Chromosomal aberrations in progressive and indolent chronic B-lymphocytic leukaemia. A longitudinal study

Chromosome analyses of B-cell mitogen-activated cells from 95 patients with chronic B-lymphocytic leukaemia revealed clonal chromosomal aberrations in 50 patients (53%), of which 24 had an extra chromosome 12 with or without other aberrations. Patients with clonal aberrations, especially those with +12, had poorer survival than other patients. Longitudinal studies, with a mean of 3.5 samplings during a median interval of 3.5 years, were performed in 41 patients, of which 24 (59%) had progressive disease. Twenty-nine of the patients in the longitudinal study (71%), 16 with and 13 without clonal aberrations, retained their karyotype unaltered. In 6 patients a clonal aberration was found only once. Six patients showed minor changes of the karyotype. The karyotype seems to be established at diagnosis, and marks the disease of the individual CLL-patient.