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Electron microscope cytochemical analysis of chronic myelocytic leukemia: a case report.

A patient with Philadelphia chromosome positive CML was studied to characterize the blast transformation. Peripheral blood and bone marrow at the onset of the blast crisis were evaluated with cytochemistry, chromosome analysis, cell surface markers, terminal transferase assay, and electron microscopy. Although light microscopic examination and cytochemistry suggested lymphoblastic morphology, ultrastructural cytochemistry demonstrated the myelomonocytic features of the transformation. This study suggests that electron microscopic cytochemistry is useful in evaluating the heterogeneous nature of the blast phase of CML.

Adult↗

Continuous infusion mitoxantrone in relapsed acute nonlymphocytic leukemia.

Mitoxantrone is a substituted anthraquinone with considerable activity against human acute leukemia. The authors' goal was to treat patients with continuous infusion mitoxantrone in order to maintain cytotoxic steady state levels with acceptable toxicity and to assess the results. Daily mitoxantrone levels showed a mean steady state plasma level of 16.8 +/- 1.4 ng/ml (range, 9.1-25.1) with a systemic clearance of 519 +/- 47 ml/minute/m2. No drug accumulation occurred. Mitoxantrone was undetectable 24 hours postinfusion. All patients, including two patients with chronic myelogenous leukemia in blast phase, had greater than 90% reduction in leukemia cell mass (marrow cellularity X percent leukemia cells) by day 6. However, six patients received 3 days of etoposide at that point because of residual acute nonlymphocytic leukemia (ANLL). Overall four patients (36%) had a complete remission; one additional patient had a bone marrow remission but also had a persistent granulocytic sarcoma. Toxicities included severe but tolerable myelosuppression, mucositis, and hepatic dysfunction. There was no correlation between mitoxantrone levels, toxicity, or clinical response. Continuous infusion produces cytotoxic plasma mitoxantrone levels and rapid clearing of ANLL from bone marrow. Further dose escalation may be possible.

Adult↗

Mylotarg (gemtuzumab ozogamicin) therapy is associated with hepatic venoocclusive disease in patients who have not received stem cell transplantation.

BACKGROUND: Mylotarg (Wyeth-Ayerst Laboratories, St. Davids, PA) is the brand name for a calicheamicin-conjugated humanized anti-CD33 monoclonal antibody (gemtuzumab ozogamicin, CMA-676) and has been approved recently for the treatment of a subset of elderly patients who have relapsed acute myeloid leukemia (AML). Mylotarg is associated with an incidence of approximately 20% Grade 3 or 4 hyperbilirubinemia and liver transaminitis in this patient population. Hepatic venoocclusive disease (VOD) has been reported in patients who have undergone stem cell transplantation (SCT) after Mylotarg therapy. Outside of the SCT setting, VOD has been associated very rarely with cytotoxic therapy. METHODS: The authors assessed the incidence of VOD in 119 patients who were receiving Mylotarg-containing non-SCT regimens. VOD was diagnosed through the use of standard Seattle and Baltimore criteria. RESULTS: A cohort of 119 (61 previously untreated, 58 with relapsed disease) patients with AML (92 patients), advanced myelodysplastic syndrome (25 patients), or chronic myeloid leukemia in blast phase (2 patients), received Mylotarg-based regimens. Fourteen (12%) developed VOD. The diagnosis of VOD was supported by histology in 2 patients and radiologic studies in a further 10 patients. Five (36%) of 14 patients with VOD had received no prior antileukemic cytotoxic therapy, including 2 patients who received single-agent Mylotarg therapy. CONCLUSIONS: Mylotarg was shown to be associated with the development of potentially fatal VOD in patients with leukemia who had not received SCT. VOD occurred when Mylotarg was used either as a single agent or when it was given with other cytotoxic agents. VOD occurred in Mylotarg-treated patients who had received no prior cytotoxic therapy. The current study concluded that risk factors for VOD should be assessed when considering Mylotarg therapy, and that attempts to avoid and treat VOD are warranted in patients who receive Mylotarg therapy.

