Chronic myelogenous leukemia in the course of chronic lymphocytic leukemia: evidence for an independent clonal origin

We report on a 69-year-old man who developed Ph-positive CML 6 years after the onset of B-cell CLL. When CML was diagnosed, both malignant cell populations were detected in bone marrow and peripheral blood. Peripheral leukocytes were fractionated by Ficoll-Hypaque density gradient, and cytogenetic and molecular studies were performed on mononuclear cell and granulocyte-enriched populations. Mononuclear cells were stimulated with either PHA or PWM. In PHA-treated cultures 76% of the metaphases were Ph-negative, while after PWM stimulation 87% were Ph-positive. A bcr rearrangement was observed in DNA from the granulocyte-enriched fraction, but not in mononuclear cells. On the contrary the IgH locus resulted in monoclonally rearranged DNA, only in peripheral blood mononuclear cells. These results indicate that the two neoplastic populations originated independently.     

负载慢性髓系白血病28的树突状细胞介导的抗淋巴细胞白血病效应

目的 构建慢性髓系白血病(CML)28的树突状细胞(DC)核酸疫苗,观察其对淋巴细胞白血病的抗肿瘤效应.方法 从pcDNA3.1HisA-CML28中克隆出6×His及CML28的cDNA全长,酶切后连接至真核表达载体pIRES2-增强型绿色荧光蛋白(EGFP);从健康人外周血中分离外周血单个核细胞(PBMC),在白介素4(IL-4)和粒-巨噬细胞集落刺激因子(GM-CSF)条件下诱导分化为DC;用电穿孔法将重组质粒pIRES2-EGFP-CML28导入DC,Western blot检测His-CML28融合蛋白的表达,荧光显微镜检测EGFP的表达;用表达CML28的DC刺激同基因型淋巴细胞作为效应细胞,淋巴细胞白血病患者的PBMC作为靶细胞,以乳酸脱氢酶(LDH)释放实验测定其抗肿瘤效应.结果 重组质粒pIRES2-EGFP-CML28导入DC后,能正确表达His-CML28融合蛋白及EGFP.经表达CML28的DC刺激的同基因型淋巴细胞能特异性杀伤淋巴细胞白血病患者的PBMC,杀伤率为68.3%,明显高于空白对照组(25.8%)和阴性对照组(20.7%),差异有统计学意义(P<0.01);而对健康人PBMC的杀伤活性较弱,杀伤率为20.5%.结论 CML28能诱导特异性的细胞免疫,负载CML28的DC疫苗在体外对淋巴细胞白血病具有显著的抗肿瘤效应.     

Interstitial insertion of varying amounts of ABL-containing genetic material into chromosome 22 in Ph-negative CML

We studied the cells from three selected patients with Ph-chromosome-negative chronic myeloid leukemia (CML) by Southern blotting, polymerase chain reaction, and in situ hybridization of informative probes to metaphase chromosomes. All three patients had rearrangement of M-BCR sequences in the BCR gene and expression of one or other of the mRNA species characteristic of Ph-positive CML. Leukemic metaphases studied after trypsin-Giemsa banding were indistinguishable from normal. The ABL probe localized both to chromosome 9 and 22 in each case. A probe containing 3' M-BCR sequences localized only to chromosome 22, and not to chromosome 9 as would be expected in Ph-positive CML. Two new probes that recognize different polymorphic regions distal to the ABL gene on chromosome 9 in normal subjects localized exclusively to chromosome 9 in two patients and to both chromosomes 9 and 22 in one patient. These results show that Ph-negative CML with BCR rearrangement is associated with insertion of a variable quantity of chromosome 9 derived material into chromosome 22q11; there is no evidence for reciprocal translocation of material from chromosome 22 to chromosome 9.     

Intensive combination chemotherapy and autologous bone marrow transplantation leads to the reappearance of Philadelphia chromosome-negative cells in chronic myelogenous leukemia.

