Question

Grinch Meister has just been told that he has a condition called pernicious anemia. Mr. Meister looked up the disease on the Internet and learned that it is caused by a decreased availability of vitamin B12. What are the effects of this condition? What treatment is available for Grinch Meister?

Answer 1

Normally a protein termed intrinsic factor(IF) is secreted by parietal cells of the gastric mucosa. IF is required for cobalamin absorption. Therefore if IF is not secreted, cobalamin will not be absorbed. There are many causes of cobalamin deficiency. The most common cause is pernicious anaemia, a disease in which the gastric mucosa is not secreting IF because of antibodies being directed against the gastric parietal cells. Other causes of cobalamin deficiency include gastrectomy, gastritis, nutritional deficiency, chronic alcoholism, and hereditary enzymatic defects of cobalamin utilization. Pernicious anaemia is a disease of insidious onset that begins in middle age or later usually after age 40,woth 60 years being the most common age at diagnosis. Pernicious anaemia occurs frequently in persons of Northern European ancestry and African American. It is caused by an absence of IF, from either gastric mucosal atrophy or autoimmune destruction of parietal cells. This results in a decrease of hydrochloric acid secretion by the stomach. An acid environment in the stomach is required for the secretion of IF.

Regardless of how much us ingested, the patient is not able to to absorb cobalamin if intrinsic factor is lacking or if there is impaired absorption in the ileum. For this reason, increasing dietary cobalamin does not correct the anaemia. However the patient should be instructed on adequate dietary intake to maintain good nutrition. Parenteral or intranasal administration of cobalamin is the treatment of choice. Without cobalamin administration, these individuals will die in 1 to 3 years. The dosage and frequency of cobalamin administration may vary. A typical treatment schedule consists of 1000mg of cobalamin I'M daily for for 2 weeks and then weekly untilbthe hematocrit is normal, then monthly for life. High dose oral cobalamin and sublingual cobalamin are also available. As long as supplemental cobalamin is used, the anaemia can be reversed.