[Management, prevention and control of pernicious anemia]

Pernicious anemia is the most frequent cause of megaloblastic anemia in our area, and it is the result of a vitamin B12 deficiency due, itself, to the decrease or absence of intrinsic factor (IF) because of gastric mucosa atrophy or autoimmune destruction of IF-producing parietal cells. With the existence of a severe gastric atrophy, there is a decrease in acid and IF production and a further change in vitamin B12 absorption. Fifty percent of the cases are associated to anti-IF antibodies, which presence in other autoimmune diseases is exceptional. In patients with pernicious anemia, measurement of anti-IF antibodies has high specificity (95%); however, measurement of anti-parietal cells antibodies has low specificity. The first-choice treatment is administration of vitamin B12 intramuscularly. The regimen is the administration of 1 mg of vitamin B12 daily for one week, weekly thereafter for one month and, then, every 2-3 months for life.