Monoclonal CLL B-cells may be induced to grow in an in vitro B-cell colony assay system

Abstract

A simple reproducible in vitro B-cell colony assay system was used to evaluate B-cell growth in controls and patients with chronic lymphocytic leukemia (CLL). All six CLL patients studied formed B-cell colonies. The number of colonies was significantly less in patients than controls (66 +/- 18 versus 127 +/- 8). CLL colonies were shown to be monoclonal and appeared to reflect the circulating malignant B-cell clone in our patient group, while the six controls studied formed polyclonal B-cell colonies. Wright-Giemsa staining showed typical plasma cells to have developed in the controls but not in the patients. Cells from CLL patients retained a more lymphoid appearance. It is believed that investigations with this B-cell assay will provide the means for further in vitro evaluation of malignant B-cell proliferation in other lymphoproliferative disorders.

In vitro growth of myeloma cells*

“…The PE ranged from 0.25 to 2.69%. These assays, with minor modifications, have been subsequently applied to study the proliferative state and radiosensitivity of bone marrow MM cells (8), the characterization of normal peripheral blood lymphocyte clonogenic cells (9), and the growth of polyclonal B-cell colonies from normal healthy volunteers, with development of typical plasma cells (10).…”