5.6 Normocytic Anemia with Intravascular Hemolysis

Question 1

Paroxysmal Nocturnal Hemoglobinuria (PNH)

Answer 1

Acquired defect in the myeloid stem cells that results in absence of GPI which makes the RBCs susceptible to lysis from complement

Question 2

Why does PNH occur at night?

Answer 2

Mild respiratory acidosis occurs with the shallow breathing of sleep leading to the activation of complement - normally RBCs would be protected, but the lack of GPI makes them lose their immunity.

Question 3

Why do PNH patients get iron deficiency anemia?

Answer 3

They are losing Hb which also contains iron

Question 4

Glucose-6-Phosphate Dehydrogenase Deficiency

Answer 4

X-linked recessive disorder resulting in a reduced half-life of G6PD which renders cells susceptible to oxidative stress

Question 5

What is G6PD protective against?

Answer 5

P. falciparum malaria

Question 6

What are the types of G6PD deficiency?

Answer 6

• African

- Mediterranean (worse effect)

Question 7

What are bite cells characteristic of?

Answer 7

G6PD Deficiency

Question 8

Immune Hemolytic Anemia

Answer 8

Ab mediated destruction of RBCs due to IgM or IgG

Question 9

What type of hemolysis does IgM immune hemolytic anemia cause?

Answer 9

Intravascular

Question 10

What is immune hemolytic anemia associated with?

Answer 10

• SLE
• CLL
• Drugs

Question 11

What type of hemolysis does IgG immune hemolytic anemia cause?

Answer 11

Extravascular

Question 12

What is a key test for IgG hemolytic anemia?

Answer 12

Direct Coombs Test

Question 13

What does the Indirect Coombs Test?

Answer 13

Tests for the presence of anti-RBC IgG Ab

Question 14

What mosquito transmits malaria?

Answer 14

Anopheles