Lymphocytes (LYPH)

The role of lymphocytes in the body

Lymphocytes are the main ‘intellectuals’ of the immune system (20-40% of the WBC), responsible for the accurate immune response. . These are key cells for fighting viruses, cancer and forming immune memory.

Types and functions:

1. B-lymphocytes -produce antibodies (immunoglobulins).
2. T-lymphocytes -destroy infected and cancerous cells.
3. NK cells -kill tumors and viruses without ‘training’.

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Norm of lymphocytes in the blood test

Parameter	Absolute value (×10⁹/L)	Percentage of WBC
Adults	1.0 – 4.8	20–40%
Children under 6 years	2.0 – 8.0	40–70%
Adolescents	1.2 – 5.2	30–50%

Note: In pregnant women, a reduction of up to 18-20% is acceptable.

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Reduced lymphocytes (Lymphopenia)

Critical level: < 0.8 ×10⁹/l (severe immunodeficiency).

Reasons:

• Viruses (COVID-19, HIV, hepatitis).
• Autoimmune diseases (SLE, rheumatoid arthritis).
• Taking immunosuppressants (after transplantation).
• Radiation/chemotherapy.
• Stress, malnutrition.

Symptoms:

• Frequent viral and fungal infections (herpes, thrush).
• Exacerbation of chronic diseases.
• Weight loss + constant weakness.
• Children have developmental delays.

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Elevated lymphocytes (Lymphocytosis)

Reasons:

1. Viral infections (mononucleosis, measles, chickenpox).
2. Tuberculosis, toxoplasmosis.
3. Leukemias (CLL, acute lymphoblastic leukemia).
4. Autoimmune processes (thyroiditis, Crohn’s disease).
5. Smoking, metal poisoning.

Symptoms:

• Enlarged lymph nodes (painless in leukemia).
• Long-term temperature (+37 … 38°C).
• Night sweats, itchy skin.
• Bone pain (with metastases or leukemia).

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What should I do if there are deviations?

• For lymphopenia:
• Test for HIV, immunoglobulins.
• Exclude hypovitaminosis (B12, zinc).
• Consultation with an immunologist for LYMPH < 0.5 ×10⁹/l.
• With lymphocytosis:
• Blood smear for atypical cells.
• Ultrasound of the lymph nodes, CT of the chest.
• With LYMPH > 5 × 10⁹/l + spleen enlargement -urgently see a hematologist!

Important: Lymphocytes-markers of latent infections and tumors. Even in the absence of symptoms, significant abnormalities require an in-depth examination!