ASXL1 gene alterations in patients with isolated 20q deletion.

Deletion 20q is a recurrent abnormality in myeloid malignancies. In our previous study, we identified fusion of the additional sex combs-like 1 (ASXL1) and teashirt zinc finger homeobox 2 genes in a patient with myelodysplastic syndrome. The objective of this study was to determine the frequency of ASXL1 breakpoints in a cohort of 36 patients with deletion 20q as the sole cytogenetic aberration. A combination of molecular cytogenetic methods was used to confirm ASXL1 gene alterations in 19 of the 36 patients, and the determination of ASXL1 gene changes in patients with deletion 20q revealed clinical and prognostic impacts.

Clonal evolution in chronic lymphocytic leukemia studied by interphase fluorescence in-situ hybridization.

The results of repeated interphase fluorescence in-situ hybridization (I-FISH, FISH) examination of 97 CLL patients and correlation of these findings with IgVH hypermutation status, ZAP-70 and CD38 expression are presented. The appearance of new, FISH-detectable, genomic aberrations during disease course, described as clonal evolution (CE), was observed in 26% of patients. The most frequent newly acquired cytogenetic abnormality was 13q deletion in 64% (16/25). In contrast to earlier studies, there was no correlation found between CE and either one of single negative prognostic factors (unmutated IgVH; CD38 positivity; ZAP-70 positivity). However, the combination of all three negative factors correlated with CE highly significantly (p=0.005) and moreover, also with a shift from lower to higher FISH risk category (p=0.010). As the prognostic data were known in all patients, this study represents the complete insight on the association of CE and other risk parameters in CLL.

Combined molecular biological and molecular cytogenetic analysis of genomic changes in 146 patients with B-cell chronic lymphocytic leukemia.

Interphase fluorescence in situ hybridization was used to detect common deletions in B-CLL patients as well as trisomy 12 and aberrations of IgH gene complex at 14q32.33 where we evaluated not only translocation-like signal pattern but also deletions. 120 (82%) patients showed genetic changes - del(13)(q14) 95 (62%), deletion of ATM gene 22 (15%), deletion of p53 gene 25 (17%) and trisomy 12 was proved in 18 (12%) cases. IgH rearrangements were detected in 45 (31%), split of the signals in 11 (8%), deletion of 3' segment flanking IgH gene in 5 (3%) and deletions of variable segment in 29 (20%) patients. Although deletions of 3' segment flanking IgH gene complex are supposed to have an adverse prognostic impact and the genetic background of variable segment deletions is believed to be most probably physiological, we assumed a detailed mapping of the 14q32.33 region will be needed to unravel these mysteries.

Prognostic relevance of the FAB morphological criteria in chronic lymphocytic leukemia: correlations with IgVH gene mutational status and other prognostic markers.

Morphological examination is the routine first step in the diagnosis of hematological malignancies, including chronic lymphocytic leukemia (CLL). Atypical cell morphology according to the FAB criteria is known to herald disease progression. Several years ago, it was proposed that FAB morphology at diagnosis had a considerable prognostic impact. However, this proposal has not been widely adopted in practice. Thus we questioned the prognostic value of the morphological examination, which was performed retrospectively in 88 patients out of our 110 institutional registry patients (70 males and 40 females, median age 57 yrs) with CLL at diagnosis. We related the results to the more modern prognostic markers. Atypical FAB morphology was shown to correlate with IgVH gene mutation status, trisomy of chromosome 12 and deletion of 17p detected either by conventional G-banding or by fluorescence in situ hybridization (FISH) analysis. The correlation of FAB morphology with CD38 antigen expression or with the histopathological pattern of bone marrow infiltration was not significant. Overall survival (OS) data were available for 84 morphologically examined patients. The patients with atypical morphology (64 patients) had a significantly shorter OS (103 months) than the 20 patients presenting with typical CLL morphology (237 months; p=0.03). Only the mutation status of IgVH genes correlated more closely with OS (p=0.002). Of note, there was no leukemia-related death within "unmutated" cases who had typical FAB morphology (p=0.14), and vice versa, the mutation status had a significant prognostic impact within the morphologically atypical cases (p=0.01). Thus FAB morphology and the mutation status may yield complementary prognostic information. OS was affected both by the presence of cytogenetic aberrations (p=0.03) - most adversely by deletions of 17p and 11q, and by CD38 expression (p=0.003). We conclude that careful examination of peripheral blood smears according to FAB is a simple, cheap and valuable tool in the first-line assessment of prognosis of CLL patients and should not be overlooked even in 3rd millennium when more sophisticated prognostic markers are at hand. This ought to be confirmed in larger prospective studies with multivariate analysis of data.