Megakaryoblastic transformation of chronic myelogenous leukemia

A 52-year-old man with Ph1-positive chronic myelogenous leukemia (CML) developed a blastic transformation in which the predominant cell type micromegakaryocytes. He did not respond to treatment. A review of the 15 previously reported cases of patients with circulating megakaryocyte abnormalities in association with either CML or a Ph1 chromosome positive myeloproliferative disorder suggests a female predominance rather than the usual male predominance of CML. Survival of the six patients reported as megakaryoblastic transformation of CML as well as this patient was poor.     

Megakaryocyte features and bcr/abl translocation in chronic myeloid leukemia following imatinib mesylate (STI571) therapy--a fluorescence in-situ hybridization study

Following therapy with imatinib (STI571) hematologic and cytogenetic response in chronic myeloid leukemia (CML) is associated with conspicuous alterations of bone marrow (BM) morphology. Besides reduction of cellularity and fibrosis, small megakaryocytes characteristic for this disorder were replaced by large, normally appearing cells of this lineage. However, it is not known whether and to which extent these changes are accompanied by a loss of the bcr/abl translocation. Therefore an immunohistochemical (CD61) and fluorescence in-situ hybridization (FISH) study was performed on sequential BM biopsies in 5 patients with CML receiving STI571 without any pretreatment. Morphometric analysis revealed that the prevalent population of 47% micromegakaryocytes (size < or = 150 microm2) was significantly reduced (15%) during therapy and that a conspicuous shift to medium-sized and large megakaryocytes occurred. According to FISH analysis in the initial BM biopsy sections 71% of all myeloid cells exhibited the bcr/abl gene and concerning megakaryopoiesis about 65% of the prominent micromegakaryocytes displayed positive signals. After treatment this peculiar cell population decreased significantly while the emerging large megakaryocytes (52%) totally lacked a bcr/abl labeling. Because cytogenetic response and reduction of micromegakaryocytes seem to be linked, this feature may be useful to monitor therapeutic efficacy by evaluating BM morphology.     

The spleen in Friend leukemia. I. Prolonged survival of leukemic mice after autoimplantation of spleen tissue.

Friend virus infection of susceptible mice led rapidly to fulminant erythroleukemia and death. Subcutaneous implantation of leukemia spleen bits into splenectomized normal animals led to their early death from Friend leukemia. In contrast, bits of leukemic spleen implanted sc into splenectomized leukemic mice prolonged the survival of these animals. Concomitant with this survival was a reversal of the virus-induced immunosuppression and an increase in the levels of circulating, neutralizing, antivirus activity. This marked difference in response to leukemic spleen implants by leukemic as compared to normal mice reflected previous contact of the former with Friend Virus. Our studies indicated that the Friend virus-infected mouse mounted a resistance to the virus infection, which under certain conditions is capable of reversing the disease process.     

Erythroleukemia-like syndrome due to busulfan toxicity in polycythemia vera.

Over a 19-year period, a patient with polycythemia vera who had undergone a splenectomy received six courses of busulfan for recurrent thrombocytosis. The total dose of busulfan given for the sixth course was greater than that used for the previous ones. Severe pancytopenia followed, which persisted for 4 months. During this period there was marked erythroid hyperplasia in the bone marrow with striking dyserythropoiesis; PAS-positive red cell precursors, as well as moderate numbers of circulating normoblasts and evidence of chronic and acute hemolysis, were present. All of these findings reverted to normal without therapy, and the polycythemic state eventually recurred. These events are interpreted as an unusual marrow reaction following busulfan overdosage rather than a transient erythroleukemia.     

Clinical and cytogenetic correlations of abnormal megakaryocytopoiesis in patients with acute leukemia and chronic myelogenous leukemia in blast crisis

