Sequential chromosome abnormalities in B cell chronic lymphocytic leukemia: a study of 13 cases.

The chromosomal constitution of stimulated lymphocytes in 13 patients with B cell chronic lymphocytic leukemia (B-CLL) were sequentially examined using polyclonal B cell activators (PBA), i.e., Epstein-Barr virus (EBV), lipopolysaccharide W from E. coli (LPS), pokeweed mitogen (PWM), and protein A from Staphylococcus aureus (PA). Of the 11 patients (44 samplings) with abnormal clones, 2 patients had only trisomy 12, 6 patients had trisomy 12 plus other clonal abnormalities, such as +8, +9, +16, +18, 6q-, 15q+, and t(4;15), and the remaining 3 cases had various clonal abnormalities other than trisomy 12, such as trisomy 3, 8, 20, 21, and insertion of #7 and #12. These findings suggest that even though trisomy 12 may be a common abnormality in B-CLL, various other abnormal clones may also be present in vivo for relatively long periods of time. It appears that stimulated lymphocytes in patients with previous therapy tend to show chromosome abnormalities more frequently than those in untreated patients.