Much ado about not...enough data: high-dose chemotherapy with autologous stem cell rescue for breast cancer

Among hematologic malignancies, there are three disorders whose behavior is governed principally by the abnormal proliferation of a malignant megakaryocytic clone or a product thereof. These disorders are essential thrombocythemia, agnogenic myeloid metaplasia, and acute megakaryoblastic leukemia. Although there are other myeloproliferative diseases that can have high platelet counts, the major pathobiology of those diseases most commonly results from the proliferation of other hematopoietic lineages. Despite the rarity of the three disorders of malignant megakaryopoiesis mentioned above, advances have been made in the diagnosis, prognosis, and treatment of these disorders in recent years. However, understanding of the cellular and especially molecular pathobiology lags far behind.     

Dok1 encoding p62(dok) maps to mouse chromosome 6 and human chromosome 2 in a region of translocation in chronic lymphocytic leukemia

A case of chronic myelogenous leukemia (CML) terminating in acute megakaryoblastic leukemia (AMKL) is here presented. Megakaryoblasts were identified by the presence of platelet peroxidase in the bone marrow as well as in pleural effusion and ascites. The clinical course, morphology and immunologic studies of the blast cells are described in this report.     

Cys2/His2 zinc-finger protein family of petunia: evolution and general mechanism of target-sequence recognition

In recent pediatric trials of acute myeloid leukemia (AML), children with Down syndrome (DS) have had significantly more megakaryoblastic leukemia and have experienced better outcome than other children. To further characterize AML in DS, Children's Cancer Group Studies 2861 and 2891 prospectively studied demography, biology, and response in AML and myelodysplastic syndrome (MDS) of children with and without DS. These studies evaluated timing of induction therapy and compared postremission chemotherapy with marrow transplantation in 1,206 children. One-hundred eighteen (9.8%) had DS, a fourfold increase in 20 years. DS patients were younger, had lower white blood cell and platelet counts, more antecedent MDS, acute megakaryoblastic leukemia or undifferentiated AML, and an under-representation of chromosomal translocations (P < .001 for each variable). Four-year event-free survival in DS was 69% versus 35% in others (P < .001). Intensively timed induction conferred significantly higher mortality in DS patients; bone marrow transplantation offered no advantage. Conventional induction followed by chemotherapy achieved an 88%, 4-year, disease-free survival in DS patients versus 42% in others (P < .001). Megakaryoblastic leukemia was unfavorable in others but prognostically neutral in DS. AML in DS is demographically and biologically distinct from AML in other children. It is singularly responsive to conventional chemotherapy and may warrant even less therapy. The increasing proportion of DS patients with AML most likely reflects changes in attitudes about entering DS patients on AML trials and possibly increasing ability to distinguish megakaryoblastic leukemia from lymphoid leukemia.     

Nursing research--taking an active interest

Transient myeloproliferative disorder (TMD) in neonates with Down syndrome is characterized by increased megakaryoblastic cells in the peripheral blood. Despite their spontaneous regression in weeks, prognosis is not always favorable because of fatal hepatic fibrosis. In this study, blood thrombopoietin (TPO) levels were measured by ELISA in six TMD patients and the expression of c-Mpl, a ligand for TPO, was examined on the blast cells from four patients by flow cytometer. At the onset, TPO level was undetectable in one patient and significantly lower in five patients than six neonatal controls (mean 0.52 fmol/ml, range 0.30-0.93 vs. 3.70, 1.38-8.33, P < 0.001), although platelet counts were similar (mean 321 x 10(9)/l, range 42-1,040 vs. 253 x 10(9)/l, 124-381). Two patients died of hepatic failure. TPO levels were measured in five patients after regression of the blast cells. With regression of blast cells, TPO levels were remarkably increased in four survived patients. In one patient with hepatic failure, TPO level was poorly elevated and relatively lower compared to the others. TPO levels were inversely correlated with blast numbers (r = -0.85, P < 0.001), but not with platelet counts (r = 0.426). Blast cells from four patients were all positive for c-Mpl. Our findings suggest that megakaryocyte mass is a major regulator of TPO levels and hepatic failure may affect the TPO level because liver is a major source of TPO production.     

