3.19 NIELL Nutritional Anemias

Question 1

Most important cause of a microcytic hypochromic anaeaeaemia

Answer 1

Iron Deficiency

Question 2

3 Transporter Proteins of Iron

Answer 2

transferrin, transferrin receptor and ferritin

Question 3

Where is Iron Absorbed from the Diet in GI tract?

Answer 3

Proximal duodenum

Question 4

Iron Stores in Macrophages

Answer 4

Ferritin and hemosiderin

Question 5

How is Iron excreted from the body???

Answer 5

ITS NOT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Question 6

Easiest store of Iron to mobilize?

Answer 6

Ferritin, it is water soluble compared to hemosiderin which is not.

Question 7

How much Iron is in 1ml of blood

Answer 7

1mg of Iron

Question 8

Labile Iron Pool

Answer 8

Iron leaving the plasma and entering the interstitual and intracellular fluid compartments 80-90mg

Question 9

Transferrin

Answer 9

• Smallest pool, but most active
• Carrying protein in the plasma
• Turns over 10xday
• Found in plasma and is 1/3 saturated with Fe
• Apotransferrin is syn in liver

Question 10

Who are at risk for Iron Deficiencies?

Answer 10

Pregnant Women>young nonpreg women>infants

Least: MEN (cheers!!) and postmenopausal women

Question 11

What is best dietary source of iron?

Answer 11

Liver

Question 12

What acts as the “doorway” for Fe to enter circulation

Answer 12

Ferroportin

-Negatively regulated by HEPCIDIN

Question 13

What facilitates transfer of Fe from a mother to her fetus??

Answer 13

Ferroportin again

Question 14

Ferriportin

Answer 14

Cellular exporter of Fe into plasma

Regulates: (1) transfer of iron from mother to fetus (2) iron absorption in intestines (3) Iron export from macrophages

Question 15

Regulation of Iron Uptake

Answer 15

Hepcidin

• Neg Reg
• Binds Iron exporter, ferriportin and degrades
• -inhibits iron flow into plasma from recycled senscent RBC
• -Inhibits duodenal enterocytes engaged in absorption of dietary iron
• -Inhibits hepatocyes that store Iron

Question 16

Factors Effecting Absorption of Non-Heme Iron

Answer 16

Increase: Reducing agents (ascorbic, gastic acid)
Decrease: (1) insoluble complexes (phytates, grains, phosphates, egg yolks) (2) Chelating agents (turkish clay)
(3) Inhibit or compete for absorption (tannic acid, tea, Ca)

Question 17

Factors outside GI tract increasing Iron Absorption

Answer 17

Hypoxia (decreases Hepcidin)
Anemia (also decreases Hepcidin)
Depletion of Iron Stores
Increased erythropoesis
--Anything that happens when Fe is low (other than ACD) or is trying to stimulate RBC production

Question 18

Cause of Fe Mal-absorption

Answer 18

GI Surgery (weird one for peptic ulcers that should never be done)
Non-Tropical Sprue: gluten allergy (immuno rxn in enterocyte) stop all grains, happens tille late childhood then goes away till 60s
Tropical Sprue: overgrowth of coliforms in jejunum: decreases folic acid
Picca: eating laundry starch and clay in stupid places that eat clay

Question 19

Causes of GI Bleeds

Answer 19

Peptic ulcer disease, Hiatal Hernia, Chronic Gastritis, Hemorrhoids, Intermitant bleeding after GI surgery, Neoplasms of the GI tract

Question 20

GI Bleeds in Infants

Answer 20

Milk allergy: boil and there is no Rxn

Meckel’s Diverticulum: make HCL in intestines that leads to bleeding

Question 21

Unusual Cause of Fe Deficiency

Answer 21

Resp Tract Bleeding (lung cancer)

• Intravascular hemolysis (autoimmune)
• Chronic Renal Dialysis
• Blood donations too often
• Factitious Bleeding (nurses taking there own blood and lying about it?)

Question 22

What did the 100 y.o. Korean Girl have and the other kid?

Answer 22

Hookworm common cause of anemia in underdeveloped countries

• Worm migrates to lung up trachea and down esophagus settling into small intestine
• Starvation is a very common cause also in underdeveloped countries

Question 23

Clinical Manifestations of Iron Deficiency

Answer 23

Symptoms
-Asymptomatic early
-Fatigue, headaches and parathesias (burning feeling), Irritability, Decrease exercise tolerance, burning tongue, Picca (eating disorder)
Physical Findings:
Pallor
Glossitis, Stomatitis, Angular Chelitis (all means Red tongue with cracks around the mouth)
Rare: koilonychia: concave nails from chronic aneaeaemia

Question 24

CBC with Iron Deficiency

Answer 24

WBC: unaffected
Hct: low
MCV: low (b/c RBC are small)
RDW: high because variable widths
Platelets: sometimes elevated
Retic Count: extremely low (not making new RBC)

Question 25

Serum Iron Parameters in Iron Deficiency

Answer 25

TIBC: High (body trying to compensate)
Serum Iron: low
% Saturation: low
Serum Ferritin: low in both men and women
-Body is depressing Hepcidin making more Transferrin to try and bind more Iron but no Iron is present

Question 26

Iron Regulation in Iron Deficiency

Answer 26

• Increase erythropoetic activity (need RBC)
• Deficiency Suppresses Hepcidin so more ferriportin is avaliable:
  (1) increase dietary iron absorption
  (2) Release Iron from stores
• -Will eventually run out and that’s when it gets bad

Question 27

Anemia and Chronic Disease

Answer 27

Chronic Inflamm/Infection secrete cytokines that INCREASE HEPCIDIN levels

• Degradation of ferriportin
• Decrease GI uptake
• Increases uptake to storage compartments
• Will have low TIBC b/c body is not making

Question 28

Treatment

Answer 28

• Iron Sulfate (oral)-occasional abdominal discomfort, bloating and weight gain
• Parental causes rash
• IV have to administer little at a time and increase slowly over time to avoid possible anaphylactic rxn
• -All the drugs have many side effects