[Leukemic B-cell colony formation in patients with B-cell prolymphocytic leukemia]

We performed in vitro B cell colony assay after coculture with phytohemagglutinin-P (PHA-P) and some cytokines (IL-2, IL-4, IL-6 and PHA-MTCM) in B leukemic cells from B-PLL and B-CLL patients. The number of colonies generated with PHA and PHA-MTCM was significantly smaller in patients with B-PLL than B-CLL. The surface markers of colony cells from a PLL patient were similar to those of circulating leukemic cells of the patient. IL-2, IL-4 and IL-6 did not enhance PHA-induced B cell colony formation in B-PLL. The expression of CD23 and CD25 antigens of the PLL cells was not enhanced after coculture with PHA for 72 hours in contrast to the enhancement of these antigens in B-CLL. B-PLL cells might be less responsive to PHA than B-CLL cells.