Anemia is a condition in which the body does not have enough healthy red Weakened stomach lining (atrophic gastritis); An autoimmune. Pernicious anemia probably is an autoimmune disorder with a genetic predisposition. The disease is more common than is expected in families. Pernicious anemia is thought to be an autoimmune disorder, and certain people may have a genetic predisposition to this disorder. There is a rare congenital.

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Pernicious anemia is one of many types of anemiaa disease marked by a reduction in red blood cells or in the oxygen-carrying substance hemoglobin found in those cells. Pernicious anemia occurs most often in persons over pernicisoa 30, although a juvenile form of the disease does occur, usually in children younger than 3 years old.

The disease shows a familial tendency and is more common in perniciisa of northern European descent. Pernicious anemia is in most cases associated with an inflammation of the stomach called autoimmune gastritis.

Pernicious anemia: MedlinePlus Medical Encyclopedia

In pernicious anemia vitamin B 12 is unavailable owing to a lack of intrinsic factora substance anemix for intestinal absorption of the vitamin. In a healthy person, intrinsic factor is produced by the parietal cells of the stomach, the cells that also secrete hydrochloric acid. Intrinsic factor forms a complex with dietary vitamin B 12 in the stomach. The complex remains intact, preventing degradation of the vitamin by intestinal juices, until it reaches the ileum of the small intestinewhere the vitamin is released and absorbed into the body.

When intrinsic factor is prevented from binding with vitamin B 12 or when the parietal cells are unable to produce intrinsic factor, the vitamin is not absorbed and pernicious anemia results. This effect is thought to stem from an autoimmune reaction in which the malfunctioning autoimnune system produces antibodies against autoinmunf factor and against the parietal cells.

Without an adequate amount of vitamin B 12the body is unable to pernicioa DNA properly. This in turn affects red blood cell production: These cells, called megaloblastsare for the most part destroyed in the bone marrow and are not released to the circulation. Some megaloblasts mature to become large red blood cells called macrocytes; they reach the circulation but function abnormally.


A deficiency of white blood cells leukopenia and platelets thrombocytopenia in the blood may occur. Symptoms of pernicious anemia include fatigueweakness, waxy pallor, shortness of breath, rapid heartbeat, unsteady gait, smooth tonguegastrointestinal disturbances, and neurological problems.

Weight loss, depressed mood, and memory loss are common in affected persons. Levels of the substances homocysteine and methylmalonic acid typically are high ansmia persons with pernicious anemia, while gastric secretions lack hydrochloric acid achlorhydria. The anemia may become severe before the disorder is diagnosed, since the vitamin deficiency develops very gradually.

Treatment involves a monthly intramuscular injection of vitamin B 12 that must be continued for life. Most patients improve quickly, although zutoinmune damage is seldom fully reversible and atrophy of the parietal cells and achlorhydria persist.

Before the discovery of treatment in the s, the modifier perniciousalthough something of a misnomer today, was appropriate, since the disease was usually fatal. We welcome suggested improvements to any of our peeniciosa. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind.

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Please note that our editors may make some formatting changes or correct spelling or grammatical errors, and may also contact you if any clarifications are needed. The Editors of Encyclopaedia Britannica. Learn More in these related Britannica articles: Pernicious anemia is a classic example of this phenomenon.

This disorder results from an autoimmune response to intrinsic factor, a substance normally found in the stomach lining with which vitamin B 1 2 must form a complex to be absorbed. Vitamin B 12 is necessary for red cells…. Throughout the first two decades of the century, the diagnosis of pernicious anemia, like that of diabetes mellitus, was nearly equivalent to a death sentence.

Unlike the more common form of so-called secondary anemia, it did not respond to…. In this disorder the stomach does not secrete intrinsic pernicioza, perhaps as the result of an immune process consisting of the production of antibodies directed against the stomach lining.


Pernicious anemia

The tendency to form such antibodies may be…. Pernicious anemia and autoimmune gastritis. Pernicious anemia stems from a failure to absorb vitamin B 12 cobalaminwhich is necessary for the proper maturation of red blood cells.

It is characteristically accompanied by a failure to secrete hydrochloric acid in the stomach achlorhydria and is in fact a symptom of severe…. More About Pernicious anemia 9 references found in Britannica articles Assorted References medicine In history of medicine: Vitamins result of absence of digestive enzymes In human disease: Diseases of nutritional deficiency alcoholism In alcoholism: Chronic diseases autoimmune disorder In immune system disorder: Pernicious anemia and autoimmune gastritis lack of intrinsic factor In intrinsic factor vitamin B 12 deficiency In blood disease: Megaloblastic anemias In nutritional disease: Help us improve this article!

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