Common causes of pernicious anemia include: Weakened stomach lining (atrophic gastritis)
In adults, pernicious anemia is associated with severe gastric atrophy and achlorhydria, which are irreversible. Coexistent iron deficiency is common because achlorhydria prevents solubilization of dietary ferric iron from foodstuffs.
A lack of vitamin B12 (vitamin B12 deficiency) causes the signs and symptoms of pernicious anemia. Without enough vitamin B12, your body can’t make enough healthy red blood cells, which causes anemia.
The symptoms of pernicious anemia may include weakness, fatigue, an upset stomach, an abnormally rapid heartbeat (tachycardia), and/or chest pains. Recurring episodes of anemia (megaloblastic) and an abnormal yellow coloration of the skin (jaundice) are also common.
The deficiency of intrinsic factor is a consequence of the presence of atrophic body gastritis (ABG), which results in the destruction of the oxyntic mucosa, and thus, the loss of parietal cells, which normally produce chlorhydric acid as well as intrinsic factor.
Pernicious anemia results from the inability to transport vitamin B12 across intestinal mucosa because of a relative lack of a gastric substance (intrinsic factor). This intrinsic factor is normally complexed to vitamin B12, making the vitamin available to mucosal cells for absorption.
Vitamin B12 deficiency is a cause of macrocytosis. Because DNA synthesis requires cyanocobalamin (vitamin B12) as a cofactor, a deficiency of the vitamin leads to decreased DNA synthesis in the erythrocyte, thus resulting in macrocytosis.
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. There are many types of anemia. Pernicious anemia is a decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B12.
Listen to pronunciation. (PAH-lee-sy-THEE-mee-uh VAYR-uh) A disease in which there are too many red blood cells in the bone marrow and blood, causing the blood to thicken. The number of white blood cells and platelets may also increase.
Autoimmune atrophic gastritis is a chronic inflammatory disease in which the immune system mistakenly destroys a special type of cell (parietal cells) in the stomach. Parietal cells make stomach acid (gastric acid) and a substance our body needs to help absorb vitamin B12 (called intrinsic factor).
Atrophic gastritis was more common in individuals with B12 deficiency, while superficial gastritis was the most common finding in controls. The incidence of intestinal metaplasia (in the antrum) was similar in the individuals with or without B12 deficiency.
Macrocytic anemia is a type of anemia that causes unusually large red blood cells. Like other types of anemia, macrocytic anemia means that the red blood cells also have low hemoglobin. Hemoglobin is an iron-containing protein that transports oxygen around the body.
When a person has autoimmune atrophic gastritis, their body mistakenly attacks healthy stomach cells, including a substance called intrinsic factor. Intrinsic factor is responsible for helping the body absorb vitamin B-12. When a person cannot absorb enough B-12, they may develop pernicious anemia.
Atrophic gastritis, also known as Type A or B gastritis, is a subtype of chronic gastritis. The key difference between atrophic and other forms of gastritis is the death of stomach glands and their replacement with intestinal and fibrous tissues.
Core tip: Chronic atrophic autoimmune gastritis is an autoimmune disease characterized by progressive parietal cells destruction leading to hypochlorhydria and intrinsic factor deficiency. These alterations may result in vitamin B12 deficiency and iron malabsorption.