Number and dynamics of micronuclei and near-tetraploidy predict prognosis in childhood acute leukaemia.

Objectives: This study aims to identify factors possibly contributing to complications in children with acute leukaemia. Despite diverse etiological causes, similar processes trigger the process of cell malignancy. Genomic instability has received considerable attention in this context.

Method: We conducted chromosomal analysis of bone marrow cells and measured the micronuclei (Mn) level in buccal cells over time. Statistical reliability assessment was performed using Analysis of variance (ANOVA), and the data were analyzed and visualized using the SPSS 12 statistical analysis software package.

Results: On the 15th day of treatment, our findings confirmed a statistically significant correlation (χ²=3.88, P=0.04) between the number of blasts in the bone marrow and unfavourable outcome in patients with a near-tetraploid chromosome clone. Additionally, on the 33rd day of treatment, we observed a correlation between an elevated number of Mn and relapses.

Discussion: While it is commonly believed that a hyperdiploid clone with >50 chromosomes in childhood acute lymphoblastic leukaemia confers favorable outcome, our study revealed partially heterogeneous results and poor prognosis in patients with a near-tetraploid clone. We have also identified a correlation between the Mn level on the 33rd day of treatment and the development of complications. It is possible that the increased Mn values and the occurrence of relapses were influenced by the individual patient's sensitivity to the genotoxic effect of the medication.