Pernicious anemia is a type of vitamin B12 deficiency anemia, a disease in which not enough red blood cells are produced due to the malabsorption of vitamin B12. Malabsorption in pernicious anemia results from the lack or loss of intrinsic factor needed for the absorption of vitamin B12. Anemia is defined as a condition in which the blood has a lower than normal amount of red blood cells or hemoglobin. The disease may come on slowly and insidiously.The most common initial symptoms are tiredness, and weakness. Other signs and symptoms of anemia include breathlessness, dizziness, a sore red tongue, lightheadedness, headaches, poor ability to exercise, cold hands and feet, low blood pressure, pale or yellow skin, chest pain, and an irregular heartbeat. The digestive tract may also be disturbed giving symptoms that can include nausea and vomiting, heartburn, upset stomach and loss of appetite. Pernicious anemia can cause osteoporosis and may lead to bone fractures. Symptoms of severe vitamin B12 deficiency can include tingling or numbness in the hands and feet, memory problems, blurred vision, unsteady walking, poor balance, muscle weakness, impaired sense of taste and smell, poor reflexes, clumsiness, depression, and confusion. Without treatment, some of these problems may become permanent.Pernicious anemia occurs due to an autoimmune response that produces antibodies that attack the parietal cells in the stomach lining and prevents them from creating intrinsic factor.
A further important advance was made in the early 1960s by Doniach with the recognition that pernicious anemia is an autoimmune disease. Pernicious anemia is eventually treated with either injections or large oral doses of B12, typically between 1 and 4 mg daily. A medical author takes the view that Mary Todd Lincoln, the wife of American President Abraham Lincoln, had pernicious anemia for decades and died from it in 1882. Research
Permeation enhancers
Treatment using oral drugs is an easier option in management but the bioavailabity of B12 is low. This is due to low absorption in the intestine, and breakdown by enzyme activity. Research continues to focus on the use of permeation enhancers or permeation absorbers in combination with the treatment. One of the better performing enhancers studied is salcoprozate sodium (SNAC). SNAC is able to form a noncovalent complex with cobalamin while preserving its chemical integrity and protect B12 from gastric acidity. This complex is much more lipophilic than the water-soluble vitamin B12, so is able to pass through cellular membranes with greater ease. Molecular dynamics are used in experiments to gain an understanding of the molecular interactions involved in the different molecules used and the degree of ease achieved in absorption across the gastric epithelium. References
External links
Pernicious anemia at Curlie