The importance of nucleolar organizer regions in pediatric acute lymphoblastic leukemia

The silver-staining of the nucleolar organizer regions (AgNORs) was performed in patients with acute lymphoblastic leukemia (ALL) to verify the role of cell proliferation in predicting complete remission and survival. Bone-marrow aspiration smears of 20 pediatric cases with ALL, were stained with argyrophilic method during the diagnosis, remission, and 3rd, 6th, 9th, and 12th months after remission. The mean NORs count (NORsc) and the mean of (nucleolar organizer regions surface/total nuclear surface x 100) value (NORss/TNs) for each case were calculated. At diagnosis, the NORsc and NORss/TNs value for the whole series were 3.30+/-0.86 and 4.77+/-1.15, respectively. In complete remission, NORsc and NORss/TNs values were 1.23+/-0.20 and 3.45+/-0.87, respectively, and the differences were statistically highly significant (p < .001). The most important parameters of prognostic factors that effect diagnosis NORss/TNs and NORsc values were found to be FAB morphology and leukocyte count according to the multivariant analysis test. AgNORs analysis is a suitable method to assess cell proliferation in bone marrow aspirate and can predict complete remission, remission duration, and survival in pediatric ALL patients.