Microcytic Anemia Flashcards
What is microcytic anemia?
Low Hgb with MVC <80 fL
What heme synthesis defects result in microcytic anemia
Anemia of chronic disease
Iron Deficiency anemia
Lead toxicity
Sideroblastic
What are the two primary etiologies of microcytic anemia?
Defects in heme synthesis & defects in globin
Increased bound transferrin (Fe+++) will result in ___________ TIBC
Decreased TIBC
Decreased bound transferrin (Fe+++) will result in ___________ TIBC
Increased TIBC
What is the enzyme required during the rate limiting step of heme synthesis?
delta-ALA-synthase + Vitamin B6
What two enzymes in the heme synth pathway are inhibited by lead
delta-ALA-dehydratase
Ferrochelatase (last step)
What does IL-6 stimulate? Where is it produced?
Stimulates Hepcidin
In the liver
What does Hepcidin inhibit? What stimulates Hepcidin?
Inhibits Ferroportin transport or Fe++ into circulation
Stimulated by IL6 & Fe++
What causes iron deficiency anemia?
Increased iron loss
Decreased iron absorption
Increase iron demand
What causes increased iron loss?
Malignancy –> older patients
Hookworm –> resource-limited
PUD –> Younger patient
Mechel Diverticulum –> <2y
Menorrhagia
What causes decreased iron absorption?
Malnutrition –> resouce-limited
Cow’s milk –> infant/children
Excessive breastfeeding –> infant/children
IBD
Celiac disease
Roux-en-Y gastric bypass
What causes increased iron demand?
Pregnancy
EPO—> CKD
In iron deficiency anemia iron, ferritin, transferrin, TIBC will do what?
Iron decreased
Ferritin decreased
Transferrin increased
TIBC increased
What causes anemia of chronic disease?
Chronic inflammatory reaction will decrease iron availability
Increased IL6 (chronic inflammation) will increase Hepcidin that will inhibit ferroportin
