3 - Pediatric Heme/Immuno

Question 1

What is the structural difference between fetal hemoglobin and adult hemoglobin?

Answer 1

Fetal hemoglobin has two alpha chains and two gamma chains
Adult hemoglobin has two alpha chains and two beta chains

Question 2

Why does fetal hemoglobin have a higher affinity for oxygen?

Answer 2

decreased inhibitory effect of 2,3-DPG (which inhibits hemoglobin-oxygen binding)

Question 3

By 6 months Gestational Age, what percentage of fetal blood is comprised of fetal hemoglobin?

Answer 3

Less than 10%

Question 4

Do premature infants have a larger or smaller proportional blood volume?

Answer 4

Larger
blood production decreases gradually throughout gestation

Question 5

What drives the gradual decrease in erythropoiesis in newborns?

Answer 5

Transition from hypoxic placental environment to high oxygen content from respiration

Question 6

What is the most common disorder of RBCs?

Answer 6

G6PD Deficiency

Question 7

What is G6PD?

Answer 7

enzyme that converts glucose to ribose-5-phosphate, which is the first step in forming NADPH

Without NADPH, the cell is very susceptible to ROS damage

Question 8

What does a G6PD deficiency cause?

Answer 8

RBCs that are easily damaged and break down prematurely, causing hemolysis

Question 9

What are the manifestations of G6PD?

Answer 9

Generally asymptomatic until there’s a stressor (a highly oxidizing event or substance)

often it’s an infection or extreme cold