Immunophenotyping of lymphocytes (CD3, CD4, CD8, NK, etc.)

Why is it needed?

This test evaluates the composition and functional state of lymphocytes – key cells of the immune system. It helps you:
✔ Diagnose immunodeficiency disorders (HIV, congenital disorders).
Control autoimmune and oncological diseases (leukemias, lymphomas).
Evaluate the effectiveness of therapy (for example, for HIV or after transplantation).

What do Markers (CD) define?

Each CD (cluster of differentiation) is a protein on the surface of cells that indicates their type and function:

Marker	Cell type	Role in immunity
CD3+	T-lymphocytes	The main “managers” of the immune response.
CD4+	T-helpers	They activate other cells (B-lymphocytes, macrophages).
CD8+	T-killers	They destroy infected and cancerous cells.
CD19+/CD20+	B-lymphocytes	They produce antibodies.
CD16+/CD56+	NK cells	They kill viruses and tumors without prior ‘training’.

Symptoms of abnormalities

Lymphocyte deficiency (immunodeficiency)

Frequent infections (pneumonia, fungal infections).
Autoimmune complications (due to an imbalance of immunity).
Cancer risks (in case of NK-cell deficiency).

Reasons:

HIV (reduced CD4+).
Chemotherapy, radiation.
Congenital disorders (for example, SCID – ‘bubble boy syndrome’).

Excess lymphocytes (hyperactivation)

Autoimmune attacks (rheumatoid arthritis, multiple sclerosis).
Allergies (with a Th1/Th2 imbalance).
Lymphoproliferative diseases (leukemias).

Reasons:

Chronic infections (hepatitis, tuberculosis).
Autoimmune diseases.
Lymphoma.

Norms in analysis

The results are presented in % of the total number of lymphocytes and absolute numbers (cells/µl).

Cell population	Relative quantity (%)	Absolute quantity (cells/µl)
CD3+ (T lymphocytes)	60–80%	900–2200
CD4+ (T-helper cells)	30–60%	500–1400
CD8+ (T-killers)	20–40%	300–800
CD4 / CD8 index	1.0–2.5	–
CD19+ (B-lymphocytes)	5–20%	100–500
CD16+ / CD56+ (NK cells)	5–20%	100–500

Important:

In children under 5 years of age, the norm is higher (especially for B and NK cells).
In HIV , the critical level of CD4+ is < 200 cells/µl (risk of AIDS-associated diseases).

When is the test scheduled?

Suspected immunodeficiency:

Frequent acute respiratory viral infections, herpes, candidiasis.

HIV diagnosis:

Monitoring of CD4+ and viral load.

Autoimmune diseases:

Rheumatoid arthritis, lupus.

Oncology:

Leukemias, lymphomas (determine the type of tumor).

How can I correct deviations?

With CD4+ deficiency (HIV):

Antiretroviral therapy (ART).
Prevention of opportunistic infections.

In case of excessive activity (autoimmune diseases):

Immunosuppressants (methotrexate, infliximab).

To support NK cells:

Zinc, vitamin D, and echinacea.

Sample result

Conclusion: Immune status is normal.

Conclusion

Имму Immunophenotyping – ‘passport’ of immunity, showing the balance of protective cells.
🔹 Rules:

CD4+: 500-1400 cells/µl,
CD4 / CD8 index: 1.0-2.5.
Снижение A decrease in CD4+ is a sign of immunodeficiency, an increase in CD8+ is a possible chronic infection.
Treatment depends on the cause (ART, immunocorrection).