Fifteen patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) who were ineligible for allogeneic bone marrow transplantation (BMT) or alpha-interferon therapy were included in this study. Eight patients were in the first late chronic phase, five were in the second chronic phase, one was in the accelerated phase, and one was in the blastic phase. Autologous bone marrow cells (median, 2.5 x 10(8) nucleated cells/kg) were stored at a median of 30 months after diagnosis. Patients were treated with cyclophosphamide (1.5 g/m2 daily for 4 days), carmustine (BCNU) (300 mg/m2), and etoposide (VP-16) (250 mg/m2 daily for 3 days) (CBV), followed by reinfusion of autologous bone marrow. Hematopoietic recovery was rapid, and toxicity was mild to moderate in 14 patients. One patient died of cytomegalovirus pneumonitis. Eight of 15 patients showed Ph suppression to less than 90% Ph-positive metaphases after autologous BMT. Major cytogenetic responses (Ph suppression to less than 35% Ph-positive metaphases) developed in four patients. Cytogenetic responses were observed in 4 of 11 patients infused with 100% Ph-positive marrows, and in all 4 patients infused with Ph-mosaic marrows (mixture of diploid and Ph-positive cells). Better results were observed when autologous BMT was performed in the chronic phase compared with the advanced phases. The major cytogenetic responses have lasted for 3, 4, 12, and 15+ months, whereas minor cytogenetic responses lasted for only a short time (less than 2 months). Three of seven patients (43%) in the chronic phase with previous resistance to alpha-interferon therapy became sensitive to alpha-interferon therapy after autologous BMT. The authors concluded that intensive chemotherapy followed by autologous BMT produced cytogenetic remissions in patients with Ph-positive CML and reinduced disease sensitivity to alpha-interferon therapy in patients previously resistant to it. This is particularly useful when treatment is given during the chronic phase and stem cells are collected at a time of previous cytogenetic remission.     

T-cell involvement in benign phase chronic myelogenous leukemia

T cells from the peripheral blood of patients with chronic myeloid leukemia (CML) were cultured with phytohemagglutinin and T-cell growth factor (TCGF) in agar culture. These T-cell colonies were pooled and expanded further in liquid culture with TCGF and then simultaneously analysed for the E-rosette receptor with the monoclonal antibody OKT11 and for the presence of the Philadelphia (Ph¹) chromosome. OKT11 analysis showed these populations to be composed 99.5% or more of T cells. In four of the seven patients the T-cell suspension showed 7/50 (14%), 3/36 (8%), 2/34 (6%), and 4/44 (9%) Ph' metaphases. Furthermore, Ph¹ metaphases were demonstrated in T-cell cultures in two patients when bone marrow metaphases simultaneously showed 90 and 100% Ph¹ negative metaphases secondary to human leukocyte interferon therapy or combination chemotherapy. A minority of T cells in benign phase CML have the Ph¹ abnormality despite reduced number of Ph¹ metaphases in bone marrow from therapy.     

Hypermetaphase and interphase fluorescence in situ hybridisation for monitoring of remission status in Philadelphia chromosome positive chronic myeloid leukaemia

Interferon (IFN) alone or in combination with cytostatic drugs, can induce major and durable cytogenetic remissions in chronic myelogenous leukaemia (CML) patients. Hypermetaphase (HMF) and interphase (IPF) fluorescence in situ hybridisation (FISH) have been described to be suitable for remission assessment. In the present study we applied HMF and IPF simultaneously to bone marrow (BM) probes from Ph-positive CML patients. As conventional cytogenetics (CC) is still deemed to be the for remission analysis we studied a group of patients analysed with this method as control. A mean of 50 metaphases was available for HMF analysis, whereas only an average of 18.7 metaphases could be analysed by CC. Remission assessment was frequently impossible by CC or HMF due to lack of metaphases, but always possible by applying IPF. Our results show that HMF should replace CC for routinely monitoring the remission status in Ph-positive CML patients and that in case of lack or insufficient number of metaphases in the majority of cases IPF is suitable for remission assessment.     

Demonstration of Philadelphia chromosome negative abnormal clones in patients with chronic myelogenous leukemia during major cytogenetic responses induced by imatinib mesylate.

Imatinib mesylate, an Abl-specific kinase inhibitor, produces sustained complete hematologic responses (CHR) and major cytogenetic responses (MCR) in chronic myeloid leukemia (CML) patients, but long-term outcomes in these patients are not yet known. This article reports the identification of clonal abnormalities in cells lacking detectable Philadelphia (Ph) chromosome/BCR-ABL rearrangements from seven patients with chronic- or accelerated-phase CML, who were treated with imatinib. All seven patients were refractory or intolerant to interferon therapy. Six of seven patients demonstrated MCR and one patient, who had a cryptic translocation, achieved low-level positivity (2.5%) for BCR-ABL by fluorescence in situ hybridization. The median duration of imatinib treatment before the identification of cytogenetic abnormalities in BCR-ABL-negative cells was 13 months. The most common cytogenetic abnormality was trisomy 8, documented in three patients. All patients had varying degrees of dysplastic morphologic abnormalities. One patient exhibited increased numbers of marrow blasts, yet consistently demonstrated no Ph-positive metaphases and the absence of morphologic features of CML. The presence of clonal abnormalities in Ph-negative cells of imatinib-treated CML patients with MCR and CHR highlights the importance of routine metaphase cytogenetic testing and long-term follow-up of all imatinib-treated patients.     

