Non Malignant Disorders Of WBC


Leukopenia is the reduction in the number of white blood cells, which may affect the overall white cell count or one of the specific populations of white blood cells.

For example, if the number of neutrophils is low, the condition is known as neutropenia. Likewise, low lymphocyte levels are termed lymphopenia.

As the principal function of white cells is to combat infection, a decrease in the number of these cells can place patients at increased risk for infection.

In pancytopenia, the other cell types in the blood (red blood cells and platelets) are similarly affected.

Low white cell counts are associated with chemotherapy, radiation therapy, leukemia (as malignant cells overwhelm the bone marrow), myelofibrosis and aplastic anemia (destruction of the bone marrow by the immune system). In addition, many common medications can cause leukopenia.


Neutropenia is a condition of an abnormally low number of a type of a particular type of white blood cell called a neutrophil. White blood cells (leukocytes) are the cells in the blood that play important roles in the body's immune by fighting off infection.

The normal WBC are of different types and include neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The average blood concentration for each type are: neutrophils 65%, lymphocytes 25%, eosinophils 4%, basophils <1%. "Neutropenia" is present when the neutrophil count is less than 2000.

Neutropenia may be associates with viral infections, pernicious anemia, aplastic anemia, neoplasms, chronic intoxication with drugs or heavy metals, malnutrition, and nonpyogenic and overwhelming infections. Pooling of white blood cells occurs with some overwhelming infections, during heart surgery, and hemodialysis.


If neutrophil levels become too high, neutrophilia results. Neutrophilia is the most common form of leukocytosis. Absolute neutrophilia refers to the increase in the total number of leukocytes in the blood as well as an increased percentage of neutrophils. This results in a neutrophil count of over 8,000.

Causes And Development

May be associated with acute infections, chronic granulocytic leukemia, erythemia, therapy with adrenocorticotrophic hormone (ACTH) or cortisone, uremia, ketosis, hemolysis, drug or heavy metal intoxication, or malignancy, or it may follow severe hemorrhage.


Eosinophils are produced in the bone marrow and are normally found in the bloodstream and the gut lining,. They contain proteins that help the body to fight infection from parasitic organisms, such as worms. But in certain diseases these proteins can damage the body.

An absolute or relative increase in the normal number of eosinophils in the circulating blood. Various limits are given; absolute eosinophilia if the total number exceeds 500/mm3, and relative if greater than 3 % but total less than 500/mm3.


Eosinophilia occurs in a wide range of conditions. Its commonest cause are allergic disease such as asthma and hay fever, whereas worldwide the main cause is parasitic infection. It can also occur in relation to common skin diseases, medicine reactions, and parasitic infections.


Increased numbers if eosinophilis are produced to fight off allergic disease or parasitic infections. This is helpful in combating parasitic infections but not in cases of allergic diseases as they accumulate in tissues and cause damage. For example, in asthma, eosinophilia causes damage to the airways of the lung.

Idiopathic Hypereosinophilic Syndrome

Idiopathic hypereosinophilic syndrome (HES) refers to a group of leukoproliferative disorders characterized by an overproduction of eosinophils that results in organ damage.

Eosinophils contain granules that store toxic proteins, which are the primary mediators of tissue damage.


Under usual circumstances, eaosinophils arrive at an area of inflammation and quickly undergo apoptosis after degranulation, though normal eosinophils live longer than neutrophils and can recirculate from the tissues. In HES, the cells may survive in the tissues for longer periods of time, thus increasing the amount of damage they can inflict.


Basophilia is an uncommon cause of leukocytosis. Basophils are inflammatory mediators of substances such as histamine. These cells, along with similar tissue-based cells (mast cells), have receptors for IgE and participate in the degranulation of white cells that occurs during allergic reactions, including anaphylaxis.

Common causes of basophilia:
- some hemolytic anemias
- iron deficiency
- after spleenectomy
- hypersensitivity / chronic sinusitis
- lung cancer
- juvenile rheumatoid arthritis


An increases in the number of monocytes in the bloodstream. Various limits are given; a total number in excess of 800/mm3. Monocytosis may be associated with chronic pyogenic infections, subacute bacterial endocarditits, infectious hepatitis, and protozoan infections.

Langerhans Cell Histiocytosis

It is an uncommon proliferative disorders of Langerhans cells. The disease may be asymptomatic involving single site such as bone or lymph nodes to an aggressive systemic disorder that involve multiple organs.

Langerhans cells are the component of the mononuclear phagocyte system. They are found in the epidermis, spleen, lymph nodes and mucosal tissues. They ingest, process and present antigens to T lymphocytes. The etiology and pathogenesis of LCH are unknown. It may be an immunological or autoimmune disorder.

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