Pernicious anemia is a type of anemia that occurs when the body cannot properly absorb vitamin B12, which is needed to make red blood cells. It is a relatively rare autoimmune disorder that affects people of all ages worldwide, particularly those over 60. The term "pernicious" means harmful, and pernicious anemia causes harm to several body systems:
- Digestive system problems that cause nausea, bloating, and weight loss.
- Nervous system damage that causes muscle weakness, numbness or tingling in your hands and feet, memory loss, and dementia.
- Heart problems that can cause palpitations (feeling as your heart is beating too fast or skipping beats).
- Weakness and fatigue.
Pernicious anemia is caused by a deficiency of intrinsic factor (IF), a glycoprotein produced and secreted by parietal cells that binds B12 and facilitates its transport to the terminal ileum for absorption. Anti-IF antibodies inhibit B12 from binding to IF, preventing B12/IF complex formation or binding to the B12/IF complex, preventing intestinal absorption. Common causes of pernicious anemia include weakened stomach lining (atrophic gastritis), an autoimmune condition in which the bodys immune system attacks the actual intrinsic factor protein or the cells in the lining of your stomach that make it, and in rare cases, it is passed down through families. Symptoms of pernicious anemia can include weakness, fatigue, pale skin, shortness of breath, and tingling or numbness in the hands and feet.
