Monosomy 21 in hematologic diseases

Clonal chromosomal aberrations in Philadelphia negative cells such as monosomy 7 and trisomy 8 may persist for years with no impact on the long term outcome in patients with chronic myeloid leukemia

The appearance of clonal chromosomal aberrations in Philadelphia negative cells (CCA/Ph-) during the treatment of chronic myeloid leukemia (CML) was recently confirmed. Importance of these findings has not been clearly defined. We present data on the time of appearance, persistence, size of the CCA/Ph- clone in terms of drugs used and hematological, cytogenetic and molecular response rates. The focus was on the peripheral blood cytopenias and myelodysplastic changes in the bone marrow microscopic evaluation. In 5 out of 155 (3,2%) CML patients, the persistent presence (up to nine years) of CCA/Ph- was found (monosomy 7 and trisomy 8 in unrelated clones in two patients treated with tyrosine kinase inhibitors; trisomy 8 in two patients on imatinib; trisomy 21 in one patient on interferon alfa treatment). Aberrations were present in median 24% Ph- cells in 3-15 subsequent analyses at different cytogenetic and molecular response time points. No evident myelodysplastic changes nor transformation to MDS/AML occurred in patients with CCA/Ph-. All the patients achieved major molecular response (MMR). It seems that CCA/Ph- presence does not affect the long term outcome in patients with chronic myeloid leukemia. Further complex monitoring of the CML patients with CCA/Ph- is still needed.

Transformed aggressive γδ-variant T-cell large granular lymphocytic leukemia with acquired copy neutral loss of heterozygosity at 17q11.2q25.3 and additional aberrations

T-cell large granular lymphocytic leukemia (T-LGLL) is a rare indolent lymphoproliferative disorder characterized by cytopenias, splenomegaly, and various degrees of T-cell lymphocytosis, due to a clonal expansion of CD8-positive cytotoxic T-cells. Phenotypic variants of T-LGLL include CD4(+) /CD8(-) T-cells, with dual CD4(-) /CD8(-) /γδ(+) T-cells being even rarer. Cytogenetic abnormalities in T-LGLL have rarely been reported, and there is scientific debate regarding the existence of aggressive or transformed variants of T-LGLL. We report a patient with T-LGLL, γδ variant, with nearly 20-year-long duration of cytopenias before transformation to an unusual clinical scenario, manifesting with marked lymphocytosis >100 × 10(9) /L and infiltration of lymph nodes, tonsils, and subcutaneous tissue. Single-nucleotide polymorphism assays revealed acquired copy neutral loss of heterozygosity at 17q and deletion of 3p21.31, in addition to trisomy 5, monosomy X, and monosomy 21. These genetic abnormalities provided a better understanding of the molecular nature and the potentiality of disease transformation.

Clinical significance of cytogenetic aberrations in bone marrow of patients with diffuse large B-cell lymphoma: prognostic significance and relevance to histologic involvement

Background

Although knowledge of the genetics of diffuse large B-cell lymphoma (DLBCL) has been increasing, little is known about the characteristics and prognostic significance of cytogenetic abnormalities and the clinical utility of cytogenetic studies performed on bone marrow (BM) specimens. To investigate the significance of isolated cytogenetic aberrations in the absence of histologic BM involvement, we assessed the implication of cytogenetic staging and prognostic stratification by a retrospective multicenter analysis of newly diagnosed DLBCL patients.

Methods

We analyzed cytogenetic and clinical data from 1585 DLBCL patients whose BM aspirates had been subjected to conventional karyotyping for staging. If available, interphase fluorescence in situ hybridization (FISH) data were also collected from patients.

Results

Histologic BM involvement were found in 259/1585 (16.3%) patients and chromosomal abnormalities were detected in 192 (12.1%) patients (54 patients with single abnormalities and 138 patients with 2 or more abnormalities). Isolated cytogenetic aberrations (2 or more abnormalities) without histologic involvement were found in 21 patients (1.3%). Two or more cytogenetic abnormalities were associated with inferior overall survival (OS) compared with a normal karyotype or single abnormality in both patients with histologic BM involvement (5-year OS, 16.5% vs. 52.7%; P < 0.001) and those without BM involvement (31.8% vs. 66.5%; P < 0.001). This result demonstrated that BM cytogenetic results have a significant prognostic impact that is independent of BM histology. The following abnormalities were most frequently observed: rearrangements involving 14q32, 19q13, 19p13, 1p, 3q27, and 8q24; del(6q); dup(1q); and trisomy 18. In univariate analysis, several specific abnormalities including abnormalities at 16q22-q24, 6p21-p25, 12q22-q24, and -17 were associated with poor prognosis. Multivariate analyses performed for patients who had either chromosomal abnormalities or histologic BM involvement, revealed IPI high risk, ≥ 2 cytogenetic abnormalities, and several specific chromosomal abnormalities, including abnormalities at 19p13, 12q22-q24, 8q24, and 19q13 were significantly associated with a worse prognosis.

Conclusions

We suggest that isolated cytogenetic aberrations can be regarded as BM involvement and cytogenetic evaluation of BM improves staging accuracy along with prognostic information for DLBCL patients.

Loss of the extra chromosome 21 in a patient with Down syndrome and myelodysplasia

Monosomy 21 is a rare acquired karyotypic abnormality associated with myeloid disorders. Occurrence of loss of one chromosome 21 in the background of trisomy 21 in Down syndrome, resulting in the pseudo-normalization of trisomy 21, is a novel finding. The case is described of a patient with Down syndrome who acquired such a genetic abnormality as a result of myelodysplastic syndrome.