Differential Diagnosis

Consider white blood cell (WBC) proliferation in patients with infections and other inflammatory states, such as autoimmune disorders.

An increase in neutrophils commonly occurs during a bacterial infection.

Lymphocytosis can be found in tuberculosis (TB), acute bowel infections, and infectious mononucleosis.

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Monocyte count is usually increased along with an elevated lymphocyte count.

Eosinophils can become increased in patients with allergic disorders, asthma, certain parasitic, and dermatologic disorders.

Elevated WBC counts may also be detected in patients with a variety of different types of leukemia and lymphomas.

Dangerous Situations

It is important to promptly recognize an elevated WBC count associated with a diagnosis of leukemia or lymphoma.

Commonly Encountered Situations

Non-neoplastic proliferations of WBCs most commonly involve an increase in neutrophils with bacterial infection.

Elevation in lymphocytes and monocytes in patients with autoimmune disease is also frequently encountered.

Suggested Additional Lab Testing

The most important test is the WBC count and differential.

Peripheral blood smear and bone marrow aspirate, with or without bone marrow biopsy, is informative in the diagnosis of certain WBC proliferative states.

Serum protein electrophoresis with further evaluation is indicated if a plasma cell dyscrasia is found.

An evaluation for infection, either bacterial or parasitic, is useful if there is an increase in eosinophils.

Tests for autoimmune diseases (e.g., systemic lupus erythematous [SLE], rheumatoid arthritis) may explain an elevated lymphocyte and monocyte cell count.