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Should a platelet limit of 600 x 10(9)/l be used as a diagnostic criterion in essential thrombocythaemia? An analysis of the natural course including early stages.

In order to evaluate the natural history of essential thrombocythaemia (ET), clinical data and prognostic factors of 143 patients with ET were retrospectively analysed (mean observation time 6.1 +/- 4.6 years). In 42 patients the early phase of the disease with initial platelet counts between 250 and 600 x 10(9)/l was assessed. In most early cases, ET was suggested by clinical symptoms (79%) and increased megakaryopoiesis (95%) with abnormal megakaryocytes in bone marrow histology (n = 34) and cytology (n = 5). Other myeloproliferative disorders and reactive thrombocytosis were excluded according to the diagnostic criteria of the Polycythemia Vera Study Group. During follow-up of the 38 early cases not treated cytoreductively at diagnosis, the platelet counts increased to >600 x 10(9)/l in 28 patients (74%) and remained between 450 and 600 x 10(9)/l in 10 patients (26%). In primarily asymptomatic patients (n = 46) with initial platelet counts above (n = 37) and below 600 x 10(9)/l (n = 9) the rates of increase of symptomatic patients were similar at about 7% per year. No influence of the initial platelet count on survival was seen in multivariate analysis of prognostic factors which included all 143 cases. Survival was mainly influenced by the rate of ET-related complications during follow-up (P = 0.002). Analysing the influence of cytoreductive therapy on symptom-free survival, platelet reduction benefited patients under 60 years (19 cytoreductively treated v 65 untreated patients, P = 0.075). The results demonstrate the possible clinical relevance of the early stages of ET and suggest that the features of pathologic megakaryopoiesis in the bone marrow are a more reliable diagnostic criterion than a definite platelet limit. Therefore, further therapeutic studies should include all stages of the disease and all age groups.

Adult↗

BCR-ABL oncoprotein is expressed by platelets from CML patients and associated with a special pattern of CrkL phosphorylation.

Constitutive tyrosine phosphorylation of CrkL was recently demonstrated in platelets from chronic myelogenous leukaemia (CML) patients but BCR-ABL tyrosine kinase could not be detected in the platelet lysates. We studied platelets from 14 CML patients with different types of BCR-ABL mRNA and with maximal platelet counts ranging from 149 to 3069 x 10(9)/l. P210BCR-ABL protein was detected by Western blotting in platelet lysates of 12/13 CML patients with active disease but not in the lysate of platelets from a Ph-positive acute lymphoblastic leukaemia (ALL) patient in remission or eight BCR-ABL-negative controls including one essential thrombocythaemia (ET) patient. Immunoblotting of p210BCR-ABL-positive platelets lysates with anti-CrkL antibody revealed a CrkL triplet consisting of one unphosphorylated and two phosphorylated forms of the protein. This CrkL phosphorylation pattern was not observed in normal platelets or CML platelets treated with ABL tyrosine kinase inhibitor CGP57148B. The presence of BCR-ABL provides an explanation for the constitutive tyrosine phosphorylation of CrkL in CML platelets. As no correlation was observed between platelet counts and platelet BCR-ABL protein expression, thrombocytosis or thrombocythaemia in CML cannot be explained by constitutive BCR-ABL-mediated CrkL tyrosine phosphorylation.

Adaptor Proteins, Signal Transducing↗

Safety and efficacy of thalidomide in patients with myelofibrosis with myeloid metaplasia.

We administered the anti-angiogenic drug thalidomide to 21 patients (12 men) with myelofibrosis with myeloid metaplasia (MMM), who were not responsive to standard treatment. Patients received thalidomide at an escalating dose from 100 to 400 mg/d. Administration of the drug was discontinued before the planned 6 months of treatment in 19 patients (90.5%), mainly because of somnolence and/or fatigue, neurological symptoms or neutropenia. Of the 13 evaluable patients (who received more than 30 d of therapy), anaemia improved in three out of seven (43%) who were treated because of anaemia; thrombocytopenia improved in two out of three (66.6%) who were treated because of thrombocytopenia; splenomegaly was reduced in four (30.8%). Undesired increases in white blood cell and platelet counts were observed in three (23.1%) and five (38.5%) patients respectively. A severity score, indexed on haematological and clinical parameters, improved in two patients (15.4%), but worsened in five (38.5%). In conclusion, standard-dose thalidomide in MMM patients is burdened with a high rate of side-effects, which prevent prolonged treatment. Because the drug is effective in improving anaemia and thrombocytopenia and in reducing splenomegaly, low-dose therapy warrants evaluation. The unexpected observation of leucocytosis and thrombocytosis suggests biological studies and better criteria for selection of patients for treatment.

