Blood Disorders

Blood disorders are common in lupus and can be very important. Hematologists, who are specialists in blood disorders, are often asked to be involved in the evaluation and treatment of patients with systemic lupus erythematosus (SLE).

The principal hematological (blood) issues of interest are:

• Anemia: low hemoglobin or red blood cells
• Thrombosis: excess blood clotting
• Blood transfusion
• Bone marrow testing

Anemia

The most common blood disorder is anemia, affecting about half of all people with active lupus. Anemia can be measured and discussed in several different ways, including a low red blood cell count, low hemoglobin, or low hematocrit. Each doctor usually has a preference for using a particular term. In the most important sense, anemia means too little hemoglobin. Hemoglobin is the protein inside red cells that carries oxygen from the lungs to all the tissues of the body. Fatigue, a very common lupus symptom, is generally the first and most common symptom of anemia.

Common Causes of Anemia

Normal red blood cells live only 120 days (about four months) and must constantly be produced by the bone marrow. The commonest explanation for anemia is reduced red cell production. This may be due to inflammation; kidney problems (when the kidneys do not produce enough of the hormone, erythropoietin, that stimulates the marrow to make more red cells); iron deficiency (without which hemoglobin cannot be made—iron deficiency may result from menstrual bleeding or from intestinal bleeding due to non-steroidal anti-inflammatory drugs); or direct depression of the bone marrow by certain lupus drugs (such as azathioprine or cyclophosphamide). Intestinal bleeding can be obvious if the stool is red, maroon, or pitch black in color, but often bleeding is so slow and gradual that special stool tests are needed to detect it.