Lymphoblastic transformation of myelodysplastic syndrome

Acute myeloblastic leukemia occurs as a complication of myelodysplastic syndromes, but the appearance of an acute lymphoblastic leukemia (ALL) has only been reported once. We describe a case in which lymphoblastic transformation occurred in the setting of a dysmyelopoietic syndrome. This leukemia was characterized by lymphoid morphology, terminal deoxynucleotidyl transferase (TdT) positivity, cytogenetic abnormalities, and immunoglobulin gene rearrangements. The patient responded to conventional therapy for this leukemia (vincristine and prednisone). Our case supports the hypothesis of a common lymphohemopoietic progenitor and suggests that in vitro tests may help identify a subset of these patients and be important in selecting appropriate therapy.     

Analysis of prognostic factors for allogeneic marrow transplantation following busulfan and cyclophosphamide in myelodysplastic syndrome and after leukemic transformation

Prognostic factors in 42 patients aged 11 to 62 (median 46) years, with myelodysplastic syndrome (MDS) or after leukemic transformation, who underwent allogeneic marrow transplantation between 1984 and 1999 were analyzed. Thirty-six had advanced disease morphology; 19 had leukemic transformation. Twenty-nine received a preparative regimen of BuCy2 and 13 busulfan 14 mg/kg, etoposide 50 mg/kg and cyclophosphamide 120 mg/kg. Severe hepatic veno-occlusive disease (VOD) occurred in three patients all of whom received anti-leukemic chemotherapy prior to transplantation. Fifteen patients (36%) died from early transplant-related complications; nine patients relapsed. The estimated 4 year disease-free survival (DFS) was 35% (95% CI 26-44%). Older age was the most significant adverse prognostic factor. Patients with leukemic transformation who underwent early transplantation had significantly better DFS than those treated first with chemotherapy (P = 0.002). Delayed toxicity was rare in these patients; no late relapses occurred. Bone Marrow Transplantation (2000) 25, 1219-1222.     

Hyperfibrinolysis in a case of myelodysplastic syndrome with leukemic spread of mast cells.

Mast cells (MC) are multipotent hemopoietic effector cells producing diverse mediators like histamine, heparin, or tissue type plasminogen activator. We report a 75-year-old male patient with myelodysplastic syndrome (MDS) of recent onset (3 months' history) associated with a massive leukemic spread of immature tryptase+ MC (tentative term: myelomastocytic leukemia). The patient presented with pancytopenia, bleeding, hypofibrinogenemia, and an increased cellular tryptase level. Moreover, an excessive elevation of plasmin-antiplasmin complexes (9,200 ng/ml; normal range: 10-150), an elevated D-dimer, and an increase in thrombin-antithrombin III complexes were found. The identity of the circulating MC was confirmed by immunophenotyping (CD117/c-kit+, CD123/IL-3R alpha-, CD11b/C3biR-), biochemical analysis (cellular ratio [ng:ng] of tryptase to histamine >1), and electron microscopy. Bone marrow (bm) examination showed trilineage dysplasia (17% blasts), 30% diffusely scattered MC, and a complex karyotype. No dense, compact MC infiltrates (mastocytosis) were detectable in bm sections. Despite hyperfibrinolysis and mediator syndrome (flushing, headache), the patient received remission induction polychemotherapy (DAV) followed by two cycles of consolidation with intermediate dose ARA-C (2 x 1 g/m2/day on days 1, 3, and 5). He entered complete remission after the first chemotherapy cycle without evidence of recurring MDS. Moreover, in response to chemotherapy, the hyperfibrinolysis and mediator syndrome resolved, and the circulating c-kit+ MC disappeared. We suggest consideration of polychemotherapy as a therapeutic option in patients with high-risk MDS of recent onset, even in the case of MC lineage involvement.     

del11(p11-13) with overexpression of Wilms' tumor gene during leukemic transformation of myelodysplastic syndrome

We report a case of leukemic transformation from myelodysplastic syndrome (MDS) with a sole chromosome abnormality of del11(p11-13). The patient had been diagnosed as having MDS (refractory anemia with excess of blast cells, RAEB) in May 1998. At that time, cytogenetic analysis of bone marrow cells showed a normal karyotype. The patient received sequential chemotherapy with low-dose cytosine arabinoside (AraC) and macrophage colony-stimulating factor (M-CSF). Complete remission was obtained with this treatment, but the disease gradually progressed after June 1999. Cytogenetical analysis showed del11(p11-13) in 6 of 40 cells analyzed at that time, and the disease had evoluted to overt leukemia in December 1999 with a gradual increase in the abnormal clone. Furthermore, mRNA of the WT1 gene located at chromosome 11p13 was overexpressed during leukemic transformation, whereas it was not detected at the time of the initial diagnosis of MDS (RAEB) in May 1998. It was thought that this chromosome deletion and overexpression of WT1 resulted in the leukemic transformation in this patient. This is the first case report of del11(p11-13) being considered to be the primary cause of leukemic transformation from MDS.     

