USMLE 2 Heme Quick Notes

Microcytic/Hypochromic anemias

Iron-def anemiaferritin, TIBC
Thalassemiasnormal/serum iron & ferritin
Anemia of
chronic disease		ferritin & transferrin,
TIBC
Sideroblastic
anemia		normal/ iron & ferritin,
TIBC

▪ iron deficiency:
2/2 ◇ intake or ◇ blood loss
o ◇ RDW, ◇ reticulocyte count
▪ thalassemia or hemaglobinopathies:
◇ globin production & elevated HbA2
o ◇ reticulocyte count & total bilirubin 2/2 hemolysis
▪ anemia of chronic disease: defective utilization of storage iron, due to suppression of RBC production by inflammatory cytokines
o ◇ ferritin = ongoing inflammation
▪ lead poisoning or sideroblastic anemia: reduced heme synthesis
▪ hemochromatosis: ◇ intestinal iron absorption & deposition
o ◇ iron, ferritin, & transferrin, ◇ TIBC
▪ RA, moderate anemia, low serum iron, low TIBC,
◇ transferrin: anemia of chronic disease
▪ a/w chronic inflammatory diseases (RA)
▪ iron trapping within macrophages, leads to poor iron availability for Hb synthesis
▪ low reticulocyte count
▪ Rx underlying cause can improve anemia
▪ exertional dyspnea, fatigue, pale conjunctiva
▪ iron deficiency is MCC of microcytic anemia
▪ iron studies confirm Dx