Secondary T-acute lymphoblastic leukaemia mimicking blast crisis in chronic myeloid leukaemia

A 34-year-old man with chronic myeloid leukaemia (CML) firstly developed a lymphoid blast crisis of B-cell type. After a second chronic phase which lasted for > 4 years with maintenance chemotherapy of hydroxyurea, 6-mercaptopurine and methotrexate, he developed a T-cell acute lymphoblastic leukaemia of TcR-gammadelta+ type. Cytogenetic analysis revealed disappearance of the t(9;22) translocation and appearance of new abnormalities consistent with the diagnosis secondary acute leukaemia. To our knowledge, secondary leukaemia in CML has not previously been reported.     

Cell lineage heterogeneity in blast crisis of chronic myeloid leukaemia

Blast cells from 45 patients with chronic myeloid leukaemia in blast crisis (CML-BC) were immunologically phenotyped with a panel of 26 monoclonal antibodies and studied for terminal deoxynucleotidyl transferase (TdT) content. Out of 45 blast-populations, 28 showed a myeloid, 14 a lymphoid, two a mixed and one an unclassifiable marker profile. In contrast to acute myeloid leukaemia (AML), we found frequent involvement of the thrombopoietic and erythropoietic systems in myeloid CML-BC. Furthermore, the marker profile on blast cells in myeloid CML-BC was different from that seen in AML. The blast cells in lymphoid blast crises of CML displayed the same lymphoid marker profile as those in acute lymphoblastic leukaemia. In three of 16 patients who were serially tested, we observed phenotypic changes in the blast cell populations. In one patient the blasts changed from lymphoid to myeloid type while remaining TdT-positive; in another case the blasts switched from granulomonocytic TdT-negative to granulomonocytic TdT-positive. In the third patient erythroid precursor cells appeared as the disease progressed. The results indicate the capacity of blast populations in CML-patients during blast crisis to differentiate along several pathways.     

Eosinophilic blast crisis in a case of chronic myeloid leukaemia

A case of typical chronic myeloid leukaemia (CML) is described, of which the terminal blast crisis was characterized by an impressive proliferation of atypical eosinophils and by the simultaneous complete deficiency of neutrophilic myeloperoxidase. Since eosinophilic cells preserved a strong peroxidase positivity, a high number of immature non-granular eosinophilic precursors could be recognized among the leukaemic blast cells, thus supporting the diagnosis of eosinophilic blast crisis of CML.     

Relapse into blast crisis following bone marrow transplantation for chronic phase chronic myeloid leukaemia: a report of five cases

A proportion of patients receiving allogeneic bone marrow transplants (BMT) for chronic myeloid leukaemia (CML) in first chronic phase relapse; most of these relapses show features of chronic phase disease. We report here a series of five patients seen at a single institution over a 10 year period who developed blast crisis as the first sign of relapse after BMT for CML in chronic phase. The blast cells were myeloid in three cases and lymphoid in two. In one case the relapse may have occurred in cells of donor origin. The possible explanations for this unusual sequence of events include incipient transformation that was not detected before BMT, undetected relapse into chronic phase proceeding into transformation post-BMT, and transformation occurring de novo post-BMT in small numbers of residual leukaemic stem cells.     

Early T-cell features in blast crisis of Ph1-positive chronic myeloid leukaemia

A patient with Ph1-positive chronic myeloid leukaemia (CML) presented in extramedullary blast crisis. Whereas the peripheral blood and bone marrow features were consistent with the chronic phase of CML, study of the enlarged lymph nodes demonstrated massive replacement by Ph1-positive blast cells of lymphoblastic morphology. Such blast cells showed diffuse acid phosphatase positivity, were positive for TdT, and had an enzyme pattern (adenosin-deaminase, purine-nucleosidephosphorilase and lactate-dehydrogenase) typical of immature T-cells. To further characterize the phenotype of the blast cells, they were analyzed for surface markers using a panel of monoclonal antibodies selected to identify differentiation antigens of T cells, B cells and myeloid cells. The results of the latter analysis were consistent with an early T-cell origin of the blast cells, since they were positive for TdT, CRIS1 (T1), E rosettes and OKT10, and were negative for OKT3, Leu3 and OKT8. These features demonstrate that T-cell markers may also be expressed in blast crisis of CML and provide evidence that T-cells may share a common stem cell with myeloid and B-cells in CML.     

