Anemia is not a specific condition, but has many causes. In a person with lupus, anemia may be caused by chronic inflammation, prolonged uremia, iron deficiency, or hemolytic anemia.
Inflammation is an important cause of anemia in lupus patients. Prolonged inflammation hinders the production of red blood cells by the bone marrow, the tissue hidden within bones that produces blood cells. Iron, which is essential for the production of hemoglobin, (the red pigment in cells), is not handled normally during inflammation and accumulates unused in the marrow tissue. Therefore, treatment with iron is useless in anemia due to inflammation. Only alleviation of the inflammatory condition restores normal red blood cell production.
Prolonged uremia due to impaired kidney function, may also cause anemia in persons with lupus. Unlike the anemia of chronic inflammation, anemia caused by prolonged uremia can be treated with androgens (male hormones) or erythropoietin, the recently developed hormone that stimulates red cell production. Occasionally, severe forms of anemia induced by chronic uremia require blood transfusions.
Iron deficiency, another common cause of anemia, is due to loss of blood from the body. Women with heavy or frequent menstrual periods may become iron deficient. Drugs used in the treatment of lupus, such as aspirin and Prednisone, can irritate the stomach and cause internal bleeding, thus resulting in iron-deficient anemia. In some cases, the seepage of blood from the stomach causes the stools to turn black. If this occurs, a person should immediately contact his or her physician. In other cases the blood loss is inapparent and detectable only by special examination of the stool (the guaiac test). Any anemic patient should have a test for blood loss from the stomach or intestines, since the source of bleeding requires identification and treatment. In contrast to anemia caused by chronic inflammation, treatment with iron tablets rapidly corrects iron-deficient anemia.
The normal red blood cell lives for about 120 days after it emerges from the bone marrow and enters the blood circulation. Some people with lupus can develop a kind of anemia called hemolytic anemia. This is a condition in which the red blood cells are prematurely destroyed. Instead of the usual life span of 120 days, the red blood cells in hemolytic anemia may live only ten to fifteen days.
There are many causes of hemolytic anemia, but the most common form of the condition in people with lupus is due to antibodies directed against red blood cells. This is called autoimmune hemolytic anemia. In this condition, auto-antibodies interact with the red blood cells causing their removal by scavenger cells (macrophages) in the spleen or the liver. Steroids such as Prednisone are usually effective in treating this type of anemia. Some patients do not respond satisfactorily to this type of treatment and may require surgical removal of the spleen (splenectomy). If the anemia is severe, a blood transfusion may be necessary.
The most common cause of thrombocytopenia in persons with lupus is immune thrombocytopenia. Often referred to as "ITP", this is caused by antibodies against platelets. Indeed, ITP may be the dominant or even sole symptom of lupus in some patients. In rare cases, ITP and autoimmune hemolytic anemia occur together. The antibodies destroy the platelets in a manner similar to the destruction of red blood cells in autoimmune hemolytic anemia. ITP is usually treated with steroids (Prednisone), but a splenectomy may be necessary in some cases.
During pregnancy, anti-platelet antibodies can cross the placenta, enter the baby's blood and cause thrombocytopenia. However, almost all babies with low platelet counts can be successfully delivered, either vaginally or by Caesarian section. Good prenatal care and the assistance of a pediatrician at the time of delivery are important for any pregnant woman with thrombocytopenia.
Venous thrombosis may require treatment with anti-coagulant drugs such as Heparin and Coumadin, particularly in cases associated with pulmonary embolus. Pulmonary embolus is a condition in which fragments of the venous clot enter the circulation and lodge in the lungs. The lupus anti-coagulant can also be detected in cases of recurrent fetal loss. When this occurs, the pregnancy is interrupted by a spontaneous abortion, usually during the first four months. Whether the lupus anti-coagulant in fact causes so-called habitual spontaneous abortion is not yet known. The best treatment for such cases of recurrent fetal loss is still subject to question. Antibodies against other kinds of blood clotting factors may occur in people with lupus, but they are quite rare.