Neutropenia is a reduction in the number of neutrophils in the blood. Neutrophilic granulocytes play an important role in the defense against infection, so that neutropenia can lead to serious systemic diseases.


What is neutropenia?

Neutrophil granulocytes, also known as neutrophils for short, are the most common white blood cells (leukocytes). The specialized immune cells are part of the innate immune system. They serve to identify and eliminate pathogenic microorganisms. The neutrophils can absorb and digest the microorganisms. They act as phagocytes. See definitionexplorer for Bisphenol A (abbreviated as BPA) Definitions.

Furthermore, their granule vesicles contain various substances that can destroy bacteria and other pathogens. Furthermore, the neutrophilic granulocytes can form the so-called NETs (neutrophil extracellular traps). These are chromatin structures that bind microorganisms and can thus render them harmless. These functions are only possible to a limited extent in neutropenia due to the lack of neutrophilic granulocytes.

Normally, one microliter of blood contains 1800 to 8000 neutrophils. Moderate neutropenia is present at 500 to 1000 neutrophils per microliter of blood. Severe neutropenia begins when the neutrophil count is less than 500 per microliter of blood.


The cause of neutropenia can lie at different levels. On the one hand, a reduced formation of granulocytes can be responsible for the neutropenia. The most important cause of such an educational disorder is damage to the bone marrow. In the process, the bone marrow can be damaged by chemicals, poisonous plants, or drugs such as diuretics, griseofulvin, chemotherapy drugs, antibiotics, chloramphenicol, or sulfonamides.

Infections can also cause bone marrow damage. Bone marrow damage often occurs after infections with parvoviruses, panleukopenia or the feline leukemia virus. Immune-related or neoplastic bone marrow damage can also cause neutropenia. Examples of neoplasms associated with damage to the bone marrow are leukemia or myelofibrosis.

Increased consumption of granulocytes can also lead to neutropenia. Neutrophilic granulocytes are consumed particularly in acute inflammation. If the demand exceeds the production capacity of the bone marrow, the neutrophils in the blood decrease. A so-called left shift occurs briefly, in which only immature neutrophils and their progenitor cells are released over a certain period of time.

Neutropenia due to increased consumption occurs mainly in very severe diseases such as sepsis, metritis or peritonitis. A so-called dysgranulopoiesis can also cause neutropenia. In dysgranulopoiesis, the formation of neutrophilic granulocytes is disturbed. The cause can lie in the development cycle of the immune cells or in a reduced release.

Dysgranulopoiesis can be caused by acute myeloid leukemia, AIDS, feline leukemia, or myelodysplasia. Acute but only transient neutropenia can be triggered by a shift of neutrophilic granulocytes into the neutrophil pool.

Such a shift is triggered by endotoxins or anaphylaxis as part of a severe allergic reaction. Congenital neutropenia is rare. Examples of such congenital neutropenias are Kostmann syndrome and glycogenosis type 1b.

Symptoms, Ailments & Signs

The lack of neutrophils does not initially cause any symptoms. However, the people affected are significantly more susceptible to infection, since the deficiency means that the immune system only functions to a limited extent. Severe neutropenia can result in life-threatening infections.

In addition, the patients feel tired, exhausted and weak. They suffer from fever, sometimes in combination with chills. Characteristic of neutropenia are painful ulcerations of the oral mucosa or gums. These are often caused by a fungal infection known as candidiasis.

Diagnosis & course of disease

If there is an increased susceptibility to infection, the suspicion of a lack of leukocytes quickly arises. If the doctor suspects neutropenia, they will send a blood sample to a laboratory for testing. The individual blood cells are counted in the differential blood count. In the case of neutropenia, the blood count shows a clear lack of neutrophilic granulocytes. In severe cases, there are only 500 neutrophils per microliter of blood. Numbers between 1800 and 8000 are normal.

If neutropenia is diagnosed, the cause must be found as quickly as possible. The anamnesis and the clinical examination provide clues to the original disease. Other symptoms such as weakness, shortness of breath, bone pain or a feeling of pressure in the abdomen can indicate leukemia.

You may even be able to feel an enlarged spleen. In order to rule out a formation disorder in the bone marrow as the cause, a bone marrow biopsy can be taken from the pelvic bone.


Neutropenia carries a high risk of serious bacterial infections because the immune system is significantly reduced due to the reduced number of neutrophilic granulocytes. However, infection with viruses does not become more likely. It is a clinical picture which, in addition to congenital causes, is often a complication of an underlying disease.