Detection and molecular characterisation of feline foamy virus serotypes in naturally infected cats

A total of 11 cases with trisomy 14 as the sole abnormality were found in the database of a large cytogenetic reference laboratory from 1993 to the present. Four of the 11 cases had an isochromosome 14q. In 8 cases, the trisomy 14 was a mosaic cell line. Eight cases were diagnosed with myelodysplasia, 2 cases had both myelodysplastic and myeloproliferative features similar to some atypical chronic myeloid leukemia cases, and 1 case had acute myeloid leukemia of M1 or M2 type. Nine were males and two females. The median age was 77 years. Referring physicians were contacted and clinical information was available in only 8 cases. Survival ranged from 1 month to approximately 3 years. An abnormal red cell morphology, such as elliptocytes or schistocytes or both, was observed in the majority of cases. This study along with the reported cases strengthens the hypothesis that trisomy 14 is a nonrandom cytogenetic abnormality associated with myeloid malignancy.     

Anagrelide, a selective thrombocytopenic agent

The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of anagrelide are reviewed. Anagrelide is a selective thrombocytopenic agent with FDA-approved labeling for the treatment of essential thrombocythemia. Clinical trials have shown that the drug may have a role in the treatment of other chronic myeloproliferative disorders, including polycythemia vera, chronic myeloid leukemia, and agnogenic myeloid metaplasia. The mechanism by which anagrelide reduces platelet count is not yet clear. The current hypothesis is that anagrelide affects the late (postmitotic) phases of megakaryocyte development. Anagrelide has a large volume of distribution and is extensively metabolized; less than 1% is recovered unchanged in the urine. Plasma half-life after a 0.5-mg dose is 1.3 hours. Anagrelide's efficacy and safety have been evaluated in open-label, noncomparative trials, in which the response rate was 60-93%. Adverse effects include headache, diarrhea, edema, palpitations, and abdominal pain. Patients with renal or hepatic dysfunction need to be closely monitored for signs of toxicity. The recommended starting dosage is 0.5 mg four times a day or 1 mg twice a day, with dosage adjustment to the lowest effective amount required to reduce and maintain platelet count below 600 x 10(9)/L. The wholesale acquisition price for 0.5-mg capsules is $350 per 100. Whether anagrelide will replace hydroxyurea as first-line therapy in some or all patients remains to be determined. Anagrelide is effective in the treatment of essential thrombocythemia and may have a role in the treatment of other myeloproliferative disorders.     

Expression of erythroid-specific genes in acute megakaryoblastic leukaemia and transient myeloproliferative disorder in Down's syndrome

Acute megakaryoblastic leukaemia (M7) and transient myeloproliferative disorder in Down's syndrome (TMD) are characterized by rapid growth of abnormal blast cells which express megakaryocytic markers. To clarify properties of the blast cells in M7 and TMD cases, we examined erythroid markers expression in blasts from six cases with M7 and seven cases with TMD in this study. Erythroid-specific mRNAs encoding gamma-globin and erythroid delta-aminolevulinate synthase were found to be expressed in blasts from most of these cases, indicating that majorities of the blasts in M7 and TMD cases have erythroid and megakaryocytic phenotypes. We also found that mRNAs encoding GATA-1 and GATA-2 are expressed in all these cases. These results suggest that M7 blasts and TMD blasts correspond to the erythroid/megakaryocytic bipotential progenitor cells.     

