Leukopenia means the “white reduction” and it is a term used to refer to the low white blood cells count.

Since Neutrophils make up the highest count of White Blood Cells, a significant decrease in the normal Neutrophil count (Neutrophilia) would cause a decrease in the normal White Blood Cell Count. The first thoughts that come in mind about a significant decrease in the white blood cells would be associated with a decrease in the Neutrophil (Neutrophilia) and that may cause terms Neutrophilia and Leukopenia to be used interchangeably to give the same meaning, which is absolutely inaccurate.

It may be also thought that the causes of Leukopenia are the same causes Neutrophilia since the Neutrophil makes the largest count of the white cells. But Leukopenia can also occur as a result reduction of Lymphocyte count (Lymphopenia), especially during the early childhood year when the normal white blood cell count of the Lymphocytes exceeds the normal Neutrophil count at that early age.

Generally speaking, Leukopenia can be a result of immune system disorders or failures related to the body members and tissues where white blood cells are produced, such like Bone Marrow deficiencies (decrease the count of Neutrophil,Eosinophil, Basophil, and Monocyte) and Spleen diseases (decrease the count of Lymphocytes).

Leukopenia is also a sign of aplastic anemia (a damage in the bone marrow and stem cells that affects the production of all blood cells types). Leukopenia is also caused by HIV and AIDS which are immune system diseases.

When a white cell defends the body against the invading microorganism or foreign particle, it surrounds and envelopes the foreign body by its protoplasm. Once the foreign body is contained inside the white cell, the enzymes in the white cell’s granules are released to breakdown the invading body and the white cell itself. If the body is being attacked by an overwhelming infection, it is expected that the large number of these invading microorganisms would cause a breaking down to a large number of white cells due to the way white cells kill the invading body. If the number of white cells that are breaking down is higher than what the body can produce, a low blood cells count will be caused.

There are 5 types of Leukopenia, each type is related to a different type of the white blood cells. The following listing shows the different types of Leukopenia and the threshold values at which each type may occur:

•             Low Neutrophil count also known as Neutrophilic Leukopenia or Neutropenia. It occurs when the count of Neutrophils is less than 2,500 cells/µL.

•             Low Eosinophils count also known as Eosinophilic Leukopenia or Eosinopenia. It occurs when the count of Eosinophils is less than 50 cells/µL

•             Low Basophils count also known as Basophilic Leukopenia or Basopenia. It occurs when the count of Basophils is lower than 20 cells/µL

•             Low Monocyte count also known as Monocytopenia.

•             Low Lymphocytes count also known as Lymphocytopenia. It occurs when the count of Lymphocytes is lower than 1,400 cells/µL in children and less than 1000 cells/µL in adults.