Coexistence of recurrent chromosomal abnormalities and the Philadelphia chromosome in acute and chronic myeloid leukemias: report of five cases and review of literature.

Progression of chronic myelogenous leukemia (CML) is frequently accompanied by cytogenetic evolution. Additional genetic abnormalities are seen in 10-20% of CML cases at the time of diagnosis, and in 60-80% of cases of advanced disease. Unbalanced chromosomal changes such as an extra copy of the Philadelphia chromosome (Ph), trisomy 8, and i(17)(q10) are common. Balanced chromosomal translocations, such as t(3;3), t(8;21), t(15;17), and inv(16) are typically found in acute myeloid leukemia, but rarely occur in CML. Translocations involving 11q23, t(8;21), and inv(16) are relatively common genetic abnormalities in acute leukemia, but are extremely rare in CML. In the literature to date, there are at least 76 Ph+ cases with t(3;21), 47 Ph+ cases with inv(16), 16 Ph+ cases with t(8;21), and 9 Ph+ cases with t(9;11). But most of what has been published is now over 30 years old, without the benefit of modern immunophenotyping to confirm diagnosis, and before the introduction of treatment regimes such as TKI. In this study, we explored the rare concomitant occurrence of coexistence current chromosomal translocation and t(9;22) in CML or acute myeloid leukemia (AML).

[Identification of complex chromosomal aberrations in acute leukemia by using conventional cytogenetics combined with multiplex fluorescence in situ hybridization].

OBJECTIVE: To explore the value of multiplex fluorescence in situ hybridization (M-FISH) technique in the detection of the complex chromosomal aberrations (CCAs) and marker chromosomes in acute leukemia (AL). METHODS: M-FISH was performed in 11 AL patients with R-banding CCAs or marker chromosomes to define the unrecognized chromosomal aberrations and the constitution of marker chromosomes, and to identify small and cryptic translocations. RESULTS: In the 11 AL cases studied, 27 numerical and 41 structural chromosomal abnormalities were detected by conventional cytogenetics (CC), among which 3 chromosomal gains and 9 chromosomal losses as well as 12 structural abnormalities were confirmed by M-FISH, and another 15 chromosomal losses were revised by M-FISH as derivative chromosomes. M-FISH detected 3 additional chromosomal gains that were undetected by CC. The other 29 structural abnormalities including 17 marker chromosomes were characterized by M-FISH. A total of 33 structural abnormalities were detected by M-FISH, in which 6 were unreported before, i.e. t(5q-;16)(? q14;q24), der(9)(Y::9::Y::9), der(7) (7::8::9), ins(20;21), der(11) (11::21::20) and der(3)t(3p-;13)(3p-;q21), most of which resulted from unbalanced translocations. Almost all chromosomes were involved in CCAs, the more common ones were chromosome 17, 5, 7, 15, 11 in AML and 8, 9, 14, 22 in ALL. CONCLUSION: Combining M-FISH with CC can raise resolution of the latter, which justifies its clinical application for the detection of CCAs and marker chromosomes.

[Study on clonal evolution of monosomy 7 in patients with aplastic anemia by interphase- fluorescence in situ hybridization].