Evidence from molecular genetic and cytogenetic analyses that bone marrow histopathology is reliable in the diagnosis of chronic myeloproliferative disorders

The reliability of histopathological diagnosis in bone marrow specimens from patients with chronic myeloproliferative disorders (CMPD) was evaluated by correlating the histological findings with molecular genetic and cytogenetic analyses of the Ph1-translocation. A rearrangement of m-bcr was detected only in patients (28/30) diagnosed histologically as chronic myeloid leukemia (CML). This finding was supported by the presence of a Ph1-chromosome in 24/26 patients with CML examined. All the patients with other types of CMPD, including polycythemia vera (PV), primary thrombocythemia (PTH) and chronic megakaryocytic-granulocytic myelosis (CMGM), as well as those with unclassifiable CMPD (CMPD.UC) were Ph1-negative (n = 38). The histopathological discrimination of CML from Ph1-negative varieties of CMPD was also reliable for patients with myelofibrosis complicating CML, CMGM and CMPD.UC. The results demonstrate that bone marrow histopathology allows a reliable diagnosis of CML. This is in contrast with hematological data such as high platelet counts which show considerable overlapping in the various forms of CMPD.     

Mpl ligand (thrombopoietin) and platelet regulation

After 35 years of research, the physiological regulator of platelet production has been isolated and its gene cloned. This discovery originates from studies performed with the myeloproliferative leukemia virus (MPLV), a murine retrovirus which induces an acute myeloproliferative syndrome in adult mice. MPLV carries in its genome the v-mpl oncogene which corresponds to a truncated form the c-mpl proto-oncogene. c-mpl encodes a cytokine receptor (Mpl-R) belonging to the hematopoietin receptor superfamily. Among the hematopoietic cell lineages, Mpl-R is preferentially expressed on late megakaryocyte progenitors, megakaryocytes and platelets. The ligand for Mpl-R, called Mpl-L or TPO or MGDF or megapoietin, is a glycosylated hormone of 352 amino acids in human which comprises two domains: the N-terminus domain shares 50% similarity with erythropoietin and is responsible for the biological activity; the C-terminus part is required for secretion. Notwithstanding its major action on megakaryocytopoiesis and thrombocytopoiesis, Mpl-L also potentiates the action of other cytokines on several hematopoietic lineages. Mpl-L/TPO/MGDF, the homeostatic regulator of platelet production, might be a useful therapeutical cytokine to treat thrombocytopenia induced in patients by chemotherapy.     

Acute myeloblastic leukemia with minimal myeloid differentiation: phenotypical and ultrastructural characteristics

AML-M0 is an infrequent form of acute myeloblastic leukemia characterized by negative reaction with myeloperoxidase (MPO), Sudan Black and lymphoid antigens and positivity for CD13 or CD33. In the present study we describe the immunophenotypical and ultrastructural characteristics of a group of AML-M0 in adult patients. Nine out 218 AML leukemias (4.1%) fulfilled the AML-M0 criteria. CD13 or CD33 were positive in eight out nine cases, with two or more positive myeloid antigens being present in 82% of the cases. Immunological MPO was positive in 57% of the cases and CD68 in 33%. In no case megakaryocytic and erythroid markers present. Four cases (44%) expressed CD7 and TdT but only two coexpressed both antigens. In none of the cases was CD3 or CD22 cytoplasmic expression found. Ultrastructurally, a low number of granules was seen in all cases whereas ferritin particles or rhopheocytosis were not observed. Ultrastructural MPO was positive in one out of five cases and platelet peroxidase (PPO) was negative in the four cases studied. Two out of six cases showed karyotypic abnormalities (hypotetraploidy and a complex karyotype, respectively). In two out three cases a rearranged pattern for JH gene was observed. TCR (Cbeta and Jgamma) rearrangements were not detected in any case. AML-M0 is an infrequent form of acute myeloblastic leukemia. A large panel of myeloid monoclonal antibodies (MoAb) and the study of the cytoplasmic expression of myeloid antigens is necessary to diagnose this form of leukemia. AML-M0 usually coexpress lymphoid markers. Ultrastructural studies may be of help to discard an immature erythroid proliferation.     

