Clinical implications of CLL cell proliferation in vitro

CLL-cell proliferation in vitro, as indicated by tritium-labelled thymidine uptake, was studied in 4-day cultures with or without the B-cell mitogens lipopolysaccharide (LPS), dextran sulphate (DxS) and Epstein-Barr virus (EBV). Thymidine uptake was not associated with Rai or Binet stage, but following mitogenic stimulation it was significantly greater in CLL-cell clones with an extra chromosome 12 or multiple chromosomal aberrations as compared to cell clones with normal karyotypes. Unstimulated thymidine uptakes did not predict outcome, but high proliferative responses to LPS- or DxS-stimulation were significantly associated with poor survival.