OBJECTIVE: To explore the clonal evolution of monosomy 7 in patients with aplastic anemia (AA). METHODS: Monosomy 7 (-7) in 81 AA patients with normal karyotype at diagnosis and 46 AA treated with immunosuppressive therapy (IST) and more than 6 months of recombinant human granulocyte colony-stimulating factor (rhuG-CSF) were detected by interphase- fluorescence in situ hybridization (FISH) retrospectively. RESULTS: There were 5.4% - 7.6% of -7 cells in 11 (13.6%) of 81 patients at diagnosis, the survival and response rate to IST in -7 positive patients did not differ significantly from that in -7 negative patients (P = 0.481, 0.865); -7 cells disappeared after IST in all of the 11 patients including 5 received long-term rhuG-CSF therapy, and none of them evolved to myelodysplastic syndromes/acute myeloid leukemia (MDS/AML) at a median follow-up of 44 months. Serial assessments of -7 clones were performed in 46 patients, none of whom detected -7 clones 3-6 months after IST, but -7 recurrence in 5 patients 12 - 15 months after IST. At a median follow-up of 48 months, FISH identified 6 patients with -7 clones while the conventional cytogenetic analysis (CCA) recognized in 5. Moreover, the first demonstration of -7 by FISH was 3 - 18 months earlier than that by CCA. All of the 6 patients with FISH detected -7 evolved to MDS/AML with -7 and four of them were retrospectively analysed for in samples at -7 diagnosis of AA, but none of them was positive. CONCLUSIONS: Monosomy 7 exists in a part of AA patients, but the preexisting -7 cells seems neither associated with fatality nor evolvation to MDS/AML. rhuG-CSF might facilitate the expansion of -7 clones; It is necessary to monitor -7 in AA, especially when received long-term rhuG-CSF therapy.

[A comparative cytogenetic analysis in large scale between adult and childhood patients with acute lymphoblastic leukemia].

This study was purposed to comparatively analyze the cytogenetic characteristics between 566 cases of adult acute lymphoblastic leukemia (aALL) and 586 cases of childhood acute lymphoblastic leukemia (cALL). The cytogenetic analysis of all the patients was performed, and the FISH detection for partial patients was carried out. The result showed that the difference of chromosome abnormality between cALL and aALL was statistically significant. The percentage of abnormal karyotypes in aALL was 62.0%, including mainly t(9;22)(q34;q11), hypodiploidy, hyperdiploidy (47 - 50), abn(6q), abn(9p) and -7, most of which conferring an unfavorable prognosis. The percentage of abnormal karyotypes in cALL was 39.2%, composed mainly of high hyperdiploidy, hypodiploidy, TEL/AML1(+), +8, hyperdiploidy (47 - 50) and +21, etc, most of which conferring a favorable prognosis. The incidences of abnormal karyotypes, total hypodiploidy, total hyperdiploidy (47 - 50), t(9;22)(q34;q11), -7, abn(7q), abn(14q32) and +Ph in aALL were significantly higher than those of cALL (p < 0.05), whereas the incidences of normal karyotype (N), high hyperdiploidy, +8, +21*2 and TEL/AML1(+) in cALL were significantly higher than those of aALL (p < 0.05). 20.5% of aALL were Ph+ aALL, with 63.8% of which being with additional abnormalities, composed mainly of +Ph, -7, i (9q+), 9p-, +8, +21, +X, 6q-, abn(14q32) and +14. In contrast, only 4.4% of cALL were Ph+ aALL, with 42.3% of which being with additional abnormalities, including mainly abn(9p), abn(7p), -7, 17p- and +21. It is concluded that almost every chromosome is involved in the numerical and structural abnormalities and complex karyotypes are common. The significant difference of chromosome abnormality exists between aALL and cALL.

[Clinical and laboratory characteristics of 16 patients with acute lymphoblastic leukemia (ALL) harboring 19p13 abnormalities].

OBJECTIVE: To investigate the clinical and laboratory characteristics of patients with acute lymphoblastic leukemia (ALL) bearing 19p13 abnormalities. METHODS: The morphologic, immunophenotypic, cytogenetic, and clinal features as well as prognosis of 16 ALL patients with 19p13 abnormalities were retrospectively analyzed. The clinical features and laboratory findings between t(1;19) and der(19) groups were compared. RESULTS: Sixteen (4.02%) out of 398 ALL patients had 19p13 abnormalities, among them 15 cases were t( 1;19) (q23;p13) [balanced t(1;19) (q23; p13) in 8 and unbalanced der(19) t(1;19) (q23;p13) in 7] and 1 case t(17;19) (q22;p13). The WBC count and blast cell number were higher in the t(1;19) group. The prognosis was better in der(19) t(1;19) group than in balanced translocation t(1;19) group. CONCLUSION: The 19p13 abnormality is one of the non-random chromosomal aberration in patients with ALL. ALL patients with 19p13 abnormalities have unique clinical features and poor prognosis.

