Neutrophil - Its Functions, Normal Count, and Related Disorders

Introduction:

The three main types of white blood cells are granulocytes, lymphocytes, and monocytes. In addition, neutrophils, eosinophils, and basophils are a subset of granulocytes. Neutrophils help prevent infections by constantly searching for signs of infection and quickly responding to trap, block, disable, digest, or ward off and kill pathogens invading particles and microorganisms.

Neutrophils play an essential role in regulating the immune system and inflammation in the body by communicating with other cells to help them repair damaged cells and mount an immune response. The neutrophils are produced in the bone marrow and makeup 50 to 70 % of all white blood cells in the blood vessels. The amount of neutrophils in the blood usually rises when a person gets sick or injured and helps the body heal. Conversely, neutrophil levels may decrease if a person has a long-term infection, cancer, or an autoimmune condition or takes certain medications.

What Are Neutrophils?

Neutrophils are the most abundant white blood cells in the body, and they function as a front-line defense of the immune system, helping to heal injuries and fight infections. It is a type of white blood cell essential to the immune system and helps the body fight infections.

When microorganisms such as bacteria and viruses invade the body, neutrophils become one of the first immune cells to react. They travel to the site of infection, where they ingest the microbes and destroy them by releasing enzymes that kill them. Neutrophils also enhance the response of other immune cells. Neutrophils are a type of granulocyte and a type of phagocyte.

What Do Neutrophils Do?

White blood cells (neutrophils, basophils, and eosinophils) circulate in the bloodstream and reach tissues to prepare for foreign objects that may cause illness, infection, or disease. The body reacts with redness and swelling (inflammation), while the neutrophils start the tissue repair process, healing injury or damage.

How Do Neutrophils Appear?

The color of neutrophils is transparent. A dye is used to modify the color of the cells so they are visible under a microscope when a physician analyzes them. When neutrophils are at rest, their shape is spherical; however, when they combat an infection, their shape changes.

Where Are Neutrophils Located?

Neutrophils are produced by bone marrow cells and travel through the body's circulating blood system to tissues, lymph nodes, and other parts.

What Are the Common Conditions That Affect Neutrophils?

Neutrophils in the body should remain in range for that particular age group. If the range shifts to high or low, conditions develop, such as -

• Neutropenia - Neutropenia is a condition seen when the neutrophil count is too low, causing swelling and multiple infections. It results from either a cancer treatment, an autoimmune disorder, or an infection.

• Neutrophilia - Neutrophilia, also known as neutrophilic leukocytosis, occurs because the neutrophil count is too high, which is often associated with a bacterial infection (the body releases immature neutrophils from the bone marrow too soon to fight the infection).

What Are the Symptoms Seen With Neutrophil Conditions?

Symptoms of a neutrophil condition include -

• Fever.

• Repeated infections.

• Sores.

• Swelling.

What Causes a High Neutrophil Count?

It is prevalent for the body to produce more neutrophils to help repair, for example, a bone fracture or severe burn. However, when the number of neutrophils does not decrease to normal levels after repairing an injury, it can turn into a condition and affect the overall health of a person. The number of neutrophils in the body may increase due to -

• Infections (especially bacterial).

• Inflammation (non-infectious).

• Injury or trauma.

• Certain types of leukemia (cancer).

• Allergic reactions to certain drugs.

• Smoking cigarettes or sniffing tobacco.

• Excessive exercise.

• Steroids.

What Causes a Low Neutrophil Count?

Neutropenia (low neutrophil count) results from the body losing neutrophils before the bone marrow can generate new ones. Neutropenia arises due to the following conditions such as -

• Infection (such as hepatitis, tuberculosis, and sepsis).

• Chemotherapy (cancer treatment).

• Bone marrow disorder or failure (leukemia).

• Vitamin deficiency (for example - vitamin B12, folate, copper, and calcium).

• Autoimmune disease (such as rheumatoid arthritis).

• Suppressed immune system.

• Aplastic anemia.

• Hepatitis A, B, or C.

• HIV (human immunodeficiency virus) or AIDS (acquired immune deficiency virus).

• Myelodysplastic syndrome.

What Is the Normal Range of Neutrophil Counts?

Absolute neutrophil count indicates the number of neutrophils contained in a blood sample. It ranges from 4000 to 11,000 neutrophils per microliter of blood for healthy adults. Numbers above 11,000 or less than 4000 are at risk for neutrophil disease.

What Are the General Tests to Check the Health of Neutrophils?

The tests to check the health of neutrophils include:

• Complete Blood Count (CBC) - A complete blood count test determines the number of cells in a blood sample that counts the number of exact cells.

• Absolute Neutrophil Count (ANC) - An ANC determines the number of neutrophil cells in a blood sample.

• Bone Marrow Biopsy - A bone marrow biopsy verifies the number of cells the body has and identifies where they grow.

What Are the Treatments Used for Neutrophil Disease?

Some treatments for both low and high neutrophil counts are mentioned below -

• Take antibiotics prescribed by the doctor.

• Get a bone marrow transplant if needed.

• Immediate discontinuation or change of medication that causes neutropenia.

• Treatment of underlying conditions that affect the neutrophil count.

• White blood cell transfusion.

• Treatment for the underlying condition.

How to Increase the Neutrophil Count?

The neutrophil is the first line of defense of the immune system of the body, and they should be adequate to fight off infections. A healthcare provider can guide one to make an action plan. They might suggest:

• Changing dosage or incorporating an immunity booster for chemotherapy.

• Getting a white blood cell transfusion.

• Stopping and changing any medication or therapy causes a low white blood cell count.

• Adding antibiotics or drugs that promote healthy white blood cell production.

• GCSF (granulocyte colony-stimulating factor) is also used to increase the neutrophil count in severe neutropenia to prevent infection.

How to Decrease the Neutrophil Count?

Neutrophils increase in number in response to the immune system to fight infection. However, if the number is above normal levels, the doctor will identify and treat possible infections with prescribed antibiotics.

Conclusion:

Neutrophils protect the body against infections and help heal injuries. In addition, neutrophils help heal and repair damaged tissue and eliminate infections. Neutrophil levels can rise or fall depending on the infection, injury, medication, hereditary disease, and stress. To maintain the neutrophil count within a healthy range, reduce the chances of infection. This includes- practicing good hygiene and eating a healthy diet. In healthy individuals, neutrophils account for 55 to 70 % of circulating white blood cells.