Lupus and Anemia
Douglas B. Cines, MD
Anemia is the condition in which an individual has less than the normal number of red cells in the blood. Anemia occurs frequently in patients with lupus and some of these patients may require special attention. How do you know if you are anemic? Patients with anemia may have no symptoms or may feel fatigued because not enough red blood cells are available to carry oxygen to muscles and other tissues. However, similar feelings of fatigue may be caused by lupus itself. Occasionally, patients who are anemic may feel dizzy, experience a rapid heart beat or chest discomfort. These symptoms are more likely to develop following exercise when the body's demand for oxygen is increased.
If you experience increasing fatigue or related symptoms, your physician may check to see if you are anemic. Your doctor may use the term "hematocrit" to describe the number of red cells in your blood. The hematocrit refers to the proportion of whole blood occupied by the red cells themselves. Usually about 40% of the blood is composed of red cells, but in patients with anemia, this proportion may be reduced to 20-30%.If you are found to be anemic, your physician may order other tests to find out the cause. There are four common causes of anemia that patients with lupus experience.
Anemia of Chronic Illness. Normally, as red blood cells age, approximately 1% of them are removed from the blood each day. The bone marrow, where all blood cells are made, replaces these cells with new ones. When lupus is active, many patients develop anemia because the bone marrow produces fewer red blood cells than are needed. The exact reason why fewer cells are produced is unknown, but in some way this is related to the tissue inflammation caused by lupus. In most patients, this form of anemia is mild and produces no symptoms. This form of anemia does not respond to changes in diet, vitamins, etc., but improves when the lupus has been controlled.
Iron Deficiency Anemia. Sometimes anemia is caused by iron deficiency. Iron deficiency is also a common cause of anemia in healthy women who do not have lupus. It usually results from loss of iron over many years due to normal menstrual bleeding. Medications used to treat lupus, such as aspirin, may cause irritation of the stomach lining leading to bleeding and iron deficiency. If you are anemic, you should get a blood test to determine if you are iron deficient before taking iron pills, because iron has no beneficial effect if the anemia is caused bv another problem.
Anemia of Kidney Disease. Some patients with lupus develop kidney damage. The kidney makes a hormone called erythropoietin that is needed by the bone marrow to produce red blood cells.
If the kidney is damaged and does not produce this hormone, the bone marrow will produce fewer red blood cells. Your doctor will be able to tell by urine and blood tests if kidney damage is responsible for the anemia. If kidney function improves with treatment, the production of erythropoietin increases and the anemia improves.
Autoimmune Hemolytic Anemia. Anemia may also result from the production of an antibody that binds to an individual's own red blood cells. 'I'his form of anemia, called autoimmune hemolytic anemia (AHA), occurs in approximately 5% of patients with lupus. An antibody is a type of protein made by the body, usually in response to infection. Patients with lupus commonly produce antibodies that bind to their own cells. In some cases, these antibodies bind to the red cells. These red cells coated with antibodies are quickly removed from the blood and destroyed by white blood cells, called macrophages, that normally destroy antibody coated viruses or bacteria as part of the body's defenses against infection. If the production of new red cells cannot keep up with this destruction, the patient becomes anemic.
Your physician can tell if you have autoimmune hemolytic anemia by looking at your blood under the microscope. If you do, the physician will see both red cells whose shape has been altered by these macrophages and a large number of newly produced, young red blood cells. The diagnosis of AHA is confirmed using the direct antiglobulin test, or Coombs' test, which measures both the presence and type of antibody bound to the red cell. The treatment of AHA depends upon its severity. If the anemia is mild, there may be no need for treatment. In one variety of uncommon AHA, called "cold-agglutinin disease", simple measures such as preventing exposure to cold may be sufficient. Periodic transfusions of warmed blood are often useful for patients with cold-agglutinin disease who have mild symptoms.
Patients with the more common, "warm-antibody" type AHA often require additional measures to correct the anemia. In most cases, the doctor will recommend the drug, prednisone, which both decreases the rate of red cell destruction and the amount of antibody produced. Sometimes prednisone must be taken for several weeks before its effect becomes apparent. Patients who do not respond to prednisone, or who require high doses of prednisone to control the anemia, may be advised to have an operation to remove their spleen. The reason why this procedure is so often recommended is that in many patients, most of the red cells to which antibodies have become attached are trapped and destroyed by macrophages within the spleen. In some patients the hormone, Danazol, or other drugs such as cyclophosphamide (Cytoxan) may also be recommended.
Transfusions are used only as a temporary measure since the transfused red cells will also quickly become coated with antibodies and will be destroyed. AHA can be managed Successfully in practically all patients with systemic lupus, but the specific recommendations for treatment vary among different patients for several reasons. First, the doctor must be sure of the diagnosis. Other causes of anemia may also be present and may contribute to the anemia. Second, the doctor must determine if the anemia is actually contributing to the patient's symptoms, since one of the major reasons to treat a patient is to improve how she/he feels. Third, the amount of medicine needed to treat AHA may vary from time to time. Patients vary widely in their ability to tolerate anemia and their ability to tolerate each form of treatment. Therefore, treatments must be custom tailored to fit each individual.
=========================================================== This information is for "informational purposes" and is not meant to be used for medical diagnosis. Always consult your physician on matters such as this.