[Detection of bcr/abl fusion gene by dual color-dual fusion fluorescence in situ hybridization].

This study was aimed to investigate the sensitivity and clinical application of interphase-dual-color and dual-fusion fluorescence in situ hybridization (DC-DF-FISH). The bcr/abl fusion gene was detected by FISH with dual-color and dual-fusion bcr/abl DNA probe in interphase cells of bone marrow from 1295 specimens. Retrospective analysis for the cases was performed by the means of conventional cytogenetic analysis (CCA) and FISH. The results indicated that in 1295 specimens from 539 patients, 456 specimens were positive involved in 310 patients, the karyotypes of 18 patients were normal, 5 patients failed to karyotyping analysis. About 75.5% (234/310) of positive patients displayed the typical DC-DF-FISH signal pattern, 76 patients showed atypical DC-DF-FISH signal patterns, 66 cases out of which showed variant signal, 16 patients displayed typical variant signals (1Y2G2R), 50 patients displayed deletion ABL and/or BCR signal. In 213 patients, the negative rate was 60% (128/213) after the treatment, 12 patients were sometimes negative and sometimes positive during the process of the treatment. It is concluded that DC-DF-FISH can be used to detect karyotypes with masked or variant Ph, gene deletion and minor residual disease (MRD) in process of treatment. The dual-color FISH technique is a much more sensitive and accurate tool for monitoring MRD and monitoring relapse, which is a necessary supplement to CCA.

[Clinical and laboratory study of a complex translocation t (6; 21; 8) (p22; q22; q22) in two patients with acute myeloid leukemia].

OBJECTIVE: To investigate the clinical and laboratory characteristics of a complex translocation t (6; 21; 8) (p22; q22; q22) in two patients with acute myeloid leukemia. METHODS: Bone marrow (BM) samples were collected at presentation, prepared by short-term (24 hours) unstimulated culture and R-binding, for conventional cytogenetic assay (CCA). The complex translocation was assayed by fluorescence in situ hybridization (FISH) with a dual-color AML1/ETO-specific probe. AML1/ETO chimeric transcript was detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In both cases CCA demonstrated a complex translocation, t (6; 8; 21) (p22; q22; q22), which was confirmed by interphase and metaphase FISH and AML1/ETO fusion transcript was detected by RT-PCR. Both the two patients were diagnosed as AML-M(2), but with different immunophenotype and therapeutic outcome. CONCLUSION: The t (6; 21; 8) (p22; q22; q22) is a rare variant of complex translocation of t (8; 21) (q22; q22). More such cases are needed for elucidating its clinical features and prognosis.

[Conventional cytogenetics and fluorescence in situ hybridization as methods for detecting MLL gene rearrangements in leukemia].

This study was aimed to compare the values of conventional cytogenetics (CC), interphase FISH and sequential R-banding and FISH analysis as methods for detecting MLL gene rearrangements. 37 acute leukemia patients were studied by CC and interphase FISH. The results showed that among them, 10 cases were 11q23(+)/MLL(+), 2 cases were 11q23(-)/MLL(+) (5.4%), 3 cases were 111q23(+)/MLL(-) (8.1%) and 22 cases were 11q23(-)/MLL(-). For some patients, different results were obtained by using CC and interphase FISH for detecting 11q23/MLL gene rearrangements. After sequential R-banding and FISH analysis for 6 patients, the chromosome related to MLL gene translocation was seen clearly in karyotypes and FISH image. It is concluded that for accurate diagnosis both CC and FISH are needed for detecting 11q23/MLL gene rearrangements, and evaluation is needed in combination of these two results. When necessary, it needs to do sequential R-banding and FISH or molecular analysis.