Iron metabolism: The Nutritional anemias (White) Flashcards
What are the normal iron compartments in the body?
(1) Hemaglobin
(2) Storage iron
(3) Myoglobin iron
(4) Labile pool
(5) Other tissue iron
(6) Transport iron.
How much iron is in 1ml of blood?
1ml of blood contains 2mg of iron
what are the characteristics of Ferritin?
Ferritin is a large hollow spherical protien that fills its core with 2000+ iron atoms.
What is the labile iron pool?
The labile iron pool is the iron that is leaving the plasma and entering interstitial and intracellular fluid compartments. (80-90g)
What are the characteristics of transferrin?
Transferrin carries iron in the plasma, it turns over 10 times a day, 1/3rd is saturated normally, syntheszied by the liver.
What are good sources of dietary iron?
Liver and meat are the best sources of dietary iron
How is iron absorption in the gut regulated?
Low iron leads to upregulation of iron transporters. Hepcidin prevents the release of iron from enterocytes to the blood via ferroportin.
What is ferroportin and how does it function?
Ferroportin transports iron out of cells. (macrophages, enterocytes, mother to fetus)
What are the functions of hepcidin?
Hepcidin is a negative regulator of iron uptake. Prevents iron from entering the plasma.
What factors increase absorption of non-heme iron?
reducing agents like ascorbic or gastric acid prevent absorption of non heme iron.
What are some factors that decrease the absorption of non-heme iron?
Insoluble complexes and chelating agents decrease the absorption of non heme iron.
What factors outside the GI tract increase absorption of iron?
(1) hypoxia
(2) Anemia
(3) Depletion of iron stores.
(4) Increased erythropoiesis.
What is the circular pathway of iron in the body?
Iron in the plasma is taken into the bone marrow and incroporated into RBCs. RBCs enter the blood stream. eventually RBCs are degraded in the spleen and the iron released back into the blood stream.
Why do infants need iron supplementation?
Milk is a poor source of iron.
What can cause malabsorption of iron?
(1) GI tract surgery
(2) Non-tropical sprue
(3) Picca
What are Billroth surgeries?
removal and resection of part of the stomach and small bowel.
What is non-tropical sprue?
Non-tropical sprue is gluten induced immunologic reaction to enterocytes causing severe malnutrition. Diet must be adjusted.
How is non-tropical sprue treated?
Non-tropical sprue is treated by avoiding all grains instead of rice and corn.
What is tropical sprue?
Tropical sprue is and overgrowth of coliforms in the jejunum that cause malabsorption.
What is the treatment for tropical sprue?
Treatment for tropical sprue involves antimicrobial treatment for 2 months (tetracycline) and folate/B12 supplementation.
What is PICCA?
The compulsive eating of dirt or starch that chelates iron in the GI tract.
What are the common causes of GI bleeding the the U.S.?
(1) peptic ulcer disease
(2) Hiatal hernia
(3) Chronic gastritis
(4) Hemorrhoids
(5) surgery
(6) neoplasms.
What are some causes of GI bleeding in infants?
(1) milk allergy
(2) meckel’s diverticulum
What are some unusual causes of Iron deficiency?
(1) respiratory tract bleeding
(2) Intravascular hemolysis
(3) Chronic renal dialysis
(4) Blood donation
(5) Factitious bleeding.
What are the most common causes of iron deficiency in pre-menopausal women?
(1) Menorrhagia
(2) Pregnancy
What is the most common cause of GI bleeding in tropical and developing countries?
Hookworm
What is the life cycle of Hookworm?
Adult worm lives in the intestines –> Eggs pass out through feces –> larvae hatch from eggs in gound –> larvae penetrate broken skin –> migrate to the lung –> up the trachea –> down the esophagus –> into small intestine.
What are the symptoms of iron deficiency chlorosis?
(1) Green pallor
(2) Sob
(3) palpitations
(4) Slight ankle edema
(5) GI complaints
(6) mental disturbances.
What are the typical symptoms of iron deficiency?
(1) Fatigue
(2) headaches and parathesias
(3) Irritability
(4) Decreased exercise tolerance
(5) Burning tongue
(6) Picca.
What are the physical findings of iron deficiency?
(1) pallor
(2) Glossitis
(3) Stomatitis
(4) Angular chelitis.
What is koilonchia?
Brittle concave nails
What are differences in a blood smear with iron deficiency?
(1) microcytosis
(2) hypochromatosis
(3) Anisocytosis
(4) Poikilocytosis.
What happens to lab values in Iron deficiency?
(1) WBC is normal
(2) Hmt is decreased
(3) MCV is decreased
(4) RDW is increased
(5) platelets may be increased
(6) reticulocytes are decreased.
What happens to TIBC and serum iron in iron deficiency?
(1) serum iron is decreased
(2) TIBC is increased
What happens to iron saturation in iron deficiency?
Iron saturation is decreased.
What happens to serum ferritin in iron deficiency?
Serum ferritin is decreased in iron deficiency
What happens to hepcidin in iron deficiency?
Hepcidin is suppressed in iron deficiency
What happens to hepcidin in chronic inflammation?
Hepcidin is increased in chronic inflammation
How is iron deficiency treated?
by iron supplementation
What are the indications for parenteral iron?
(1) malabsorption,
(2) Intolerance to oral iron
(3) uncooperative patient
What are some of the major problems with parenteral iron administration?
(1) arthralgia,
(2) hypotension
(3) nausea/vomiting
(4) anaphylactic reactions.
