Neutropenia

Neutropenia ( syn. neutropenia, granulocytopenia ) describes the reduction of neutrophils in the blood. It is the most common form of leukopenia, ie the decrease in the number of white blood cells (leukocytes).

The number of neutrophils in the blood of a healthy person is variable and ranges between 1,800 and 8,000 cells per microliter. With a decrease of neutrophils to 1000 per microliter is called a mild form of neutropenia, in 500 to 1,000 neutrophils per microliter of a moderate form and a neutrophil count of less than 500 per microliter of a severe form of neutropenia.

A febrile neutropenia is also more than an hour before sustained fever over 38 ° C or recurring fever above 38.5 ° C.

Neutrophils are important in the defense against infections and part of the innate defense system of the body. Therefore, it occurs in patients with neutropenia easy to infections. The most severe form of neutropenia is agranulocytosis.

• 2.1 General measures
• 2.2 use of growth factors

Pathogenesis and associated diseases

Decreased formation of granulocytes

A bone marrow damage is the most important cause of Education disorders. Possible triggers are drugs ( side effect of diuretics, sulfonamides, griseofulvin, chloramphenicol, and other antibiotics, as well as chemotherapeutic agents ) as well as toxic chemicals and plants.

Even infectious ( parvovirus, panleukopenia, feline leukemia virus which, Ehrlichia ) or neoplastic (eg leukemia, myelofibrosis ) or immune-mediated bone marrow damage may be the cause.

Due to the decrease in the number of neutrophils, a transient suppression of the immune system is caused. Extent and duration of neutropenia and thus the risk of infection will depend on the type of injury.

Increased consumption of granulocytes

Neutrophils are used in acute inflammation in a large scale. If demand exceeds capacity while the formation in the bone marrow, there is a decrease in the number of cells in the blood. It can simultaneously a left shift occur because only immature neutrophils and metamyelocytes ( precursor cells of neutrophils ) are released.

Therefore, neutropenia occurs mainly in the acute phase of very serious systemic diseases such as sepsis, peritonitis ( inflammation), metritis or mastitis gangränoser.

Dysgranulopoese

Impaired formation of neutrophils ( Dysgranulopoese ) can also cause neutropenia. It can be due to a locked development cycle or by reduced bone marrow release despite adequate education. Possible causes of the disease are the myelodysplasia, acute myeloid leukemia, and viral infections (AIDS, immune deficiency syndrome of cats, feline leukemia ).

Congenital neutropenia

A congenital neutropenia occurs when food man syndrome.

Increased margination

A shift of neutrophils from the circulating component in the so-called marginal Neutrophilenpool (bound to the endothelial cells of small blood vessels neutrophils) can cause an acute but transient neutropenia. Possible triggers include anaphylaxis or endotoxins. Most of these neutropenia but already re-formed before the physician or veterinarian is sought.

Therapy

The treatment depends on the underlying disease. Symptomatic granulocyte -colony stimulating factor G -CSF may be used. G- CSF growth factors for granulocytes. Under certain circumstances, a reverse isolation is required.

General measures

The development of neutropenia requires a series of preventive measures and treated. It should include general hygienic precautions are taken. Patients with prolonged neutropenia should only be countered with a mask and disinfected hands. Optionally, the isolated accommodation in a single room is required.

Use of growth factors

G-CSF has a specific growth factor which stimulates the maturation of neutrophils. As the drug G-CSF is recombinantly either from E. coli ( filgrastim ), or mammalian cells ( CHO cells, lenograstim ) was prepared. The amino acid sequence of filgrastim and lenograstim is identical. In addition, there exists G -CSF in PEGylated form ( pegfilgrastim ).

G -CSF is used in supportive cancer therapy to prevent neutropenic infections and to support the antibiotic therapy in case of severe infection. The four leading professional societies DGHO, NCCN, ASCO and EORTC recommend a precautionary, primary prophylactic G- CSF treatment, when the risk of febrile neutropenia is 20 percent. G -CSF is given in addition to chemotherapy administered protocol and timely can. A sketched in the guidelines algorithm suggests a GCSF administration in certain cases ( comorbidities, poor general condition, female gender ) also at a risk 10 to 20 percent. Secondary prophylactic use of G-CSF in subsequent cycles after onset of fever in the neutropenic phase of prior chemotherapy cycle recommended if the maintenance of dose intensity as well as the timely delivery of chemotherapy for treatment success is crucial.

The more intense the administered chemotherapy, the longer the period of neutropenia. By the use of growth factors such as G -CSF, the time of neutropenia is reduced by several days. The compliance of the distances between the chemotherapy cycles can be positively influenced by the preventive use of G -CSF.