Chromosome abnormalities in chronic lymphocytic leukemia revealed by cytochalasin B and Epstein-Barr virus.

Peripheral blood lymphocytes from eight patients with chronic lymphocytic leukemia (CLL) were cultured with Epstein Barr virus (EBV) and cytochalasin B. All eight cytochalasin B cultures had analyzable metaphases whereas only six of the EBV cultures were successful. Furthermore, the number of abnormal metaphases and the mitotic indices were greater in the cytochalasin B cultures than in the EBV cultures. Trisomy 12, alone or in combination with other abnormalities, was the most frequent cytogenetic finding. Structural abnormalities of chromosomes #6 and #14 were also found. Cytochalasin B appears to be an effective mitogen for demonstrating abnormal metaphases in patients with CLL.