Neutrophils are white blood cells that act as the immune system’s primary defense against bacterial and fungal infections. When a person undergoes chemotherapy, a common side effect is a significant drop in these infection-fighting cells, a condition known as neutropenia. This temporary state occurs because chemotherapy drugs target all rapidly dividing cells, including the stem cells in the bone marrow that produce new blood cells. Maintaining neutrophil counts is important for reducing the risk of severe infection and ensuring that cancer treatment can proceed on schedule.
Understanding Chemotherapy-Induced Neutropenia
Chemotherapy drugs are designed to destroy rapidly dividing cancer cells. This mechanism also impacts the body’s healthy, rapidly dividing cells, particularly the blood-forming stem cells within the bone marrow. Damage to these stem cells results in a reduced production of all blood components, including neutrophils. Neutropenia is established when the absolute neutrophil count (ANC) drops below 1,500 cells per cubic millimeter of blood.
The lowest point in the neutrophil count following a chemotherapy cycle is referred to as the nadir. This period typically occurs between seven and fourteen days after the infusion, though the exact timing depends on the specific drugs used. During the nadir, the body is most vulnerable to infection, and the risk increases if the ANC falls below 500 cells/mm³. The body usually begins to restore neutrophil production within three to four weeks, allowing the count to rebound before the next treatment cycle.
Primary Medical Strategies to Boost Counts
The most direct strategy for increasing neutrophil production involves prescription medications called Granulocyte Colony-Stimulating Factors (G-CSFs). These synthetic proteins mimic a naturally occurring substance that stimulates the bone marrow to produce and release neutrophils. G-CSFs help shorten the duration and lessen the severity of neutropenia, preventing the need for treatment delays.
G-CSFs are typically given as a subcutaneous injection. Common examples include filgrastim, which requires daily injections for several days, and pegfilgrastim, a modified, long-acting version. Pegfilgrastim is often preferred because a single injection, usually given 24 to 72 hours after chemotherapy, is sufficient for the entire cycle. This timing ensures the growth factor begins working once the chemotherapy agent has cleared the system.
G-CSFs prompt the bone marrow to accelerate the maturation and release of neutrophils, raising the nadir count. This intervention is used for patients receiving chemotherapy regimens associated with a greater than 20% risk of developing febrile neutropenia (neutropenia accompanied by a fever). A common side effect is bone pain, caused by the rapid expansion of blood-producing cells. This discomfort can often be managed with common pain relievers.
Essential Infection Prevention During Low Counts
While medical strategies increase cell counts, patient actions must minimize exposure to pathogens through infection control measures. Maintaining strict hand hygiene is the most important practical step, requiring frequent washing with soap and water for at least twenty seconds, especially before eating and after using the restroom. Alcohol-based hand sanitizer should be used when soap and water are not available.
Environmental and social precautions are necessary during periods of low counts. This involves avoiding crowded public spaces and close contact with anyone who has an active infection, such as a cold, the flu, or chickenpox. Taking an oral temperature daily is a monitoring step, as fever may be the only sign of a serious infection when the neutrophil count is low.
Patients must contact their oncology team immediately if they experience a single temperature reading of 101°F (38.3°C) or a temperature of 100.4°F (38°C) that lasts for more than one hour. Other symptoms requiring immediate attention include chills, a new cough, shortness of breath, or any redness, swelling, or discharge around a catheter or surgical site. Food safety requires careful attention to prevent foodborne illness, which the compromised immune system cannot easily fight.
Food safety rules are essential:
- All meats and eggs must be cooked thoroughly to safe internal temperatures.
- Leftovers should not be kept for more than three days.
- Raw or undercooked foods, including sushi, unpasteurized dairy products, and certain deli meats, should be avoided.
- All fresh fruits and vegetables must be washed or scrubbed before consumption, even those labeled as pre-washed.
Supportive Measures and Lifestyle Adjustments
Supportive care plays a complementary role in helping the body recover and sustain neutrophil production. Adequate rest is important because the body uses energy to repair damaged tissues and regenerate blood cells following chemotherapy. Establishing a regular sleep schedule optimizes the body’s natural restorative processes.
Maintaining hydration by drinking fluids supports overall blood volume and cellular function. A balanced diet rich in protein, vitamins, and minerals provides the building blocks for new blood cell creation in the bone marrow. However, dietary changes alone cannot replace medical interventions or G-CSF administration for increasing counts.
Patients should discuss all supplements, including vitamins and herbal remedies, with their oncologist before consumption. Some supplements may interact with chemotherapy drugs or blood thinners, and none have been scientifically proven to boost neutrophil counts. Managing emotional stress through relaxation techniques or gentle activity, if approved by the care team, contributes positively to general well-being during treatment.