1. MLAB 1315- Hematology Keri Brophy-Martinez
Unit 9: Iron Metabolism and Hypochromic Anemias

2. Iron Metabolism Primary function of iron is oxygen transport
Iron absorption and storage is influenced by:
The amount and type of available iron in the diet
Incomplete absorption due to GI tract problems
Current iron stores
Increased demand (pregnancy, the growth years)
Excessive loss due to acute or chronic hemorrhage
menstrual period for women of childbearing years, GI bleeding for men

3. Clinical Syndromes of Iron Metabolism
Iron Deficiency Anemia (IDA)
This is the most common form of anemia.
IDA occurs when the iron stores in the body are inadequate to preserve homeostasis.
Peripheral blood smear in IDA is microcytic-hypochromic. If IDA is caused by bleeding, leukocytosis and thrombocytosis are possible.
Typical lab findings in addition to low RBC, Hgb, Hct, MCV, MCH, MCHC:
to normal retic
Serum iron
↑ Total iron-binding capacity (TIBC)
↓ Serum ferritin

4. Clinical Syndromes of Iron Metabolism
Dysfunction of Iron Utilization
Usually this is due to an existing disease condition and is known as anemia of chronic disease. This will be discussed in a later section.

5. Clinical Syndromes of Iron Metabolism
Iron Excess and Sideroblastic States
Hemosiderosis - accumulation of excess iron in tissue macrophages which could be due to organ bleeding
Hemochromatosis
Hereditary condition caused by increased iron absorption which deposits in vital organs such as the liver, spleen and pancreas which then become fibrotic.
People with this take on a bronze color.
Therapy consists of iron removal by therapeutic phlebotomy or chelation

6. Clinical Syndromes of Iron Metabolism
Iron Excess and Sideroblastic States
Sideroblastic anemia
Primary is genetic
Secondary caused by:
Certain therapeutic drugs
Chronic transfusions (for aplastic anemia, leukemia, thalassemia)
Alcoholism and food fads
Use of iron utensils or increased iron in water
Diagnostic lab finding is ringed sideroblasts in the bone marrow and Pappenheimer bodies in peripheral blood.

7. Clinical Syndromes of Iron Metabolism
Iron Excess and Sideroblastic States
Lead poisoning
Lead interferes with iron storage in the mitochondria
Lead damages the activity of enzymes used for heme synthesis (basophilic stippling)

8. Clinical Syndromes of Iron Metabolism
Heme synthesis
Porphyria - excessive production of porphyrins in the bone marrow (or liver)
Rare disease caused by accumulation of porphyrins in developing RBC’s
Characterized by dermal photosensitivy and rash caused by the sun. The original werewolf was probably a person with erythropoietic porphyria.