Macrocytic Anemia

Question 1

Megaloblastic Anemia definition

Answer 1

Impaired RBC DNA synthesis/repair -> BIG RBCs (and very few of them)

Question 2

Megaloblastic anemia is caused by deficiencies in ___ or ___

Answer 2

B12 (Cobalamin)
Folate

Question 3

vit B12 deficiency from decr intrinsic factor is called ____ anemia

Answer 3

Pernicious

Decr Intrinsic Factor -> Decr B12 absorption in ileum

Question 4

___ infx -> Hypochlorhydria (low stomach acid) -> decr Vit B12 absorption in ileum -> Vit B12 deficiency (Megaloblastic anemia)

MC organism

Answer 4

H. pylori

Question 5

Autoimmune Atrophic Gastritis

Answer 5

• Autoantibodies against parietal cells and Intrinsic factor (IF)
• Decr parietal cells -> Decr IF -> Decr B12 absorption

Question 6

List MC populations for:
* Vit B12 deficiency
* Folate deficiency

Answer 6

• Vit B12 -> Vegans, Elderly, Autoimmune, Immunocomp (GI infx -> decr absorption)
• Folate -> ETOH, Preg, Baby, Kidney failure (Hemodialysis)

Question 7

Which Megaloblastic anemia causes loss of sensation/neuropathy and “megaloblastic madness”?

Answer 7

Vit B12 deficiency

Question 8

Which Megaloblastic Anemia has a faster onset of ss (weeks/months)

Answer 8

Folate deficiency

GLOSSITIS

Question 9

Peripheral blood smear shows Hypersegmented Neutrophils +
Macro-ovalocytes (big & oval RBCs). Type of macrocytic anemia?

Answer 9

Megaloblastic anemia
d/t B12 or Folate deficiency

Question 10

Megaloblastic Anemia labs

• High Homocysteine & MMA = ____ deficiency
• High MMA (Methylmalonic acid) = ____ deficiency
• High Homocysteine & Norm MMA = _____ deficiency

B12, Folate, or BOTH?

Answer 10

• High Homocysteine = BOTH
• High MMA = B12 ALONE
• High Homocysteine & Norm MMA = Folate

Question 11

Pernicous Anemia Tx: how should B12 supp be given (route)?

Answer 11

IV/IM

• Anything that isn’t oral bc these ppl have decr GI absorption
• Pernicous anemia = B12 deficiency d/t low intrinsic factor (IF)
• Low IF -> decr B12 absorption

Question 12

How does ETOH cause Pancytopenia?

Pancytopenia = LOW
HgB, Retic, Platelets, WBC, Hct

Answer 12

ETOH -> Bone marrow toxicity -> Myelosuppression (stem cell) -> Low end products (HgB, Retic, Platelets, WBC, RBC)

Question 13

Drugs that interfere with Erythropoiesis

Answer 13

Methrotrexate
5-FU
Hydroxurea
ETOH

Question 14

Drug that decreases Folic Acid absorption in the Jejunum?

Answer 14

Phenytoin (Dilantin)

• Acute -> Sz, Sedation, Confusion
• Chronic -> Megaloblastic anemia, Aplastic anemia, Pancytopenia, Gingival hyperplasia, peripheral neuropathy

Question 15

Myelodysplastic Syndromes (MDS)

Answer 15

• “Bone marrow failure DO”
• Anormal bone marrow stem cells
• “The factory that makes your blood cells is not working well”
• RISK: MDS -> Acute Myeloid Leukemia (AML)
• > 60yo, Hx Radiation

Question 16

Myelodysplastic Syndromes (MDS) have a risk of turning into ____

Answer 16

Acute Myeloid Leukemia (myeloid cell CA)

Question 17

Myelodysplastic Syndromes (MDS) Tx

Answer 17

1. Blood Transfusions
2. Heme stimulating factors (EPO, WBC)
3. Bone marrow transplant
4. Chemo, immunosup
5. Lenalidomide (Revlimid) - form of thalidomide (birth defects)

• RBC (EPO): Darbepietin (Procrit/Aranesp)
• WBC: Neulasta (pegfilgrastim), Neupogen (filgrastim)

Question 18

Hashimotos (autoimmune hypothyroidism) can lead to ___ deficiency

Answer 18

B12

Autoimmune Atrophic Gastritis = Autoimmune destruction of parietal cells -> decr Intrinsic factor -> decr B12 “Pernicious Anemia”

Question 19

Where are these absorbed:
Iron =
Folate =
B12

Answer 19

Iron = Duodenum
Folate = Jejunum
B12 = Ileum