Macro Anemias

Question 1

What is the definition of macrocytic anemia?

Answer 1

Anemia with MCV >100 fL

Macrocytic anemia is characterized by larger than normal red blood cells.

Question 2

What are the two categories of macrocytic anemia?

Answer 2

• Megaloblastic
• Non-Megaloblastic

Question 3

What causes megaloblastic macrocytic anemia?

Answer 3

Impairment in DNA synthesis due to B12 or folate deficiency, leading to asynchrony between nuclear and cytoplasmic development.

Question 4

What is the typical MCV range for megaloblastic anemia?

Answer 4

Usually between 100-115 fL, but can go up to 150 fL.

Question 5

What is the most common misdiagnosed deficiency in the elderly?

Answer 5

Vitamin B12 deficiency (Cobalamin)

Question 6

What is pernicious anemia?

Answer 6

A subclass of megaloblastic anemia caused by lack of intrinsic factor, leading to decreased B12 absorption.

Question 7

What is the role of intrinsic factor in vitamin B12 absorption?

Answer 7

Intrinsic factor binds to B12 in the intestines, allowing its absorption into the bloodstream.

Question 8

What happens to reticulocyte counts in megaloblastic anemia?

Answer 8

Decreased reticulocytes due to ineffective hematopoiesis.

Question 9

What is the chemistry finding in megaloblastic anemia?

Answer 9

• Increased bilirubin
• Increased LDH
• Low serum B12

Question 10

What distinguishes folate deficiency from B12 deficiency?

Answer 10

Folate deficiency does not cause neurological symptoms.

Question 11

What is the best method to determine vitamin B12 deficiency?

Answer 11

Radioimmunoassay, with samples protected from light.

Question 12

What are common laboratory findings in peripheral blood morphology for megaloblastic anemia?

Answer 12

• Oval macrocytes
• Hypersegmented neutrophils
• Howell Jolly bodies

Question 13

What is the typical MCV range for non-megaloblastic macrocytic anemia?

Answer 13

Usually >100 but <110 fL.

Question 14

What is the typical response in reticulocyte count after initiating B12 treatment?

Answer 14

Increased reticulocytes in peripheral blood.

Question 15

What are the laboratory findings for folate deficiency?

Answer 15

• Increased MCV
• Increased MCH
• Normal MCHC
• Increased RDW

Question 16

What are the characteristics of Oval Macrocytes?

Answer 16

B12/Folate deficiency, often associated with HSN and rare Cabot rings

Oval macrocytes are typically seen in macrocytic anemia related to vitamin deficiencies.

Question 17

What conditions are associated with Round Macrocytes?

Answer 17

Liver disease, Alcoholism, Hypothyroidism

Round macrocytes can be indicative of underlying liver pathology.

Question 18

What do Polychromatic Macrocytes indicate?

Answer 18

Marrow response, commonly seen in newborns

Polychromatic macrocytes are indicative of an active bone marrow response to anemia.

Question 19

What is Pseudo Macrocytosis?

Answer 19

Red blood cell agglutination due to cold agglutinins

Pseudo macrocytosis can artificially elevate MCV readings.

Question 20

What does a CBC show in macrocytic anemia?

Answer 20

• MCV increased >100 fL
• No Pancytopenia
• Howell-Jolly bodies present
• Basophilic stippling

The CBC can help differentiate between types of anemia based on the morphology of red blood cells.

Question 21

What chemistry results are expected in macrocytic anemia?

Answer 21

• Increased Bilirubin
• Increased LD
• Elevated liver function tests (AST, ALT, GGT)
• Normal B12 and Folate levels

These results can indicate hemolysis and liver dysfunction.