Introduction:

Chronic lymphocytic leukemia (CLL) that arises by malignant transformation of mature B cell is the most common leukemia in elderly. CLL is characterized by accumulation of CD5⁺CD19⁺ cells in the peripheral blood and lymphoid organs. While CD8⁺ T lymphocytes response intracellular pathogen and tumor, CD4⁺ T lymphocytes regulate immune response. T follicular (Tfol) cells stimulate affinity maturation and class-switch recombination in B lymphocytes due to cytokine and surface molecules. In this study, we aimed to investigate CD4⁺T, CD8⁺T and CD3⁺CD4⁺CXCR5⁺ follicular T (Tfol) cells in the peripheral blood of the CLL patients compared to healthy controls.

Materials and Methods:

Peripheral blood samples were collected from 37 patients with CLL and 16 healthy subjects. CD4⁺ T, CD8⁺ T and Tfol cells in peripheral blood samples were analyzed by flow cytometry.

Results:

CD4⁺ T, CD8⁺ T and Tfol cells were decreased in all lymphocyte population, CD4⁺T cells are decreased, and CD8⁺ T and Tfol cells are increased but in T cell population. There was no differences T cell subgroups and clinical outcome.

Conclusions:

Although the high CD8⁺ T lymphocyte and Tfol cell ratios observed in patients may not be a prognostic marker for the clinical course of the disease, the increased Tfol cell ratio as a result of the disease may be the source of the cytokines required for the survival and proliferation of leukemic B cells and the induction of enzymes that were thought to be associated with chromosomal deletions in these cells.

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