The Nitty before The Gritty

Question 1

This protein is a regulator of ferroportin

Answer 1

Hepcidin

Question 2

Male: RBC count, Hgb, & HCT Normal Ranges

Answer 2

RBC: 4.5 - 5.9 x 10^6 (△ 1.4)
Hgb: 13.5 - 17.5 x 10^3 (△ 4.0)
HCT: 41.0 - 53.0 (△12.0)

Question 3

Female: RBC count, Hgb, & HCT Normal Ranges

Answer 3

RBC: 4.0 - 5.2 x 10^6 (△1.2)
Hgb: 12.0 - 16.0 x 10^3 (△4.0)
HCT: 36.0 - 46.0 (△10.0)

Question 4

MCV, MCH, MCHC Normal Ranges

Answer 4

MCV: 80 - 96 (△20%)
MCH: 29 - 32 (△10%)
MCHC: 33.4 - 35.5 (△~5.0%)

Question 5

What are the two morphological traits that can be used to categorize anemias?

Answer 5

MCV & MCHC

Question 6

What is the form of most ingested Fe?

Answer 6

Ferric State (Fe3+)

Question 7

What is the purpose of DCYTB?

Answer 7

Reductase enzyme to convert ingested Fe from Ferric (3+) to Ferrous (2+) for optimal absorption.
DCYTB = Duodenal Cytochrome B

Question 8

Which of these is the optimal environment for Fe absorption?

a. Basic
b. Acidic
c. Amphoteric
d. Neutral

Answer 8

B. Acidic

Optimal pH is <4.0 for reducing agents such as ascorbic acid

Question 9

What protein moves Ferrous iron into the enterocyte?

Answer 9

DMT1 (Divalent Metal Transporter 1)

Question 10

What two proteins are required for transport of iron out of the enterocyte?

Answer 10

Ferroportin 1 (FPN1, for transport out)
Hephaestin (for oxidization of Fe to the Ferric state)
Note: Hephaestin is a copper-dependant enzyme

Question 11

Hepcidin is produced by what organ?

Answer 11

Liver

Question 12

Which of these cells does FPN1 NOT transport iron out of?

a. Enterocyte
b. Hepatocyte
c. Epithelial
d. Macrophage

Answer 12

C. Epithelial Cells

Question 13

Match the functions to the correct cells (more than one may apply)

A. Macrophage
B. Enterocyte
C. Hepatocyte

1. Iron Absorption
2. Iron Storage
3. Iron Recycling

Answer 13

A. 3
B. 1 & 2
C. 2

Question 14

When the body Fe storage is low, what is the expected level of Hepcidin?

Answer 14

Hepcidin should also be low. It’s upregulated when Fe stores are adequate/high.

Question 15

What protein is directly affected by the hemochromatosis gene (HFE) and how?

Answer 15

In an adequately supplied iron environment, HFE stimulates the production of Hepcidin in order to decrease FPN1 and thusly decreased iron transport.

The way I remember is “Hemochromasis gene stops hemochromatosis” by making hepcidin to stop FPN export of iron

Question 16

Which iron enzyme is named after a Greek god?

Answer 16

Hephaestin (Hephaestus is the Greek god of metallurgy, metalworking, volcanoes, etc.)

Easy way to remember how Hepahestin functions is “Hephaestus needs metals to work with”, ie. copper-dependent and converts iron back to Ferric state

Question 17

What is the relationship between EPO and Hepcidin?

Answer 17

EPO stimulates release of the hormone erythroferrone (ERFE), which suppresses Hepcidin.

Question 18

What binds to Fe3+ to produce Transferrin?

Answer 18

Apotransferrin (binds to Fe3+ in serum after FPN1 transport out)

Question 19

How many Fe3+ can Transferrin carry?

a. 4
b. 2
c. 8
d. None, it only carries the 2+ Ferrous state

Answer 19

b. 2 atoms of Fe3+ (Ferric)

Question 20

What allows Transferrin to be internalized into nRBCs and Retics?

Answer 20

Transferrin Receptor 1(TfR1) on the surface of the RBC

Question 21

Arrange the steps of Iron absorb & transport to RBCs in the right order:

a. Conversion to Fe3+ by Hephaestin
b. Transport of Fe2+ to enterocyte by DMT1
c. Conversion to Fe2+ by DCYTB
d. Transferrin picks up Fe3+ in circulation
e. Fe3+ ingested
f. FPN1 exports Fe3+ from enterocyte
g. Acidification of endosome to convert iron to Fe2+
h. Engulfment of transferrin via TfR1
i. Delivery of transferrin to nRBCS/Retics
j. Insertion of Fe2+ into protoporphyrin IX via ferrochelatase
k. Transport into cytoplasm by DMT1
l. DMT1 transport of Ferrous iron to mitochondria or stored as Ferritin

Answer 21

E–C–B–A–F–D–I–H–G–K–L–J

This one’s a long answer so apologies on that end lmao

Question 22

What’s the calculation for MCV?

Bonus points: What’s the reference range?

Answer 22

(HCT/RBC) x 10 = MCV

Reference range is 80-96 fL

Question 23

What’s the calculation for MCH?

Bonus points: What’s the reference range?

Answer 23

(Hgb/RBC) x 10 = MCH

Reference range is 29-32 pg

Question 24

What’s the calculation for MCHC?

Bonus points: What’s the reference range?

Answer 24

(Hgb/HCT) x 100 = MCHC

Reference range is 33.4-35.5 %

Question 25

State the calculation for corrected Reticulocyte %

Answer 25

Raw retic x (pt HCT/45) = corrected retic

Question 26

State the calculation for Reticulocyte Maturation

Answer 26

1+ ((45 - pt raw %) x (0.1/Δ2%)) = Days Maturation

Question 27

State the calculation for RPI

Bonus points: What’re the normal & marrow response reference ranges?

Answer 27

(Corrected %) / (Days Maturation) = RPI

Reference ranges: 0.5-1.5% for normal, >1.5% for marrow response

Question 28

An increase in ERFE will result in what level of change for serum Fe?

a. Increased
b. Decreased
c. No net change
d. The question is misleading, ERFE directly affects ferrochelatase

Answer 28

A. Increased due to hepcidin suppression