''Lymphoid'' blast crisis of chronic myeloid leukaemia is associated with distinct clinicohaematological features

We measured the circulating levels of interleukin (IL)-6 in adult T-cell leukaemia/lymphoma (ATL) patients using an enzyme-linked immunosorbent assay. The IL-6 levels in 59 ATL patients (median 8.2 pg/ml; range < 1.0 to 185.7 pg/ml) were significantly higher than in 30 healthy controls (median < 1.0 pg/ml; range < 1.0 to 3.5 pg/ml) ( P  < 0.0001) or 32 human T-lymphotropic virus type-I (HTLV-I) carriers (median 4.2 pg/ml; range  < 1.0 to 13.3 pg/ml) ( P  = 0.002). Among the ATL patients, the IL-6 levels in the acute- or lymphoma-type patients were significantly higher than those in the chronic-type patients ( P  < 0.0001). The IL-6 levels were also higher in the patients with B symptoms than in those without B symptoms ( P  = 0.039), and were significantly correlated with increased serum lactate dehydrogenase (LDH) ( P  = 0.0004) and C-reactive protein (CRP) ( P  < 0.0001) and decreased serum albumin ( P  = 0.0003) values. The patients with elevated IL-6 levels had inferior overall survival periods compared to those with normal IL-6 levels ( P  = 0.025). ATL is a single disease entity, although its clinical features are quite diverse; the increased production of cytokines may cause the diversity of clinical features. The results of our study indicate that IL-6 is one such cytokine.     

Interaction of cyclosporin A and etoposide. Clinical and in vitro assessment in blast phase of chronic myeloid leukaemia

Summary Combination chemotherapy has had a low impact on survival of blast crises in chronic myelogeneous leukaemia (CML) which may be due to drug resistance. This work attempted to correlate the clinical response and some experimental evidence for the MDR phenotype. Blast cells were positive for P-glycoprotein using APAAP assay. In vitro tests showed that etoposide was partially toxic to blast cells when used alone but had its toxicity increased by nearly sixfold when combined with cyclosporin A (CSA). The patient responded poorly to treatment with etoposide combined with mitoxantrone and high-dose ara-c. However, when etoposide was associated with CSA, this patient returned to the chronic phase reinforcing our in vitro studies. Because no serious toxicity was seen clinically, we are inclined to consider the circumvention protocol an useful strategy to treat blast crises of CML.     

Rearrangements of immunoglobulin and TCR genes in lymphoid blast crisis of Ph + chronic myeloid leukaemia

Clonal rearrangements of immunoglobulin heavy chain genes as well as both T cell receptor (TCR) delta and gamma genes were found in four cases of blast crisis of Ph+ chronic myeloid leukaemia with unequivocal B cell precursor (common) immunophenotype. In one case, the TCR beta chain gene was also rearranged. Although the developmental sequence of TCR delta, gamma and beta rearrangements in T lymphocytes appeared to be respected, a full phenotypic effect, characteristic of T cell was not observed in these otherwise typical 'common' blast cells. Cytogenetic analysis ruled out the occurrence of TCR rearrangement due to structural chromosome changes. A high incidence of unexpected TCR gene rearrangements has been previously reported in the de novo 'common' acute lymphoblastic leukaemias (ALL). Our cases of chronic myeloid leukaemia (CML) in lymphoid blast crisis show that genotypic similarities may exist between these two haematological entities.     

Clinical and genetic studies of ETV6/ABL1-positive chronic myeloid leukaemia in blast crisis treated with imatinib mesylate

Most chronic myeloid leukaemia (CML) patients are genetically characterized by the t(9;22)(q34;q11), generating the BCR/ABL1 fusion gene. However, a few CML patients with rearrangements of 9q34 and 12p13, leading to ETV6/ABL1 chimaeras, have also been reported. Here we describe the clinical and genetic response to imatinib mesylate treatment of an ETV6/ABL1-positive CML patient diagnosed in blast crisis (BC). A chronic phase was achieved after acute myeloid leukaemia induction therapy. Then, treatment with imatinib mesylate (600 mg/d) was initiated and the effect was assessed clinically as well as genetically, including by repeated interphase fluorescence in situ hybridization studies. Until d 71 of imatinib mesylate therapy, stable improvements in the clinical and laboratory features were noted, and the frequency of ABL1-rearranged peripheral blood cells decreased from 56% to 11%. At d 92, an additional t(12;13)(p12;q13), with the 12p breakpoint proximal to ETV6, was found. The patient relapsed into BC 126 d after the start of the imatinib mesylate treatment and succumbed to the disease shortly afterwards. No mutations in the tyrosine kinase domain of ABL1 of the ETV6/ABL1 fusion were identified in the second BC. However, whereas the ETV6/ABL1 expression was seemingly the same at diagnosis and at second BC, the expression of ETV6 was markedly lower at the second BC. This decreased expression of wild-type ETV6 may have been a contributory factor for the relapse.     