Adult↗

Cell-specific abnormal prenylation of Rab proteins in platelets and melanocytes of the gunmetal mouse.

The mutant gunmetal mouse exhibits reduced rates of platelet synthesis, abnormalities of platelet alpha and dense granules and hypopigmentation. Several of these features resemble those of human alpha/delta platelet storage pool disease, grey platelet syndrome and Hermansky-Pudlak syndrome. Gunmetal mice have reduced levels of Rab geranylgeranyltransferase (RabGGTase), which adds lipophilic prenyl groups to the carboxyl terminus of Rab proteins. The degree of prenylation and the subcellular distribution of several Rab proteins were evaluated in mutant platelets, melanocytes and other tissues. Significant deficits in prenylation and membrane binding of most Rabs were observed in platelets and melanocytes. In contrast, minimal alterations in Rab prenylation were apparent in several other gunmetal tissues despite the fact that RabGGTase activity was equally diminished in these tissues. The mutant tissue-specific effects are probably due to increased concentrations of Rab proteins in platelets and melanocytes. These experiments show that Rab proteins are differentially sensitive to levels of RabGGTase activity and that normal platelet synthesis, platelet organelle function and normal pigmentation are highly sensitive to the degree of prenylation and membrane association of Rab proteins. Further, the tissue-specific effects of the gunmetal mutation suggest that RabGGTase is a potential target for therapy of thrombocytosis.

Alkyl and Aryl Transferases↗

Splenectomy in a case of splenic vein thrombosis unmasks essential thrombocythemia.

We report a patient with splenic vein thrombosis (SVT) in whom splenectomy resulted in the unmasking of essential thrombocythemia (ET). He had portal hypertension with haematemesis, resulting in anaemia requiring repeated blood transfusions. Investigations revealed SVT. Following splenectomy, he suffered a transient ischaemic attack episode, associated with persistent thrombocytosis (> 2000 x 10(9)/l). Other myeloproliferative disorders were excluded and a diagnosis of ET was established. He responded to hydroxyurea but, due to financial constraints, he discontinued treatment and subsequently relapsed. The association of ET with SVT is rare and the diagnosis of ET was missed initially as the platelet count was normal prior to splenectomy.

Adult↗

Interleukin-6 secreting phaeochromocytoma associated with clinical markers of inflammation.

Phaeochromocytomas have been shown to produce not only catecholamines but other neuropeptides and hormones, with a variety of clinical manifestations. We report a 70-year-old female patient with phaeochromocytoma exhibiting sustained hypertension, low-grade fever, thrombocytosis, and elevated levels of plasma fibrinogen and C-reactive protein. Serum interleukin (IL)-6 levels were significantly elevated, whereas serum IL-1 alpha and IL-1 beta were not detectable. After surgical removal of the tumour, hypertension and low-grade fever disappeared, and the laboratory finding including serum IL-6 concentrations became normal. Immunohistochemical study of the tumour showed positive staining for IL-6. Culture of the resected tumour revealed the production of large amounts of IL-6. It is suggested that IL-6 secreted by the tumour was responsible for some of the clinical manifestations in this patient.

Adrenal Gland Neoplasms↗

Numbers of colony-forming progenitors in patients with systemic mastocytosis: potential diagnostic implications and comparison with myeloproliferative disorders.