It has been suggested that abnormalities of chromosome 3 at bands q21 and q26 are associated with the presence of increased numbers of abnormal megakaryocytes in patients with hematologic malignancies. The pretreatment bone marrows of 287 patients with leukemia (acute myeloid leukemia (AML), 225 patients; acute lymphocytic leukemia (ALL), 36 patients; or chronic myelogenous leukemia in blast crisis (CML-B), 26 patients) were reviewed to identify those with normal or increased numbers of megakaryocytes. Thirty-two patients with AML, one with ALL, and 10 with CML-B had normal or increased numbers of megakaryocytes. Of the 32 patients with AML, 19 patients had significant numbers of mononuclear or binuclear small megakaryocytes as well as megakaryocytes with separated nuclei ("micromegakaryocytes"). Cytogenetic analyses were obtained in 29 of 32 patients with AML and showed inv(3)(q21q26) (one patient); Ph1 (two patients); -5 and/or -7 (seven patients); normal karyotypes (10 patients). No patient with micromegakaryocytes had a chromosomal abnormality associated with a favorable prognosis. Overall, among 225 patients with AML, four had inv(3)(q21q26) or t(3;3)(q21;q26). Only one of these four patients had normal or increased numbers of megakaryocytes, although all four had micromegakaryocytes. One patient with CML-B had inv(3)(q21q26) but had decreased numbers of megakaryocytes and a platelet count of 24 x 10(3)/microliters. All five patients with abnormal chromosome 3 at bands q21 and q26 had additional cytogenetic abnormalities (Ph1 in two patients; -7 in three patients). Mean and median platelet counts were greater than 100,000/microliters for patients with marrow megakaryocytosis regardless of morphology, as well as for the patients with abnormalities involving 3q21 and 3q26. Abnormalities of megakaryocyte morphology, increases in the numbers of megakaryocytes, and normal to increased platelet counts are not uncommon in patients with acute leukemia and CML-B, and are not uniquely associated with changes involving chromosome 3.     

Changes in DNA associated with induction of erythroid differentiation by dimethyl sulfoxide in murine erythroleukemia cells.

The Friend virus-infected murine erythroleukemia cell can be induced to differentiate along erythroid cells in culture with various compounds, including dimethyl sulfoxide. DNA from murine erythroleukemia cells cultured with dimethyl sulfoxide shows a decrease in sedimentation rate in alkaline sucrose gradients after alkali lysis of the cells. These changes can be detected as early as 27 hr after the beginning of culture. Similar results are observed with DNA of the cells cultured with other inducers, butyric acid and dimethylacetamide, but not with DNA from a variant cell line resistant to induction with dimethyl sulfoxide. Ultraviolet irradiation, which is known to cause similar changes in the sedimentation rate of DNA in alkaline sucrose gradients, induces differentiation of the murine erythroleukemia cells. These studies suggest that alterations in DNA may be related to events involved in the induction of differentiation of murine erythroleukemia cells by dimethyl sulfoxide.     

Paroxysmal nocturnal hemoglobinuria terminating as erythroleukemia.

A case of a patient who developed erythroleukemia 3 years into the course of paroxysmal nocturnal hemoglobinuria (PNH) is presented. A case of erythroleukemia with a positive sucrose lysis test has been reported, but our case appears to be the first with a long clinical course of PNH evolving into erythroleukemia. The association between these two diseases, their possible clonal origin, and how they fit into the myelodysplastic syndromes are discussed.     

Acquired Pelger-Huet anomaly in erythroleukemia

The Pelger-Huet anomaly was found in association with erythroleukemia in a 62-year-old female who was known to have had normal granulocyte morphology 9 months previously. This is the third reported case of the coexistence of Pelger-Huet anomaly with erythroleukemia and the first case in which normal morphology was known to have been present prior to the development of erythroleukemia. Although the pseudo-Pelger-Huet anomaly has been reported in association with numerous neoplastic and non-neoplastic hematologic diseases, its pathogenesis and the clinical significance of its presence remain to be elucidated.     

Erythroleukemia: a comparison between the previous FAB approach and the WHO classification

Erythroleukemia is, within FAB classification, a proliferation of erythroblasts superior to 50% and of myeloblasts superior to 30%. The new WHO classification abolishes the frontier between RAEB-t with 20% and leukemia with 30% of blasts. AML6 variant is a new entity characterized by the proliferation of immature erythroblasts and the absence of non-erythroid blast cells. We analyzed 16 erythroleukemia, 5 RAEB-t and 2 AML6 variants to clarify their relationship.We suggest on survival, karyotype and cytologic characteristics that secondary erythroleukemia are the same entity as RAEB-t, confirming the WHO classification and that amongst de novo erythroleukemia, there is 'AML6 variant' with pure erythroid lineage proliferation.     

Spontaneous regression of Friend murine leukemia virus-induced erythroleukemia. IV. Effects of radiation and athymia on leukemia regression in mice.