Adolescent↗

Leukocyte alkaline phosphatase: another organ-specific alkaline phosphatase.

We have used enzyme specific inhibitors and heat inactivation to distinguish Leukocyte alkaline phosphate (LAP) from other organ-specific alkaline phosphatases as well as to compare LAP from normal granulocytes and leukemic cells with elevated LAP. The heat inactivation and inhibition curves of LAP are quite different from those of other organ-specific alkaline phosphatases. The inhibition curves and heat inactivation characteristics of LAP from normal granulocytes and that obtained from chronic granulocytic leukemia (CGL) blast phase cells with elevated LAP are identical. These data suggest that LAP is distinct from other organ-specific alkaline phosphatases, particularly placental alkaline phosphatase. We also conclude that the LAP present in cells with elevated levels is very similar or identical to that of normal granulocytes.

Alkaline Phosphatase↗

Intensive retreatment of adults and children with acute lymphoblastic leukemia.

Twenty-three patients (16 adults) failing their first or subsequent (n = 8) intensive treatment for de novo acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia lymphoid blast phase (n = 2) were managed with protocol POG 8201, originally introduced in relapsed ALL of childhood. In this programme, a four-drug induction phase is followed by early consolidation with teniposide-cytarabine, intrathecal chemotherapy, continuation weekly chemotherapy alternating teniposide-cytarabine with vincristine-cyclophosphamide, and periodic reinduction courses. Fourteen adults and five children with ALL achieved a complete response (CR) (86 per cent). The highest response rate (100 per cent) was obtained in 12 patients treated at first relapse after an initial CR of greater than 18 months (p = 0.07). Median duration of CR was 8 months in adults and 11 months in children. A longer than previous one CR (inversion) was obtained in four cases. Four ALL patients were successfully transplanted from a matched sibling after 3-11 months from achievement of CR. Median overall survival in adults with ALL was 11 months, significantly longer than for 40 comparable cases treated intensively but without rotational continuation therapy in previous years (p less than 0.001). This regimen is applicable to adults with relapsed ALL, where prolongation of survival may allow time for effective salvage with bone marrow transplantation.

Adolescent↗

Possible association of a new translocation, t(7;11)(p15;p15), with Ph1 chromosome-negative chronic myelogenous leukemia.

A Ph1 chromosome-negative chronic myelogenous leukemia (CML) with t(7;11)(p15;p15) in a 6-year-old girl is reported. Three cases of 7;11 translocation have been reported so far. The patients concerned were between 37 and 72 years of age; 2 of them had CML and the other had acute myelomonocytic leukemia. Data from these 4 cases suggest that the 7;11 chromosome translocation may be related to a subgroup of Ph1-negative CML, specifically to one that may easily proceed to blast phase, or to "subacute" myelogenous leukemia. The present case demonstrates that CML with this chromosome abnormality is not restricted to adults but also affects children. The t(1;11)(q21 or 23;p15) reported in another case with Ph1-negative CML may be a variant of this translocation.

Bone Marrow↗

T-lymphocyte entry into the central nervous system.

The entry of T-lymphocytes into the parenchyma of the central nervous system is a critical early feature in the pathogenesis of many experimental and spontaneously occurring immune-mediated illnesses. The physiological mechanisms controlling this entry have not been elucidated. This study reports that T-cell entry into the rat CNS appears to be primarily dependent upon the activation state of the lymphocytes; T-lymphoblasts enter the CNS (and all other tissues examined) in an apparently random manner while T cells not in blast phase are excluded. Antigen specificity, MHC compatibility, T-cell phenotype, and T-cell receptor gene usage do not appear related to the ability of cells to enter. This study demonstrates that when T-lymphoblasts are introduced into the circulation they rapidly appear in the CNS tissue. Their concentration in the CNS reaches a peak between 9 and 12 hr, and lymphocytes which have entered, exit within 1 to 2 days. Cells capable of reacting with a CNS antigen remain in the tissue or cyclically reenter to initiate inflammation if they are able to recognize their antigen in the correct MHC context. This observation also appears to pertain to the entry of activated T cells into many other tissues, although their concentrations in these non-CNS sites was not quantitated.

