What is Neutrophilia?

Neutrophils, often referred to as the “soldiers of our natural defense system,” are the first cells that rush to the location of an infection to fight and destroy germs by producing substance called reactive oxygen species. They also have an important role in dealing with both short-term and long-term inflammation and autoimmune diseases, which are conditions where the body’s immune system mistakenly attacks its own cells.

In adults, the usual count of white blood cells (cells that help the body fight infections) is between 4,000 to 11,000 cells per microliter, with 60% to 70% of those being mature neutrophils in the bloodstream.

The number of neutrophils in the bloodstream, known as the absolute neutrophil count (ANC), usually ranges from 2,500 to 7,000 neutrophils per microliter in adults. If the count of white blood cells exceeds 11,000 cells per microliter, it’s referred to as leukocytosis. Neutrophilia, a form of leukocytosis, is characterized by an increase in the ANC to more than 7,700 neutrophils per microliter (around 70% of 11,000 cells per microliter), which is significantly higher than the average.

What Causes Neutrophilia?

Neutrophilia is a medical condition that happens when your body has too many neutrophils, a type of white blood cell, in your blood. Neutrophilia happens for different reasons and can be grouped into three categories.

Firstly, we can have “Factitious Neutrophilia”. This happens when either the blood sample is not properly mixed with substances that prevent it from clotting (like citrate or heparin); or if it’s mixed with Ethylenediaminetetraacetic acid (EDTA). This can create lumps of platelets – tiny blood cells that help your body form clots, confusing automatic cell counters and making it seem like there are more neutrophils than there really are.

Next, we have “Primary Neutrophilia”. This happens when your bone marrow, the spongy tissue inside your bones, produces too many neutrophils. Chronic Idiopathic Leukocytosis is an example of this where your body just naturally has a high neutrophil count. Myeloproliferative Neoplasms (MPNs) are a group of diseases where your body makes too many red and white blood cells and even platelets, resulting in primary neutrophilia. Genetic or Inherited neutrophilia also falls under this category where certain genetic conditions can cause an increase in neutrophil count.

Lastly, there’s “Secondary Neutrophilia”. This happens in response to other factors like infection, inflammation, certain medications, and even stress. Infections and inflammation frequently lead to secondary neutrophilia. For instance, bacterial infections are often associated with an increase in young forms of white blood cells while viral infections can lead to high neutrophil count with unusual looking lymphocytes – another type of white blood cells. Sometimes, Non-hematological cancers (cancers not related to the blood) and medications could also cause this condition.

It’s important also to remember some other factors like stress, intensive physical activity, temperature changes, negative habits like smoking, obesity, or surgery could also result in secondary neutrophilia. Understanding the cause of neutrophilia is important because it aids in determining the best way to manage and treat it.

Risk Factors and Frequency for Neutrophilia

It’s tricky to predict who is more likely to develop neutrophilia because many factors can play a role. Personal habits and lifestyle such as being a smoker, the level of stress in your life, and how much exercise you do, can all impact your risk of developing this condition. When investigating differences between ethnic groups, it’s noted that black people generally have lower total WBC and neutrophil counts compared to white people. However, the Latino community tends to have higher counts of leukocytes (average difference of 0.16×10^9/L) and neutrophils (average difference of 0.11×10^9/L).

Signs and Symptoms of Neutrophilia

Doctors need to evaluate a person’s medical and family history for clues related to elevated white blood cell count. This includes:

Signs of current or past infections or inflammation
Previous complete blood count (CBC) results
Recent changes in medication
Signs of blood or other types of cancer (such as weight loss, loss of appetite, swollen glands, unidentified lumps, body aches, fatigue, night sweats, fever, or cold-like symptoms)
Family history of high white blood cell count
Records of intense exercise, smoking, or new physical or emotional stress
History of poor spleen function or surgical removal of the spleen

A physical examination should be thorough, aiming to rule out any signs related to the history given above. The examination should cover:

Vitals such as fever and rapid heart rate
Head and neck check for pale face and eye whites and swollen glands
Lung examination for abnormal breathing sounds
Abdomen check for bloating, pain, lumps, and enlarged liver or spleen
Joint examination for redness, tenderness, swelling, or distortion
Skin examination for new sores, lumps, and color changes

The medical condition called LAD is characterised by gum disease, repeated skin and mucous membrane infections, lack of pus formation, slow wound healing, and delayed separation of the umbilical cord in newborns.

Testing for Neutrophilia

When a doctor suspects a condition called neutrophilia, which is an abnormally high number of white blood cells called neutrophils in the blood, they usually start the investigation with blood tests. The Complete Blood Count (CBC) is a common blood test that can provide information about the number of different blood cells, including neutrophils. By looking at this test and another one called peripheral blood smear, doctors can begin to determine possible causes of neutrophilia.

Several other tests can also be helpful to make the distinction between primary neutrophilia, where the condition originates within the bone marrow, and reactive neutrophilia, which occurs in response to something else like infection or inflammation. For example, your doctor could order tests to measure inflammation markers, checks on your liver and kidney functions, and for your blood’s clotting ability. They may also order cultures of various body fluids, such as blood, sputum (mucus coughed up), urine, wound drainage, stool, and cerebrospinal fluid (fluid around the brain and spinal cord) to check for infection. Another specific test can detect a type of bacteria that causes diarrhea, called Clostridium difficile.

