Neutrophils are a type of white blood cell, also known as leukocytes, which play a role in the body’s natural defense system. These cells are produced in the bone marrow and circulate throughout the bloodstream, monitoring for signs of trouble. Their presence is a normal and necessary component of a healthy immune response, working to protect the body from foreign invaders. Understanding their function provides insight into their significance for overall health.
The Role of Neutrophils in Your Immune System
Neutrophils act as the immune system’s initial line of defense, swiftly responding to sites of infection or injury. When pathogens like bacteria or fungi enter the body, neutrophils are among the first immune cells to arrive at the affected area. They are attracted by chemical signals released by damaged tissues or invading microorganisms.
Upon reaching the site, neutrophils engulf and destroy these harmful invaders through a process called phagocytosis. They contain granules filled with enzymes and other antimicrobial substances that break down and neutralize the threats. This rapid response helps contain infections before they can spread, making neutrophils effective against bacterial and fungal pathogens. Their activity also contributes to the inflammatory response, which is a localized reaction designed to eliminate the initial cause of cell injury and clear out damaged tissue.
Understanding Your Neutrophil Count
Neutrophil levels are assessed as part of a complete blood count (CBC) test. This test includes a “differential,” which breaks down the percentages of each type of white blood cell. A neutrophil count of “61” refers to 61% of your total white blood cell count.
For healthy adults, the percentage of neutrophils falls within a range of 40% to 60% of the total white blood cell count, although some sources may indicate a range up to 75%. A value of 61% falls within this healthy range, suggesting a well-functioning immune system. Normal ranges can vary slightly between different laboratories, and factors like time of day or even gender can influence counts.
When Neutrophil Levels Are Off
When neutrophil levels deviate from the typical range, it can indicate an underlying health issue. Neutrophilia refers to a higher-than-normal neutrophil count. Common causes include bacterial or fungal infections, as the body produces more neutrophils to fight off the invaders. Acute inflammation resulting from conditions like a heart attack, burns, or certain autoimmune diseases such as rheumatoid arthritis can also elevate neutrophil levels. Certain medications, including corticosteroids, can also lead to increased neutrophil counts.
Conversely, neutropenia describes a lower-than-normal neutrophil count. This condition can increase the risk of infection. Causes of neutropenia include issues with bone marrow production, such as those seen in certain cancers like leukemia or myelodysplastic syndromes. Some viral infections, autoimmune diseases (where the body attacks its own neutrophils), and certain medications, particularly chemotherapy drugs, can also lead to low neutrophil levels. Any abnormal neutrophil count warrants medical evaluation to determine the specific cause and appropriate course of action.