Since the early 1980s we observed populations of T lymphocytes and NK cells of B-cell chronic lymphocytic leukemia (B-CLL)patients, reveal changes as compared with T and NK cells of healthy donors. The aim of this study was to determine relations between T-lymphocyte subpopulations and NK-cell subsets in patients with B-CLL in various stages of the disease.Peripheral blood cells of B-CLL patients had been analysed by means of flow cytometry and monoclonal antibodies. Lymphocyte surface markers had been evaluated by means of direct immunofluorescence. We evaluated the absolute number of each lymphocyte subset. Study results revealed that there was a significant increase in the number of T- and NK-cell populations that correlates with the progression of the disease. Following effective therapy of B-CLL Rai stage III/IV patients (blood lymphocyte count <30x109/l) there was a considerable decrease of  T CD3+ and T CD8+ lymphocytes (to control values) and a significant decrease of T CD4+ and NK cells (below minimal control values). The number of T and NK cell subpopulations was not constant and this instability might have been the cause of immune response impairment observed in B-CLL patients. T lymphocytes and NK cells showed normal expression of an adhesion LFA-1 molecule.

Keywords: Rai stage, B-cell chronic lymphocytic leukemia, NK cells, T cell subpopulations