Recurrent annular erythema in juvenile chronic myelogenous leukaemia

Juvenile chronic myelogenous leukaemia (JCML) is a rare haematological malignancy of myelomonocytic lineage that affects patients less than 4 years of age and is known as an entity different from adult-type chronic myelogenous leukaemia. In JCML, skin manifestations are relatively common but most of them have been reported as a non-specific eruption, which histologically may show changes resembling neurofibromatosis or xanthogranuloma. We present a 2-year-old boy with JCML who developed a recurrent annular erythema in which leukaemic infiltrates were confirmed histologically, even though his bone marrow examination suggested that be remained in haematological remission.     

Leptomeningeal disease in pre-leukemic syndrome: cytogenetic abnormality versus cellular morphology

Refractory anemia with excess blasts in transformation (RAEB-T) is a pre-leukemic syndrome that can progress to acute myelogenous leukemia (AML). Although leptomeningeal disease in AML is rare and it is commonly associated with specific cytogenetic abnormalities, it has not been documented in RAEB-T. We report a woman who experienced seizures and had subarachnoid enhancement on MRI suggestive of leukemic infiltrates in the leptomeninges. Her bone marrow aspirate revealed 6.6% blasts and the presence of Auer rods, findings consistent with a diagnosis of RAEB-T. Subsequent cytogenetic analysis detected an uncommon deletion of chromosome 11q23, and the breakpoint on chromosome 11 is identical to that seen in AML patients having leptomeningeal disease and translocation between chromosome 9 and 11. Although RAEB-T is not considered as leukemia and is thought unlikely to involve the central nervous system, the presence of leptomeningeal disease and 11q23 deletion in our patient suggests that cytogenetic abnormality may be an important determinant of neurological complications, regardless of a diagnosis of RAEB-T or AML which is based on cellular morphology.     

Thrombopoietin enhances the production of myeloid cells, but not megakaryocytes, in juvenile chronic myelogenous leukemia

We previously reported the aberrant growth of granulocyte-macrophage (GM) progenitors induced by a combination of stem cell factor (SCF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in juvenile chronic myelogenous leukemia (JCML). We examined here the effects of thrombopoietin (TPO) on the proliferation and differentiation of hematopoietic progenitors in JCML. In serum-deprived single-cell cultures of normal bone marrow (BM) CD34+CD38high cells, the addition of TPO to the culture containing SCF + GM-CSF resulted in an increase in the number and size of GM colonies. In the JCML cultures, in contrast, the number of SCF + GM-CSF-dependent GM colonies was not increased by the addition of TPO. However, the TPO addition caused an enlargement of GM colonies in cultures from the JCML patients to a significantly greater extent compared with the normal controls. There was no difference in the type of the constituent cells of GM colonies with or without TPO grown by JCML BM cells. A flow cytometric analysis showed that the c-Mpl expression was found on CD13+ myeloid cells generated by CD34+CD38high BM cells from JCML patients, but was at an undetectable level in normal controls. The addition of TPO to the culture containing SCF or SCF + GM-CSF caused a significant increase in the production of GM colony-forming cells by JCML CD34+CD38neg/low population, indicating the stimulatory effects of TPO on JCML primitive hematopoietic progenitors. Normal BM cells yielded a significant number of megakaryocytes as well as myeloid cells in response to a combination of SCF, GM-CSF, and/or TPO. In contrast, megakaryocytic cells were barely produced by the JCML progenitors. Our results may provide a fundamental insight that the administration of TPO enhances the aberrant growth of GM progenitors rather than the recovery of megakaryocytopoiesis.     