Additional specialized tests like a bone marrow biopsy (a procedure where a small sample of bone marrow is removed for examination), flow cytometry (a technique used to measure properties of cells), and certain genetic testing can further assist in diagnosing neutrophilia. The bone marrow biopsy can be particularly helpful when doctors are looking for blood and other cancers that spread to or start in the bone marrow. Flow cytometry comes in handy for diagnosing certains types of blood cancers. There’s a condition called LAD which can be diagnosed specifically through molecular testing or flow cytometry.

Imaging, such as CT scans of the head, neck, chest, abdomen, and pelvis, can also support doctors in finding causes of neutrophilia. If CT scans aren’t conclusive, an MRI of the same regions might be helpful. Other imaging methods, like a PET scan (a type of imaging test that helps reveal how your tissues and organs are functioning), chest X-ray, and diagnostic ultrasound (uses high-frequency sound waves to capture images inside your body) can also be used based on the symptoms and suspected cause of neutrophilia.

Treatment Options for Neutrophilia

If you have neutrophilia, which means a high number of a type of white blood cell called neutrophils, the treatment will typically focus on addressing the root cause of this increase. For instance, in a condition called leukemoid reaction, where the white blood cell count exceeds 50,000, urgent treatment methods may include a procedure called leukapheresis (which helps to reduce the number of white cells in the blood), along with rapid and adequate hydration, and a particular medication known as hydroxyurea. These actions help to prevent complications associated with abnormal clot formation.

If there is an infection or inflammation causing the increase in neutrophils, the use of antibiotics and anti-inflammatory medications will be used. For certain types of bone marrow disorders known as myeloproliferative neoplasms (MPNs), drugs that reduce the production of certain cells, such as hydroxyurea, are often used. We should regularly check your complete blood count, a test that keeps track of the cells in your blood, while you’re taking this medication.

In some cases, the neutrophilia may be caused by a medication you’re taking. If that happens, your doctor will keep a close eye on your situation. It might be necessary to stop taking that medication if it’s causing complications.

For a specific type of cancer called chronic myeloid leukemia (CML), treatment options include a drug called imatinib. This drug works by blocking a specific protein that’s the product of an abnormal gene found in CML. Additionally, allogeneic hematopoietic stem cell transplant, which is a procedure that replaces your unhealthy bone marrow (the material inside your bones that makes blood cells) with healthy bone marrow from a donor, may be an option.

If you’re diagnosed with a myeloproliferative neoplasm, you may need to see a hematologist, a doctor who specializes in blood disorders. They can provide you with further examination and treatment options.

When examining the cause of a high number of neutrophils, a type of white blood cell, in the blood (or neutrophilia), doctors consider a variety of possible reasons. These include:

Different types of infections such as bacterial, viral, fungal, and parasitic
Conditions causing both short and long-term inflammation, like granulomatous diseases, vasculitis, and inflammatory bowel disease
Leukemoid reaction, or an extreme increase in white blood cells
Types of cancer that affect the blood or other parts of the body
Some medications
A lack of a spleen or an underperforming spleen
Physical and emotional triggers like stress, smoking, intense exercise, pregnancy, or obesity
Tissue damage from surgery, injuries, or burns
mistakes in the lab tests
Inherited disorders such as LAD (Leukocyte adhesion deficiency), or hereditary neutrophilia where high white blood cell count runs in the family

What to expect with Neutrophilia

The outcome of neutrophilia, which is an increase in a type of white blood cell called neutrophils, typically rests on how well the root cause of the condition is managed. Neutrophilia that occurs due to infection or inflammation often gets better with treatment. If certain medications are causing the condition, stopping their usage can help resolve it.

For patients suffering from Chronic Myeloid Leukemia (CML), a type of cancer that affects blood-forming cells in the bone marrow, their outlook has been significantly improved thanks to drugs known as TKIs, such as Imatinib. Moreover, Hematopoietic Cell Transplantation (HCT), a procedure in which a patient receives healthy blood-forming cells, has been successful in enhancing survival rates in patients with Leukocyte Adhesion Deficiency (LAD), a rare immune disorder.

Possible Complications When Diagnosed with Neutrophilia

The complications of a medical condition known as neutrophilia are primarily related to its root causes. These include:

Excessive clotting of the blood associated with extreme white blood cell reactions
Bloodstream infection, severe systemic bacterial infection, and failure of multiple organs if infections go untreated
Poor wound healing, serious gum disease, severe cognitive impairment, and failure to grow properly if Leukocyte Adhesion Deficiency (LAD) is untreated
Blood clots, bleeding, transformation into acute form of leukemia, and scarring tissue in the bone marrow can be observed in untreated Myeloproliferative Neoplasms (MPNs)

Preventing Neutrophilia

Patients should learn about quitting smoking, losing weight, eating a balanced diet and practicing relaxation methods as part of dealing with neutrophilia, a condition where there is a high number of a certain type of white blood cells, often linked to physical and emotional triggers. Additionally, it’s worth knowing about the potential side effects of certain medications, such as ATRA, lithium, and G-CSF, which can also give rise to neutrophilia.