Low white blood cell count, also called leukopenia, is a condition that can be caused by a number of diseases and medical conditions. Because white blood cells (leukocytes) defend the body against infections, it is important to determine the cause of a low white blood cell count and treat the underlying cause so that white blood cell levels return to normal.
Definition
There should be approximately 4,500 to 10,000 leukocytes in 1 microliter of blood. When the number of white blood cells drops below this normal range, it is known as leukopenia. Because normal reference ranges differ from one laboratory to another, it's important to discuss white blood cell count results with a physician to determine if there is any cause for concern.
Causes
There are a number of causes of leukopenia. Medical conditions and drugs that cause damage to the bone marrow can reduce the number of new white blood cells. Myelodysplastic syndrome, leukemia and aplastic anemia are examples of such diseases. Viral, bacterial and parasitic infections such as Epstein-Barr virus, HIV and tuberculosis can lead to a decreased white blood cell count. Chemotherapy kills healthy cells along with malignant cancer cells, so the white blood cell count may decrease during a course of chemotherapy for cancer. Autoimmune diseases, such as lupus, which are also known as collagen-vascular diseases, can mistake healthy white blood cells for foreign bodies and attack them with antibodies. Another cause of a low white blood cell count is when the spleen destroys too many white blood cells.
Risks
When the white blood cell count is below normal, there is an increased risk for developing infection. This is because the white blood cells are responsible for protecting the body against diseases. Special precautions may be taken to prevent infection if you are diagnosed with this condition. They include frequent hand washing, avoiding dental work and avoiding people who are sick with contagious illnesses.
Diagnosis
This condition can be diagnosed with a simple blood test known as the white blood cell count (WBC). The white blood cell count is often included as a part of the more comprehensive complete blood count, which also checks the levels of red blood cells and platelets in the blood. The blood sample for this test is obtained by placing a needle into one of the veins in the arm. The sample is sent to the laboratory for analysis and the laboratory reports the results of the test to the ordering medical professional.
Treatment
There is no treatment specifically for leukopenia. This condition must be resolved by treating the underlying cause. If chemotherapy or radiation therapy are causing the low white blood cell count, treatment may be delayed until the number of white blood cells increases. Medications that cause leukopenia may be stopped and replaced with drugs that do not have this side effect. Treatment for diseases of the bone marrow can help restore the white blood cell count to normal. If none of these treatment options are successful, a blood transfusion may be required.
