RELATIONSHIP BETWEEN MORPHOMETRIC ANALYSIS OF NUCLEOLAR ORGANIZER REGIONS AND CELL-PROLIFERATION IN ACUTE LEUKEMIAS

Silver-stained nucleolar organizer regions in interphase cells have be en widely studied as a cell kinetic parameter in different tissues. Ma ny different approaches have been used for this evaluation, often lead ing to conflicting results. The aim of our study was to analyze severa l commonly used AgNOR parameters in bone marrow smears of 32 newly dia gnosed cases of acute leukemia: number of clusters and dots, percentag e of cells with one cluster (cells in;a long G1 phase), total and perc entage of silver-stained area per nucleus, mean size of AgNORs, and th e Ruschoff index. These parameters were compared with the in vitro inc orporation of bromodeoxyuridine (BrdU), A significant correlation was found between the BrdU index and the mean number of clusters (r = 0.60 ), dots (r = 0.60), percentage of cells with one cluster (r = -0.63), as well as with the mean size of AgNORs (r = -0.63) and the Ruschoff i ndex (r = 0.72). in a factor analysis, total AgNOR area, its percentag e of nuclear area, the mean AgNOR size, and the nuclear area formed on e factor (factor of area parameters), and clusters, dots, the percenta ge of cells with one cluster, and BrdU index made another factor (fact or of proliferation parameters). The Ruschoff index participated equal ly in both factors. Based on these data, we postulate that the number of clusters and dots are related to the percentage of cells in S-phase and the AgNOR area may be related to the cell duplication time, as ha s been reported in the literature. Mean size of AgNORs is smaller in h ighly proliferating cells. Probably the Ruschoff index is related to t he percentage of cells in S-phase as well as to the cell duplication t ime, and seems to be the best AgNOR parameter for the global evaluatio n of cell kinetics in acute leukemias. (C) 1998 Wiley-Liss, Inc.