Thrombopoietin serum concentration in patients with reactive and myeloproliferative thrombocytosis

We wished to test whether thrombopoietin (TPO) is entirely regulated by receptor binding or if other factors may play a role in the mechanism of TPO regulation. Therefore, we analyzed the TPO serum levels in 43 patients with reactive (secondary) thrombocytosis and in 37 with myeloproliferative thrombocytosis. Thrombocytosis was defined as a platelet level greater than 440 x 10(9)/l. Forty-two patients (98%) with reactive thrombocytosis had high concentrations of IL-6 correlating with elevated C-reactive protein levels. Twenty-three patients (53%) in this group had TPO serum concentrations of more than 300 pg/ml (normal: below 300 pg/ml). Only nine patients (24%) with myeloproliferative thrombocytosis had TPO serum levels above normal range, whereas 28 patients (76%) had normal levels of TPO. No correlation between the TPO serum levels and the concentrations of IL-6 or EPO was established. The other investigated thrombopoietic cytokines (IL-3, IL-11, GM-CSF) were unmeasurable; therefore, a correlation could not be assessed. We conclude that TPO concentrations are not strictly inversely related to platelet count. TPO serum levels are elevated especially in a considerable percentage of patients with reactive thrombocytosis, arguing for the existence of additional mechanisms of TPO regulation.     

The O'Brien filter test in the differential diagnosis of disorders with high-grade thrombocytosis

In the differential diagnosis of primary and secondary thrombocytosis, platelet function test can be used. We have examined the possible role of O'Brien's filter test in the differentiation of primary and secondary thrombocytosis in 53 patients with myeloproliferative diseases with primary thrombocytosis and in 21 patients with other disorders complicated by secondary thrombocytosis. By using heparin as an anticoagulant, the sensitivity of O'Brien's filter test proved to be 75%, and it's specificity was 85.7%. In blood samples anticoagulated with citrate, the sensitivity was 100% and specificity 83.3%. Based on these studies we suggest the use of O'Brien's filterometer as a screening test in the differential diagnosis in patients with elevated (> 400 x 10(9)/L) platelet count. In case of normal results, the causes of reactive thrombocytosis should be cleared first, while with pathologic results, haematological examination of the patients should be performed.     

No treatment for low-risk thrombocythaemia: results from a prospective study

Essential thrombocythaemia (ET) is a chronic myeloproliferative disorder characterized by the occurrence of thromboembolic episodes, particularly in patients aged > 60 years or with a previous history of thrombosis, and/or by haemorrhages in patients with an exceedingly high platelet count. In these subgroups of patients the use of cytoreductive therapy is beneficial in terms of risk/benefit ratio. Only limited anecdotal data are available on the thrombotic or haemorrhagic risk and survival in young asymptomatic ET patients with a platelet count < 1500 x 10(9)/l. Therefore the optimal management of these patients is unknown. To assess the incidence of thrombosis and haemorrhages in this group of patients we carried out a prospective observational study in a cohort of 65 patients with ET, aged < 60 years, with no history of thrombosis or haemorrhage and platelet count < 1500 x 10(9)/l, and in 65 age- and sex-matched controls. Patients were not treated with cytoreductive therapy until the occurrence of thrombosis or haemorrhage. Arterial or venous thrombotic events were objectively documented both in cases and in controls. The median follow-up was 4.1 years, with an incidence of thrombosis in patients and controls of 1.91 and 1.50 cases/100 patient-years, respectively. The age- and sex-adjusted risk rate ratio was 1.43 (95% CI 0.37-5.4). Only three minor haemorrhagic episodes occurred in patients, with an incidence of 1.12 cases/100 patient-years. Pregnancy and surgery were not associated with thrombosis in these patients. We conclude that the thrombotic risk in young ET patients, with no thrombotic history and a platelet count < 1500 x 10(9)/l, is not increased compared to the normal population and that a conservative therapeutic approach should therefore be considered in these patients.     

