Pernicious anemia is an insidious condition causing fatigue, weakness, digestive problems and neurological impairment. Pernicious anemia is linked to stomach disorders or chronic gastritis.
*pernicious (adj) – causing death or serious harm.
At one time, pernicious anemia was fatal, and the average survival period was one to three years. Today, the condition is treatable and to an extent reversible, with the exception of some types of nerve damage. In most people, pernicious anemia is a life-long condition.
Pernicious anemia (PA) is also called Addison’s disease or Addison’s anemia, named after the British physician Thomas Addison, who first described the condition in 1849. Other terms for pernicious anemia include Biermer’s anemia or Addison-Biermer anemia.
Cause of Pernicious Anemia
The cause of pernicious anemia is, ultimately, a deficiency of Vitamin B12. Vitamin B12 is essential to the proper development of red blood cells. Since the body doesn’t manufacture Vitamin B12, it gets its B12 supply from incoming food. Foods high in Vitamin B12 include liver, red meat and dairy products.
To absorb Vitamin B12, the body produces a protein known as intrinsic factor (IF). Gastric parietal cells in the stomach lining are responsible for producing intrinsic factor.
To be absorbed by the body, Vitamin B12 must bind to intrinsic factor. The body then absorbs B12 in the small intestine. Lack of intrinsic factor, or damage to the gastric parietal cells, can prevent the body from receiving adequate amounts of B12.
Pernicious Anemia and Chronic Gastritis
Chronic or atrophic gastritis can cause an imbalance in stomach acidity due to ongoing inflammation of the stomach lining and destruction of the gastric cells. In some cases, the immune system is compromised, and the body may attack itself. Causes of chronic or atrophic gastritis may include:
- Helicobacter pylori bacterial infection (infection of the stomach lining; a common cause of ulcers)
- consistently poor diet, starvation or fasting
- ongoing stress or anxiety
- post-traumatic stress disorder
- underlying medical condition such as TMJ disorder (TMJ and Stomach Disorders: About the Vagus Nerve)
- infection by the tapeworm Diphyllobothrium latum
Underproduction of stomach acids (achlorhydria or hypochlorhydria) can also cause symptoms similar to heartburn or acid reflux, and is linked to bacterial infection.
In rare cases, pernicious anemia is genetic, known as congenital pernicious anemia. The condition may occur in infants and children who are born without the ability to produce intrinsic factor, or who have difficulty absorbing Vitamin B12 together with intrinsic factor. Congenital pernicious anemia is inherited when the child gets the defective gene from each parent.