Blood group change in a patient with blastic transformation of a myelodysplastic syndrome

Summary Loss of certain red blood cell antigens has been described in patients with acute myelocytic leukemia (AML). This paper describes the loss of blood group A antigen in a patient with AML. The acute leukemia in this patient was preceded by a myelodysplastic syndrome for several months. At the time of diagnosis the patient's red cells showed the 0 Rh(D)⁺ phenotype. After induction of complete remission with two courses of Daunorubicin, Cytosin-arabinosid, and Etoposid his blood group reverted to A₂. Serological studies including saliva analysis revealed that the original blood group was very likely A.     

核因子-κB活化抑制增强高三尖杉酯碱诱导白血病细胞凋亡

目的　研究地塞米松 (DXM)和长春新碱 (VCR)对高三尖杉酯碱 (HH)诱导白血病细胞凋亡与核因子 κB (NF κB)活化的影响。方法　采用TdT介导的dUTP缺口末端标记技术(TUNEL)、DNA电泳方法观察HH诱导K5 6 2 n细胞凋亡 ,采用电泳迁移率变动分析 (EMSA)观察HH诱导K5 6 2 n细胞NF κB活化。结果　用 (0 5、5、5 0 ) μmol/L的HH均能诱导K5 6 2 n细胞凋亡率分别为 (30 0 0± 3 34,4 7 13± 3 18,6 8 6 3± 8 14 ) % ,与对照组相比 ,有良好的浓度依赖关系 (P <0 0 5 ) ;DXM 1μmol/L和VCR 0 1μmol/L本身无诱导K5 6 2 n细胞凋亡的作用 ,但均能增强HH 0 5μmol/L诱导的K5 6 2 n细胞凋亡 ,凋亡增加率分别为 85 8%和 114 6 % (P值均 <0 0 5 )。K5 6 2 n细胞未经药物诱导NF κB也有轻度活化 ;HH 0 5 μmol/L可明显诱导K5 6 2 n细胞NF κB活化 ,DXM 1μmol/L和VCR 0 1μmol/L能显著抑制HH 0 5 μmol/L诱导的NF κB活化 ,抑制率分别为 32 0 %和39 4 % (P值均 <0 0 5 )。结论　HH诱导K5 6 2 n细胞凋亡的同时激活NF κB ;DXM和VCR可通过抑制NF κB活化 ,增强其诱导K5 6 2 n细胞凋亡的作用。     

Erythropoietin-dependent transformation of myelodysplastic syndrome to acute monoblastic leukemia.

Acute monoblastic leukemia (acute myeloid leukemia [AML], French-American-British type M5a) with leukemia cutis developed in a patient 6 weeks after the initiation of erythropoietin (EPO) therapy for refractory anemia with ringed sideroblasts. AML disappeared from both marrow and skin after the discontinuation of EPO. Multiparameter flow cytometric analysis of bone marrow cells demonstrated coexpression of the EPO receptor with CD45 and CD13 on the surface of blasts. The incubation of marrow cells with EPO, compared to without, resulted in 1.3- and 1.6-fold increases, respectively, in tritiated thymidine incorporation and bromodeoxyuridine incorporation into CD13(+) cells. Clinical and laboratory findings were consistent with the EPO-dependent transformation of myelodysplastic syndrome (MDS) to AML. It is concluded that leukemic transformation in patients with MDS treated with EPO may be EPO-dependent and that management should consist of the discontinuation of EPO followed by observation, if clinically feasible.     

