The red blood cells are critical for transporting oxygen throughout the body. Anemia describes any condition in which there is reduced red blood cell numbers, which can cause pallor and chronic fatigue. Macrocytic anemia is unique among types of anemia because of the appearance of larger than normal red blood cells. This kind of anemia needs to be treated based on the underlying disorder causing the problem.
There are actually two different types of macrocytic anemias, the Merck Manual says. The first type, known as megaloblastic macrocytic anemia, is the most common and is the result of vitamin deficiency such as B-12 and folate. The second type, known as non-megaloblastic macrocytic anemia, can be due to several different clinical problems, such as liver disease and problems with the bone marrow. In some cases, the cause of non-megaloblastic macrocytic anemia cannot be identified.
Before macrocytic anemia can be treated, the exact type and cause should be identified in order for treatments to be effective. Diagnosing macrocytic anemia is typically done by performing what is known as a peripheral blood smear. On a blood smear, the size and number of the red blood cells can be determined. Megaloblastic macrocytic anemia is notable for the presence of small specks within red blood cells known as Howell-Jolly bodies, the Merck Manual reports, which are the result of immature red blood cells being released into the body to compensate for the anemia. Patients may also have their blood tested for vitamin deficiencies. Patients who have non-megaloblastic macrocytic anemia may need to have the health of their livers and bone marrow checked.
Megaloblastic Short-Term Treatment
Patients who have megaloblastic macrocytic anemia require immediate correction of their vitamin deficiency. If the megaloblastic anemia is due to a folate deficiency, this can be achieved by having the patient take folate supplements daily. A vitamin B-12 deficiency can be somewhat harder to correct, however, and may require daily injections of the vitamin. Rarely, megaloblastic macrocytic anemia is the result of a deficiency in vitamin C, the Mayo Clinic says; these cases can be treated with oral vitamin C supplementation.
Patients with a vitamin B-12 deficiency may suffer from an underlying disorder that prevents the body from absorbing B-12, MedLinePlus says. Long-term management of the associated macrocytic anemia thus depends on treating the cause of the vitamin B-12 malabsorption. Vitamin B-12 deficiency can be due to a poor diet or such conditions as Crohn's disease or a tapeworm infection. Patients with a B-12 deficiency should be evaluated for these conditions to see if the anemia can be corrected without the use of lifelong vitamin supplementation.
Non-Megaloblastic Macrocytic Anemia
Non-megaloblastic macrocytic anemia can be more difficult to treat because it is not caused by vitamin deficiency disorders. Because this condition can be caused by liver disease, patients may need to have blood tests that check the health of the liver. Certain bone marrow diseases, including some leukemias, can also cause non-megaloblastic macrocytic anemia. These can be diagnosed using a bone marrow biopsy; treatment of bone marrow disorders can be complicated, depending on the type of disease present.