Mutational analysis of N-RAS and GAP-related domain of the neurofibromatosis type 1 gene in chronic myelogenous leukemia

RAS mutations can be detected in a variable number of patients with myeloproliferative disorders such as myelodysplastic syndromes and acute myeloid leukemia, but are rare events in chronic myelogenous leukemia in chronic phase. However, there is good evidence supporting the involvement of RAS signalling pathway in CML and this could be due to alterations in RAS activity regulatory proteins. The neurofibromatosis (NF1) gene down-regulates the RAS signal transduction pathway through the inhibitory function of its GAP-related domain (GRD) on RAS protein. The loss or alteration of neurofibromin (the NF1 protein) may produce a disfunction similar to point mutations in the RAS gene resulting in the permanent stimulation of the RAS signal transduction pathway. Mutations involving the GRD region of the NF1 gene (GRD-NF1) have been described in a variety of tumors such as colon carcinoma and astrocytoma. Germline mutations and deletions in the NF1 gene, as seen in neurofibromatosis type 1, are also associated with certain myeloid disorders. In the present work, we sought to identify mutations in the codons 12/13 and 61 of RAS gene and in the Lys-1423 codon of GRD-NF1, which are well known hot spots in these genes, in a group of 36 adults and ten children with chronic myelogenous leukemia in chronic phase and blast crisis. Using the PCR-SSCP and the allele-specific restriction assay (ASRA) techniques, we were not able to observe any RAS or NF1 detectable mutation. These findings suggest that RAS and GRD-NF1 mutations are not involved either in chronic phase or in the progression to blast crisis in chronic myelogenous leukemia in adults and children.     

Bcr-Abl efficiently induces a myeloproliferative disease and production of excess interleukin-3 and granulocyte-macrophage colony-stimulating factor in mice: a novel model for chronic myelogenous leukemia

The bcr-abl oncogene plays a critical role in causing chronic myelogenous leukemia (CML). Effective laboratory animal models of CML are needed to study the molecular mechanisms by which the bcr-abl oncogene acts in the disease progression of CML. We used a murine stem cell retroviral vector (MSCV) to transduce the bcr-abl/p210 oncogene into mouse bone marrow cells and found that expression of Bcr-Abl/p210 induced a myeloproliferative disorder that resembled the chronic phase of human CML in 100% of bone marrow transplanted mice in about 3 weeks. This CML-like disease was readily transplanted to secondary recipient mice. Multiple clones of infected cells were expanded in the primary recipients, but the leukemia was primarily monoclonal in the secondary recipient mice. Mutation analysis demonstrated that the protein tyrosine kinase activity of Bcr-Abl/p210 was essential for its leukemogenic potential in vivo. Interestingly, we found that the leukemic cells expressed excess interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the diseased mice. These studies demonstrate that expression of Bcr-Abl can induce a CML-like leukemia in mice much more efficiently and reproducibly than in previously reported mouse CML models, probably due to efficient expression in the correct target cell(s). Our first use of this model for analysis of the molecular mechanisms involved in CML raises the possibility that excess expression of hematopoietic growth factors such as IL-3 and GM-CSF may contribute to the clinical phenotype of CML.     

Efficient and rapid induction of a chronic myelogenous leukemia-like myeloproliferative disease in mice receiving P210 bcr/abl-transduced bone marrow

Expression of the 210-kD bcr/abl fusion oncoprotein can cause a chronic myelogenous leukemia (CML)-like disease in mice receiving bone marrow cells transduced by bcr/abl-encoding retroviruses. However, previous methods failed to yield this disease at a frequency sufficient enough to allow for its use in the study of CML pathogenesis. To overcome this limitation, we have developed an efficient and reproducible method for inducing a CML-like disease in mice receiving P210 bcr/abl-transduced bone marrow cells. All mice receiving P210 bcr/abl-transduced bone marrow cells succumb to a myeloproliferative disease between 3 and 5 weeks after bone marrow transplantation. The myeloproliferative disease recapitulates many of the hallmarks of human CML and is characterized by high white blood cell counts and extensive extramedullary hematopoiesis in the spleen, liver, bone marrow, and lungs. Use of a retroviral vector coexpressing P210 bcr/abl and green fluorescent protein shows that the vast majority of bcr/abl-expressing cells are myeloid. Analysis of the proviral integration pattern shows that, in some mice, the myeloproliferative disease is clonal. In multiple mice, the CML-like disease has been transplantable, inducing a similar myeloproliferative syndrome within 1 month of transfer to sublethally irradiated syngeneic recipients. The disease in many of these mice has progressed to the development of acute lymphoma/leukemia resembling blast crisis. These results demonstrate that murine CML recapitulates important features of human CML. As such, it should be an excellent model for addressing specific issues relating to the pathogenesis and treatment of this disease.     