BCL2/BCL-X(L) inhibition induces apoptosis, disrupts cellular calcium homeostasis, and prevents platelet activation

Apoptosis in megakaryocytes results in the formation of platelets. The role of apoptotic pathways in platelet turnover and in the apoptotic-like changes seen after platelet activation is poorly understood. ABT-263 (Navitoclax), a specific inhibitor of antiapoptotic BCL2 proteins, which is currently being evaluated in clinical trials for the treatment of leukemia and other malignancies, induces a dose-limiting thrombocytopenia. In this study, the relationship between BCL2/BCL-X(L) inhibition, apoptosis, and platelet activation was investigated. Exposure to ABT-263 induced apoptosis but repressed platelet activation by physiologic agonists. Notably, ABT-263 induced an immediate calcium response in platelets and the depletion of intracellular calcium stores, indicating that on BCL2/BCL-X(L) inhibition platelet activation is abrogated because of a diminished calcium signaling. By comparing the effects of ABT-263 and its analog ABT-737 on platelets and leukemia cells from the same donor, we show, for the first time, that these BCL2/BCL-X(L) inhibitors do not offer any selective toxicity but induce apoptosis at similar concentrations in leukemia cells and platelets. However, reticulated platelets are less sensitive to apoptosis, supporting the hypothesis that treatment with ABT-263 induces a selective loss of older platelets and providing an explanation for the transient thrombocytopenia observed on ABT-263 treatment.     

Impaired differentiation and apoptosis of hematopoietic precursors in a mouse model of myelodysplastic syndrome

Expression of a NUP98-HOXD13 (NHD13) fusion gene, initially identified in a patient with myelodysplastic syndrome, leads to a highly penetrant myelodysplastic syndrome in mice that recapitulates all of the key features of the human disease. Expansion of undifferentiated lineage negative (lin(neg)) hematopoietic precursors that express NHD13 was markedly inhibited (30-fold) in vitro. Decreased expansion was accompanied by decreased production of terminally differentiated cells, indicating impaired differentiation of NHD13 precursors. Rather than differentiate, the majority (80%) of NHD13 lin(neg) precursors underwent apoptotic cell death when induced to differentiate. These findings demonstrate that NHD13 lin(neg) cells provide a tractable in vitro system for studies of myelodysplastic syndrome.     

Altered oncoprotein expression and apoptosis in myelodysplastic syndrome marrow cells

Ineffective hematopoiesis with associated cytopenias and potential evolution to acute myeloid leukemia (AML) characterize patients with myelodysplastic syndrome (MDS). We evaluated levels of apoptosis and of apoptosis-related oncoproteins (c-Myc, which enhances, and Bcl-2, which diminishes apoptosis) expressed within CD34+ and CD34- marrow cell populations of MDS patients (n = 24) to determine their potential roles in the abnormal hematopoiesis of this disorder. Marrow cells were permeabilized and CD34+ and CD34- cells were separately analyzed by FACS to detect: (1) a subdiploid (sub-G1) DNA population, and (2) expression of Bcl-2 and c-Myc oncoproteins. Within the CD34+ subset, a significantly increased percentage of cells demonstrated apoptotic/sub- G1 DNA content in early (ie. refractory anemia) MDS patients compared with normal individuals and AML patients (mean values: 9.1% > 2.1% > 1.2%). Correlated with these findings, the ratio of expression of c-Myc to Bcl-2 oncoproteins among CD34+ cells was significantly increased for MDS patients compared to those from normal and AML individuals (mean values: 1.6 > 1.2 > 0.9). Bcl-2 and c-Myc oncoprotein levels were maturation stage-dependent, with high levels expressed within CD34+ marrow cells, decreasing markedly with myeloid maturation. Treatment of seven MDS patients with the cytokines granulocyte colony-stimulating factor plus erythropoietin was associated with decreased levels of apoptosis within CD34+ marrow cells and may contribute to the enhanced hematopoiesis in vivo that was shown. These findings are consistent with the hypothesis that altered balance between cell-death (eg, c-Myc) and cell-survival (eg, Bcl-2) programs were associated with the increased degrees of apoptosis present in MDS hematopoietic precursors and may contribute to the ineffective hematopoiesis in this disorder, in contrast to decreased apoptosis and enhanced leukemic cell survival in AML.     

