Leukopenia

White blood cells can protect the body by producing antibodies or engulfing and destroying infectious organisms. Neutrophils and monophils engulf bacteria, viruses and other organisms so that they are destroyed. Lymphocytes produce antibodies that attack infectious or malignant cells so that they are destroyed. Basophils and eosinophils play a role in the body's response to allergens and parasitic organisms.

White blood cells are produced in the bone marrow, so any medical condition that disrupts or halts bone marrow function can cause a low white blood cell count. Drugs can also suppress the function of the bone marrow, which can slow down production of new white blood cells. Autoimmune diseases and severe infections are also known to cause a low white blood cell count.

Low white blood cell counts make it easier for an infection to develop in the body. When the WBC count is reduced, the body's immune system cannot respond efficiently. This increases the risk of serious infections, especially in people with compromised immune systems. People with HIV/AIDS, cancer and other chronic conditions may have an increased risk of overwhelming infection.

Low white blood cell count usually does not cause any symptoms. If the WBC count is low enough, infection can develop, which can cause fever, aches and pains and other signs of infection. Leukopenia can be diagnosed with a simple WBC count test or the more comprehensive complete blood count (CBC). The WBC count determines the total number of white blood cells in a blood sample. The CBC determines the total white blood count, but also determines how many of each type of white blood cell are present.

Treating a low white blood cell count can be done in several ways. If it is possible to treat the underlying cause of the leukopenia, white blood cell levels can be restored and low white blood counts can be prevented. If the low white blood count is due to chemotherapy or immunosuppressive drugs, it may be necessary to stop these drugs until white blood cell counts increase. Growth factors can be used to stimulate the production of new white blood cells. However, someone with a bone marrow tumor may not be able to take growth factors, as they increase the risk that a tumor will grow larger.