It can also be a result of taking certain medications or certain treatments. These risk factors can even lead to the complete loss of neutrophils with devastating effects. The complete absence of the corresponding granulocytes, also known as agranulocytosis, is characterized by a very severe clinical picture with chills, fever and a greatly increased heart rate. This is caused by a real bacterial invasion of the body with bacteria.

With the absence of neutrophilic granulocytes, the body’s primary defense against these invaders is also absent. In addition to the fever and chills, the mucous membranes in the pharynx (throat), in the tonsils (tonsils) and even in the anal and genital areas die off. The whole thing is accompanied by local swelling of the lymph nodes. Painful aphthae develop in the mouth area in the form of aphthous stomatitis.

Agranulocytosis can in turn lead to life-threatening sepsis. In addition to the use of broad-spectrum antibiotics, strict protection against infection and the discontinuation of triggering medications are required to save the lives of patients.

When should you go to the doctor?

Low blood pressure, fever, and chills are signs of neutropenia. Anyone who notices these symptoms should consult their doctor. Medical advice is particularly important for complaints that appear to be without reason and are associated with physical discomfort. In these cases, neutropenia may be the underlying cause, which if left untreated can lead to other physical problems. If signs of infection are noticed, a visit to the hospital is recommended. People who suffer from the above symptoms in connection with chemotherapy or radiation therapy should inform the responsible doctor.

People with an immune disorder are also among the risk groups and should consult their family doctor as soon as possible. The doctor can diagnose the neutropenia and start treatment. People with a relevant medical history (low blood pressure, cardiovascular disease, etc.) should also seek medical advice. In addition to the family doctor’s practice, the cardiologist or an internist can be consulted. Depending on the cause, physical therapists and alternative physicians may also be involved in treatment. Children are best presented to the pediatrician when the symptoms mentioned occur.

Treatment & Therapy

The therapy depends on the underlying disease. For symptomatic treatment, patients receive granulocyte colony-stimulating factors (G-CSF). G-CSF is a peptide hormone that stimulates the formation of granulocytes. The drug is made from either E. coli or CHO cells.

The four major cancer societies recommend preventive treatment with G-CSF when the risk of neutropenia is 20 percent. Reverse isolation may be required. Reverse isolation isolates people with weak immune systems. Staying in special isolation wards in hospitals is intended to protect patients from infectious diseases.

There are locks in front of the patient rooms in the isolation wards. Staff and visitors may only enter the rooms with protection and after certain disinfection measures. Regardless of the symptomatic therapy, a causal therapy must be carried out. If the neutropenia is caused by a serious infectious disease, the blood values ​​will return to normal after the infection has subsided. Bone marrow diseases, on the other hand, require special treatment.

Outlook & Forecast

The clarification of the cause of the neutropenia is decisive for the further course of the disease and thus for the prognosis. The state of health is often only determined after a longer period of time. The patients usually suffer from an increased susceptibility to infections, so that the actual diagnosis of neutropenia usually takes place very late.

The earlier the cause can be determined, the better the further course. A special therapy is necessary to treat the patient in the best possible way. Drug therapy can significantly alleviate the symptoms. In some cases, a bone marrow transplant is also necessary to achieve an improvement in general health.

Despite all efforts, many patients do not fully recover. The treatment is associated with numerous complications, so that a cure is not always given. The patient needs long-term treatment and regular medical check-ups so that the organism is supported in the best possible way.

Since the disease is associated with a number of impairments, it represents an immense burden for the patient and their relatives. Everyday life must be adapted to the physical conditions. This often leads to the person concerned reporting a reduced sense of well-being in the long term, and subsequent psychological disorders are possible. Stays in isolated wards are often necessary to achieve improvements.


Most neutropenias are unpreventable. If there is an increased risk with chemotherapy, G-CSF can be administered preventively.


In most cases, the measures and options for follow-up care in neutropenia are significantly limited. For this reason, the person affected should consult a doctor immediately at the first signs and symptoms of the disease in order to prevent the further occurrence of other complications and symptoms. Self-healing is also not possible, so medical treatment is unavoidable.

Most patients are dependent on regular check-ups and examinations by a doctor during treatment in order to identify and remove further tumors at an early stage. The person affected by neutropenia should protect themselves particularly well against various infections. Often the care and support of one’s own family is also very important, which can alleviate the development of depression and other psychological upsets.

The patient should rest and rest, avoiding exertion and physical activity in order not to unnecessarily burden the body. In some cases, neutropenia can also reduce the patient’s life expectancy. Further follow-up measures are usually not available to the patient.