BACKGROUND: An increase in colony-forming progenitor cells (CFU) is typically seen in myeloproliferative disorders (MPD). Systemic mastocytosis (SM) is a haemopoietic neoplasm involving myeloid progenitors similar to MPD. In the present study, we measured the levels of peripheral blood (pb) and bone marrow (bm) CFU in patients with different categories of SM, and compared them with those obtained in MPD patients and healthy controls. MATERIALS AND METHODS: Numbers of CFU (CFU-GM, BFU-E, CFU-GEMM) were measured in a colony assay in 25 patients with SM [indolent SM (ISM), n = 15; smouldering SM (SSM), n = 3; SM with an associated haematologic clonal non-mast cell lineage disease (SM-AHNMD), n = 5; aggressive SM (ASM), n = 1; mast cell leukaemia (MCL), n = 1] and 37 with MPD [chronic myeloid leukaemia (CML), n = 10; polycythemia vera (PV), n = 8; essential thrombocytosis (ET), n = 9; idiopathic myelofibrosis (IMF), n = 10]. RESULTS: In the patients with MPD, elevated numbers of pb CFU were detected in all groups when compared with healthy controls (P < 0.05). In most of the patients with ISM, circulating CFU levels (CFU-GM, BFU-E, and CFU-GEMM) were within the normal range. In SSM, pb CFU-GM levels were normal in two patients, and elevated in a third patient. In the "SM-AHNMD-group", CFU levels were found to reflect the nature of the AHNMD: in SM with concomitant acute myeloid leukaemia (SM-AML, n = 2), the levels of CFU were low or undetectable, whereas in SM with chronic myelomonocytic leukaemia (SM-CMML, n = 2), elevated numbers of pb CFU-GM were found. CONCLUSION: The numbers of CFU are normal in patients with ISM, but elevated in some patients with SSM and SM-CMML. An elevated CFU level in SM should raise the suspicion of an associated MPD (CMML) or smouldering SM, a novel SM-subtype that shares several features with MPD and sometimes progresses to an overt SM-MPD.

Adult↗

Acute coronary disease in essential thrombocythemia and polycythemia vera.

OBJECTIVES: The aim of this study is to report our experience on myocardial infarction (MI) in patients with essential thrombocythemia (ET) and polycythemia vera (PV). DESIGN: Patients with PV and ET consecutively diagnosed and followed in authors' Department between 1 July 1986 and 30 June 1996. SUBJECTS: Over the past 10 years we have followed 170 patients with ET and 149 with PV, diagnosed according to the Polycythemia Vera Study Group (PVSG) criteria. The patients were divided into 3 groups on the basis of the age at diagnosis (group A < 40, B 41-65, C > 65 years). INTERVENTIONS: In all patients with PV phlebotomies and/or myelosuppressive therapy were used to keep haematocrit level lower than 45%. Hydroxyurea was given to patients with ET with a positive history for major vascular complications or with an extreme thrombocytosis. Aspirin therapy (ASA) (100 mg per day) was administered in patients with microvascular disturbances or previous thrombosis (in patients with PV also in the presence of atherosclerotic risk factors). MAIN OUTCOME MEASURES: Frequency of MI in patients with ET and PV with and without ASA therapy. RESULTS: 9.4% of patients with ET and 11.4% of those with PV had MI. 17.6% of patients with PV were younger than 40 years at the moment of MI in contrast to 0% of those with ET. 75% of patients with ET and 70.6% of those with PV with MI had atherosclerotic risk factors such as smoking, hypertension, diabetes, dyslipidaemia. All patients with MI received ASA 100 mg daily after thrombosis and four of the ET group developed a transient ischaemic attack (TIA) afterwards. Four subjects with PV during the follow-up had TIAs and two peripheral arteriopathy in spite of ASA treatment. CONCLUSIONS: MI is less common in patients with ET younger than 40 years than in older patients. Association of MI and cardiovascular risk factors is frequent in patients with ET and PV. A low dose of ASA could be able to reduce the number of coronary thrombosis without increasing bleeding complications in patients with elevated platelet count and common atherosclerotic risk factors. However, a larger population must be evaluated to confirm our hypothesis.

Adult↗

Ovarian fibrosarcoma producing multiple cytokines.

