What is leukopenia?

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Last updated: February 20, 2025 • View editorial policy

From the Guidelines

Leukopenia is a condition characterized by an abnormally low white blood cell count in the blood, specifically a total white blood cell count below 4,000 cells per microliter of blood in adults. To diagnose leukopenia, a complete blood count (CBC) test is required [ 1 ]. If confirmed, further testing may be needed to determine the underlying cause. Common causes of leukopenia include:

  • Viral infections
  • Certain medications (e.g., chemotherapy drugs, antibiotics)
  • Autoimmune disorders
  • Bone marrow disorders
  • Severe infections Treatment depends on the underlying cause and may include:
  • Stopping or changing medications that may be causing the condition
  • Treating underlying infections or diseases
  • In severe cases, medications to stimulate white blood cell production (e.g., Filgrastim) may be prescribed, although the use of growth factors should be avoided in patients with moderate-to-severe SARS-CoV-2 infection [ 1 ]. Patients with leukopenia are at higher risk for infections due to reduced immune function. They should take precautions such as:
  • Practicing good hygiene
  • Avoiding crowds and sick individuals
  • Eating a healthy diet to support immune function
  • Seeking prompt medical attention for signs of infection Understanding leukopenia is important because white blood cells are crucial for fighting infections and maintaining overall health. A low count can significantly impact the body's ability to defend against pathogens. In the context of COVID-19, patients with haematological malignancies and neutropenia are potentially at a higher risk of having severe COVID-19, and empirical antibacterial therapy should be initiated promptly pending further workup [ 1 ].

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Definition of Leukopenia

  • Leukopenia is a common finding in the outpatient setting, typically occurring due to a significant reduction in neutrophils, which comprise 50% to 70% of circulating leukocytes 2
  • It is an abnormal reduction of circulating white blood cells, especially the granulocytes, and is often used interchangeably with neutropenia 3
  • Leukopenia is a blood disease in which the number of circulating white blood cells diminishes, and can result from reduced production of white blood cells or increased utilization and destruction, or both 3, 4

Causes of Leukopenia

  • Infection, drugs, malignancy, megaloblastosis, hypersplenism, and immunoneutropenia are responsible for most cases of neutropenia 3
  • Primary neutropenia is very rare, and sometimes, particularly in children, primary neutropenia is hereditary and may be associated with other developmental defects 3
  • Familial Mediterranean fever (FMF) can cause leukopenia, mainly due to autophagy and apoptosis processes 4
  • In children, decreased leukocyte values are usually due to the decrease in the number of neutrophilic granulocytes, and can be associated with viral infections or immune-mediated neutropenias 5
  • Certain medications, such as acyclovir, can also cause transient leukopenia and erythroblastopenia 6

Clinical Implications

  • The major danger of neutropenia is the risk of infection, and management requires identification of the cause and effective antimicrobial therapy, especially when serious systemic infection is present 3
  • Patients with febrile neutropenia should undergo treatment with antibiotics, and other treatments are aimed at management of the underlying cause of neutropenia 2
  • Early recognition of underlying conditions, such as FMF, can help to prevent unnecessary invasive procedures and complications, such as amyloidosis 4

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.