Therapeutic dilemmas: balancing the risks of bleeding, thrombosis, and leukemic transformation in myeloproliferative disorders (MPD)

With these uncertainties, which patients with ET and PV should receive myelosuppressive therapy and accept its possible risks? Remembering the generalization from the literature that most patients with ET who are to have a catastrophic thrombosis either have it at the time of diagnosis or after preceding, less severe thrombotic symptoms, it is acceptable to omit myelosuppressive therapy in asymptomatic patients with ET. Young patients with PV and no thrombotic manifestations can similarly be managed with phlebotomy alone. There is no evidence in the literature to show that myelosuppressive therapy should be used simply because the platelet count is high or to prevent transition to myeloid metaplasia. In patients with ET or PV with previous thrombotic manifestations, the risk/benefit ratio probably favors myelosuppressive therapy. The PVSG studies also suggest that patients over the age of 70 with PV are at particular risk for thrombosis and should be treated with myelosuppression. No myelosuppressive agent has been shown to be superior to hydroxyurea. Patients who fail on hydroxyurea should not be treated with 32P or alkylating agents. Anagrelide or interferon would be more appropriate. The PVSG-05 study suggests that high doses of aspirin, i.e. approximately 1.0 grams per day, are not indicated. Trials of low dose aspirin to prevent thrombosis are encouraged. There is no way to predict which patients will have hemorrhagic complications and, as mentioned, one study suggests that there will be few (44). Patients with thrombocytosis and pathological bleeding, i.e. hemorrhagic thrombocythemia, generally improve with myelosuppressive therapy. This syndrome is to be distinguished from patients who bleed with normal or low platelet counts, generally in the setting of myeloid metaplasia (14). These patients have an acquired disorder of platelet function due to platelet production from abnormal megakaryocytes. An occasional patient will benefit from increasing the platelet count by splenectomy.     

Frequently subnormal semen profiles of normal volunteers recruited over 17 years

Microcinematographic documentation of mitoses, amitoses, endomitoses, or cytoplasmic fusion shortly after completion of mitoses was done in bone marrow specimens of patients with quantitative platelet disorders and controls. In patients with platelet disorders, most mitoses with cell duplication occurred in large promegakaryocytes after 4-fold nuclear and cytoplasmic enhancement. Normal specimens showed polyploidization happening in small megakaryoblasts, while mitoses with cell duplication were seen only after cultivation in freeze-thawed sera of patients with platelet disorders. Frequently, lymphocytes were observed to contact megakaryoblastic cells undergoing mitoses, amitoses and endomitoses and to enter the cytoplasm of megakaryocytes (emperipolesis), leaving it again after several hours.     

Surgery for cholecystocholedocholithiasis in a patient with asymptomatic essential thrombocythemia: report of a case

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by a remarkable increase in the platelet count and various clinical symptoms. The perioperative management of patients with ET has yet to be determined, especially when there are no clinical symptoms. We report herein the case of a woman with gallstones whose preoperative hematological data showed remarkable thrombocythemia, but her coagulation studies were normal. The Philadelphia chromosome was negative and bone marrow cytology showed a marked increase in megakaryocytes. Surgery was performed under a diagnosis of cholelithiasis with ET. Considering her severe thrombocythemia and obesity, sufficient heparin was administered to prevent deep vein thrombosis; however, this precipitated postoperative bleeding, necessitating a reoperation. A functional abnormality of the patient's platelets was suspected, and the aggregation by adenosine diphosphate was subsequently found to be significantly inhibited. As patients having ET with no symptoms might have depressed platelet aggregability despite remarkable thrombocythemia, when abdominal surgery is performed, prophylactic therapy for deep vein thrombosis should be avoided. Hence, the preoperative aggregation study of platelets might offer useful information about whether postoperative antithrombotic therapy is indicated.     