Study on pathophysiology of the myelodysplastic syndromes (MDS)--pattern of dysmegakaryopoiesis related to leukemic transformation

A series of 116 patients with MDS consisted of 74 cases of RA, 10 cases of RARS, 14 cases of RAEB, 9 cases of RAEB-T and 9 cases of CMML, were studied on the quantity and morphological abnormalities of megakaryocytes in relation to over all survival and leukemic change. The amount of megakaryocytes was graded into four groups; marked hypoplasia (O), moderate hypoplasia (L), normoplasia (N) and hyperplasia (H), RA cases showed heterogeneous pattern; containing 14 cases (18.9%) of group (O), 18 cases (24.3%) of group (L), 31 cases (41.9%) of group (N) and 11 cases (14.9%) of group (H). RARS, RAEB, RAEB-T and CMML cases were classified into group (N) or group (H). The heterogeneous pattern of RA did not relate to leukemic change, but over all survival tended to be shorter in group (N) cases. A significant number of young female cases of RA were involved in group (O). Morphological abnormalities of MDS megakaryocytes were classified into five types; I, mononuclear micromegakaryocytes, II, binuclear micromegakaryocytes, III, mononuclear small megakaryocytes, IV, multiseparated-nuclear megakaryocytes and V, megakaryocytes with bizzare nuclei. RAEB and RAEB-T cases uniformly showed marked dysmegakaryopoiesis ranging from type I to V. whereas RA, RARS and CMML cases showed mild dysmegakaryopoiesis. Only five cases (6.4%) of RA cases had type I micromegakaryocytes. Eight RA cases with type I on diagnosis or obtaining it during the clinical course tended to develop acute myeloid leukemia (5 cases) or to transform to RAEB sooner or later. In two cases of RAEB in which hematological improvement was obtained with low dose cytosine arabinoside regimen, disappearance of type I micromegakaryocytes was noted. A female case with 5q-anomaly surviving more than 10 years showed marked megakaryocyte hyperplasia and almost exclusively type III and IV megakaryocytes. These findings indicated that pattern of dysmegakaryopoiesis, especially appearance of type I, was closely related to leukemic change in MDS. Thus quantitative and qualitative evaluations of MDS megakaryocytopoiesis seemed important to understand the further heterogeneity of pathophysiology in MDS subtypes.     

Analyzing transformation of myelodysplastic syndrome to secondary acute myeloid leukemia using a large patient database

One‐third of patients with myelodysplastic syndrome (MDS) progress to secondary acute myeloid leukemia (sAML), with its concomitant poor prognosis. Recently, multiple mutations have been identified in association with MDS‐to‐sAMLtransition, but it is still unclear whether all these mutations are necessary for transformation. If multiple independent mutations are required for the transformation, sAML risk should increase with time from MDS diagnosis. In contrast, if a single critical biological event determines sAML transformation; its risk should be constant in time elapsing from MDS diagnosis. To elucidate this question, we studied a database of 1079 patients with MDS. We classified patients according to the International Prognostic Scoring System (IPSS), using either the French‐American‐British (FAB) or the World Health Organization (WHO) criteria, and statistically analyzed the resulting transformation risk curves of each group. The risk of transformation after MDS diagnosis remained constant in time within three out of four risk groups, and in all four risk groups, when patients were classified according to FAB or to the WHO‐determined criteria, respectively. Further subdivision by blast percentage or cytogenetics had no influence on this result. Our analysis suggests that a single random biological event leads to transformation to sAML, thus calling for the exclusion of time since MDS diagnosis from the clinical decision‐making process. Am. J. Hematol. © 2012 Wiley Periodicals, Inc.     

Inhibition of neutrophil elastase prevents the development of murine dextran sulfate sodium-induced colitis

Background Neutrophil elastase (NE) is a major secretory product from activated neutrophils and a major contributor to tissue destruction. However, little is known about the pathogenic contribution of NE to ulcerative colitis (UC). This study was designed to investigate the contribution of NE by measuring NE activity in plasma and colonic mucosal tissue from UC patients and a murine acute colitis model, and to elucidate the therapeutic effect of the NE-specific inhibitor ONO-5046. Methods The NE enzyme activities in plasma and colonic mucosal tissue from UC patients were directly measured using an enzyme–substrate reaction. Acute colitis was induced in mice by administration of 1.5% dextran sulfate sodium (DSS) for 5 days. DSS-induced colitis mice were then treated with ONO-5046 (50 mg/kg body weight) intraperitoneally twice a day. Results In UC patients, the NE enzyme activity was significantly elevated in both the plasma and colonic mucosal tissue compared with healthy controls. In DSS-induced colitis mice, the NE enzyme activity increased in parallel with the disease development. ONO-5046 showed therapeutic effects in DSS-treated mice by significantly reducing weight loss and histological score. ONO-5046 suppressed the NE enzyme activities in both plasma and culture supernatant of colonic mucosa from DSS-induced colitis mice. Conclusions ONO-5046, a specific NE inhibitor, prevented the development of DSS-induced colitis in mice. NE therefore represents a promising target for the treatment of UC patients.