A case of ovarian fibrosarcoma producing multiple cytokines is presented. The tumor occurred in the left ovary of a Japanese woman with epigastralgia, remittent fever, leukocytosis and slight thrombocytosis with moderate increase of mast cells in bone marrow, but lack of hormonal abnormality. The resected tumor of the ovary was well encapsulated and it was composed of spindle-shaped tumor cells and scattered tubules with marked mast cell infiltration. The tumor recurred in the pelvic cavity 14 months later, accompanied by similar signs and symptoms as occurred with the primary tumor. Serum levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha were elevated. The recurrent tumor showed similar histological findings to those of the primary tumor, except for lack of tubules. Tumor cells revealed a focally positive immunoreaction for vimentin, IL-6 and TNF-alpha and alpha-inhibin. Reverse transcription-polymerase chain reaction using total RNA obtained from the recurrent tumor demonstrated mRNA expression of IL-6, IL-10, TNF-alpha and stem cell factor. This is a rare case of ovarian fibrosarcoma producing multiple cytokines, resulting in atypical clinical findings.

Cytokines↗

Branch retinal vein occlusion in Churg-Strauss syndrome.

The case is reported of a 64-year-old man who was diagnosed as having Churg-Strauss syndrome associated with branch retinal vein occlusion, without accompanying retinal vasculitis. It was assumed that the blood thrombocytosis caused a hypercoagulable state and thromboembolism leading to the branch retinal vein occlusion.

Churg-Strauss Syndrome↗

Continuous- and semicontinuous-flow blood centrifugation systems: therapeutic applications, with plasma-, platelet, lympha-, and eosinapheresis.

Blood centrifugation, with a continuous-flow or semicontinuous-flow system, was used in the treatment of 17 patients with various hematologic disorders. Total plasma exchange (TPE) controlled symptoms of hyperviscosity and arrested bleeding in three patients. In two patients, TPE made is possible to perform urgent surgical procedures. It was a very valuable adjuvant in the treatment of one patient with a Factor VIII inhibitor. Eosinapheresis was not of significant value in the therapy of syndromes associated with eosinophilia. Lymphapheresis significantly reduced peripheral lymphocytosis, aiding in the chemotherapeutic control of chronic lymphosarcoma cell leukemia in one patient. It was of questionable value in the maintenance therapy of two patients with Sézary syndrome. Plateletapheresis significantly reduced peripheral platelet count in thrombocytosis, making it possible to minimize the chemotherapeutic dose and permitting urgent surgical procedures in two patients.

Adult↗

Heme oxygenase-1 deficiency: the first autopsy case.

This article describes the first autopsy case of heme oxygenase (HO)-1 deficiency. A 6-year-old boy who presented with growth retardation; anemia; leukocytosis; thrombocytosis; coagulation abnormality; elevated levels of haptoglobin, ferritin, and heme in serum; a low serum bilirubin concentration; and hyperlipidemia was diagnosed as HO-1 deficient by gene analysis several months before death. Autopsy showed amyloid deposits in the liver and adrenal glands and mesangioproliferative glomerular changes in kidneys, in addition to an irregular distribution of foamy macrophages with iron pigments. Fatty streaks and fibrous plaques were noted in the aorta. Compared with HO-1--targeted mice, the present case seems to more severely involve endothelial cells and the reticuloendothelial system, resulting in intravascular hemolysis, disseminated intravascular coagulation, and amyloidosis with a short survival. This contrasts to the predominant iron metabolic disorders of HO-1--targeted mice with a long survival.

Adrenal Gland Diseases↗

The chronic myeloproliferative disorders: clonality and clinical heterogeneity.

The chronic myeloproliferative disorders (MPD), polycythemia vera (PV), chronic idiopathic myelofibrosis (IMF), essential thrombocytosis (ET), and chronic myelogenous leukemia (CML), are thought to be clonal disorders arising in a multipotent hematopoietic progenitor cell. However, establishing the diagnosis of an MPD other than CML is problematic due to a lack of clinically applicable clonal markers. Furthermore, in some patients, in whom a classical MPD phenotype is present, the hematopoietic stem cells appear to be polyclonal, suggesting that the chronic MPD other than CML may actually be a genetically heterogeneous group of disorders. Furthermore, since the aberrant clone is believed to arise from a multipotent hematopoietic stem cell, the non-CML chronic MPD-ET, PV, and IMF-could be related. Additional unresolved issues regarding the MPD include: identification of the multipotent hematopoietic progenitor cell involved, the molecular basis for the clinical heterogeneity amongst the individual MPD, the clinical significance of clonality in non-CML MPD, and reconciliation of therapy with the clonal and clinical heterogeneity of these disorders. Determination of clonality has largely been carried out using X chromosome-linked polymorphisms, but such studies are limited to women and with increasing patient age are compromised by skewing of allelic expression in both neutrophils and T lymphocytes, making the results difficult to interpret. X chromosome-linked polymorphism studies have indicated that in PV the target stem cell is one that gives rise to both lymphoid and myeloid progenitors. Recently, two epigenetic markers have been identified in the MPD: impaired expression of the thrombopoietin receptor, Mpl, in platelets and megakaryocytes, and overexpression in neutrophils of the mRNA of a gene designated polycythemia rubra vera-1 (PRV-1). The role of these epigenetic abnormalities in the diagnosis of the MPD remains to be established. Currently, given the unresolved issues with respect to the clinical and clonal heterogeneity of the MPD, treatment needs to be tailored individually in patients with an MPD.

