Flow cytometric analysis of the immunophenotype of leukemic B-cells has proved to be of additional value in the study of CLPD, especially as regards prognostic assessment. In this area, expression of several cell surface and intracellular immunophenotypic markers has been correlated with prognosis in B-CLPD. As an example, proliferation-associated markers—evaluated either as the proportion of CD71+ and Ki67+/MIB1+ cells or the percentage of S-phase cells— have proved to be of prognostic relevance in B-CLPD other than CLL (4,88,89): high numbers of proliferating cells correlate with a higher tumor grade in NHL and worse clinical outcome (4,88). Similarly, recent studies suggest that quantitative evaluation of P-integrin levels expression on neoplastic B-cells correlates with the metastatic potential of the disease in patients with B-cell NHL (95).
The use of new treatment strategies based on protein targets present on the surface of neoplas-tic B-cells will potentially expand the prognostic utility of immunophenotyping in CLPD as regards prediction of response to therapy. As an example, large multicenter studies (10) have recently shown higher response rates to anti-CD20 therapy in patients with FL, MCL, and LPL, compared with CLL/SLL cases. These findings suggest the existence of an association between the levels of CD20 expression on neoplastic B-cells and response to anti-CD20 therapy, as the number of CD20 molecules per cell is typically lower in CLL/SLL than in the other groups of B-CLPD patients (11,12,52). Also, further studies are necessary in this field both to confirm such preliminary observations and to determine whether this also applies to other treatment protocols that directly target markers expressed on the surface membrane of the neoplastic B-cells such as CD52 (9,96).
Was this article helpful?