Pernicious Anemia (cont.)

Medical Author:
Medical Editor:

What is megaloblastic anemia?

Sometimes, anemias are subclassified based upon the size and microscopic appearance of the red blood cells. In this regard, pernicious anemia is a form of megaloblastic anemia. Megaloblastic anemia refers to an abnormally large type of red blood cell (megaloblast). Megaloblasts are produced in the bone marrow when vitamin B-12 or folic acid levels are low. Megaloblastic anemia can also be caused by other disease of the bone marrow and can be a side effect of some cancer chemotherapy drugs.

What causes pernicious anemia?

Pernicious anemia is considered to be an autoimmune disease, in which the body's own immune system mistakenly damages its own tissues. It is believed that the decreased absorption of vitamin B-12 from the gastrointestinal tract in pernicious anemia results from the presence of an autoantibody against intrinsic factor (IF), a protein made in the stomach that is necessary for the absorption of vitamin B-12. Normally, vitamin B-12 binds to intrinsic factor in the stomach, and this facilitates its absorption by the small intestine further along in the digestive process. Along with the autoimmune process that attacks the IF protein and lowers IF levels in stomach secretions, another autoimmune reaction against the stomach lining cells also occurs, resulting in a form of inflammation known as chronic atrophic gastritis.

Pernicious anemia is sometimes associated with other autoimmune diseases such as Graves' disease, Hashimoto's thyroiditis and vitiligo (depigmentation or blanching of skin areas).

Medically Reviewed by a Doctor on 12/4/2013

Patient Comments

Viewers share their comments

Pernicious Anemia - Symptoms Question: The symptoms of pernicious anemia can vary greatly from patient to patient. What were your symptoms at the onset of your disease?
Pernicious Anemia - Treatments Question: What was the effective treatment for you pernicious anemia?
Pernicious Anemia - Share Your Experience Question: What was the cause of your megaloblastic (pernicious) anemia? Please share your experience.
Pernicious Anemia - Causes Question: Was there an underlying condition that caused your pernicious anemia?