Neutropenia: An overview

• Introduction
• Causes
• Symptoms and Diagnosis
• Treatment
• Neutropenia in Cancer

Introduction

Neutropenia refers to a low level of white blood cells. Cancer patients are at higher risk of developing neutropenia because commonly used treatments for cancer such as radiation therapy and chemotherapy destroy cells that grow at a fast rate – such as white blood cells. Since white blood cells play an important role in preventing infection, any time your white blood cell count drops, you are at higher risk of getting an infection. Throughout the course of cancer treatment it is normal practice for doctors to monitor the levels of red and white blood cells and to take action if these become too low.

Causes

There are 2 main ways neutropenia can develop: if existing neutrophils are destroyed faster than they can be replaced, or if the production of neutrophils in the bone marrow is reduced.
1) Neutrophils are used up or destroyed: infections, allergic disorders, certain drugs, autoimmune diseases where people make antibodies that destroy neutrophils and result in neutropenia, and people with an enlarged spleen (which traps and destroys neutrophils).
2) Production of neutrophils in the bone marrow is suppressed: people with cancer, a rare condition called aplastic anaemia, viral infections such as influenza, bacterial infections such as tuberculosis, myelofibrosis, or deficiencies of vitamin B12 or folic acid. People who have received radiation therapy that involves the bone marrow may also develop neutropenia. Many drugs, including phenytoin, chloramphenicol, and drugs used in chemotherapy can also affect neutrophil production, as can certain rare hereditary diseases.

Symptoms and Diagnosis

Neutropenia can develop suddenly over a few hours or days (acute neutropenia), or it can develop gradually and last for months or years (chronic neutropenia). Because neutropenia itself has no specific symptoms, it is usually diagnosed when an infection occurs. In acute neutropenia, a person can develop fever and painful sores (ulcers) around the mouth and anus. Bacterial pneumonia and other severe infections can follow. In chronic neutropenia, the course may be less severe if the number of neutrophils is not extremely low, and the course can occasionally be intermittent (cyclic neutropenia). When a person has frequent or unusual infections, a doctor suspects neutropenia and orders a complete blood cell count to make the diagnosis. A low neutrophil count indicates neutropenia. In many cases, the neutropenia is expected and the cause is known, as in those receiving chemotherapy or radiation therapy. When the cause is not known, it must be determined.

Treatment

The treatment of neutropenia depends on its cause and severity. Drugs that may cause neutropenia are discontinued whenever possible, and exposures to suspected toxins are avoided. Sometimes the bone marrow recovers by itself without treatment. The neutropenia accompanying viral infections (such as influenza) may be transient and resolve after the infection has cleared. People who have mild neutropenia generally have no symptoms and may not need treatment. People who have severe neutropenia can succumb to infection because their bodies are not as able to fight invading organisms. When these people develop infections, they are generally hospitalized and immediately given strong antibiotics, even before the cause and exact location of the infection are identified. Fever, the symptom that usually indicates infection in a person who has neutropenia, is an important sign that immediate medical attention may be needed. Substances called ‘colony-stimulating factors’, which stimulate the production of white blood cells, are sometimes helpful. Steroid medications may help if the neutropenia is caused by an autoimmune reaction. In some cases, removing an enlarged spleen may cure the neutropenia. When neutropenia is caused by another disease (such as tuberculosis or leukemia or other cancers), treatment of the underlying disease may resolve the neutropenia. Bone marrow (or stem cell) transplantation is not used to treat neutropenia itself, but it may be recommended to treat certain serious causes of neutropenia, such as aplastic anaemia or leukaemia.

Neutropenia in Cancer

Since white blood cells are destroyed as a side effect of chemotherapy, there is nothing specifically that you can do to prevent neutropenia from occurring.
Nonetheless, there are several things that you can do to reduce your risk of getting an infection when your white blood cells are low:

• Take action at the first signs of infection and seek medical advice to help prevent it from spreading and getting worse. Signs and symptoms of infection include: fever, chills or sweats, shortness of breath, soreness or swelling in your mouth, ulcers or white patches in your mouth, pain or burning with urination, redness, pain or swelling of any area of your skin, pus or drainage from any open cut or sore, a general feeling of being unwell, even if you don’t have a temperature or any other sign of an infection.
• Perform excellent daily personal hygiene: with attention to hand-washing, sanitary hygiene eg. using pads rather than tampons.
• Minimise chances of getting an infection: avoid contact with people who are unwell, has been recently given a live vaccine (such as the oral polio vaccine), try to avoid crowds eg. take public transport at off-peak times, wear shoes to prevent cuts on feet, wear sunscreen, before receiving any vaccine, make sure it is approved by your oncologist.
• Neutropenic precautions: regular monitoring of temperature (contact doctor if fever), avoid uncooked foods (such as salads of raw vegetables or fruits, raw meats or fish salads, natural cheeses, uncooked eggs), speak to doctor before undergoing any dental work.

Diseases presenting with neutropenia include:

• Anaemia of Chronic Disease
• Tuberculosis (TB)

References