Association between the proliferative rate of neoplastic B cells, their maturation stage, and underlying cytogenetic abnormalities in B-cell chronic lymphoproliferative disorders: Analysis of a series of 432 patients

Limited knowledge exists about the impact of specific genetic abnormalities on the proliferation of neoplastic B cells from chronic lymphoproliferative disorders (B- CLPDs). Here we analyze the impact of cytogenetic abnormalities on the proliferation of neoplastic B cells in 432 B-CLPD patients, grouped according to diagnosis and site of sampling, versus their normal counterparts. Overall, proliferation of neoplastic B cells highly varied among the different B-CLPD subtypes, the greatest numbers of proliferating cells being identified in diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Compared with normal B cells, neoplastic B-CLPD cells showed significantly increased S + G₂/M-phase values in mantle cell lymphoma (MCL), B-chronic lymphocytic leukemia (B-CLL), BL, and some DLBCL cases. Conversely, decreased proliferation was observed in follicular lymphoma, lymphoplasmacytic lymphoma/ Waldenstrom macroglobulinemia (LPL/ WM), and some DLBCL patients; hairy cell leukemia, splenic marginal zone, and MALT-lymphoma patients showed S + G ₂/ M phase values similar to normal mature B lymphocytes from LN. Interestingly, in B-CLL and MCL significantly higher percentages of S + G ₂/M cells were detected in BM versus PB and in LN versus BM and PB samples, respectively. In turn, presence of 14q32.3 gene rearrangements and DNA aneuploidy, was associated with a higher percentage of S + G₂/M-phase cells among LPL/WM and B-CLL cases, respectively.