Neutrophils (NEUT)

The role of neutrophils (NEUT) in the body

Neutrophils are the most numerous white blood cells (50-75% of all WBC), the main ‘rapid response’ against bacteria and fungi. They are called the ‘first line of defense’.

Key features:

1. Phagocytosis is the absorption and digestion of bacteria.
2. Release of antimicrobial substances (defensins, lysozyme).
3. Formation of pus (dead neutrophils + microbes).
4. Trigger inflammation (signal infection).

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The norm of neutrophils in the blood test

Parameter	Absolute value (×10⁹/L)	Percentage of WBC
Adults	1.8 – 7.5	48–75%
Children	1.5 – 8.5	30–60%
Newborns	6.0 – 26.0	50–70%

Note: In pregnant women, an increase of up to 12-14 ×10⁹/l is acceptable.

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Reduced neutrophils (Neutropenia)

Critical levels:

• Easy: 1.0-1.5 ×10⁹/l
• Average: 0.5-1.0 ×10⁹/l
• Heavy: <0.5 ×10⁹/l (risk of fatal infections!)

Reasons:

• Viruses (influenza, measles, HIV).
• Chemotherapy/radiation.
• Autoimmune diseases (SLE, rheumatoid arthritis).
• Vitamin B3/folate deficiency.
• Congenital pathologies (Kostmann’s syndrome).

Symptoms:

• Frequent purulent infections (sore throats, pneumonia).
• Ulcers in the mouth, bleeding gums.
• Temperature + weakness for no obvious reason.
• Children have developmental delays.

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Elevated neutrophils (Neutrophilosis)

Reasons:

1. Bacterial infections (sepsis, tuberculosis).
2. Injuries/burns/heart attacks (tissue necrosis).
3. Stress/physical activity.
4. Oncology (leukemias, stomach cancer).
5. Smoking, pregnancy.

Symptoms:
Depend on the underlying disease:

• Purulent discharge (from wounds, sputum).
• Fever + sweating.
• Pain in the affected organ (for example, with appendicitis).

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What should I do if there are deviations?

• With neutropenia:
• Avoid contact with patients.
• Urgent visit to a hematologist for NEUT < 0.5 ×10⁹/l (risk of sepsis!).
• Analysis for antineutrophil antibodies (ANA).
• With neutrophilosis:
• Search for the source of infection (CRP, procalcitonin, crops).
• With NEUT > 20 ×10⁹/L , exclude leukemia (bone marrow biopsy).

Important: Neutrophils are the first to react to danger – their fluctuations require a quick diagnosis!