Immunocompetent cells in patients with malignant disease.I. the lack of naturally occurring killer cell activity in the unfractionated circulating lymphocytes from patients with chronic lymphocytic leukemia (CLL)

Abstract

The unfractionated, buffy coat cells of patients with chronic lymphocytic leukemia (CLL) were compared with their counterpart cells from normal volunteers for the capacity to lyse chromium‐labeled xenogeneic target cells in vitro. Whereas killer cells were consistently detected in the circulation of normal individuals, no significant numbers of killer cells could be detected in the circulation of CLL patients. It is concluded that either these cells are not present in the circulation of CLL patients or that they are present in small numbers undetectable by this procedure. The possibility that killer cells in CLL patients are diluted by the much larger number of immunoincompetent cells has been ruled out.