The hypereosinophilic variant of Ph''-positive chronic myeloleukemia

AIM: To confirm clonal nature of idiopathic hypereosinophilic syndrome (IHES), its relevance to Ph'-positive chronic myeloid leukemia. MATERIALS AND METHODS: 3 cases of idiopathic hypereosinophilic syndrome are reported with morphologic analysis of bone marrow cells and cytogenetic examinations. In one patient the presence of Ph'-chromosome was confirmed at fluorescent in situ hybridization (FISH) and molecular-genetic analysis (bcr/abl). Samples of bone marrow, spleen and liver were examined pathohistologically. RESULTS: The presence of chromosome anomaly t(9;22), i.e. Ph'-chromosome, associated with chronic myeloid leukemia (CML) was identified in all the 3 cases. There was also myeloid hyperplasia in the bone marrow (with primarily mature, eosinophilic granulocytes), spleen and liver, depression of megakaryocyto- and erythropoiesis. 2 patients had similar clinical symptoms which was not typical for CML in chronic phase: fever, elevated ESR, clear-cut anemia and thrombocytopenia. In the absence of hyperleukocytosis, blood and bone marrow eosinophils remained high (42.5, 21.5, 42.5% and 21.4, 7.1, 6.5%, respectively) due to "mature" forms. The number of blasts in the bone marrow was maximum 2.4%. CONCLUSION: The literature and the obtained data suggest closeness of idiopathic hypereosinophilic syndrome and Ph'-positive CML within myeloproliferative diseases.     

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.     

The Philadelphia chromosome negative chronic myeloproliferative disorders: a practical overview

The chronic myeloid disorders are collectively characterized by a stem cell origin of the clonal process and a variable tendency to undergo indigenous disease transformation and leukemic conversion. Classification of the chronic myeloid processes is based primarily on the presence or absence of the Philadelphia chromosome (bcr-abl translocation) and secondarily on the morphologic picture of the bone marrow in conjunction with the clinical manifestation. Essential thrombocythemia (ET), polycythemia vera (PV), and agnogenic myeloid metaplasia (AMM) constitute the classical group of bcr-abl negative chronic myeloproliferative disorders. PV is characterized by a clonal increase in red blood cell mass, AMM by bone marrow fibrosis, and ET by thrombocytosis. Most of these features, however, are not diagnostically specific, and secondary causes of erythrocytosis, thrombocytosis, and bone marrow fibrosis must be excluded. Treatment may be deferred or limited to phlebotomy alone in some patients with ET or PV, respectively. In contrast, thrombosisprone patients with PV or ET require drug therapy, and new platelet-lowering agents are increasingly being used. In this article, current diagnostic and therapeutic issues of ET, PV, and AMM are discussed.     

Long term treatment of myeloproliferative disease with interferon-alpha-2b: feasibility and efficacy

BACKGROUND: Recombinant interferon-alpha-2b (rIFN-alpha-2b) has shown therapeutic potential in patients with chronic myelogenous leukemia and other myeloproliferative disorders (MPDs), including the ability to suppress the abnormal hematopoietic clone and to reverse myelofibrosis. This study was conducted to evaluate further the efficacy and safety of rIFN-alpha-2b in a large group of patients with polycythemia vera, essential thrombocythemia, or agnogenic myeloid metaplasia and to determine maintenance of response after treatment discontinuation. METHODS: Induction therapy began with subcutaneous rIFN-alpha-2b at 5.0 x 10(6) IU/day until a complete or partial response was achieved. Treatment continued at 2.5 x 10(6) IU/day until spleen size and hematologic parameters stabilized. RESULTS: Fifty-four patients were studied (median follow-up, 7.3 years); at last follow-up 27 patients still were participating (median follow-up, 3.8 years). Twenty-four of 24 patients with thrombocythemia (100%) and 14 of 14 patients with hyperleukocytosis (100%) responded to induction therapy, whereas 26 of 39 patients (67%) experienced > 10% decrease in splenomegaly. Thirty-nine of 54 patients (72%) maintained response for a median of 39 weeks after withdrawal of rIFN-alpha-2b; repeat courses in previously responding patients produced similar results. The survival rate at 8 years was 60%. rIFN-alpha-2b generally was well tolerated, but toxicity caused treatment withdrawal in 7 patients (13%). CONCLUSIONS: rIFN-alpha-2b can produce regression of splenomegaly and control of leukocyte and platelet counts in patients with MPD. These responses are sustained for prolonged periods in some patients after therapy discontinuation. In patients with recurrent disease, disease control can be attained again with reinitiation of rIFN-alpha-2b. Therefore this therapy should be an important treatment consideration for patients with MPD.