Christian Chena

Academia Nacional de Medicina, Covunco Centro, Neuquén, Argentina

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Publications (10)15.34 Total impact

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    ABSTRACT: Monoallelic deletion of 13q14.3 (13q14x1) is the most common abnormality in chronic lymphocytic leukemia (CLL). As a sole alteration, it predicts a favorable outcome. Biallelic 13q14.3 (13q14x2) deletion or concomitant 13q14x1/13q14x2 has been scarcely evaluated in the literature. We present the clinical, cytogenetic and fluorescence in situ hybridization (FISH) analysis of six CLL patients with normal karyotypes and 13q14x2 and their comparison to cases with 13q14x1 as a single abnormality. A total of 103 CLL patients were studied. Cytogenetic and FISH analysis were performed on stimulated peripheral blood lymphocytes. Specific fluorescence DNA probes for CLL were used. Six out of 103 (5.8%) patients showed normal karyotypes and 13q14x2. It was observed as a single alteration in one patient and combined with 13q14x1 in five cases. Biallelic clones were larger than monoallelic ones in 3/5 patients (60%). The comparison of clinical and hematological data between 13q14x1 and 13q14x2 groups showed progression of the disease in all 13q14x2 patients respect to 12/32 (37.5%) cases with 13q14x1 (P = 0.008), significant differences in the distribution by Rai stage (P = 0.042) and a tendency of a higher lactate dehydrogenase level in 13q14x2 patients (P = 0.054). Treatment free survival for 13q14x2 group was 28.5 months, shorter than those observed in patients with 13q14x1 alone (49 months). Our data would suggest that 13q14x2 could represent a more aggressive FISH anomaly than 13q14x1 alone, probably as a consequence of clonal evolution and/or due to the complete inactivation of this critical region by mean of more complex mechanisms.
    No preview · Article · Jun 2008 · European Journal Of Haematology
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    ABSTRACT: We describe the cytogenetic, fluorescence in situ hybridization (FISH), and molecular findings in a patient who developed a typical chronic lymphocytic leukemia (CLL) 20 months after the diagnosis of a Philadelphia (Ph)-positive chronic myeloid leukemia. Unstimulated bone marrow culture showed a 46,XX,t(9;22)(q34;q11) karyotype, and interphase FISH detected the presence of a BCR/ABL fusion signal in 13% of cells. On stimulated bone marrow culture, a normal karyotype and a 13q14 deletion by interphase FISH with D13S319 probe in 14% of the cells were found. Molecular studies detected the chimeric BCR/ABL messengers by nested reverse-transcriptase polymerase chain reaction. The B-cellular clone was documented by the presence of a clonal heavy chain immunoglobulin rearrangement. The coexistence of these two hematologic malignancies leads to questions about their cell(s) of origin. We provide evidence that CLL arose in a Ph-negative clone. The implications of these findings are discussed.
    No preview · Article · Sep 2005 · Cancer Genetics and Cytogenetics
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    ABSTRACT: Genomic aberrations can now be identified in approximately 80% of chronic lymphocytic leukemia, small lymphocytic lymphoma (CLL/SLL) patients. In the present study, four new structural changes involving chromosomes 17 and 12 in CLL/SLL patients are described. Five patients were selected for inclusion in the present report among a total of 92 cases with diagnosis of CLL/SLL. Cytogenetic studies and fluorescence in situ hybridization (FISH) analysis to detect some of the most frequent cryptic aberrations occurring in CLL/SLL patients were performed. Clinical studies are also described. Four cases showed structural rearrangements of chromosome 17. A psu dic(17;2)(p11.2;p21), leading to p53 deletion, was observed in a patient who developed a mixed cellularity Hodgkin's disease coexisting with the CLL/SLL in the same lymph node. Epstein Barr virus was detected in the Reed-Sternberg cells. Two cases had a balanced translocation t(2;17)(p21;q23). Both patients showed trisomy 12 and clonal evolution and one of them also had 11q deletion. In addition, a der(17)t(12;17)(q13;q25) as a part of a complex karyotype, and a complex translocation t(5;12;19) (q15;p11;q13) were also found. Four patients had an adverse clinical outcome and died because of disease progression. Four unreported nonrandom chromosome aberrations in CLL/SLL patients, one of them who might represent a new recurrent abnormality, are described. These uncommon abnormalities, mostly associated with evolving disease, may have implications for the understanding of genetic events associated with disease progression in this pathology.
