The hemoglobin begins to rise after about a week, and becomes normal after several weeks. The MCV takes about 3 months to become normal. Blood Transfusion may be dangerous in severe chronic anaemias because of volume overload. Critically-ill patients should be transfused carefully, one or two units of PRBC at a time, using diuretics as well. There is an autoimmune attack on the gastric parietal cell manifest histologically as atrophic gastritis.
Patients are unable to secrete acid or intrinsic factor.
There is a significant association with vitiligo and thyroid disease. There may be a family history of Pernicious Anaemia and thyroid disease. Vitamin B 12 concentrations in the elderly Serum vitamin B 12 levels are often low in the elderly. The cause is unknown, but may be partly dietary, and partly inability to digest the vitamin B 12 from the food binders. Contrary to what was once thought, these patients may have a true deficiency of the vitamin.