Types of Anemia

Study Notes

Anemia is a condition where the blood does not have enough healthy red blood cells.
Red blood cells carry oxygen to the body's organs.
Decreased red blood cell production can be caused by several factors including iron deficiency, vitamin B12 deficiency, and folic acid deficiency.
Iron Deficiency Anemia is when the body does not have enough iron to make healthy red blood cells which occurs from not eating enough iron, poor absorption of iron, or losing too much iron.
Iron is absorbed in the small intestine.
Intestinal conditions like inflammatory bowel disease and bowel resection can cause poor iron absorption.
Achlorhydria is a condition where the stomach does not produce enough stomach acid to help absorb iron.
Anemia of inflammation and chronic disease (AI/ACD) is caused by chronic inflammation which can be due to cancer, chronic kidney disease, chronic immune-related diseases e.g. rheumatoid arthritis and systemic lupus erythematosus, and infection.
AI/ACD anemia limits the body’s ability to use iron
The body needs vitamin B12 and folic acid to make DNA, which is needed to make red blood cells.
Pernicious anemia is a type of anemia that occurs when the body does not absorb enough vitamin B12 due to a lack of intrinsic factor, a glycoprotein produced by gastric parietal cells that binds to vitamin B12.
Excessive iron loss can happen via heavy menstrual bleeding, ulcers or neoplastic lesions, and excessive bleeding following surgery or trauma.

The activation of the immune system is a key factor in the dysregulation of iron homeostasis in AI/ACD anemia.
Elevated levels of interleukin-6 (IL-6) lead to increased expression of hepcidin.
Hepcidin is an acute-phase protein that reduces iron absorption from the gastrointestinal tract (GIT) and inhibits iron release from macrophages.
Increased levels of cytokines also affect erythroid precursor proliferation and differentiation.
Patients with chronic kidney disease (CKD) often have dysregulation of erythropoietin (EPO) production and responsiveness.
Cancer infiltration of the bone marrow can also impair erythropoiesis.

Iron Deficiency Anemia
- Oral Iron Therapy
  - Ferrous sulfate
- Parenteral
  - CosmoFer
  - Venofer
  - Hemafer
Vitamin B12 Deficiency Anemia
- Kinetics:
  - Vitamin B12 (Cyanocobalamin) is completely absorbed following parenteral administration.
  - Oral vitamin B12 is poorly absorbed via the gastrointestinal tract (GIT).
Folic Acid Deficiency Anemia
- Feroglobin
- Folic Acid

Porphyria is a group of rare genetic disorders that result from defects in the biosynthesis of heme.
Heme is a molecule found in red blood cells that carries oxygen in the blood throughout the body.
Acute Intermittent Porphyria (AIP) is a common type of porphyria.
Symptoms of AIP include abdominal pain, nausea, vomiting, constipation, muscle weakness, and neurological problems such as seizures and paralysis.
King George III, who ruled England during the American Revolution, suffered from AIP and his mental health declined throughout his reign.
The decision made by the deranged King George III ultimately led to the American Revolution.