(Limited) Differential for MACROCYTIC anemia

1)B12 and Folate deficiency
2)Reticulocytosis (either from recent bleeding, hemolytic anemia, bone marrow recovery after chemo, HCT, Epo administration, or repletion of iron/B12/folate stores
3)Alcohol
4)Liver disease
5)Hypothyroidism
6)HIV
7)Myelodysplastic syndrome
8)Pregnancy

Labs to check if you suspect Hemolysis:

1)START with Reticulocyte Count-elevated (can also be due to blood loss)
2)Elevated LDH
3)Elevated Indirect Bilirubin
4)Low Haptoglobin
5)Spherocytes on peripheral smear

Remember if + Coombs (DAT)- if positive, dealing with immune mediated hemolytic anemia (eg: warm, cold agglutinins, or drug induced)