    No preview · Article · Jan 2004 · European Journal Of Haematology
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    ABSTRACT: We have evaluated genomic aberrations by conventional cytogenetics and fluorescence in situ hybridization (FISH) analysis in a series of 57 Argentinean B-cell chronic lymphocytic leukemia (B-CLL) patients. The studies were performed on stimulated peripheral blood lymphocytes. FISH analysis for trisomy 12, 13q14 deletion, and monosomy of TP53 (also known as p53) was performed according to standard protocols. Our results showed 46.3% of patients with clonal chromosomal alterations by conventional cytogenetics and 80.7% by FISH. Trisomy 12 was found in 21.9% of patients by G-banding analysis and in 35% by FISH studies. Allelic loss of 13q14 was observed in 63.2% patients, most of them showing D13S319 and D13S25 deletion; 11% of patients showed TP53 monosomy. Coexistence of trisomy 12 and 13q14 deletion was found in 17.5% of patients. In this group, deletion 13q14 was the prevalent clone, with percentages 25-35% higher than those observed for trisomy 12, suggesting clonal evolution. The coexistence of trisomy 12 with deletion 13q14 was observed in a higher frequency than reported in the literature. A probable adverse prognosis is suggested for this group of patients, likely related to clonal evolution.
    No preview · Article · Nov 2003 · Cancer Genetics and Cytogenetics
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    ABSTRACT: We report the clinical, cytogenetic, fluorescence in situ hybridization (FISH) and molecular findings in a 54-yr-old male patient diagnosed with B-cell chronic lymphocytic leukemia (B-CLL), who showed progression to a diffuse large B-cell lymphoma (Richter's syndrome). Genetic studies were performed at diagnosis and during the Richter's transformation (RT). A clonal karyotype with two dicentric chromosomes, psu dic(12,21)(q24;q10) and dic(17,18)(p11.2;p11.2), was found. Both rearrangements were confirmed by FISH. Molecular cytogenetics analysis using p53 probe showed monoallelic loss of this tumor suppressor gene in 43.8% and 77.3% of cells for the first and the second studies, respectively). In both studies, deletions of D13S319 (18% and 12% of cells) and D13S25 loci (13% and 12% of cells) at 13q14 were found. Polymerase chain reaction analysis showed the MBR/JH rearrangement of the bcl-2 gene. FISH studies using LSI bcl-2/IgH probe allowed quantifying the clonal cell population with this rearrangement (4% and 6.6% of cells at diagnosis and RT, respectively). To our knowledge, this is the first case with a psu dic(12,21) described in B-CLL. The low percentage of cells with the 13q14 deletion and bcl-2/IgH rearrangement suggests that they were secondary events that resulted from clonal evolution. Our patient had a short survival (9 months) and a clear lack of response to several therapeutic agents, confirming the association of p53 gene deletion and karyotypic evolution with disease progression.
    No preview · Article · Nov 2002 · European Journal Of Haematology

  • No preview · Article · Aug 2002 · Medicina
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    ABSTRACT: We have reviewed 4164 patients with various hematologic disorders cytogenetically studied in our laboratory during the last 25 years to analyze the frequency of constitutional chromosome aberrations (CCA) and to evaluate their association with hematologic malignancies. Our population of patients included 1133 pediatric patients and 3031 adults. Twenty-four (0.58%) cases showed CCA. They included four patients with Robertsonian translocations, one patient with a balanced translocation, two patients with sex chromosome abnormalities, and 17 cases with Down syndrome (DS). Nonsignificant differences among the frequency of patients with CCA from our hematologic series and those observed in the two largest combined surveys of livebirth published (0.65-0.84%) were found. The incidence of DS patients in our population (0.41%) was approximately three times higher than of that observed at birth (0.12-0.17%; P<0.001). The total incidence of constitutional chromosome abnormalities in the non-DS hematologic patients was 0.168% (7 of 4164) lower than of that observed in the newborn population (0.51-0.67%; P<0.001). Nonsignificant differences were found when the incidences of structural aberrations and sex chromosome anomalies were individually compared with the data of the overall population. Our results suggest that the presence of a CCA, other than DS, would not predispose patients to hematologic malignancies.
