Blood is made up of many different parts, but those that are most often affected by lupus are the red blood cells, the white blood cells, and the platelets. Blood disorders are common in lupus.

The main issues having to do with lupus and the blood are:

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

Hematologists, who are specialists in blood disorders, are often involved in the evaluation and treatment of individuals with lupus.

How does lupus affect white blood cells?

White blood cells are actually made up of several different types of cells, including neutrophils (also called granulocytes), lymphocytes and monocytes. White blood cells are the body’s main defense against infection. A reduction in the number of white blood cells is called leukopenia; a particular reduction in granulocytes is called neutropenia (or granulocytopenia).

Leukopenia and neutropenia are very common in active lupus, but rarely are white cell counts low enough to lead to infection. Counts may be lowered by azathioprine, cyclophosphamide and some other drugs. Therefore, white cell counts are always monitored during treatment with these agents. If counts go too low, the prescribed drug is usually stopped briefly or the dosage is reduced. When infections occur in lupus, they are more often related to alterations in the body's immune system that are not reflected in routine blood counts.