Anemia occurs when your body has too few red blood cells. Pernicious anemia is low red blood cell level due to low levels of vitamin B12 (also called cobalamin).
At Seattle Cancer Care Alliance (SCCA), our team of experts provides comprehensive diagnostic and medical care for people with many types of anemia, including this type.
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What is pernicious anemia?
Vitamin B12 is important for many processes in your body, including cell multiplication. Red blood cell production is particularly sensitive to low B12 levels.
In pernicious anemia, your body makes antibodies that attack cells in your stomach called parietal cells. Normally, parietal cells make intrinsic factor, a protein that has to bind to B12 so your intestines can absorb this vitamin from your diet. If your parietal cells are destroyed, you don’t have intrinsic factor, and you can’t absorb enough B12 to maintain a healthy red blood cell count.
Red blood cells carry oxygen from your lungs to the rest of your body. When your red blood cell count is low, this process is impaired, and your tissues don’t get as much oxygen as they need.
There are other reasons your body might be low in B12, such as an imbalance of bacteria in your intestine, another disease in your stomach or gut or a medicine that limits how much B12 you can absorb. You could also be low in B12 if you don’t get enough through your diet — for instance, if you are vegan (eating no animal-based products) and you do not take B12 supplements. Low B12 for any reason can lead to anemia. Sometimes the term “pernicious anemia” is used for any anemia caused by B12 deficiency; some sources use this term only for anemia that stems from problems with intrinsic factor.
Symptoms and diagnosis of pernicious anemia
When your blood cannot deliver enough oxygen throughout your body, you may feel weak, dizzy or short of breath. You may notice chest pain, a rapid or irregular heartbeat, headaches, cold hands and feet or pale skin.
Without treatment, pernicious anemia can lead to other health concerns, including sores or chapping in the corners of the mouth; a smooth, red tongue with reduced sensation of taste; tingling or numbness from nerve damage; memory loss, dementia or other neurologic conditions; and heart or digestive problems. Lack of vitamin B12 can also lead to a decrease in other types of blood cells, such as white blood cells and platelets.
SCCA offers a full array of services to diagnose anemia and determine the cause.
Your doctor will ask about your medical and family history and examine you. You will have a blood test (complete blood count) to check the levels of your blood cells, the volume of space your red blood cells take up in your blood (hematocrit) and the size of your red blood cells.
B12 deficiency causes fewer red blood cells and a lower volume of red blood cells in the blood, but typically each individual red blood cell is larger than normal. This is called macrocytosis, so this type of anemia is called macrocytic.
If you have anemia, additional blood tests can help your doctor tell which type you have. For instance, blood tests can be used to check your B12 level, evaluate your body’s use of B12 and look for antibodies that may be present if you have pernicious anemia. Endoscopy may also be used to check for problems in your stomach and gut that can explain decreased B12 absorption.
To learn more about your body’s ability to make healthy red blood cells, you may need other tests too. You may have a bone marrow biopsy — removing a small sample of bone marrow to examine under a microscope. Bone marrow makes young blood-forming cells, called hematopoietic stem cells, that develop into mature white or red blood cells or platelets. You may hear doctors mention the term “megaloblastic anemia.” This refers to changes in your stem cells that result in larger red blood cells if you are low in B12.
Pernicious anemia treatment
Treatment of pernicious anemia requires building up and then maintaining your vitamin B12 stores. Typically, pernicious anemia prevents normal absorption of B12 taken by mouth, so it is very likely you’ll need B12 supplements by injection. But some people with pernicious anemia can absorb some vitamin B12 orally and may take B12 in pill form.
Pernicious anemia can become severe enough to require blood transfusions to increase your red blood cell level.
If another condition is causing your lack of intrinsic factor or poor absorption of B12, you’ll need treatment to correct that as well. The type and duration of treatment will depend on the underlying problem.
SCCA’s team of doctors provides a full range of treatment options for anemia and the conditions that may lead to it.
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