An Overview of White Blood Cell Disorders

White blood cell disorders are indicated when the body has too many or too few white blood cells (WBCs or leukocytes)—one of the four components of your blood. These cells, manufactured in the bone marrow, are involved in inflammatory responses and play an important role in your immune system's ability to fight infections. Some white blood cell disorders (e.g., autoimmune neutropenia) are benign, while others (e.g., leukemia) are malignant. These conditions can affect both adults and children.

While a high WBC count is worth concern, it can occur when a disease, infection, or inflammation is present in the body and—on its own—may not indicate a white blood cell disorder. Your doctor will likely perform additional testing to determine the cause of your abnormal WBC levels.

Symptoms of white blood cell disorders vary based on the type of illness, though some people do not have any symptoms at all.

Symptoms, when they occur, are predominantly related to infection and include:

• Frequent or recurrent infections
• Fever
• Mouth ulcers
• Skin abscesses
• Pneumonia
• Fatigue
• Malaise
• Unexplained weight loss

WBC disorders fall under two major categories: proliferative disorders, meaning an increase in WBCs, and leukopenias, which involve a decrease in WBCs.

These can occur when there is a change in white blood cell production, a problem with cellular function, or another issue with a particular type of white blood cell. The driving reason behind these events can differ depending on the disorder.

Common white blood cell disorders and their causes include:

• Leukocytosis, an increased number of white blood cells: Possible causes include bacterial or viral infections, certain medications, allergies, smoking, inflammatory diseases, autoimmune disorders, a genetic condition, and cancer.
• Leukemia: Cancer of the cells that produces white blood cells in the bone marrow; possible causes include genetic predisposition, smoking, and chemical or radiation exposure.
• Autoimmune neutropenia, when the body produces antibodies that attack and destroy neutrophils: The condition is associated with various conditions, including Crohn's disease and rheumatoid arthritis.
• Severe congenital neutropenia, which is secondary to a genetic mutation. People with severe congenital neutropenia have recurrent bacterial infections.
• Cyclic neutropenia: This is also due to a genetic mutation. The neutropenia occurs in cycles of about 21 days.
• Chronic granulomatous disease: This is a disorder where multiple types of WBCs (neutrophils, monocytes, macrophages) are unable to function properly. It is an inherited condition and results in multiple infections, particularly pneumonia and abscesses.
• Leukocyte adhesion deficiencies (LAD syndromes), rare genetic disorders where the white blood cells are unable to move to areas of infection

As with other blood disorders, the first test commonly performed is a complete blood count (CBC). This may be specifically ordered because you are having recurrent or unusual infections and your doctor suspects a white blood cell disorder. But since a CBC is also done as part of an annual physical, the test may incidentally detect such a condition.

In reviewing results, your healthcare provider will be looking for a change in either your total WBC count or in the number of a particular type of WBC. Your results will be compared to the appropriate reference range for WBC counts. These can vary from lab to lab, but on average are as follows:

• Men: 5,000 to 10,000 WBC per microliter of blood
• Women: 4,500 to 11,000 WBC per microliter of blood
• Children (from infancy to adolescence): 5,000 to 10,000 WBC per microliter of blood
• Newborns (under 2 weeks of age): 9,000 to 30,000 WBC per microliter of blood

Note: African-Americans have lower baseline WBC counts than whites.

If your results are above or below normal, your physician will then work on determining why. Sometimes the cause is temporary, like an elevation in the WBC count during an active infection. In these circumstances, the CBC is often repeated to ensure that things have returned to normal.

Your physician may also request a blood smear—a test where a small amount of blood is placed on a glass slide so a physician can examine your blood cells under a microscope to look for abnormalities that might point to a disorder (and its cause).

If you require further evaluation, your primary care provider may refer you to a specialist. WBC disorders are usually treated by hematologists who specialize in blood disorders or immunologists who specialize in disorders of the immune system.

Since white blood cells are produced in the bone marrow, a bone marrow biopsy might be needed to complete the workup.

Treatment of WBC disorders depends largely on the type of disorder and any underlying causes. People with WBC disorders need to be monitored regularly to ensure their treatment regimen is working.

Possible treatments include:

• Antibiotics, which are used to treat and prevent related infections
• Dietary supplements, such as iron and vitamins B-9 (folate) and B-12 (cobalamin)
• Colony-stimulating factors (CSF) or growth factors, medications that can stimulate white blood cell production in the bone marrow
• Stem cell transplantation, which can be used for curative therapy in some cases

White blood cell transfusions are rarely used as research does not show that they lower the risk of death or infection in people with WBC disorders.

There is a wide range of WBC disorders, and the impact one can have on your life will depend on your individual diagnosis. Many of these issues are chronic health concerns, and living well with them means working closely with your healthcare team to manage your condition. Fatigue can be a common concern for people with WBC disorders, so listen to your body and rest when you need to. It is also helpful to practice prevention strategies to avoid contracting contagious illnesses, such as influenza and other colds and viruses.