    No preview · Article · May 2002 · Cancer Genetics and Cytogenetics
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    ABSTRACT: Some prognostic factors are useful in chronic lymphocytic leukemia (CLL): lymphocyte doubling time, clinical stage and bone marrow pattern infiltration, while others, such as the percentage of CD38+ cells, are under study and require confirmation. The objective of this study was to evaluate whether there is an association between morphology, lymphocyte immunophenotype, soluble CD23 (sCD23) and progression free survival (PFS). A total of 36 non-treated patients were enrolled. We analysed prospectively: morphology (typical, mixed and PL-CLL); immunophenotypic profile (Matutes score); sCD23 plasma levels; clinical stage; lymphocyte doubling time; beta 2 microglobulin and karyotype abnormalities. Disease progression (need of treatment, progression to advanced stages, development of bulky organomegaly) and death related to disease were considered as events. Md of follow-up 24 mo. RESULTS: Stage 0: 11/36, PFS 80%; I: 10/36 PFS 90%; II: 13/36; III and IV: 2/36. SLE > or = II PFS 37%. p = 0.023. Lymphocyte doubling time < 12mo. 7/31; > 12mo. 24/31. PFS 28% vs. 80% p < 0.001. Karyotype: normal 13/28, abnormal 15/28. PFS 92% vs. 54% p = 0.053. Trisomy 12: positive 7/30, negative 23/30, PFS 66% vs. 65%. beta 2 microglobulin: normal 9/35; high 26/35. PFS 100% vs. 53% p = 0.006. sCD23 < 350 Ul/ml: 15/32; > 350 Ul/ml: 17/32. PFS 92% vs. 53% p = 0.005. Immunophenotype: Score 5: 15/36, Score 4: 19/36, PFS 64%. Score 3: 2/36. p = 0.516. Morphology: typical 17/35, mixed 17/35, PFS 81% vs. 57%, p = 0.099. PL-CLL 1/35. CONCLUSIONS: sCD23 was suitable to predict PFS, specially useful for early stages without additional markers of active disease. Morphology (excluding PL-CLL) and immunophenotype, two common tools, were not useful for the study purpose.
    No preview · Article · Jan 2002 · Medicina
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    ABSTRACT: Cases with partial trisomy 12 have rarely been found in B-cell chronic lymphocytic leukemia (CLL). We report our clinical, cytogenetic and fluorescence in situ hybridization (FISH) findings in a CLL patient with a duplication of part of the long arm of chromosome 12 between bands q13–q22. This patient was the only case with this duplication among the 112 cases (0.9&percnt;) of CLL cytogenetically analyzed in our laboratory. FISH studies using unique-sequence specific probes for the RB-1 (retinoblastoma) gene and the D13S319 locus at the 13q14 band showed a monoallelic loss for the D13S319 locus (20&percnt; of cells) with a diploid RB-1 gene. Our case showed an atypical morphology (35&percnt; prolymphocytes), a high proliferation rate and progression of the disease, indicating that the duplication of this region may be equivalent to complete trisomy 12 in CLL patients.
    No preview · Article · Jan 2000 · Acta Haematologica
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    ABSTRACT: We report a case of B-cell chronic lymphocytic leukemia (B-CLL) with aberrant expression of the T-cell-associated antigen CD8, as revealed by two-color flow-cytometric analysis. DNA studies showed immunoglobulin heavy-chain gene rearrangement, but not of gamma-chain T-cell receptor, confirming the B-cell origin of the neoplastic cells. Ploidy analysis showed a tetraploid population and high S-phase fraction. B-CLL cells also carried trisomy 12, detected by fluorescence in situ hybridization. The identification of more cases with the same features would be necessary to establish the prognosis of this subtype of B-CLL.
    No preview · Article · Feb 1999 · Acta Haematologica