Changes in AgNOR configurations during the evolution and treatment of chronic lymphocytic leukemia

The evolution of the pattern of nucleolar organiser regions (AgNORs) in cir culating lymphocytes during the stable phase and after chemotherapy in CLL was analysed. Peripheral blood smears were stained by the AgNOR technique a t diagnosis, during observation follow-up in stable phase, or at the beginn ing and at the end of chemotherapy in patients with progressive disease. Th e changes in the AgNOR pattern were compared with those of TTM used as a tu mour burden parameter. Among 52 cases that entered the study, 29 were in st able phase and 23 had progressive disease and received chemotherapy. During stable phase, the AgNORs as well as TTM remained constant. In treated pati ents, the relative reduction of tumour mass was correlated with a decrease in the percentage of lymphocytes containing one AgNOR cluster. The percenta ge of cells with one compact nucleolus before chemotherapy was inversely co rrelated with the relative amount of tumor reduction after treatment. We co nclude that the AgNOR pattern in CLL describes the cell kinetic changes dur ing the evolution of the disease and is a prognostic factor for tumor reduc tion after treatment.