Analysis of the p53 gene in patients with isochromosome 17q and Ph1-positive or -negative myeloid leukemia

Increased incidence of p53 gene aberrations or chromosome 17p monosomy resulting from an isochromosome 17q [i(17q)] has been observed with transition of chronic myelogenous leukemia (CML) to myeloid blast crisis (BC), and in some patients with poor risk acute myeloid leukemia (AML) progressing from myelodysplastic syndrome (MDS). These data suggested that disease progression may be linked to bi-allelic inactivation of p53. Here, we report on p53 gene analyses of nine patients with CML-BC and AML who showed an i(17q) as characteristic cytogenetic anomaly. Using Southern blots, agarose gel electrophoresis and single-strand conformation polymorphism analyses of PCR products from genomic DNA and cDNA, spanning exons 4 through 9, we did not detect any structural abnormalities of the remaining p53 allele. These findings question the hypothesis that p53 gene alterations are the principal molecular event responsible for progression of CML chronic phase or MDS to i(17q)-positive CML-BC or AML, respectively.     

The course of post-traumatic amnesia: three little words

In November 1996, word reached the University of Washington that Philip Fialkow and his wife, Helen, had died while trekking in Nepal. Over a 30-year period, Dr Fialkow and his colleagues used the cellular mosaicism resulting from X-chromosome inactivation in females as a marker system to investigate the clonal development of human hematopoietic disorders. This review discusses the impact that these studies have had on our understanding of hematopoietic stem cell relationships and the pathogenesis of human neoplasia in general. To appreciate the special role played by studies on clonality, it is necessary to consider how little was known about the origin of leukemias and myeloproliferative disorders and the limited techniques available for their study in the early to mid 1960s. Dr Fialkow and his coworkers were the first to show that myeloproliferative disorders and acute myelogenous leukemias (AML) are clonal diseases at the time of diagnosis and to elucidate the level of differentiation manifested by the originating cell type. Although the myelodysplastic disorders were found to involve a pluripotent stem cell, heterogeneity was found in the level of stem cell involvement in AML. Evidence was obtained to support a multistep pathogenesis of these diseases as well as a clonal but cytogenetically normal stage in some cases of Ph-positive chronic myelogenous leukemia, AML, acute lymphoblastic leukemia and myelodysplasia.     

Philadelphia chromosome-positive acute lymphoblastic leukemia

The Philadelphia (Ph1) chromosome, ubiquitous in chronic myelogenous leukemia, also is commonly seen in acute lymphoblastic leukemia, particularly in adults. Whereas the presence of the Ph1 chromosome is associated with high white blood cell count and older age, the Ph1 chromosome is known to be an independent poor prognostic factor. Most Ph1+ patients are able to achieve remissions with intensive, systemic chemotherapy, but treatment is complicated by early relapse. Because of the uniformly poor prognosis and response to therapy in childhood and adult Ph1+ acute lymphoblastic leukemia, aggressive and investigational therapies should be considered early in the course of this disease.     

Juvenile chronic myelogenous leukemia: report of the Italian Registry. Associazione Italiana di Ematologia Oncologia Pediatrica (AIEOP)