Age Factors↗

Hematopathologic findings in chronic idiopathic myelofibrosis.

Until now scant knowledge was available about the dynamics of chronic idiopathic myelofibrosis (CIMF). However, follow-up studies are in keeping with a stepwise evolution starting with a prefibrotic (hypercellular) phase that progressively transforms into the classical fibro-osteosclerotic endstage with myeloid metaplasia. Prefibrotic CIMF is characterized by a granulocytic and megakaryocytic myeloproliferation lacking an increase in reticulin. Most conspicuous are abnormalities of megakaryopoiesis with regard to their histotopography and maturation. There is a more than 65% probability of progression from an early to advanced CIMF accompanied by increasing anemia, splenomegaly, and leuko-erythroblastosis. A significant relationship is recognizable among frequency, tortuosity, and luminal dilation of the microvessels and the extent of myelofibrosis. Quantity of CD34(+) progenitor cells in the bone marrow (BM) reveals a close association with advancement of disease (fibrosis, splenomegaly, anemia, peripheral blasts) and therefore prognosis. Cell kinetic studies show increased proliferation associated with a higher rate of apoptosis in initial (hypercellular) stages, as well as a reduced endoreduplicative activity of megakaryopoiesis and a blocked synthesis phase of the erythroid precursors. It is noteworthy that prefibrotic and early CIMF often present with a marked thrombocytosis mimicking essential thrombocythemia. Regarding prognosis, early CIMF is associated with a significantly more favorable survival than advanced stages.

Antigens, CD34↗

Conventional and new treatment options for myelofibrosis with myeloid metaplasia.

The pathogenetic mechanisms underlying the clonal myeloproliferation and reactive marrow fibrosis that characterize myelofibrosis with myeloid metaplasia (MMM) are poorly understood. Recent advances into the pathophysiology of the disease have not yet translated into effective therapeutic options for patients. There is no standard treatment, and no therapies identified yet, besides allogeneic stem cell transplantation, that will significantly change the natural history of MMM. Treatment is therefore palliative and is geared towards alleviating symptoms of the disease and improving blood counts. Conventional therapies for anemia include androgens and corticosteroids. Cytoreductive agents such as hydroxyurea are indicated for symptomatic organomegaly and the control of leucocytosis or thrombocytosis. Several novel agents have been investigated in the recent past, and include antiangiogenic agents and signal transduction inhibitors that target the angiogenic and fibrogenic cytokines that have been implicated in the pathogenesis of the detrimental bone marrow stromal reaction. Ultimately, an improved understanding of the biological factors that cause the clonal myeloproliferation in MMM will lead to the development of effective therapeutic interventions.

Androgens↗

Lack of association between antiphospholipid antibodies and thrombocytopenia in patients with Wegener's granulomatosis.

