Monocytes (MONO)

The role of monocytes (MONO) in the body

Monocytes are the largest white blood cells (3-10% of the WBC) that act as ‘janitors’ and ‘conductors’ of the immune system. These are the only blood cells that can turn into macrophages – ‘eaters’ of infections.

Main functions:

1. Phagocytosis – absorption of bacteria, fungi, dead cells
2. Presentation of antigens – training of other immune cells
3. Regulation of inflammation – cytokine production
4. Control of chronic infections (tuberculosis, syphilis)
5. Participation in tissue regeneration

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Norm of monocytes in the blood test

Показатель	Абсолютное значение (×10⁹/л)	Процент от WBC
Взрослые	0.1-0.8	3-10%
Дети	0.05-1.1	2-12%
Беременные	до 1.0	до 12%

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Reduced monocytes (Monopenia)

Critical level: <0.04 ×10⁹/L

Main reasons:

• Aplastic anemia
• Leukemias
• Purulent bacterial infections
• Taking corticosteroids
• Chemotherapy

Symptoms:

• Frequent bacterial infections
• Long-term wound healing
• General weakness
• Increased bleeding

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Elevated monocytes (Monocytosis)

Reasons:

1. Chronic infections (tuberculosis, brucellosis)
2. Autoimmune diseases
3. Hematological diseases
4. Oncological processes
5. Recovery period after infections

Symptoms:

• Long-term subfebrility
• Enlarged lymph nodes
• Night sweats
• Weight Loss
• Joint pain

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What should I do if there are deviations?

With monocytosis:

1. Exclude tuberculosis (Mantoux test, quantiferon test)
2. Check for autoimmune diseases (ANF, CRP)
3. Ultrasound of internal organs
4. Consultation with a hematologist at a level >1.0 × 10⁹/l

When filling in:

1. Bone marrow analysis
2. HIV testing
3. Evaluation of drug therapy
4. Monitoring every 2-4 weeks

Important: Isolated changes in the level of monocytes are rarely of clinical significance – it is important to evaluate them in conjunction with other blood parameters!