BACKGROUND: Since juvenile chronic myeloid leukemia (JCML) represents no more than 2% of leukemia in children, clinical and investigative experience of this disorder has been limited. In order to evaluate the diagnostic criteria currently applied, to provide centralized facilities for blood culture and to collect data on treatment, and to propose a uniform treatment protocol in our country, a National Registry for JCML was recently established in the "Associazione Italiana di Ematologia Oncologia Pediatrica" (AIEOP). PATIENTS: Out of the 24 cases reported from 9/35 centres, 22 were considered sufficiently documented and were enrolled in the Registry. Clonogenic assay on marrow and peripheral blood cells was performed in all available cases. RESULTS: Common features were non-specific clinical (fever, splenomegaly, hepatomegaly, lymphadenomegaly) and hematologic alterations (anemia, thrombocytopenia, leukocytosis usually < 50 x 10(9)/l, monocytosis, circulating immature granulocytes, increased HbF, normal karyotype). In 11 out of 11 cases, in vitro blood cultures showed the spontaneous growth of CFU-C in the absence of any exogenous source of colony-stimulating activity. Twelve of the 22 patients (55%) are alive (probability of survival 47.7%); most patients were treated according to an acute myeloid leukemia-directed schedule; 5/7 children treated with interferon were alive with disease after a median time of 29 months from diagnosis (range 8-95 months); 4/5 children who underwent bone marrow transplantation were alive in complete remission 10, 24, 42 and 118 months, after the diagnosis. Age < 1 year at presentation was the most significant prognostic factor in terms of probability of survival (80% vs 28%; p = 0.0024). CONCLUSIONS: JCML must be considered in young children for whom acute leukemia has been suspected but ruled out; in vitro cultures should be considered mandatory to confirm the diagnosis. Age less than one year at the presentation was associated with prolonged survival. Only bone marrow transplantation was followed by prolonged disease-free survival, whereas intensive chemotherapy seemed not very effective and potentially associated with life-threatening complications. Interferon therapy appears to be a promising alternative to chemotherapy while the value of unrelated marrow donor is explored.     

Chronic myelogenous leukemia

Chronic myelogenous leukemia is a clonal hematopoietic malignancy characterized by a balanced translocation between chromosomes 9 and 22 that results in the generation of an abnormal bcr/abl fusion protein with increased tyrosine kinase activity. This abnormal fusion protein has transforming activity for hematopoietic cells in vitro and causes chronic myelogenous leukemia-like myelopoiesis in mice. Chronic myelogenous leukemia progenitor cells display abnormalities in their interactions with bone marrow stroma, perhaps due to defective adhesion molecule function. Conventional therapies for chronic myelogenous leukemia include hydroxyurea, busulfan, or interferon. Treatment with interferon may prolong overall survival, especially in patients who achieve a cytogenetic response. Related donor marrow transplantation can result in long-term survival in more than 65% of patients treated early in the course of disease. For patients without an available matched sibling donor, unrelated donor marrow transplantation or autologous marrow transplantation are alternative therapeutic options.     

Nf1 regulates hematopoietic progenitor cell growth and ras signaling in response to multiple cytokines

Neurofibromin, the protein encoded by the NF1 tumor-suppressor gene, negatively regulates the output of p21(ras) (Ras) proteins by accelerating the hydrolysis of active Ras-guanosine triphosphate to inactive Ras-guanosine diphosphate. Children with neurofibromatosis type 1 (NF1) are predisposed to juvenile chronic myelogenous leukemia (JCML) and other malignant myeloid disorders, and heterozygous Nf1 knockout mice spontaneously develop a myeloid disorder that resembles JCML. Both human and murine leukemias show loss of the normal allele. JCML cells and Nf1-/- hematopoietic cells isolated from fetal livers selectively form abnormally high numbers of colonies derived from granulocyte-macrophage progenitors in cultures supplemented with low concentrations of granulocyte-macrophage colony stimulating factor (GM-CSF). Taken together, these data suggest that neurofibromin is required to downregulate Ras activation in myeloid cells exposed to GM-CSF. We have investigated the growth and proliferation of purified populations of hematopoietic progenitor cells isolated from Nf1 knockout mice in response to the cytokines interleukin (IL)-3 and stem cell factor (SCF), as well as to GM-CSF. We found abnormal proliferation of both immature and lineage-restricted progenitor populations, and we observed increased synergy between SCF and either IL-3 or GM-CSF in Nf1-/- progenitors. Nf1-/- fetal livers also showed an absolute increase in the numbers of immature progenitors. We further demonstrate constitutive activation of the Ras-Raf-MAP (mitogen-activated protein) kinase signaling pathway in primary c-kit+ Nf1-/- progenitors and hyperactivation of MAP kinase after growth factor stimulation. The results of these experiments in primary hematopoietic cells implicate Nf1 as playing a central role in regulating the proliferation and survival of primitive and lineage-restricted myeloid progenitors in response to multiple cytokines by modulating Ras output.     

