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.     

Detection of the blastic crisis cell clone in chronic myeloid leukaemia

Three patients with Ph1 positive chronic myeloid leukaemia (CML) were followed until the occurrence of blastic transformation by means of cytogenetic analysis of whole marrow or blood cells, of blast cell enriched fractions from marrow or blood and of colonies grown from these cell fractions in two culture systems. Karyotypic evolution was used to indicate the development of new clones from pre-existing cell lines either as transient phenomena during the chronic phase or as the ultimate indicators of a blastic crisis (BC). The clones which were to lead to a BC were detected some months before the clinical diagnosis of the BC. At a time before overt BC had become clinically manifest, the BC clone outgrew the other ones in culture and thus also in vitro showed specific proliferative advantages over the cell lines characteristic of the chronic phase of CML.     

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.     

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.     

Cytogenetics of chronic myeloid leukaemia.

The standard Philadelphia (Ph) translocation t(9;22), its variants and a proportion of Ph-negative cases are positive for the BCR-ABL fusion gene, as determined by molecular analysis. Extensive deletions of chromosome 9 and 22 derived sequences around the translocation breakpoints on the derivative 9 are seen in 10-30% of patients at diagnosis and may confer a worse prognosis. Additional cytogenetic changes can occur in the few months before or during disease progression and are often specific for blast morphology; however, the molecular basis of the most common additional cytogenetic abnormalities is largely unknown. Cytogenetics is important for monitoring patient response to treatment but is increasingly being replaced by the more sensitive and less invasive techniques of RT-PCR and FISH.     

Ph-negative chronic myeloid leukaemia

An analysis of five patients with Philadelphia chromosome (Ph) negative chronic myeloid leukaemia (CML) revealed that two were clinically and haematologically identical to Ph-positive CML whereas three should be reclassified as chronic myelomonocytic leukaemia (CMML). At a molecular level the first two patients showed the same juxtaposition of c-abl and bcr genes as is seen in Ph-positive CML. These genomic changes were not seen in the other three patients. Observations on these five patients suggest that the clinical course and prognosis of the rare patient who carries the Ph 'molecular defect' but lacks the Philadelphia chromosome is no different from Ph-positive CML.     

Immune responses to chronic myeloid leukaemia.

The negative impact of donor marrow T lymphocyte depletion on relapse of chronic myeloid leukaemia (CML) following bone marrow transplantation strongly suggests that the leukaemia is particularly susceptible to immune regulation. The immune response to CML may be mediated by major histocompatibility (MHC) locus unrestricted natural killer and lymphokine activated killer cells, or by MHC-restricted CD4 and CD8 lymphocytes. Interaction with the leukaemia is both by direct cell-contact cytotoxicity, and indirectly via cytokines and growth factors. T4 and T8 lymphocytes recognize a spectrum of minor histocompatibility antigens on the leukaemia cell which may be non-specific, leading to graft-versus-leukaemia and graft-versus-host reactions, or present only on myeloid cells leading to a tissue restricted response. The possibility that the P210 protein derived from the BCR/ABL fusion gene on chromosome 22 leads to the presentation via MHC molecules of leukaemia-specific peptide antigens is currently under investigation. Developments in understanding the immune response to CML open up the possibility of developing leukaemia-specific immunotherapy strategies.     

''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.     

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.     

Poor response to intensive chemotherapy in de novo acute myeloid leukaemia with trilineage myelodysplasia

Summary. The findings of morphologically dysplastic features in haemopoietic cells in de novo acute myeloid leukaemia (AML) has been named AML with trilineage myelodysplasia (AML/TMDS). We analysed the clinical data, karyotypes, and treatment outcomes of 230 de novo AML patients treated with the Japan Adult Leukaemia Study Group AML-87 protocol. 40 (17%) patients had AML/TMDS. Platelet count was significantly higher ( F =0·006) and bone marrow blasts were fewer ( P =0·01) in the AML/TMDS group than in the AML without TMDS. Abnormal karyotype was shown in 12/30 patients (40%) analysed.
The complete remission (CR) rate for AML/TMDS was significantly lower than AML without TMDS (63% v 81%) ( P =0·01). The overall survival curves showed that the 40 patients with TMDS had a significantly worse survival than the 190 without TMDS ( P =0·0005). AML/TMDS also showed significantly worse disease-free survival (DFS) ( P =0·0001).
Multivariate analysis revealed that the absence of TMDS in AML was the most significant factor in obtaining CR ( P =0·01) and a significant factor in predicting longer DFS ( P =0·04). Our data suggest that AML/TMDS responds poorly to intensive chemotherapy. Further study is required to determine the best treatment strategy for AML/TMDS and the biological differences between AML/TMDS and other types of AML.