Phenotypic Characterization of Normal and CML CD34-Positive Cells: Only the Most Primitive CML Progenitors Include Ph-neg Cells

We studied the sequence of acquisition of CD33, CD38 and HLA-DR antigens on CD34+ cells from marrow and blood of Ph-chromosome positive CML patients and normal marrow. We examined the Ph status of the various CML cell populations. The mean proportions of normal and CML CD34+ cells expressing CD33 and CD38 were not significantly different. However, a significantly greater proportion of CML CD34+ cells expressed HLA-DR antigens compared with normal CD34+ cells and the level of HLA-DR expression per CML cell was abnormally high. When the sequence of acquisition of these antigens on normal and CML CD34+ cells was evaluated using 3-colour fluorescence analysis, the results suggested that HLA-DR was expressed earlier than CD38 or CD33 and these findings were confirmed by following the acquisition of CD38 and CD34t/DR + /CD38-subpopulation during liquid culture. We performed cytogenetic studies on CD34+ subpopulations in 6 cases. In 4 cases there were some Ph-negative metaphases detectable in the CD34+/DR-subpopulation (range 12.5 to 60%). In the CD34+/DR+ fractions, however, all 6 patients had only Ph-positive metaphases and only 1/5 patients had detectable Ph-negative metaphases in the CD34+/CD38-subpopulation. We conclude that expression of HLA-DR antigens may precede the expression of CD38 on CD34+ cells during normal stem cell differentiation. In CML DR may be expressed aberrantly and Ph-negative cells are found predominantly in the DR negative sub-population.     

Philadelphia chromosome mosaicism at diagnosis in chronic myeloid leukemia: clinical correlates and effect on imatinib mesylate treatment outcome

In chemotherapy-treated patients with chronic myeloid leukemia (CML), the karyotypic detection of Philadelphia chromosome (Ph)-negative metaphases at diagnosis (i.e. Ph mosaicism) is not considered significant as a prognostic factor for survival. In the current retrospective study, clinical correlates and prognostic relevance of Ph mosaicism were evaluated in 63 Ph-positive patients with CML, including 59 in chronic phase and 4 in accelerated phase, receiving imatinib mesylate as either first (n = 46) or second (n = 17) line therapy. Thirteen patients (21%) displayed Ph-negative metaphases at diagnosis and, compared to the other 50 patients with 100% Ph-positive metaphases, presented with significantly lower leukocyte count (p = 0.0004), circulating blast percentage (p = 0.02), and incidence of palpable splenomegaly (p = 0.02). Ph mosaicism did not correlate with other CML-pertinent prognostic factors including Sokal score (p = 0.4) or the presence of additional chromosome changes (p = 0.96) found in 10 patients (16%). Neither Ph mosaicism nor the presence of additional chromosome changes affected complete or partial cytogenetic remission rates to IM. Multivariable analysis identified Ph mosaicism as a risk factor for shortened survival. Due to the small sample size, the current preliminary observations require validation in a larger group of patients.     

Comparison of chromosome banding analysis, interphase- and hypermetaphase-FISH, qualitative and quantitative PCR for diagnosis and for follow-up in chronic myeloid leukemia: a study on 350 cases.

For the diagnosis of CML and for monitoring of treatment response the detection of the t(9;22)(q34;q11) or the BCR-ABL rearrangement is necessary. Chromosome banding analysis (CA) is still the gold standard but other techniques like Southern blot, fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) are available. We analyzed 350 CML patients at different stages of disease in parallel with CA, interphase-FISH (IP-FISH), hypermetaphase-FISH (HM-FISH) and RT-PCR. In 20 cases with no Ph(+) metaphases in CA, HM-FISH detected 0.2 to 10% BCR-ABL(+)metaphases. After IP-FISH 107 samples were judged as negative. However, in 17 of these samples HM-FISH detected BCR-ABL(+) metaphases (0.3-11%), and in eight cases CA detected Ph(+) metaphases (2.5-25%). A comparison of IP-FISH performed on uncultivated cells vs cells cultivated for 48 h in 70 cases revealed a higher proportion of BCR-ABL+ cells in the cultivated samples. If nested PCR was negative, all other methods were negative in all cases too. In addition, 94 cases were evaluated using real-time PCR (LightCycler technology). The BCR-ABL/cABL ratio measured showed a high correlation with all other methods. Interestingly, a wide range in the BCR-ABL/ABL ratio was observed especially in patients who showed 100% Ph-positive metaphases in CA. In conclusion, CA, IP-FISH, HM-FISH and real-time PCR give reliable results but differences due to measurement of different target structures have to be kept in mind when using these data for definition of remission status.     

