In vitro functional studies of mononuclear cells in patients with CLL: evidence for functionally normal T lymphocytes...

In vitro functional studies of mononuclear cells from 34 patients with B-cell type CLL were investigated and the results of these studies were as follows: 1) The T lymphocytes from patients with CLL were capable of responding normally to PHA or PWM, of inducing allogeneic normal B lymphocytes to respond to these mitogens and of stimulating normally to allogeneic lymphocytes in "one-way" mixed lymphocyte reaction; 2) The monocytes from these patients were capable of enhancing the T lymphocyte response to mitogens and of stimulating normally to allogeneic lymphocytes; and 3) The leukemic B lymphocytes were incapable of responding to mitogens even in the presence of normal T lymphocytes and their enhancer cell activity on T lymphocyte response or their stimulating capacity on allogeneic lymphocytes was depressed. These observations suggest that the T lymphocytes and monocytes from patients with CLL are functionally normal while the leukemic B lymphocytes from these patients are functionally abnormal.