What is Pernicious Anemia ?
Blood circulates throughout the body performs a number of essential functions. It carries oxygen, takes carbon dioxide and transports nutrients essential to the maintenance of life. In addition,blood serves as a vehicle for messengers that act at a distance such as hormones and helps the various parts of the body communicate with each other.Blood cells work together with the liquid part of blood (plasma) which perform these important tasks. Most of the cells that make up blood are red blood cells (erythrocytes). The blood also contains white blood cells (leukocytes), although their number is less important. Their role is to defend the body against foreign bodies – including bacteria, viruses and fungi.
Anemia occurs when blood does not contain enough haemoglobin (a compound of iron and protein in red blood cells that carry oxygen) or that the red blood cells are not enough as numerically. Lack of red blood cells is caused by a deficiency of vitamin B12 which is pernicious anemia. The term pernicious was adopted many years ago when there was no effective treatment against this disease that was inevitably fatal. Nowadays, there are excellent treatments and the majority of people lead a normal life with very few side effects.
Pernicious anemia can affect all racial groups but it is more common in light-skinned people, especially those of scandinavian descent or Northern Europe.It does not usually manifest itself before the age of 30 years, although there is a juvenile form. About 4% of Canadians have low levels of vitamin B12.
Pernicious Anemia Causes
Pernicious anemia is caused by a deficiency of vitamin B12 which is necessary for the normal production of red blood cells. It is often hereditary. Risk factors include a history of endocrine diseases, auto-immune diseases, family history of pernicious anemia and scandinavian ancestry or Northern Europe.
Meat and dairy products are our main source of vitamin B12 that we consume. However, pernicious anemia is not just caused by an insufficient consumption of these foods except among strict vegetarians. It is usually due to a failure in the complex process of the absorption of vitamin B12 in the digestive tract.
Vitamin B12 is absorbed in the small intestine and cells which line a portion of the stomach must produce a substance called intrinsic factor. This substance binds to vitamin B12 and both are absorbed together in the lower part of the small intestine (ileum), just before the junction between the small intestine and the large intestine (or colon). If there has been lesion of the ileum, or the removal of the latter during a surgical procedure, the combination of intrinsic factor-vitamin B12 is not absorbed. Often, people who suffer from diseases such as Crohn’s have undergone the removal of a portion of the ileum (part of the small intestine that absorbs vitamin B12). These people should get tested to check for a deficiency in vitamin B12 and be treated.
The lack of intrinsic factor can also be congenital (present at birth). The juvenile or congenital pernicious anemia usually occurs before the age of three years. It is believed that in the congenital form, it is sufficient that only one parent is a carrier of the gene to transmit the disease to the child.
The less common causes of decreased absorption of vitamin B12 include chronic pancreatitis, malabsorption syndrome, certain medications and very rarely, increased metabolism of vitamin B12 due to a hyperthyroidism of long standing. Older people absorb less vitamin B12 from food which is why they are more often affected by the deficiency of vitamin B12.
Pernicious anemia is often associated with certain endocrine disorders (glandular), auto-immune diseases including type 1 diabetes, hypoparathyroidism, Addison’s disease and testicular dysfunction.
Pernicious Anemia Symptoms and Complications
In most cases, there are no early signs of pernicious anemia. Shortness of breath and decreased exercise tolerance may occur when the disease progresses. Sometimes, heartbeat accelerates and are more noticeable. People with pernicious anemia often have very low hemoglobin. White blood cell count (cells to fight infections) and platelets (cells necessary for blood clotting and to stop bleeding) may also decline.
Other possible symptoms of pernicious anaemia are;
- Paleness of the skin
- Sore and shiny tongue
- Low appetite and weight loss
- Tingling and numbness of hands and feet
- Instability in gait and loss of balance (especially in the dark)
- Changes in mental status, including loss of memory, irritability, mild depression and dementia
- Blindness of the colours (yellow-blue)
- In the absence of treatment, deficiency in vitamin B12 can affect gradually the sensory and motor nerves and cause neurological problems.
Anemia may also affect the gastrointestinal tract and the cardiovascular system, cause inflammation of the tongue, alter the sense of smell ,cause bleeding gums and loss of reflexes. In very severe cases, it often creates paranoia, delusions and mental confusion.
Pernicious anemia is a chronic disease that evolves slowly and steadily. Formerly, the disease was little known and there was no treatment. Today, the prognosis is excellent. Administration of supplements of vitamin B12 is enough to remedy deficiency and allows person to live a normal life.
If anemia evolves for a long period before being detected, it may cause damage to certain parts of the body, mainly the nervous system and the digestive tract. Polyps can form in the stomach which increases the risk of cancer of the stomach. It is worth noting that a deficiency in vitamin B12 will alter the appearance of the epithelial cells of the cervix of the uterus; Thus, if it is not treated in woman, a pap test could give a false positive result.
Pernicious Anemia Diagnosis
The common symptoms are likely to increase a doctor to prescribe various tests for anemia. One of these tests will measure the concentration of vitamin B12 in the blood. The blood will then be examined under a microscope to assess the size and shape of red blood cells. In the case of pernicious anemia, these cells will be larger and less numerous than normal.
If the tests reveal a low concentration of vitamin B12 in the blood, your doctor may order additional tests to confirm that your body has sufficient concentrations to ensure normal cellular processes. It is rare that doctors appeal to an analysis of the bone marrow to confirm the diagnosis.
Previously, the test Schilling was part of the diagnostic approach, but it is no longer necessary in the current practice.
Stomach cancer is more common in people with pernicious anemia. The doctor will need to ensure monitoring of all clinical findings (e.g. presence of symptoms, positive result to the research of blood in the stool) and evoking the possibility of a violation of the digestive system. Doctors may prescribe additional tests, such as x-rays or an endoscopy (an examination of the inside of the body with a device equipped with a flexible tube).
Pernicious Anemia Treatment And Prevention
The main treatment for this type of anemia is to do injections of vitamin B12. Sometimes it is difficult to calculate the dose of vitamin B12 required, because this dose must also restore the reserves of the vitamin in the liver.
At the beginning, between 5 and 7 injections are given over a short period of time. The effect of this treatment usually begins to be felt within 48 to 72 hours which should eliminate the need for a blood transfusion. Later, the injections will be administered once per month. It has recently been demonstrated that maintenance treatment with very high doses of vitamin B12 (0.5 mg to 2 mg per day) taken by mouth, making injections unnecessary.
Pernicious anemia cannot be treated without the supervision of a doctor. Nevertheless, a well-balanced diet is essential to provide other elements which are necessary for the formation of blood cells healthy, including folic acid, iron and vitamin C.
Treatment with vitamin B12 should be continued for life, unless if we can correct the cause of the disability.