The spontaneous regression of the erythroleukemia induced by the regressing Friend murine leukemia virus (F-MuLV) complex was inhibited by irradiation of the animals prior to F-MuLV inoculation. This inhibition was proportional to the dose of radiation used. Treatment of the mice with the bone-seeking isotope 89Sr also inhibited erythroleukemia regression, which implicates the same effector mechanisms involved in the resistance to F-MuLV or F-MuLV-induced immunosuprression. Erythroleukemias induced in athymic nude mice by the regressing F-MuLV complex exhibited higher rates of lethality than did the leukemias in heterozygous or homozygous thymus gland-containing controls. These data suggested the involvement of the immune system in erythroleukemia regression and the specific participation of thymus cells and an 89Sr-susceptible function, perhaps marrow-dependent cells, in the process of regression.     

The cytotoxicity of Pseudomonas exotoxin A, inactivated by modification of the cell-binding domain I, is restored when conjugated to an erythroid cell-specific targeting agent

To be capable of selective killing of tumor cells, the non-selective Pseudomonas aeruginosa exotoxin A must have its cell-binding domain inactivated or removed and then be chemically linked to, or genetically fused with, a specific targeting agent. In the present study, epsilon-NH2 groups of lysine residues of the cell-binding domain of exotoxin A were extensively propionylated with N-succinimidyl-3-propionate (NSP). The NSP-treated exotoxin retained its cytocidal ADP-ribosyltransferase activity, but it could no longer bind to, and inhibit the proliferation of, Friend murine erythroleukemia cells. Cytotoxicity (i.e., the ability to inhibit proliferation) for the Friend erythroid cells was restored completely to the NSP-inactivated exotoxin by conjugating it to ADIF, an autocrine factor secreted by chicken erythroleukemia cells which selectively inhibits the differentiation of erythroid cells such as Friend erythroleukemia cells without inhibiting their proliferation.     

Attempt to modify Rauscher-virus leukemogenesis by modulation of lymphoreticular and hematopoietic tissue

Rauscher erythroleukemia virus of the mouse was originally isolated from an animal bearing a lymphocytic neoplasm. In order to control extraneous influences on leukemia development, we modulated thymus-dependent and bursa-dependent lymphatic tissues and the granulopoietic and erythropoietic components of hemoreticular tissues during the latent period of leukemia development. In all experiments the same type of erythroleukemia was found with some variation in the course of the disease.     

Erythroleukemia in a renal transplant recipient.

A 53-year-old male developed acute erythroleukemia three years after renal transplantation. He had received three years of immunosuppressive therapy with azathioprine. A preleukemia phase associated with chromosome abnormalities was recognized. Azathioprine has been associated with chromosome abnormalities. The chronic stimulation of an abnormal erythroid clone by transplantation may have hastened the development of erythroleukemia.     

Evidence that a novel human differentiation-inhibiting protein blocks the dimethyl sulfoxide-induced differentiation of erythroleukemia cells by inhibiting the activation of membrane protein kinase C.

We have previously reported (J. P. Durkin et al., Blood, 79: 1161-1171, 1992) the isolation of a human differentiation-inhibiting protein (DIP) which selectively inhibits and blocks the differentiation of erythroid burst-forming unit progenitor cells in bone marrow colony assay, and the dimethyl sulfoxide (DMSO)-induced differentiation of cultured murine erythroleukemia (MEL) cells. DIP blocks MEL cell differentiation directly, without affecting the ability of the cells to proliferate. In the present study, DIP (at < 1 ng/ml) inhibited MEL cell differentiation only when added to the culture medium within 1 h after DMSO induction, indicating that it blocked an early, critical step in erythroleukemia cell differentiation. The protein kinase C (PKC) inhibitor H-7 also maximally inhibited the differentiation of MEL cells during this same period following induction, suggesting that DIP may have blocked an early PKC-dependent process. Indeed, DIP was found to abolish a transient increase in membrane PKC activity which was triggered in MEL cells within 10-30 min after DMSO addition. This increase in membrane PKC activity resulted from the activation of an inactive pool of PKC residing on membranes, and not from the translocation of cytosolic PKC to membranes. DMSO also stimulated membrane PKC activity and differentiation in human erythroleukemia cells and HL-60 myeloid leukemia cells. As was the case with MEL cells, DIP prevented the early activation of PKC and the differentiation of human erythroleukemia cells. However, it did not inhibit the early increase in PKC activity in HL-60 cells or the subsequent differentiation of these cells. These results suggest that DIP blocks erythroleukemia cell differentiation by inhibiting an early and critical activation of inactive membrane PKC.     

