A subpopulation of suppressor cells in Richter's syndrome with both monocytic and T-lymphocytic characteristics

We evaluated T-lymphocyte functions in the peripheral blood of a patient with B-cell chronic lymphocytic leukemia after transformation to large cell lymphoma (Richter's syndrome). A subpopulation of E-rosette adherent cells were found with T-lymphocytic surface markers (OKT3+/8+/4+), monocytic characteristics (latex ingestion, nonspecific esterase staining), and suppressor activity. In contrast to the patient's nonadherent T-cells, this subpopulation suppressed PHA proliferation of autologous lymphocytes, pokeweed mitogen (PWM)-induced proliferation of normal non-T cells, and a mixed lymphocyte reaction. Further studies are warranted in patients with Richter's syndrome, in order to determine the frequency and significance of our findings.