AGNOR CLUSTERS AS A PARAMETER OF CELL-KINETICS IN CHRONIC LYMPHOCYTIC-LEUKEMIA

Aims-To study correlations between the pattern of silver stained nucle olar organiser regions (AgNORs) in chronic lymphocytic leukaemia (CLL) and parameters of tumour kinetics. To investigate whether quantitatio n of the AgNOR pattern can be used to discriminate between patients wi th stable and progressive disease. Methods-Peripheral blood smears fro m 48 patients with CLL, classified as having either stable or progress ive disease (Rai stage III or IV; bulky lymph nodes or massive splenom egaly; or peripheral lymphocytes >100 x 10(9)/1), were studied. For ea ch patient, total tumour mass (TTM) and for patients undergoing a peri od of observation without treatment, the TTM duplication time (DT) and the lymphocyte doubling time (LDT) were calculated. Results-Four cell types could be distinguished according to their AgNOR pattern: (1) ce lls with a single cluster; (2) cells with a single compact nucleolus; (3) cells with two compact nucleoli; and (4) cells with several scatte red dots. The percentage of cells with clusters was the AgNOR paramete r which correlated best with TTM and LDT. Correlations were also seen between the proportion of cells with clusters and age and haemoglobin concentration. A significant correlation with DT could be detected onl y when age was kept constant. Linear discriminant analysis revealed th at the percentage of cells with clusters was the most important progno stic factor. This alone classified 94% of the patients correctly (jack knive procedure) as either stable or progressive CLL. Conclusions-The percentage of circulating lymphocytes with clusters of AgNORs can be u sed as a parameter of tumour kinetics in CLL and helps to discriminate between patients with stable and progressive disease. For practical p urposes, a value of more than 13% of cells with clusters is suggestive of progressive disease.