Effects of imatinib and interferon on primitive chronic myeloid leukaemia progenitors

Imatinib has impressive activity against chronic myeloid leukaemia (CML), but does not appear to completely eradicate the disease. Although responses to interferon-alpha (IFN) are slower and less dramatic than those to imatinib, they can be durable even after discontinuation of the drug. Unlike imatinib, the specific mechanisms responsible for IFN's clinical activity in CML are unknown. We found that IFN induced a G1 cell cycle arrest, as well as terminal differentiation, of the CML cell line KT-1 and CML CD34+ cells from clinical specimens. Myeloid growth factors augmented the antileukaemic activity of IFN, and neutralising antibodies directed against myeloid growth factors inhibited IFN's antileukaemic activity. We next directly compared the effects of imatinib and IFN against differentiated and primitive CML progenitors from newly-diagnosed patients. Although less active against CML granulocyte-macrophage colony forming units than imatinib, IFN was significantly more toxic to primitive CML progenitors responsible for the maintenance of long-term cultures. Imatinib and IFN appear to have divergent effects on CML progenitors at different stages of maturation, with imatinib more active against differentiated CML progenitors and IFN more active against primitive CML progenitors. The different target cells for these agents may explain the disparities in the kinetics and durability of their clinical responses. At least part of the clinical effect of IFN in CML appears to result from its ability to differentiate primitive CML progenitors.     

Extramedullary presentation of the blast crisis of chronic myelogenous leukaemia

We report the clinical histories and a multiparameter pathological study of the extramedullary lesions of seven patients with chronic myelogenous leukaemia in whom the initial clinical presentation of blast crisis (BC) was in an extramedullary site (lymph nodes in six, mandibular mass in one). Bone marrow BC was demonstrated simultaneously or within a few months in four patients. Three patients received chemotherapy only, four underwent bone marrow transplant. Six patients died within 1 year from diagnosis of extramedullary BC, one is alive without disease. The longest survivals (12+, 12, 11 months) were those of patients who never developed bone marrow BC and were recipients of bone marrow transplant. Studies of extramedullary disease included: histology; histochemistry for chloracetate esterase (CAE) and lysozyme; assays for TdT; electron microscopy; immunofluorescence for Fc-receptors, immunoglobulins and lymphoid and myeloid antigens by a panel of monoclonal antibodies; and cytogenetics. Three cases were classified as myeloid BC based on histochemistry and/or ultrastructure and immunology (OKM1+, MCS2+, IG10+); two as lymphoid BC (CAE-, lysozyme-, TdT+), one of them expressing a T-cell phenotype. Cytogenetic analysis of extramedullary lesions and simultaneous or subsequent bone marrows demonstrated identical karyotypes in three patients and significantly different karyotypes in one.     

Ph1 positive blast crisis of chronic myeloid leukaemia exhibiting features characteristic of early T blasts

Leukaemic cells from a patient in the blast crisis of chronic myeloid leukaemia were subjected to a surface marker analysis using a panel of monoclonal antibodies recognizing differentiation antigens of myeloid (MY7, MY906, VIM D5, MØ P9), erythroid (VIE G4), megakaryocyte (AN51), T-lymphoid (WT1, 10.2, OKT3, OKT4, OKT6, OKT8, OKT11A) and B-lymphoid cells (B1, B2, Y29/55), common ALL-antigen (VILA1), non-lineage- restricted antigens (OKT9, OKT10), monomorphic HLA-DR determinants (7.2) as well as TdT. When the patient entered his first blast crisis, his blasts expressed a phenotype corresponding to an immature myeloid cell (7.2+, MY7+, My906+, VTM D5-). Ph¹- chromosome-positive blasts from this patient's first relapse had completely changed their surface marker characteristics: they had become TdT-positive and exhibited surface features characteristic of early T blasts (WT1+, 10.2+, OKT9+, OKT10+, 7.2-, OKT6-). Together, these features provide evidence that myeloid cells may share a common precursor with T cells.     

Successful allogeneic bone marrow transplantation after reversion to chronic phase of blast crisis in chronic myeloid leukemia

A female with chronic myeloid leukemia (XX Ph 1 +) in blast crisis (localized to pleura and lymph nodes) was treated by polychemotherapy. After reversion to the chronic phase, an allogeneic bone marrow transplantation (BMT) was performed. Sixteen months after BMT, no sign of the disease was present (XY Ph 1 -).     

Vindesine-prednisone in the treatment of blast crisis of chronic myeloid leukemia

Eight patients with chronic myeloid leukemia in blast crisis were treated with a combination of vindesine and prednisone. Complete remission was achieved in three patients; partial remission was achieved in three. All six responders received maintenance treatment with hydroxyurea and 6-mercaptopurine. The median duration of survival was 9 months. Two patients had long-term survival: one survived 32 months and the other is alive after 30 months. These data suggest that vindesine-prednisone polychemotherapy might improve the prognosis of blast crisis in chronic myeloid leukemia.