From the Guidelines
Neutropenia is defined as an absolute neutrophil count (ANC) of less than 500 cells/µL, or a neutrophil count that is expected to decrease to less than 500 cells/µL within 48 hours. This definition is based on the most recent and highest quality study available, which emphasizes the importance of early identification and management of neutropenia to prevent life-threatening infections 1. The severity of neutropenia can be classified as mild, moderate, or severe, with infection risk increasing as neutrophil counts decrease.
Causes and Risks
Neutropenia can result from various causes, including certain medications (particularly chemotherapy drugs), viral infections, autoimmune disorders, congenital disorders, or bone marrow problems that affect blood cell production. Patients with neutropenia are at increased risk of developing bacterial and fungal infections, which can become life-threatening, especially when neutrophil counts fall below 500 cells/µL 1.
Management
Management of neutropenia depends on the underlying cause and severity, ranging from monitoring to antimicrobial prophylaxis or granulocyte colony-stimulating factors (G-CSF) to stimulate neutrophil production in severe cases. The use of G-CSF has been recommended to reduce the risk of bacterial infections in patients with depressed absolute neutrophil count due to HIV disease or drug therapy 1.
Key Considerations
It is essential to note that symptoms of neutropenia itself are not apparent, but the infections that result from it may cause fever, chills, sweating, mouth sores, pneumonia, or other signs of infection. Early involvement of an infectious diseases specialist, a surgeon, and a dermatologist familiar with these patients may result in improved outcomes, especially in cases of skin and soft tissue lesions 1. Blood cultures and radiographic imaging should be performed as clinically indicated to define the extent of infections and guide management.
Patient Risk Assessment
Cancer patients with fever and neutropenia can be divided into low- and high-risk groups, with the Multinational Association for Supportive Care in Cancer (MASCC) score being a validated tool to differentiate between high-risk and low-risk patients 1. High-risk patients have a MASCC score less than 21 and are more likely to develop disseminated or complex infections.
From the Research
Neutropenia Definition
- Neutropenia is a condition characterized by a low count of white blood cells, specifically neutrophils, which are a type of white blood cell that plays a crucial role in fighting infections 2, 3, 4, 5, 6.
- It is often a side effect of chemotherapy, which can cause myelosuppression, resulting in a reduction of platelets and red and white blood cells 2.
- Neutropenia can increase the risk of infections and febrile neutropenia, a medical emergency that requires early therapeutic intervention 3, 6.
Causes and Risks
- Chemotherapy-induced myelosuppression is a common cause of neutropenia 2, 3, 4, 5, 6.
- Patients with cancer receiving myelosuppressive chemotherapy are at risk of developing neutropenia and febrile neutropenia 3, 6.
- The risk of hospitalization for neutropenic complications is higher in patients with myeloid malignancies than in those with solid tumors 6.
Treatment and Management
- Granulocyte colony-stimulating factors (G-CSFs) such as filgrastim and pegfilgrastim are used to reduce the incidence and duration of neutropenia and febrile neutropenia 2, 3, 4, 5, 6.
- Pegfilgrastim has a longer half-life than filgrastim and is associated with a lower rate of severe neutropenia, chemotherapy dose reduction, and treatment delay 4, 6.
- The pegfilgrastim on-body injector (OBI) is a device that facilitates the time-released auto-injection of pegfilgrastim, eliminating the need for a next-day hospital visit 6.