Nonrandom Chromosomal Aberrations in Chronic Lymphocytic Leukemia Revealed by Polyclonal B-CelI-Mitogen Stimulation

Peripheral blood lymphocytes from 1 1 patients with chronic lymphocytic leukemia were stimulated by Epstein-Barr virus (EBV), lipopolysaccaride from Escheirichia (LPS), and phytohemagglutinin (PHA). Chromosome analysis with the Q-banding technique after 5 days incubation revealed an extra chromosome 1 2 in 5 of the patients and a translocation between chromosome 1 1 and chromosome 1 4 in 1 . Two patients had a deletion of chromosome 6, and only 3 patients had a normal karyotype. In most patients, the abnormalities were found in the majority of metaphases after stimulation with EBV, IPS, or both mitogens, while PHA revealed a normal karyotype, with the exception of a total of 4 metaphases in 3 patients. An extra chromosome 1 2 appears to be specifically associated with chronic lymphocytic leukemia. The frequency of chromosomal abnormalities in this disease appears to be much higher than has previously been thought.