In a normal healthy body, a protein called intrinsic factor is secreted in the stomach. This protein binds itself to B12 and enables this vitamin to be absorbed during the digestion process. Vitamin B12 is required for the production of red blood cells, which are important for carrying oxygen to cells in the body. In pernicious anemia, the intrinsic factor is lost, therefore B12 isn’t properly absorbed. The red blood cells are unable to divide normally and release out of the bone marrow.
What causes a loss of intrinsic factor?
Intrinsic factor is produced by the stomach lining, which is sensitive. Therefore, stomach surgery can cause the production of this protein to be halted. It can also be due to an immune system reaction where cells in the stomach are destroyed. In very rare cases, intrinsic factor can be missing at birth.
How does this disorder present itself?
There are usually no symptoms to begin with, and then gradually the symptoms develop. These symptoms include getting tired easily, general weakness, tongue soreness, tingling and numbness in the hands and feet, unsteady gait, confusion, blurred vision, gum bleeding, dizziness, mild depression.
What happens if the condition isn’t treated?
There can be progression towards heart failure or significant permanent nerve damage. It used to be a chronic fatal disease, in the days before the correct treatment was discovered.
How does a medical professional make a diagnosis?
There are numerous tests which can be done such as complete blood count, schillings test, biopsy specimen, reticulocyte count, bone marrow biopsy, serum LDH. A schilling test will show if the B12 deficiency is because of an absence of intrinsic factor. Essentially, this test is a measure of how much B12 is excreted in the urine after a dose of B12 having been taken in.
What is the appropriate treatment?
B12 injections are prescribed. There might be a need for up to eight injections in the first month. After this, the total level of B12 in the body is measured, and usually the injections are carried on each month depending on overall B12 level. It is also advised that sufferers take folic acid and iron supplements, to help the B12 work more efficiently.
What is the prognosis?
The earlier the detection the better. Correct treatment and early detection should mean a normal life. If it is detected late, there may be some irreversible nerve damage. Someone with pernicious anemia is between two and three times more likely to develop stomach cancer. It may therefore be appropriate to be tested for this, there is a debate among medical professionals on whether this is necessary.