Animals↗

Interferon alfa-2b in the treatment of chronic granulocytic leukemia.

Studies of the effect of interferon on the growth of colonies of myeloid leukemic blasts, myeloma colony-forming cells and normal hemopoietic precursor cells have shown that interferon does not specifically inhibit the growth of the malignant cells in culture, i.e. the growth of the malignant and the normal precursor cells are inhibited equally. However, interferon markedly reduces the self-renewal capacity of acute myeloid leukemic blasts and myeloma cells. This observation suggested that interferon should be tested for its ability to prolong remissions rather than as a remission-inducing agent. We have tested the ability of interferon alfa-2b (Intron A; Schering-Plough) to prolong remissions induced by busulfan in patients with chronic granulocytic leukemia (CGL). The leukocyte doubling time (Td) and remission duration on no therapy was compared to the values observed during interferon alfa-2b maintenance therapy. Fourteen patients have been started on study and seven have received interferon alfa-2b for three months or more. All seven have shown slowing of the leukocyte Td and prolongation of the remission duration after interferon alfa-2b therapy. A larger study, with longer follow-up, will be required to determine whether interferon alfa-2b therapy will slow or prevent progression of CGL to the blast phase and prolong survival.

Adolescent↗

On the pathogenesis of preleukemic myelodysplastic syndromes: development of a dysplastic hemopoietic proliferation in the rat after a single pulse dose of dimethylbenz(a)anthracene (DMBA).

After a single pulse dose of DMBA, rats develop bone-marrow hypoplasia, which is almost compensated for by regeneration after 16 weeks. Subsequently, dysplastic signs of hemopoiesis appear in all experimental animals as massive extrusion of normoblasts into the peripheral blood, red-cell aniso- and poikilocytosis, nuclear deformities, atypical mitoses, and PAS-positivity, as well as megaloblastoid maturation dissociation of erythroblasts and nuclear and granulation anomalies of neutrophilic granulocytes and monocytes, comparable to human "pseudo-Pelger cells" and "paraneutrophils". At the time of death (112-497 days after DMBA pulse) experimental animals showed hyperplastic bone marrow with increased granulopoietic/erythropoietic ratios and an augmented, mainly erythropoietic, hemopoiesis in the spleen, with splenomegaly in six rats. Splenic hemopoiesis is accompanied by white pulp atrophia. The cause of death was septicopyemia in three rats, anemia in three, and bleeding in one rat. None of the animals developed a leukemic blast phase. Myelodysplastic changes in this experiment are the same as have been shown to precede leukemia in rats treated with five DMBA pulses (Fohlmeister et al. 1981). Possible relations of myelodysplasia and leukemia are discussed.

9,10-Dimethyl-1,2-benzanthracene↗

Secondary chronic myelogenous leukemia after autologous peripheral blood stem cell transplantation for lymphoma.

A 31-year-old woman was diagnosed with intestinal lymphoma (high-grade mucosa-associated lymphoid tissue lymphoma, stage IIE) in September 1996. Eleven courses of chemotherapy were administered, but the results were poor. She received autologous peripheral blood stem cell transplantation (PBSCT) in September 1997. Leukocytosis was noted, and chronic myelogenous leukemia was diagnosed 8 months after the PBSCT, progressing to blast phase 10 months later. We report this case because secondary chronic myelogenous leukemia after stem cell transplantation is rare.

Adult↗

Induction of insulin receptor expression of human leukemic cells by 1 alpha, 25 dihydroxyvitamin D3.

The HL-60 and U-937 leukemic cell line and explants of fresh human leukemia cells were differentiated in vitro by incubation with 1 alpha, 25 dihydroxyvitamin D3 (Vit D). Morphologic change to monocytes was demonstrated in the promyelocytic (HL-60) line but not in the U-937 line and four of five leukemic cells. One patient with chronic granulocytic leukemia in the myeloid blast phase had incomplete morphologic change with Vit D treatment. In all cells studied, an increase in specific insulin receptor binding was independent of morphologic maturation. An increase in insulin receptor expression by Vit D was an early monocytic membrane marker dissociated from morphologic and functional alterations.

