From the Guidelines
The neutrophil absolute count of 1.8 to 7.5 × 10^9/L is considered the normal reference range for neutrophils in the blood, as indicated by general medical knowledge and various studies 1. Neutrophils are the most abundant type of white blood cells and play a crucial role in the body's immune defense against infections, particularly bacterial infections. A value of 1.8 is at the lower limit of normal, while 7.5 is at the upper limit. Values within this range indicate proper immune function. If a patient's neutrophil count falls below 1.8, they may have neutropenia, which can increase susceptibility to infections, as suggested by the practice parameter for the diagnosis and management of primary immunodeficiency 1. Counts above 7.5 may indicate infection, inflammation, stress, or certain medications. Regular monitoring of neutrophil counts is important for patients on medications that can affect bone marrow function, those undergoing chemotherapy, or those with conditions affecting white blood cell production, as noted in the management recommendations for chronic myelomonocytic leukemia 1. It is essential to consider the clinical context and other laboratory results when interpreting neutrophil counts, as emphasized in the guidelines for acute lymphoblastic leukemia 1. Key points to consider include:
- Neutrophil counts below 1.8 × 10^9/L may indicate neutropenia and increased susceptibility to infections
- Neutrophil counts above 7.5 × 10^9/L may indicate infection, inflammation, stress, or certain medications
- Regular monitoring of neutrophil counts is crucial for patients with conditions affecting white blood cell production or those undergoing chemotherapy
- Clinical context and other laboratory results should be considered when interpreting neutrophil counts.
From the Research
Neutrophil Absolute Trends
The normal range for neutrophil absolute is between 1.8 and 7.5 x 10^9/L.
- The lower limit of this range is 1.8 x 10^9/L
- The upper limit of this range is 7.5 x 10^9/L
Neutropenia Definition and Classification
Neutropenia is defined as an absolute neutrophil count < 1500 cells/mm^3 2.
- It can be graded as mild (1000-1500 cells/mm^3), moderate (500-1000 cells/mm^3), or severe (< 500 cells/mm^3) 2
- Neutropenia can be classified according to its etiology as congenital or acquired 2
- Acquired neutropenia can be further defined according to its etiology or pathology 2
Neutropenia Diagnosis and Treatment
The diagnosis and treatment of neutropenia involve a stepwise approach, focusing first on reaching a provisional diagnosis and treatment plan, then proceeding to a final diagnosis 3.
- Patients with acute febrile neutropenia should be treated with antibiotics 3
- Patients at high risk of severe neutropenia (> 20% risk) after myelosuppressive chemotherapy should be treated prophylactically with a myeloid growth factor, usually granulocyte colony-stimulating factor (G-CSF) 3
Neutrophil-to-Lymphocyte Ratio
The neutrophil-to-lymphocyte ratio (NLR) is a novel hematological parameter for systemic inflammation and stress 4.
- A normal range of NLR is between 1-2, with values higher than 3.0 and below 0.7 in adults being pathological 4
- NLR can be used as a reliable and cheap marker of ongoing cancer-related inflammation and a valid indicator of prognosis of solid tumors 4
Neutrophil Functions in Inflammation and Tissue Repair
Neutrophils play an essential role in the control of infectious diseases and tissue repair 5, 6.