Analysis of proliferating cell fraction determined by monoclonal antibody to M1-subunit ribonucleotide reductase and Ki-67 in relation to p53 proteinexpression in fine-needle aspirates from non-Hodgkin's lymphomas

The purpose of this study was to analyse the proliferative fraction with th e monoclonal antibody M-1-R-R to M1-subunit ribonucleotide reductase and wi th MIB-1 to Ki-67 antigen in relation to p53 protein expression in fine nee dle aspirates from B-cell non-Hodgkin's lymphomas. One hundred and thirty-seven cases, previously diagnosed and sub-typed acco rding to the Kiel classification and characterized by immunophenotyping, we re included in the study. The M-1 subunit ribonucleotide reductase (M-1-R-R ), Ki-67 and p53 antigens were detected using monoclonal antibodies on stor ed cytospin preparations. There was a good correlation (r = 0.72) between Ki-67 and M-1-R-R positive cell fraction in both high and low grade lymphomas, High-grade lymphomas ha d a median percentage of M-1-R-R/MIB-1 positive cells of 53.0/73.0 for lymp hoblastic, 61.0/52.0 for immunoblastic and 33.5/41.0 for centroblastic lymp homas, respectively. In low grade lymphomas figures of median percentage of M-1-R-R/MIB-1 were 9.0/15.0 for centroblastic/centrocytic, 11.0/9.5 for ch ronic lymphocytic leukaemia, 16.0/27.0 for centrocytic and 12.0/9.0 for imm unocytomas, respectively. The median percentages of M-1-R-R/MIB-1 for high and low grade lymphomas were 37.0/50.5 and 11.0/12.0, respectively. In the p53 positive cases the proliferation rate as measured by staining for M-1-R -R and MIB-1 was higher than in p53 negative cases, but the difference was not statistically significant. The results show that cytospin material obtained by fine needle aspiration and stored at -70 degrees C for years can be used reliably for both peroxid ase-avidin-biotin and three-step alkaline phosphatase immunocytochemical st aining. In addition, proliferation fraction determined by M-1-R-R monoclona l antibody staining correlates well with that measured by an established ma rket for cell proliferation, the Ki-67 antibody. However, the proliferation fraction as measured by the two antibodies diffe rs in the various subtypes of non-Hodgkin's lymphoma which indicates that t hey may contribute different prognostic information.