Improved calculations of compactness and a reevaluation of continuous compact units

This is the case of a 71 year old male who developed multiple myeloma (MM) and chronic myelogenous leukemia (CML) within a two year period. The patient initially presented with osteolytic lesions of the lumbar spine, and following the initial work-up a diagnosis of multiple myeloma with an IgG kappa paraproteinemia was made and appropriate treatment was given. Two years later the patient developed a progressively worsening leukocytosis which was found to be due to Philadelphia Chromosome (Ph1) positive CML. The occurrence in the same patient of two distinct hematologic malignancies suggests a neoplastic transformation of a pluripotent stem cell. A review of the literature appears to support the existence of a relationship between MM and CML as well as a relationship between MM and the myeloproliferative disorders.     

Chromosome studies in "preleukemia". III. Myelofibrosis

Cytogenetic studies were done on 18 patients with myelofibrosis or the closely related syndrome, undifferentiated myeloproliferative disorder (MPD). Clones of cells with chromosome abnormalities were demonstrated in the blood of eight individuals, including two with a history of radiation therapy and two with "acute myelofibrosis". Trisomy 8 was present in the latter two patients, but otherwise, there was no consistent cytogenetic pattern or correlation with specific hematologic findings. Sixteen of these patients have been followed for more than 1 year or until death; none has progressed to leukemia. The results indicate that chromosome abnormalities are relatively common in this disorder, but as with polycythemia vera, and unlike some other "preleukemic" states, the aberrant clones in myelofibrosis do not appear to indicate that clinical leukemia is imminent.     

A follow-up study of bone marrow chromosomes and in vitro colony growth in patients with mastocytosis

Proliferation of mast cells can give rise to many clinical manifestations in patients, and an association with hematological disorders has been pointed out. The study was initiated to determine whether patients with mastocytosis show a clinical progression in relation to bone marrow cell parameters analyzed. During a median follow-up period of 5.5 years, 10 patients with mastocytosis were re-examined with regard to clinical symptoms, urine histamine metabolites (U-MeImAA), bone marrow cells examined with chromosome analyses, and in vitro stem cell growth for CFU-GM. Seven patients showed a clinical progression with increase of either symptoms, bone marrow infiltrates of mast cells or U-MeImAA. One patient with a myeloproliferative bone marrow morphology had a malignant course. Four of the 7 patients showed an increased colony growth, while 3 showed a decreased growth, in the second examination compared with the first examination. One patient had a persistent clone with the chromosome aberration 9p+. A variable pattern was observed in the other patients, in resemblance with findings in chronic myeloproliferative disorders. Our conclusion is that mastocytosis belongs to the myeloproliferative disorders.     

Factors related to aortic pulse-wave velocity in patients with non-insulin-dependent diabetes mellitus

Treatment of recurrent leukemia after bone marrow transplantation with the transfusion of lymphocytes from the marrow donor has been successful in a majority of patients with chronic myelogenous leukemia and a minority of patients with acute myeloid leukemia and myelodysplastic syndrome. It has been disappointing in patients with acute lymphoblastic leukemia and in advanced stages of chronic myelogenous leukemia. In chronic-phase chronic myelogenous leukemia remissions were of good quality and the actuarial relapse rate was less than 20% at 3 years. In acute leukemias remissions were less durable. Graft-versus-host disease and marrow aplasia were the major complications of this form of treatment. In patients with marrow aplasia hematopoiesis could be restored by infusion of donor marrow without further conditioning treatment. Preceding or concomitant treatment with interferon alpha is not essential for a response, but the exact role of interferon alpha remains to be determined in a randomized study. Similarly, the best time for treatment remains to be defined. Treatment of cytogenetic and molecular recurrence of chronic myelogenous leukemia is most effective in preventing marrow aplasia, but a few patients may be treated unnecessarily, for some cytogenetic recurrences may remit spontaneously. The mechanism of the graft-versus-leukemia reaction is still not clear. Effector cells and target antigens remain to be defined. Observations are compatible with a graft-versus-host reaction directed against minor histocompatibility antigens presented at the cell surface of hematopoietic cells, but reactions against leukemia-specific antigens are possible. Future studies will focus on differences of reactions against possible leukemia-specific antigens and histocompatibility antigens on hematopoietic cells and cells of other organs.     

