White blood cells, also known as leukocytes, are the cells of the immune system which our body produces in order to fight against the foreign objects and infectious diseases. There are five different types of white blood cells, and they are all produced from a hematopoietic stem cell in the bone marrow. Leukocytes are found all the way through the body, in the blood and lymphatic system. The blood measurements and total count of the number of white blood cells is one of the most accurate indicators of the disease. White blood cells normally occupy 1% of whole blood mass, and are usually found in a range between 4×109 and 1.1×1010 in a liter of blood. Elevated levels of white blood cells are called leukocytosis, while the condition characterized by the low white blood cell count is known as leucopenia.
Leucopenia, a decrease in the number of white blood cells, is also known as leukocytopenia. This is a potentially serious condition, which puts patients at an increased risk of various infections. A subtype of leucopenia, characterized by the decrease in the number of circulating neutrophil granulocytes, the most abundant white blood cells, is known under the name neutropenia. Sometimes, doctors will speak about the leucopenia in the terms of neutropenia, since this is the most important sign of an infection risk.
Causes of low white cell count
Low levels of white blood cells are often associated with certain medical procedures such as chemotherapy and radiation therapy. In some cases, low white cell count occurs as a result of leukemia, when malignant cells overwhelm the bone marrow, interrupting the normal course of blood cell production. Low levels of white blood cells are sometimes caused by myelofibrosis and aplastic anemia, failure to produce blood cells and platelets.
Low white cell count can also be caused by various diseases and infections including simple influenza, certain types of cancer, malaria, tuberculosis, and enlargement of the spleen, psittacosis and sepsis.
Certain bad dietary habits can sometimes result in low white cell counts, since they are associated with copper and zinc deficiency. This condition is sometimes caused by certain medications such as clozapine, which affects total absence of all granulocytes, immunosuppressive drugs, medications used in the treatment of multiple sclerosis, antidepressants, medication used to treat smoking addiction, and minocycline antibiotic.
Condition known as pseudoleukopenia is when the leukocytes are marginalized in the blood vessels so that they can scan for the site of infection. If this is the case, the total number of white blood cells will be increased, but it will appear low in a blood sample, since the sample of blood does not include these marginalized leukocytes.