Treatment-related leukemia in Hodgkin's disease: a multi-institution study on 75 cases

Hematological and cytogenetic characteristics of 75 cases of therapy-related acute non lymphoid leukemia (t-ANLL) occurring in Hodgkin's disease (HD) are analysed in this multi-institution study. Combined radio and chemotherapy had been given in 88 per cent of patients, either as adjuvant (44 per cent) or as salvage modality (44 per cent). Radiotherapy alone and chemotherapy alone had been given in 3 per cent and 9 per cent respectively. Eighty per cent of patients were in remission of HD and 71 per cent off-therapy while developing leukemia. The median latent time from remission of HD to leukemia was 34 months. The myeloblastic variety of leukemia accounted for 43 per cent of total cases; the myelomonocytic and monocytic for 17 per cent and 4 per cent, the promyelocytic and erythroblastic variants for 5 per cent and 7 per cent of t-ANLL. Twenty four per cent of cases were unclassifiable; one of these was TdT-positive. Dysplastic features of erythrocytic line were invariably present with circulating erythroblasts; defects of granulocytes, circulating megathrombocytes and micromegakaryocytes were also present. Bone marrow hypoplasia and marked fibrosis were documented in 47 per cent and 30 per cent of cases. Preleukemia heralded overt leukemia in 73 per cent of cases; 37 per cent had refractory anemia with no excess of blasts; 16 per cent of preleukemias were unclassifiable. Cytogenetics revealed chromosome abnormalities in 83 per cent of cases; 72 per cent presented chromosome 5 and/or 7 monosomy or partial deletion (5q- or 7q-) of the long arm (94 per cent in the combined modality therapy group). In 3 cases, a pure monosomy 7 was observed; in none 5q-alone. Response rate to conventional therapy was 14 per cent; low and high-dose cytarabine were of little benefit. Long-term CR (28 + and 16 + months) was achieved in 2 cases with allogeneic bone marrow transplantation (BMT) as first-line therapy. A better knowledge of t-ANLL in HD and new therapies, including BMT, may improve the prognosis of this late complication of intensive HD treatment.     

Erythroleukemia: a need for a new definition.

The new WHO classification abolishes the frontier between RAEB-t with 20% of blasts and leukemia with 30% of blasts. We review the definitions of erythroleukemia and discuss the relationship between FAB AML6, RAEB-t and AML6 variant. We ask whether secondary erythroleukemias are the same entity as RAEB-t on survival, karyotype and cytologic characteristics. We suggest that 'AML6 variant' with pure erythroid lineage proliferation would be the real de novo erythroleukemia. Current FAB AML6 entity will probably be classified in either subgroup (1) multilineage dysplasia; (2) therapy-related leukemia; or (3) acute erythroid leukemia subdivided into erythroleukemia (erythroid/myeloid) and pure erythroid leukemia, in the WHO classification - a classification which highlights the importance of clinical and cytogenetic prognostic factors.     

Erythroleukemia following drug induced hypoplastic anemia.

Three patients with drug-induced hypoplastic anemia terminating 2 to 6 years after presentation with erythroleukemia are described. All were treated for prolonged periods with androgen and corticosteroid and two of the patients showed apparent dependence on this therapy for optimal hematologic status. The leukemic phase was heralded by loss of this dependence and development of sideroblastic dyserythropoiesis with progression to bizarre erythroid hyperplasia and fatal cytopenia. The exact relationship between androgen and corticosteroid therapy and the erythroleukemia remains speculative.     

Deletion of 3(p14p23) in secondary erythroleukemia arising in long-term survivors of small cell lung cancer

Cytogenetic studies were done on the leukemia cells of two patients with small cell lung cancer (SCLC) who developed erythroleukemia (acute nonlymphocytic leukemia, French-American-British M6) after combined modality chemotherapy and radiotherapy for their lung cancer. Surprisingly, both erythroleukemias exhibited the del(3)(p14p23) predominantly found in SCLC. In four other patients who had secondary erythroleukemias associated with other cancers, no deletions of 3p were found. These findings could be accounted for by one of three possible mechanisms: (a) an inherited recessive gene (anti-oncogene or tumor suppressor gene) in this region of 3p was uncovered by the combined modality therapy, (b) an inherited predisposition to damage of both chromosomes at 3p14 leads to SCLC and erythroleukemia after exposure to carcinogens and/or chemotherapy-radiotherapy, or (c) the finding of lineage specificity for the 3p deletion with the presence of the 3p deletion in SCLC and erythroleukemia suggests a common bone marrow precursor.