| 释义 |
neutropenia
neu·tro·pe·ni·a N0074350 (no͞o′trə-pē′nē-ə, nyo͞o′-)n. An abnormally low level of neutrophils in the circulating blood.
[neutro(phil) + -penia.]
neu′tro·pen′ic (-pĕn′ĭk) adj.neutropenia (ˌnjuːtrəˈpiːnɪə) n (Pathology) an abnormal reduction in the number of neutrophils in the blood, as seen in certain anaemias and leukaemiasneu•tro•pe•ni•a (ˌnu trəˈpi ni ə, ˌnyu-)
n. an abnormal decline of neutrophils in the blood. [1930–35] Thesaurus| Noun | 1. | neutropenia - leukopenia in which the decrease is primarily in number of neutrophils (the chief phagocytic leukocyte)leucopenia, leukopenia - an abnormal lowering of the white blood cell countcyclic neutropenia - neutropenia that occurs periodically |
Translationsneutropenia
Neutropenia DefinitionNeutropenia 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.DescriptionThe 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:- greater than 1000. Normal protection against infection
- 500-1000. Some increased risk of infection
- 200-500. Great risk of severe infection
- lower than 200. Risk of overwhelming infection; requires hospital treatment with antibiotics
Causes and symptomsCausesNeutropenia 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:- medications that affect the bone marrow, including cancer drugs, chloramphenicol (Chloromycetin), anticonvulsant medications, and antipsychotic drugs (Thorazine, Prolixin, and other phenothiazines)
- hereditary and congenital disorders that affect the bone marrow, including familial neutropenia, cyclic neutropenia, and infantile agranulocytosis
- cancer, including certain types of leukemia
- radiation therapy
- exposure to pesticides
- vitamin B12 and folate (folic acid) deficiency
DESTRUCTION OF WBCS. WBCs are used up at a faster rate by:- acute bacterial infections in adults
- infections in newborns
- certain autoimmune disorders, including systemic lupus erythematosus (SLE)
- penicillin, phenytoin (Dilantin), and sulfonamide medications (Benemid, Bactrim, Gantanol)
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:- hemodialysis
- felty's syndrome or malaria, the neutrophils accumulate in the spleen
- bacterial infections, the neutrophils remain in the infected tissues without returning to the bloodstream
SymptomsNeutropenia 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.DiagnosisDiagnosis 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.TreatmentTreatment of neutropenia depends on the underlying cause.MedicationsPatients 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.SurgeryPatients with Felty's syndrome who have repeated infections may have their spleens removed.PrognosisThe 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.ResourcesBooksLinker, Charles A. "Blood." In Current Medical Diagnosisand Treatment, 1998, edited by Stephen McPhee, et al., 37th ed. Stamford: Appleton &Lange, 1997.Key termsCyclical 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.neutropenia [noo″tro-pe´ne-ah] diminished numbers of neutrophils" >neutrophils in the blood.congenital neutropenia agranulocytosis." >infantile genetic agranulocytosis.cyclic neutropenia a chronic form marked by regular, periodic episodic recurrences, associated with malaise, fever, stomatitis, and various infections. Called also periodic neutropenia.drug-induced neutropenia that caused by medications; the most common mechanisms are immunological (formation of antibodies destructive to neutrophils or of immune complexes that bind to neutrophils), followed by inhibition of granulopoiesis and direct damage to bone marrow or precursor cells of the granulocytic series.idiopathic neutropenia agranulocytosis.Kostmann's neutropenia agranulocytosis." >infantile genetic agranulocytosis.malignant neutropenia agranulocytosis.neonatal neutropenia, alloimmune neutropenia in the newborn due to in utero incompatibility between its immunoglobulin G antigens and those of the mother's blood; the mother's blood produces antibodies that cross the placenta and sensitize fetal neutrophils. Affected infants may have fever, pneumonia, septicemia, and other infections that can be fatal. The condition eventually resolves as the infant's immunoglobulin replaces that from the mother.periodic neutropenia cyclic neutropenia.neu·tro·pe·ni·a (nū'trō-pē'nē-ă), The presence of abnormally small numbers of neutrophils in the circulating blood. Synonym(s): neutrophilic leukopenia, neutrophilopenia [neutrophil + G. penia, poverty] neutropenia (no͞o′trə-pē′nē-ə, nyo͞o′-)n. An abnormally low level of neutrophils in the circulating blood.
neu′tro·pen′ic (-pĕn′ĭk) adj.neutropenia Hematology An absolute ↓ in neutrophils–normal, 2,500-7,000/mm3; serious infections occur if < 500/mm3 See Congenital neutropenia, Cyclic neutropenia. Cf Neutrophilia. neu·tro·pe·ni·a (nū'trō-pē'nē-ă) Condition that occurs when neutrophil counts fall below the normal percentage in circulating blood. [neutrophil + G. penia, poverty]neutropenia A reduction in the numbers of NEUTROPHIL POLYMORPHS (polymorphonuclear leucocytes) in the blood. This may prejudice the body's ability to resist infection.neu·tro·pe·ni·a (nū'trō-pē'nē-ă) The presence of abnormally small numbers of neutrophils in the circulating blood. [neutrophil + G. penia, poverty]neutropenia
Words related to neutropenianoun leukopenia in which the decrease is primarily in number of neutrophils (the chief phagocytic leukocyte)Related Words- leucopenia
- leukopenia
- cyclic neutropenia
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