Calcitriol↗

Significant telomere shortening in childhood leukemia.

Telomere length was studied by Southern analysis in five cases of childhood acute leukemia. In four cases, the length of the telomere sequence of the blast phase cells was shortened as compared with that of the cells examined during remission. Study of telomere length during chemotherapy for hematologic malignancies may show rapidly dividing subpopulations of malignant cells and thereby guide further treatment needs. In addition, such loss of telomere sequence would give rise to chromosomal instability and could be one of the mechanisms of oncogene activation in acute leukemia.

Blotting, Southern↗

Cross-talk between Bcr-Abl tyrosine kinase, protein kinase C and telomerase-a potential reason for resistance to Glivec in chronic myelogenous leukaemia.

To prevent the resistance to Glivec in patients with chronic myelogenous leukaemia (CML), it is necessary to get a good understanding of its potential mechanisms. The present hypothesis accents on the mechanisms whereby Bcr-Abl tyrosine kinase remains inhibited by Glivec, but alternative signalling pathways become activated-the potential reason associates with activation of telomerase after long-term treatment with Glivec and recovery of cell proliferation and immortality. The hypothesis is based on the observations about differences in telomere dynamics and telomerase activity between chronic and blast phases of CML patients, as well as about the potential effect of Glivec on the cross-talk between telomerase, Bcr-Abl tyrosine kinase and protein kinase C family-key enzymes in CML. It proceeds from recently published data, demonstrating that protein kinase C activates and c-Abl tyrosine kinase inhibits telomerase. During optimization of chemical structure, Glivec loose its effect on protein kinase C and enhances the effect on Bcr-Abl tyrosine kinase, resulting in a high potential to activate telomerase indirectly through its effect on both kinases. Experimental preclinical data are given in confirmation of this hypothesis.

Antineoplastic Agents↗

Coexistence of different clonal populations harboring the b3a2 (p210) and e1a2 (p190) BCR-ABL1 fusion transcripts in chronic myelogenous leukemia resistant to imatinib.

In this study, we report the case of a Philadelphia (Ph) positive chronic myelogenous leukemia (CML) patient with the presence of p190 and p210 BCR-ABL1 mRNA fusion transcripts derived from e1a2 and b3a2 BCR-ABL1 genomic rearrangements, respectively. The presence of e1a2 BCR-ABL1 genomic rearrangement was seen in 2 different clones, one with the rearrangement and another one with the rearrangement and deletion of the BCR gene of the non-rearranged chromosome 22. After treatment with imatinib, the p210 transcript could not be detected, whereas p190 was still present 6 months after initiation of imatinib therapy and progression to blast phase. The absence of p210 transcript post treatment indicates that the clone with b3a2 responded to imatinib and that the observed resistance was associated to cells harboring the e1a2 genomic rearrangement. Despite resistance of this patient to imatinib, no evidence of mutations in the kinase domain of ABL1 was found. Loss of normal BCR in one cell clone may contribute to the resistance to imatinib due to the lack of BCR mediated inhibition of BCR-ABL1.

Aged↗

Mayo Clinic experience with allogeneic and syngeneic bone marrow transplantation, 1982 through 1990.

Between April 1982 and July 1990, 101 patients underwent allogeneic or syngeneic bone marrow transplantation at the Mayo Clinic. This patient population consisted of 30 with acute nonlymphocytic leukemia, 25 with acute lymphoblastic leukemia, 29 with chronic granulocytic leukemia, and 17 with other diseases (aplastic anemia in 7, myelodysplastic syndrome in 5, and lymphoma in 5). The results achieved in our patients who underwent transplantation in first complete remission of both acute nonlymphocytic leukemia and acute lymphoblastic leukemia compare favorably with previously reported results. Only 1 of 15 patients (7%) with acute nonlymphocytic leukemia and 2 of 8 patients (25%) with acute lymphoblastic leukemia who underwent transplantation in first complete remission had a relapse. Thus, we recommend early bone marrow transplantation during initial complete remission for patients with either of these disorders who have adverse prognostic factors. In contrast, of 12 patients with either acute nonlymphocytic leukemia or acute lymphoblastic leukemia who underwent transplantation during relapse, 11 died within 6 months. Therefore, such patients should be offered new experimental treatments. Our patients with chronic granulocytic leukemia fared better when they underwent transplantation early during the course of their disease rather than during the accelerated or blast phase. Prospective studies are needed to determine the best approach in these patients.

