Neutropenia (redirected from malignant neutropenia)

Neutropenia 

Definition

Neutropenia is an abnormally low level of neutrophils in the blood. Neutrophils are white blood cells (WBCs) produced in the bone marrow that ingest bacteria. Neutropenia is sometimes called agranulocytosis or granulocytopenia because neutrophils make up about 60% of WBCs and have granules inside their cell walls. Neutropenia is a serious disorder because it makes the body vulnerable to bacterial and fungal infections.

Description

The normal level of neutrophils in human blood varies slightly by age and race. Infants have lower counts than older children and adults, and African Americans have lower counts than Caucasians or Asians. The average adult level is 1500 cells/mm3 of blood. Neutrophil counts (in cells/mm3) are interpreted as follows:

Causes and symptoms

Causes

Neutropenia may result from three processes:

DECREASED WBC PRODUCTION. Lowered production of white blood cells is the most common cause of neutropenia. It can result from:

DESTRUCTION OF WBCS. WBCs are used up at a faster rate by:

SEQUESTRATION AND MARGINATION OF WBCS. Sequestration and margination are processes in which neutrophils are removed from the general blood circulation and redistributed within the body. These processes can occur because of:

Symptoms

Neutropenia has no specific symptoms except the severity of the patient's current infection. In severe neutropenia, the patient is likely to develop periodontal disease, oral and rectal ulcers, fever, and bacterial pneumonia. Fever recurring every 19-30 days suggests cyclical neutropenia.

Diagnosis

Diagnosis is made on the basis of a white blood cell count and differential. The cause of neutropenia is often difficult to establish and depends on a combination of the patient's history, genetic evaluation, bone marrow biopsy, and repeated measurements of the WBC.

Treatment

Treatment of neutropenia depends on the underlying cause.

Medications

Patients with fever and other signs of infection are treated for seven to 10 days with antibiotics. Nutritional deficiencies are corrected by green vegetables to supply folic acid, and by vitamin B supplements.

Medications known to cause neutropenia are stopped. Neutropenia related to pesticide exposure is treated by removing the patient from the contaminated environment.

Patients receiving chemotherapy for cancer may be given a blood growth factor called sargramostim (Leukine, Prokine) to stimulate WBC production.

Surgery

Patients with Felty's syndrome who have repeated infections may have their spleens removed.

Prognosis

The prognosis for mild or chronic neutropenia is excellent. Recovery from acute neutropenia depends on the severity of the patient's infection and the promptness of treatment.

Resources

Books

Linker, Charles A. "Blood." In Current Medical Diagnosisand Treatment, 1998, edited by Stephen McPhee, et al., 37th ed. Stamford: Appleton &Lange, 1997.

Key terms

Cyclical neutropenia — A rare genetic blood disorder in which the patient's neutrophil level drops below 500/mm3 for six to eight days every three weeks.

Differential — A blood cell count in which the percentages of cell types are calculated as well as the total number of cells.

Felty's syndrome — An autoimmune disorder in which neutropenia is associated with rheumatoid arthritis and an enlarged spleen.

Granulocyte — Any of several types of white blood cells that have granules in their cell substance. Neutrophils are the most common type of granulocyte.

Neutrophil — A granular white blood cell that ingests bacteria, dead tissue cells, and foreign matter.

Sargramostim — A medication made from yeast that stimulates WBC production. It is sold under the trade names Leukine and Prokine.

Sequestration and margination — The removal of neutrophils from circulating blood by cell changes that trap them in the lungs and spleen.

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neutropenia /neu·tro·pe·nia/ (noo?tro-pe´ne-ah) diminished number of neutrophils in the blood.

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neu·tro·pe·ni·a (ntr-pn-)

n.

The presence of abnormally small numbers of neutrophils in the blood. Also called neutrophilic leukopenia.

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neutropenia (nuˈ·trō·pēˑ·nē·),

n an atypical decrease in the number of neutrophils circulating within the blood. The condition is associated with infection, rheumatoid arthritis, acute leukemia, chronic splenomegaly, or a deficiency in vitamin B₁₂.

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neutropenia (noo´trōpē´nē),

n a relative or absolute decrease in the normal number of neutrophils in the circulating blood. Various limits are given; e.g., absolute neutropenia may exist when the total is less than 1700 cells/mm³ regardless of the percentage, whereas relative neutropenia may exist when the total percentage of neutrophils is less than 38% and the total number is not less than 1500/mm³. It may be associated with viral infections, pernicious anemia, sprue, aplastic anemia, bone marrow, neoplasms, chronic intoxication with drugs or heavy metals, malnutrition, and nonpyogenic and overwhelming infections. See also neutrophil.

neutropenia, cyclic,

n a condition in which there is a depression in the number of circulating white cells, especially the neutrophils, at intervals of about 21 days. It lasts for approximately 10 days; during this time, gingival inflammation and aphthous ulcer occur.

Cyclic neutropenia.

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neutropenia

a diminished number of neutrophils in the blood.

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cyclic neutropenia

periodic neutropenia. See also canine cyclic hematopoiesis.

malignant neutropenia

agranulocytosis.

periodic neutropenia

see canine cyclic hematopoiesis.