What does a neutropenia (absolute neutrophil count) of severe neutropenia mean?

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Last updated: April 16, 2025View editorial policy

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From the Guidelines

A neutropenia of 0.3 indicates a severe deficiency in neutrophils, significantly increasing the risk of serious infections, and requires immediate medical attention. This condition is characterized by an absolute neutrophil count (ANC) of 0.3 × 10^9 cells per liter of blood (or 300 neutrophils per microliter), which is substantially lower than the normal range of 1.5 to 8.0 × 10^9/L 1. Neutrophils play a crucial role in defending against bacterial and fungal infections, and their severe deficiency puts patients at a high risk of developing febrile neutropenia, a condition that can lead to major complications, such as hypotension, acute renal, respiratory, or heart failure, with a mortality rate of up to 11% 1.

Key Considerations

  • Patients with severe neutropenia are at a high risk of developing febrile neutropenia, which is a medical emergency requiring prompt antibiotic treatment 1.
  • The underlying cause of neutropenia, such as medication side effects, bone marrow disorders, or certain infections, must be identified and addressed to effectively manage this condition.
  • Protective isolation, prophylactic antibiotics, and possibly granulocyte colony-stimulating factor (G-CSF) medications like filgrastim may be necessary to stimulate neutrophil production and prevent infections 1.
  • The use of hematopoietic growth factors, such as G-CSF, should be guided by evidence-based recommendations, taking into account the risk of complications, such as severe thrombocytopenia and potential long-term risks, like acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) 1.

Management

  • Immediate medical attention is required for patients with severe neutropenia, and treatment should be guided by evidence-based guidelines and individual patient needs.
  • Fever in someone with severe neutropenia is considered a medical emergency, and prompt antibiotic treatment is essential to prevent serious complications.
  • The dosage schedule, route of application, and potential risks of G-CSF and pegfilgrastim should be carefully considered, with a recommended dose of 5 µg/kg/day of G-CSF, and a single dose of either 100 µg/kg or a total dose of 6 mg of pegfilgrastim 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Neutropenia Definition

  • Neutropenia is defined as an absolute neutrophil count (ANC) less than 1.5 × 10(9)/L 2, 3.
  • Severe neutropenia is defined as an ANC less than 0.5 × 10(9)/L 2.

Interpretation of ANC 0.3

  • An ANC of 0.3 × 10(9)/L falls into the category of severe neutropenia, which is a well-known risk factor for susceptibility to bacterial infections 2.
  • Patients with severe neutropenia are at a higher risk of developing life-threatening sepsis, shock, and even death 4.

Management and Treatment

  • Management of severe chronic neutropenia includes commonsense precautions to avoid infection, aggressive treatment of bacterial or fungal infections, and administration of granulocyte colony-stimulating factor (G-CSF) 2, 3.
  • G-CSF may be administered to facilitate the recovery process with daily monitoring of neutrophil count 4.
  • Patients with severe chronic neutropenia have a risk of eventually developing myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) and require monitoring for this complication 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

How I diagnose and treat neutropenia.

Current opinion in hematology, 2016

Research

Neutropenia Induced by Ceftriaxone and Meropenem.

European journal of case reports in internal medicine, 2024

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.

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