Evidence for a selective antileukemic effect of cytosine arabinoside in chronic granulocytic leukemia

On the basis of in-vitro studies indicating that low concentrations of cytosine arabinoside exert preferential inhibition of granulocyte-macrophage colony-forming cells from patients with chronic granulocytic leukemia vs normal subjects, we treated two outpatients with low doses of this agent, administered by subcutaneous infusion for 12-31 days. Both patients continued their usual activities, including employment, during these infusions. They exhibited only Ph-positive metaphases at entry into the protocol but in both cases, Ph-positive cells were reduced to approx. 10% of marrow metaphases, after 2-3 successive infusions. Both patients exhibited significant increases in Ph-positive cells, to 46 and 72% of marrow metaphases, during subsequent chemotherapy with hydroxyurea, in dosage sufficient to maintain granulocytopenia and a normal serum B12 level. After additional cytosine arabinoside, both patients again showed decreases in Ph-positive cells, to 7% (p less than 0.01) and 19% (p less than 0.0001), respectively. This clinical experience is consistent with the conclusion that cytosine arabinoside (but not, hydroxyurea) exerts a selective antileukemic effect in some patients with CGL.     

Analysis of Philadelphia chromosome-negative BCR-ABL-positive chronic myelogenous leukemia by hypermetaphase fluorescence in situ hybridization.

Background: In 5%–10% of patients with of chronic myelogenous leukemia (CML), the Philadelphia chromosome (Ph) is not identified, despite the presence of the associated BCR–ABL molecular abnormality (Ph-negative, BCR–ABL-positive CML) because of sub-microscopic rearrangements.Patients and methods: Six patients with Ph-negative, BCR–ABL-positive CML were investigated. The Ph chromosome detection via fluorescence in situ hybridization after 24-hour mitotic arrest of bone marrow cultures resulting in several hundreds of metaphases (hypermetaphase FISH or HMF) was useful in explaining the nature of the six cases.Results: Four patients had a low frequency of Ph-positive cells by HMF (5.7%, 4.8%, 3.9%, 0.2%), i.e., a typical Ph translocation. However, two cases involved a 9q34 inserted into chromosome 22q11 (74.2% and 92%), without a deletion from chromosome 22 and reciprocal translocation onto 9, i.e., not a typical Ph translocation. The pattern of UBCR gene rearrangement was characterized by the same genomic recombination of 5-BCR and c-ABL, both in the four cases of typical translocation (9;22) and in the two cases of insertion of 9q34 into chromosome 22q11.Conclusions: The HMF identified two different bases for Ph-negative, BCR–ABL-positive cells in CML – presence of low frequency of cells with typical Ph translocations or presence of cells with ABL insertions into the BCR gene on chromosome 22.     

Prediction of initial cytogenetic response for subsequent major and complete cytogenetic response to imatinib mesylate therapy in patients with Philadelphia chromosome-positive chronic myelogenous leukemia

BACKGROUND: Obtaining a major (Philadelphia chromosome [Ph] of < 35%) or a complete cytogenetic response (Ph of 0%) has been associated with excellent long-term survival. Cytogenetic response may continue to improve with therapy. Because early allogeneic stem cell transplantation (SCT) may be associated with a better outcome, early parameters predicting for subsequent cytogenetic responses would optimize the treatment decision-making. METHODS: The current study was performed to analyze whether early cytogenetic responses may be predictive of later major or complete cytogenetic responses to imatinib mesylate therapy in patients with Ph-positive chronic myelogenous leukemia (CML). RESULTS: Two hundred sixty-one patients with Ph-positive, chronic-phase CML after failure with interferon therapy who were treated with imatinib mesylate therapy were analyzed. A persistence of 100% Ph-positive cells after > or = 6 months of imatinib mesylate therapy was associated with a major cytogenetic response rate of 9-13% and a complete cytogenetic response rate of 0-4%. However, a minor cytogenetic response after 3-12 months of therapy still was associated with high rates of major (68-83%) or complete (35-54%) cytogenetic response rates. CONCLUSIONS: Patients with Ph-positive, chronic-phase CML who have persistent 100% Ph-positive disease after > or = 6 months of imatinib mesylate therapy may be offered allogeneic SCT or considered for alternative investigational therapies.     

