Detection of Activated T Lymphocytes in Blood (T4) (CD4+CD25+, CD3+HLA-DR+, CD4+HLA-DR+, CD8+HLA-DR+)

This is a comprehensive immunological blood test aimed at determining the amount of activated T lymphocytes in peripheral blood. The test is conducted using flow cytometry, identifying T cells by specific activation markers on their surface.

Activated T cells are part of the immune system that actively participate in the response to infection, inflammation, autoimmune processes, or other immune stimuli.

What does this test show?

The test evaluates the following subpopulations of activated T lymphocytes:

• CD4+CD25+ – activated T helper cells; CD25 is an early activation marker for T cells;
• CD3+HLA-DR+ – total number of activated T lymphocytes;
• CD4+HLA-DR+ – activated T helper cells;
• CD8+HLA-DR+ – activated cytotoxic T cells.

HLA-DR is a later activation marker indicating a prolonged or more intense immune response.

Results are presented as percentages and, depending on the laboratory methodology, may also be indicated in absolute numbers.

When is the test recommended?

The test may be prescribed for:

• assessing active immune response;
• suspected or diagnosed autoimmune diseases;
• chronic or acute infections;
• assessing inflammation activity;
• monitoring the effects of immunosuppressive or immunomodulatory treatment;
• suspected immune system hyperactivity or imbalance.

How are the results evaluated?

Increased levels of activated T lymphocytes may indicate:

• active infectious process;
• exacerbation of autoimmune disease;
• systemic inflammation;
• immune system hyperactivity.

Decreased indicators may be associated with immune suppression or the effects of certain treatments.

Results are always evaluated in conjunction with clinical symptoms and other laboratory test data. Final interpretation is provided by a physician, considering the overall condition of the patient.