FLOW CYTOMETRIC EVALUATION OF PROLIFERATING CELL NUCLEAR ANTIGEN EXPRESSION IN HUMAN HEMATOPOIETIC MALIGNANCIES

Cell proliferation is a strong prognostic factor in various malignanci es including non-Hodgkin's lymphoma's (NHL). Several methods to evalua te tumour proliferation are available based on immunohistochemical and flow cytometric techniques, but none has been widely accepted for mul ticenter studies. In the present study 51 samples from patients with h aematological disorders were analysed for the expression of proliferat ing cell nuclear antigen (PCNA) by a previously described flow cytomet ric approach. S-phase specific PCNA (PCNA-S) as well as growth fractio n-associated PCNA (PCNA-tot) expression were evaluated. The mean value for PCNA-S was 9,0% and for PCNA-tot 17,4%. PCNA-S and PCNA-tot corre lated strongly to each other (r(s) = 0.969, p < 0.001) and to the S-ph ase fraction determined by DNA histogram analysis (r(s) = 0.927 and 0. 934 respectively, p < 0.001). In 23 cases with NHL in vivo iododeoxyur idine (IdUrd) labelling was performed to assess the labelling index (I dUrd-LI, i.e. S-phase fraction), S-phase duration time (Ts) and potent ial tumour doubling time (Tpot). IdUrd-Li correlated significantly to both PCNA-S and PCNA-tot (r(s) = 0.704 and 0.622 respectively, p < 0.0 01 and 0.02). In conclusion, especially the PCNA-S seemed to be a cand idate for future larger studies of proliferation related aspects of ha ematological malignancies.