基因扫描分析CML病人外周血的T细胞克隆性

 应用RT-PCR方法扩增12例CML病人外周血单个核细胞的T细胞受体(CR)Vβ24个亚家族基因的互补决定区3(CDR3), 了解VβT细胞的分布情况, 8例正常人和T细胞株K37作为对照。 PCR产物进一步经基因扫描分析确定T细胞克隆性。 结果发现12例CML外周血中分别表达3－21Vβ亚家族T细胞, 8例正常人则表达除Vβ20外的全部VβT细胞, K37细胞仅表达Vβ9。基因扫描分析显示12例CML中8例病人的部分Vβ亚家族PCR产物至一主峰图象, 提示为克隆性生长的T细胞。 推测这是宿主对白血病细胞相关抗原的一种直接反应。 该方法有可能作为白血病特异性免疫治疗的临床研究的一种新的分子生物学研究方法。     

Spontaneous sister chromatid exchange in normal bone marrow and Ph-positive chronic myelocytic leukemia

The frequency of spontaneous sister chromatid exchange was studied in normal marrow derived from 38 healthy donors and 40 untreated patients with chronic phase CML. The sister chromatid exchange frequency was significantly lower in the leukemic cells (range, 2.32 +/- 1.31 to 4.76 +/- 2.37 per metaphase; mean, 3.18 +/- 0.49) than in normal marrow (range, 2.36 +/- 1.44 to 5.54 +/- 2.24 per metaphase; mean, 3.92 +/- 0.72). The contraction status of chromosomes was comparable in normal and Ph-positive metaphases. The reduction of sister chromatid exchange in leukemic cells was seen in all chromosome groups. The analysis of cell cycle specific proliferation according to the typical staining patterns of metaphases due to the number of cell cycles during which bromodesoxyuridine was substituted, revealed longer cell cycle times for the leukemic cells.     

Extramedullary blast crisis in a patient with Philadelphia chromosome-positive chronic myelogenous leukemia in complete cytogenetic remission

Treatment of Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) with recombinant interferon-alpha (IFN-A) results in complete disappearance of the Ph chromosome in about 10% to 15% of patients in early chronic phase. This group has a long survival and very low incidence of blast crisis. The first known case is reported of extramedullary blastic transformation in a patient with medullary complete cytogenetic response (0% Ph-positive metaphases) to IFN-A. Four episodes of extramedullary blast crisis have occurred in this patient. The first three episodes were lymphoid by morphology and cytochemical stains. Molecular analysis confirmed breakpoint cluster region rearrangement. The most recent transformation was myeloid in nature and involved bone and pulmonary parenchyma. The patient is currently undergoing a second autologous transplantation with stored bone marrow that is Ph negative. The patient has survived more than 18 months since the first episode of blast crisis, and the bone marrow is normal.     

Fluorescence in Situ Hybridization (FISH) Is a Reliable Diagnostic Tool for Detection of the 9; 22 Translocation

The fluorescence in situ hybridization (FISH) technique for detection of the 9;22 translocation was compared with the “gold standard” of conventional cytogenetics. For this purpose, both methods were applied to 81 bone marrow aspirates and/or peripheral blood specimens comprising 50 CML cases and controls from 31 patients without CML. Independently, core biopsies of these 81 patients were investigated by three histopathologists. Conventional karyotype analysis from unstimulated bone marrow cells was successful in 71/81 cases and demonstrated the Ph-chromosome in 42/46 CML patients. With FISH, results were obtained in all 81 cases investigated, confirming fusion of the bcr and abl genes in all cytogenetically Ph-positive patients. Among the five Ph-chromosome-negative specimens bcr/abl fusions were detected in only one patient. The percentage of cells found to be Ph-positive by both methods was correlated, but in individual cases considerable differences in the numbers of Ph-positive cells were observed. Different results may be due to selection of cells after in vitro cultivation predominantly.

FISH proved to be a very reliable technique for specimens that do not contain dividing cells. With FISH, large numbers of cells can easily be scored which is an advantage compared to conventional cytogenetics. Therefore, this method is particularly suitable for those whose therapy is being monitored or a relapse is suspected. However, the FISH results should be evaluated critically with respect to the practical limit of sensitivity since non-specific fusion signals can also be observed in a small percentage of cells in non-CML cases. It is suggested that each laboratory define its own threshold of bcr/abl fusion signals for diagnosing Ph-positive CML by FISH.