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

The evolution of the pattern of nucleolar organiser regions (AgNORs) in circulating lymphocytes during the stable phase and after chemotherapy in CLL was analysed. Peripheral blood smears were stained by the AgNOR technique at diagnosis, during observation follow-up in stable phase, or at the beginning and at the end of chemotherapy in patients with progressive disease. The changes in the AgNOR pattern were compared with those of TTM used as a tumour burden parameter. Among 52 cases that entered the study, 29 were in stable phase and 23 had progressive disease and received chemotherapy. During stable phase, the AgNORs as well as TTM remained constant. In treated patients, the relative reduction of tumour mass was correlated with a decrease in the percentage of lymphocytes containing one AgNOR cluster. The percentage of cells with one compact nucleolus before chemotherapy was inversely correlated with the relative amount of tumor reduction after treatment. We conclude that the AgNOR pattern in CLL describes the cell kinetic changes during the evolution of the disease and is a prognostic factor for tumor reduction after treatment.