FLOW-CYTOMETRY DETECTION OF MINIMAL DNA ANEUPLOIDY IN MATURE LYMPHOIDLEUKEMIAS - COMPARISON WITH METAPHASE AND INTERPHASE CYTOGENETICS

The relative DNA content of peripheral blood cells from 79 cases with lymphoid leukemias was analyzed by a dual-parameter flow cytometric an alysis. The leukemia samples corresponded to: chronic lymphocytic leuk emia (CLL) 40, CLL with more than 10% prolymphocytes (CLL/PL) 12, CLL mixed 9, prolymphocytic leukemia (PLL) 5, and B-cell lymphoma in leuke mic phase 13. DNA aneuploidy was found overall in 26 (32.9%) of the ca ses and these corresponded to: 7 (17.5%) with CLL, 7 (58.3%) with CLL/ PL, 4 (44.4%) with CLL mixed, 2 (40%) with PLL and 6 (46.2%) with B-ce ll lymphoma. There was a good correlation between DNA content and cyto genetics/fluorescent in situ hybridization in all but 2 cases as follo ws: 6 of 7 cases with diploid DNA had normal karyotype and only one ha d trisomy 12: 4 of 6 cases with hyperdiploid DNA had trisomy 12, one h ad tetraploidy and only one had a normal karyotype. Two cases were hyp odiploid both by DNA and cytogenetic analysis. Our findings demonstrat e a higher incidence of DNA aneuploidy in B-cell lymphoma in leukemic phase, PLL, and atypical CLL in comparison with typical CLL and a good correlation with cytogenetics. We conclude that flow cytometric DNA a nalysis represents a useful, sensitive, and rapid method to detect and monitor minimal changes of DNA content in leukemic lymphocytes withou t the need of short-term cultures.