- results in iron overload
causes of sideroblastic anemia
- hereditary or acquired
- drugs: chloramphenicol, linezolid
si/sx of sideroblastic anemia
- pale
- dizziness, fatigue
- hepatosplenomegaly
lab findings for sideroblastic anemia
- microcytic, hypochromic
- neutropenia if Cu def
- liver and kidney abnormalities d/t iron overload
- increased serum iron, transferrin, serum ferritin
- decreased TIBC
- get lead or copper lev if suspected
- peripheral smears
peripheral smear findings for sideroblastic anemia
- abnormal cell shapes
- basophilic stippling
- target cells
- pappenheimer bodies
treatment for sideroblastic anemia
- transfusion and chelation as needed
- if INH induced start B6 repletion
- if CU def then replete
- splenectomy c/i in congenital
- doesnt respond to EPO
- severe- bone marrow transplant