BACKGROUND AND OBJECTIVE: In patients with Wegener's granulomatosis (WG), thrombocytopenia is less common than thrombocytosis. An increased prevalence of antiphospholipid antibodies (aPL), which is associated with thrombocytopenia, has been noted in patients with WG. The aim of this study was to examine the relationship between thrombocytopenia and aPL in patients with WG. METHODS: Thrombocytopenic episodes were searched for in a random sample of 83 patients with WG. Stored sera obtained during thrombocytopenia, which was defined as platelet count below 130 x 10(9)/L, were examined by 2 different enzyme-linked immunosorbent assays (ELISA) for IgG and IgM anticardiolipin antibodies (aCL) and for IgG antiphosphatidylserine antibodies (aPS). Screening for lupus anticoagulant was performed by use of activated partial thromboplastin time (aPTT). Results were compared with the prevalence of aPL in 20 consecutive nonthrombocytopenic patients with WG. RESULTS: Six cases with thrombocytopenic episodes were found in the group of 83 patients with WG. Increased IgG and IgM aCL were detected in 1 patient, who also had elevated IgG aPS. A positive test result solely for IgM aCL was found in another patient. These findings were consistent in both ELISA for aPL. Five patients were being treated with cyclophosphamide when thrombocytopenia occurred. In the group of nonthrombocytopenic patients with WG, elevated IgG aCL and IgG aPS were consistently detected in 1 patient in both ELISA. Three other patients had positive results in single tests, which were not confirmed by the second assay. In all patients, aPTT was normal. CONCLUSIONS: Thrombocytopenia is a rare finding in patients with WG. A similar prevalence of aPL in thrombocytopenic and nonthrombocytopenic patients with WG provides no evidence that aPL play a major role in the pathogenesis of these events. Thrombocytopenia in WG is more likely caused by the myelotoxic effect of preceding cyclophosphamide treatment. We found a frequency of aPL in WG that exceeds frequencies seen in the general population but does not approximate those detected in systemic lupus erythematosus and closely related disorders. Semin Arthritis Rheum 31:4-11.

Adult↗

Splenic irradiation in myelofibrosis with myeloid metaplasia: a review.

Morbidity from myeloid metaplasia and myelofibrosis arises from progressive anemia and abdominal discomfort related to massive splenomegaly, which may be associated with hypercatabolic symptoms. To date, no therapy, other than allogeneic bone marrow transplantation, has been shown to cure or to prolong the survival of these patients. Thus, current management strategies are palliative and include red cell transfusional support and androgen therapy for anemia; chemotherapeutic agents for control of thrombocytosis, leukocytosis, and hypermetabolic symptoms; and splenectomy or splenic irradiation for symptomatic splenomegaly. The major indication for splenic irradiation is left upper quadrant discomfort related to massive splenomegaly, usually in patients for whom splenectomy is contraindicated or has been declined. In most patients, it provides relief from abdominal pain and a moderate reduction in splenic size. Although responses are transient, some patients may experience prolonged relief. Splenic irradiation can result in prolonged myelosuppression in certain patients. This calls for cautious dosing, because individual sensitivity is variable and cannot be predicted. The use of splenic irradiation does not preclude subsequent splenectomy; however, the increased risk of postoperative hemorrhage should discourage consideration of splenic irradiation as an alternative or a temporizing measure before splenectomy when indicated.

Humans↗

Splenectomy in chronic myeloid leukemia and myelofibrosis with myeloid metaplasia.

Myelofibrosis with myeloid metaplasia (MMM) is a collective term that describes the related disorders AMM, PPMM, and PTMM. The chronic myeloid disorders include chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, and agnogenic myeloid metaplasia (myelofibrosis). These disorders display varying propensities for pathologic enlargement of the spleen which can lead to mechanical discomfort, hypercatabolic symptoms, anemia, thrombocytopenia, and portal hypertension. Splenectomy has been found to be of little benefit in the early stages of chronic myeloid leukemia. Similarly, the benefit of splenectomy in advanced cases is limited to symptomatic palliation and treatment of delayed engraftment after allogeneic bone marrow transplantation. Although polycythemia vera and essential thrombocythemia are also characterized by splenomegaly, splenectomy is not considered a therapeutic option in the absence of transformation of the disease into myelofibrosis with myeloid metaplasia. Splenectomy has been studied most in myelofibrosis with myeloid metaplasia. Although there is no clear survival advantage to splenectomy in this disorder, the surgical procedure can result in substantial palliation of mechanical discomfort, hypercatabolic symptoms, portal hypertension, and anemia. However, the procedure is associated with an approximately 9% mortality rate, and the postsplenectomy occurrence of extreme thrombocytosis, hepatomegaly, and leukemic transformation is of major concern.

Humans↗