Determining the number of white blood cells present in a blood sample can give medical professionals important clues about what is causing a patient's symptoms. Leukopenia, or low white blood cell count, can indicate a number of medical conditions or reactions to prescription drugs. Once leukopenia has been identified, further testing can be done to determine its cause and provide proper treatment.
Prescription Drugs
Prescription drugs can cause a decrease in the white blood cell count. For example, a drug called clozapine is associated with low white blood cell counts. Sirolimus is another drug that can cause leukopenia. Antibiotics and diuretics can also be responsible for reduced white blood cell counts.
Bone Marrow Failure
Bone marrow failure can be the cause of low white blood cell counts. Aplastic anemia is one of the most common types of bone marrow failure and can be caused by radiation therapy, toxins, infections and drugs such as antibiotics and chemotherapy medications. This condition can also occur without a specific cause.
Liver or Spleen Disorders
Liver and spleen diseases are possible causes of leukopenia. One spleen condition that can result in reduced white blood cell counts is hypersplenism. This is defined as an overactive spleen, which results in the premature destruction of blood cells. Splenomegaly, or an enlarged spleen, can also be responsible for the development of leukopenia.
Autoimmune Diseases
Several autoimmune disorders can lead to low white blood cell counts. In autoimmune diseases, the immune system produces antibodies that attack healthy cells. When the white blood cells are attacked and destroyed, the total white blood cell count can be reduced. Lupus and rheumatoid arthritis are known causes of reduced white blood cell counts. Other autoimmune diseases can also cause this condition.
Infectious Diseases
Several infectious diseases can lead to leukopenia. HIV/AIDS and histoplasmosis are known causes of this condition. In HIV and AIDS, the immune system becomes weakened, and the inability to successfully fight infection is reduced. Histoplasmosis as a disease caused by a fungus. This fungus, known as Histoplasma capsulatum, affects the lungs and other organs.
Hemodialysis
Leukopenia occurs within the first hour of hemodialysis when cellophane membrane equipment is used. Hemodialysis as a procedure used to filter the blood when the kidneys are no longer working.
Laboratory Error
Laboratory errors can be responsible for artificially low white blood cell counts. Laboratory errors can include sample contamination, use of inappropriate containers, missing tubes, nonrefrigerated samples, patient identification errors and errors caused by problems with laboratory equipment. If a laboratory error is suspected, the white blood cell count can be repeated to confirm low results or obtain a more accurate result.
References
- Journal of Clinical Investigation; P.R. Craddock, J. Fehr, A.P. Dalmasso, K.L. Brighan and H.S. Jacob
- University of Maryland Medical Center--Clozapine
- Pharmacy Benefits Management Service--Transplant Therapy
