Anemia (pt 1/3) Iron, B12, Folic Acid, IL Flashcards
What is Hematopoiesis?
Process by which RBCs are made
-happens in the bone marrow
_____+ _____ = Hematopoietic Cell
Essential Nutrients + Growth Factors = Hematopoietic cells
What are the Essential Nutrients?
Iron
Vitamin B12
Folic Acid
What is a Hematopoietic Cell?
Immature cell that can develop into all types of blood cells
What is the most common cause of anemia?
Iron Deficiency
How do we get iron?
-Iron is recycled from damaged RBCs (don’t need a large intake usually)
-Only a small amount of iron is lost each day therefore dietary requirements are low
Iron requirements increase in what situations?
-Growing children
-Pregnant women
-Menstruating women
What is Hepcidin?
A peptide produced primarily by the liver.
-Regulates the absorption, transport and storage of iron.
How does low iron cause anemia?
-Iron forms the nucleus of the iron-porphyrin heme ring → hemoglobin
-↓iron = small RBCs with insufficient hemoglobin
-Microcytic (small) Hypochromic (less red) Anemia
What are S/Sx of Iron Deficiency?
-Fatigue, weakness
-pale/yellowish skin
-Dizziness/lightheadedness
-Irregular heartbeat
-Shortness of Breath
-Cold hands/feet
-Chest pain
-HA
What kind of anemia does low Iron cause?
Microcytic, Hypochromic
What are the laboratory abnormalities associated with Iron-deficiency anemia?
-Low serum Fe (<30 mcg/dl), increased transferrin iron-binding capacity
-% Transferrin saturation of <10%
-Low serum ferritin levels (stored iron) <20 mcg/L
What type of anemia occurs with Folic Acid Deficiency?
-Macrocytic Normochromic Anemia
What are the laboratory abnormalities associated with Folic Acid Deficiency Anemia?
Low Serum Folic Acid level
-< 4 ng/mL
What type of anemia occurs with Vitamin B12 deficiency?
-Macrocytic Normochromic Anemia
What are the laboratory abnormalities associated with Vitamin B12 deficiency anemia?
-Low Serum Cobalamin
-Increased Serum Homocysteine
-Increased Serum Methylmalonic Acid
-Increased Urine Methylmalonic Acid
What is Serum Homocysteine?
-Can be used to establish a diagnosis of Vit B12 deficiency.
-Methylcobalamin is required for the conversion of homocysteine to methionine.
-B12 deficiency decreases the formation of methylcobalamin, thereby increasing homocysteine levels (because it’s not being used to convert).
What is the stored form of Iron?
Ferritin
How is iron transported into the blood?
By Ferroportin (Fp)
How is iron actively transported in the blood?
By Transferrin (Tf)
In the blood, what are the two locations iron is transported to?
1) Erythroid precursors in the bone marrow for synthesis of hemoglobin
2) Hepatocytes for storage as Ferritin
How is iron reclaimed after it is used?
Macrophages that phagocytize senescent (old) erythrocytes (RBC) reclaim the iron (in the spleen or other tissues, macrophages) from the RBC hemoglobin and either export it or store it as ferritin.
What offers negative feedback by inhibiting ferroportin (the active transporter than pulls iron into the blood)?
High hepatic iron stores increase hepcidin synthesis, and hepcidin inhibits ferroportin (the active transporter)
What conditions require additional iron therapy?
-Infants especially premature infants
-Children during rapid growth periods
-Pregnant and lactating women
-Chronic Kidney Disease (2/2 RBC loss during hemodialysis)
-Inadequate absorption: Malabsorption post-gastrectomy for pts with severe small bowel disease; Normal process of iron function occurs in intestinal epithelial cells.
-Blood loss (Most common cause of iron deficiency anemia in adults):
Menstruating women lose 30 mg of iron with each menstrual period. Those with heavy bleeding can lose much more.
In men/post-menopausal women, the most common site of bleeding is the GI tract.