Donor lymphocyte infusions

Donor lymphocyte infusions for treatment of relapse after allogeneic bone marrow or stem cell transplantation is being used with increasing frequency. Study of this form of adoptive immunotherapy will shed light on different aspects of cell-mediated cytotoxicity such as antigen presentation, processing, immune recognition, lymphocyte subsets involved, and mechanism of cell death. Donor lymphocyte infusions are extremely effective for cytogenetic relapses or chronic-phase relapses of chronic myelogenous leukemia, but are less effective in acute leukemias or other disorders. Donor lymphocyte infusions are associated with a significant risk of morbidity and mortality due to graft-versus-host disease and pancytopenia. Lower cell doses, earlier infusions, and selective depletion of CD8+ lymphocytes have been proposed as methods of diminishing these toxicities. Current research is focusing on methods of making donor lymphocyte infusions more effective in the nonchronic myelogenous leukemia setting, and decreasing their toxicity without losing their clinical efficacy in the treatment of relapsed chronic myelogenous leukemia.     

Leg ulceration with associated thrombocytosis: healing of ulceration associated with treatment of the raised platelet count

Thrombocytosis is the cause of various complications in myeloproliferative disorders. We present the case of a 54-year-old woman with chronic myelogenous leukaemia who developed large ulcers on both lower legs that were refractory to standard treatment. As concomitant thrombocytosis persisted despite treatment with hydroxyurea, the new megakaryocyte inhibitor anagrelide (Agrelin) was administered and led to normalization of the platelet count within 11 days. The leg ulcers started to heal after 2 weeks and disappeared over a period of 5 months. Our findings argue for a pathogenic role of platelets in the development of leg ulcers in patients with thrombocytosis due to a myeloproliferative disorder.     

Megakaryoblastic termination of myeloproliferative disorders

Megakaryoblastic termination of myeloproliferative disorders is rare. The morphology of megakaryoblastic transformation can be subtle and is often mistaken for myeloid or lymphoid proliferations. Previously reported observations suggest a relatively poor prognosis for this category of patients, making precise diagnosis imperative. A multifaceted approach using morphology, ultrastructure, cytochemistry, and immunological membrane analysis may be helpful. We present two cases of myeloproliferative disorder with aggressive megakaryoblastic phases (myelofibrosis with agnogenic myeloid metaplasia and chronic myeloid leukemia with blast crisis). The clinical course is described and the results of the morphological, cytochemical, ultrastructural, and cytogenetic studies of both cases are presented. In addition, immunochemical studies (flow cytometry) and platelet function studies (aggregation, beta-thromboglobulin, and platelet factor IV release) were done for one of these patients.     

Cytotoxic T cells overcome BCR-ABL-mediated resistance to apoptosis

Chronic myeloid leukemia is a disease marked by expanded clonal hematopoiesis; it is incurable by chemotherapy or radiation but is cured in a majority of patients receiving bone marrow transplantation from nonidentical sibling donors, an outcome generally attributed to a T cell-mediated graft-versus-leukemia effect. In this report, we examine the effect of the P210BCR-ABL fusion protein of the BCR-ABL oncogene, the molecular hallmark of chronic myelogenous leukemia, on the sensitivity of mouse cell lines to apoptosis induced by chemotherapy, radiation, or activated cytotoxic T lymphocytes (CTLs). We find that, although cells expressing P210BCR-ABL by gene transfer are more resistant than their normal counterparts to apoptosis induced by chemotherapy or radiation, they are equally susceptible to apoptosis induced by alloreactive CTLs. These results show that CTLs overcome BCR-ABL-mediated resistance to apoptosis and, therefore, provide a biological correlation for the success of allogeneic bone marrow transplantation in chronic myelogenous leukemia.