Pernicious anemia

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Pernicious anemia refers to a type of autoimmune anemia. Antibodies are directed against intrinsic factor or parietal cells which produce intrinsic factor. Intrinsic factor is required for vitamin B₁₂ absorption, so impaired absorption of vitamin B{{ssub can result.

The term pernicious anemia is sometimes used more loosely to include non-autoimmune causes of vitamin B₁₂ deficiency.

Contents

1 Diagnosis
2 History
3 Symptoms
4 Treatment
5 See also
6 External links

Diagnosis

Blood testing typically shows a macrocytic anemia, and low levels of serum vitamin B₁₂. A Schilling test can then be used to distinguish between pernicious anemia, vitamin B₁₂ malabsorption, and vitamin B₁₂ deficiency. Approximately 90% of individuals with pernicious anemia have antibodies for parietal cells, however only 50% of individuals with these antibodies have the disease.

History

The treatment for pernicious anemia was first devised by William Murphy who bled dogs to make them anemic and then fed them various substances to see what (if anything) would make them healthy again. He discovered that ingesting large amounts of liver seemed to cure the disease. George Minot and George Whipple then set about to chemically isolate the curative substance and ultimately were able to isolate the vitamin B₁₂ from the liver. For this, all three shared the 1934 Nobel Prize in Medicine. As a result, pernicious anemia is now treated with either vitamin B₁₂ injections (hydroxocobalamin or cyanocobalamin), or large oral doses of vitamin B₁₂, typically between 2 and 4 mg daily.

Maurice Beddow Bayly, an anti-vaccinationist and anti-vivisectionist, campaigned against the use of liver therapy, having failed to recognise the nature of the disease (despite reciting the necessary information) .

Symptoms

Pernicious anemia may cause inflammation of the tongue (glossitis). It is also associated with premature greying, blue eyes, vitiligo, and blood group A.

Treatment

Treatment is with vitamin B₁₂ (hydroxycobalamin or cyanocobalamin) injected intramuscularly. Body stores (in the liver) are refilled with half a dozen injections in the first couple of weeks and then maintenance with monthly to quarterly injections throughout the life of the patient.

B₁₂ has traditionally been given parenterally to ensure absorption. However, oral replacement is now an accepted route, as it has become increasingly appreciated that sufficient quantities of B₁₂ are absorbed when large doses are given. This absorbance does not rely on the presence of intrinsic factor or an intact ileum. Generally 10 to 20 mg daily is required [link]. By contrast, the typical Western diet contains 5–7 µg of B₁₂ (Food and Drug Administration (FDA) Daily Value ).

External links

[The Pernicious Anaemia Society], a UK-based charitable organisation which operates a [forum] where you can discuss Pernicious Anaemia with other sufferers around the world.