Academic Medical Centers↗

Additional t(11;17)(q23;q21) in a patient with Philadelphia-positive mixed lineage antigen-expressing leukemia.

We describe very uncommon phenotypic and cytogenetic findings in a 40-year-old female with blast phase of Philadelphia chromosome (Ph)-positive CML. In addition to the t(9;22)(q34;q11) that was detected in all metaphases, a t(11;17)(q23;q21) was identified in 15 of 20 metaphases. Reverse transcription-polymerase chain reaction showed the major and minor bcr/abl fusion transcripts in the cells from a bone marrow (BM) sample. Fluorescence in situ hybridization (FISH) analysis also showed that fusion signals of the bcr and abl probes were found in 95% of blastic cells and in 64% of neutrophils. MLL gene rearrangement was also detected in some blastic cells but not in neutrophils by FISH analysis. Phenotypically, blastic cells expressed mixed lineage antigens such as CD34, CD33, CD13, CD19, CD7, and CD41. Immunogenotypically, some population of BM cells showed monoclonal rearrangements of immunoglobulin heavy chain and T-cell receptor gamma chain genes by Southern blot analysis. Clinical course was aggressive, and therapy was poorly tolerated. Such findings seem to support an association between Ph and an abnormality of 11q23 with poor prognosis, and suggest that the expression of both abnormal genes may be related to this mixed lineage antigen-expressing leukemia.

Adult↗

The chimeric BCR-ABL gene.

The 1982 discovery that in chronic myeloid leukaemia (CML) the ABL proto-oncogene is translocated to the BCR gene located on chromosome 22 initiated many studies on the structural organization and function of these genes. The nucleotide sequence of the entire BCR and major parts of the ABL gene has now been determined. However, the actual cause of the fusion of BCR with ABL remains essentially unknown. Mouse models have been helpful to unravel the normal cellular function of BCR and ABL, as well the activity of BCR-ABL, although a single mechanism explaining the transforming activity of the latter has not been discovered. The cause of progression of the disease remains unknown, and no single genetic abnormality has been linked to the blast phase of CML. Much has been learned concerning the molecular biology of CML, but answers to the fundamental questions above may be expected in the coming years in parallel to increasing knowledge of genome structure, signal transduction and cell cycle control.

Animals↗

Both AML1 and EVI1 oncogenic components are required for the cooperation of AML1/MDS1/EVI1 with BCR/ABL in the induction of acute myelogenous leukemia in mice.

We have previously shown that BCR/ABL, a fusion protein generated by the t(9;22)(q34;q11) translocation found in the vast majority of chronic myelogenous leukemia (CML), cooperates with AML1/MDS1/EVI1 (AME), a fusion transcription factor generated by a t(3;21)(q26;q22) translocation identified as a secondary mutation in some cases of CML during the blast phase (CML-BC), in the rapid induction of an acute myelogenous leukemia (AML) in mice. In this study, we evaluated the leukemogenic potential of EVI1-, MDS1/EVI1- and AML1-related oncoproteins (AML1Delta, AML1/MDS1). We found that ectopic expression of either EVI1 or MDS1/EVI1 impaired hematopoiesis. However, neither EVI1 nor MDS1/EVI1 was sufficient for inducing AML in mice, although EVI1 did induce some hematologic neoplasia other than AML with a low efficiency. In addition, unlike AME, none of the EVI1- or AML1-related oncoproteins examined were capable of fully cooperating with BCR/ABL in the induction of AML. The results indicate that both the AML1 and EVI1 oncogenic components are required for the leukemogenic potential of AME and for the cooperation of AME and BCR/ABL in the induction of AML.

Animals↗