Kim Champion

The hallmark of chronic myeloid leukemia (CML) is the BCR-ABL fusion gene, which is usually formed as a result of the t(9;22) translocation. Patients with CML show considerable heterogeneity both in their presenting clinical features and in the time taken for evolution to blast crisis. In this study, metaphase fluorescence in situ hybridization showed that a substantial minority of patients with CML had large deletions adjacent to the translocation breakpoint on the derivative 9 chromosome, on the additional partner chromosome in variant translocations, or on both. The deletions spanned up to several megabases, had variable breakpoints, and could be detected by microsatellite polymerase chain reaction in unfractionated bone marrow and purified peripheral blood granulocytes. The deletions were likely to occur early and possibly at the time of the Philadelphia (Ph) chromosome translocation: deletions were detected at diagnosis in 11 patients, were found in all Ph-positive metaphases, and were more prevalent in patients with variant Ph chromosomes. Kaplan-Meier analysis showed a median survival time of 36 months in patients with a deletion; patients without a detectable deletion survived > 90 months. The survival-time difference was significant on log-rank analysis (P =. 006). Multivariate analysis demonstrated that the prognostic importance of deletion status was independent of age, sex, percentage of peripheral blood blasts, and platelet count. Our data therefore suggest that an apparently simple, balanced translocation may result not only in the generation of a dominantly acting fusion oncogene but also in the loss of one or more genes that influence disease progression. (Blood. 2000;95:738-743)

We evaluated the role of granulocyte colony-stimulating factor (G-CSF) in patients with severe aplastic anemia (SAA) treated with antithymocyte globulin (ATG) and cyclosporine (CSA). Between January 2002 and July 2008, 192 patients with newly diagnosed SAA not eligible for transplantation were entered into this multicenter, randomized study to receive ATG/CSA with or without G-CSF. Overall survival (OS) at 6 years was 76% ± 4%, and event-free survival (EFS) was 42% ± 4%. No difference in OS/EFS was seen between patients randomly assigned to receive or not to receive G-CSF, neither for the entire cohort nor in subgroups stratified by age and disease severity. Patients treated with G-CSF had fewer infectious episodes (24%) and hospitalization days (82%) compared with patients without G-CSF (36%; P = .006; 87%; P = .0003). In a post hoc analysis of patients receiving G-CSF, the lack of a neutrophil response by day 30 was associated with significantly lower response rate (56% vs 81%; P = .048) and survival (65% vs 87%; P = .031). G-CSF added to standard ATG and CSA reduces the rate of early infectious episodes and days of hospitalization in very SAA patients and might allow early identification of nonresponders but has no effect on OS, EFS, remission, relapse rates, and mortality. This study was registered at www.clinicaltrials.gov as NCT01163942.

Studies of X chromosome inactivation patterns are central to many aspects of our understanding of the pathogenesis of haematological malignancies. In patients with myeloproliferative disorders and myelodysplastic syndromes the demonstration of skewed X inactivation patterns in multiple haemopoietic lineages has been taken to indicate a stem cell origin for these groups of diseases. However, stem cell depletion or selection pressures can also produce skewed X inactivation patterns and might increase with age. We have therefore used the HUMARA assay to study X inactivation patterns of elderly patients with myeloproliferative disorders together with an age‐matched control group of normal elderly women. A clonal pattern (clonal granulocytes and polyclonal T cells) was observed in 23.1% of normal women and 63.4% of patients with myeloproliferative disorders. This is the first report of X inactivation patterns in purified subpopulations of blood cells in normal elderly women. These results have three significant implications. Firstly, the finding of clonal granulocytes and polyclonal T cells in normal elderly women is likely to reflect age‐related stem cell depletion or selection pressures. Secondly, the demonstration of clonal granulocytes and polyclonal T cells is not a useful diagnostic marker for myeloproliferative disorders or myelodysplastic syndromes in elderly women. Thirdly, our data raise the possibility that clonal blood cell patterns may precede rather than follow mutations which subsequently give rise to myelodysplastic or myeloproliferative phenotypes.