Simultaneous, bilateral anterior ischemic optic neuropathy (AION) in polycythemia vera: a case report

BACKGROUND: Polycythemia vera (PV) is a hemopoetic disorder. Apparently, although thrombosis accounts for the majority of morbidity, AION has not been associated with PV so far. PATIENT AND FINDINGS: A 63 y-old woman with PV was hospitalized because of acute liver failure. She also experienced bilateral painless loss of vision. Bilateral, pale optic disc swelling with flame-like hemorrhages, more pronounced in the right eye, constricted visual fields, and relative afferent papillary defect (RAPD) on the right side were present. Computer tomography scan revealed no signs of intraorbital pathology, elevated intracranial pressure or hemorrhages. CLINICAL COURSE: We interpreted the findings as AION associated with the hyperviscosity syndrome. Liver transplantation had to be carried out in the next days. Three weeks later, vision improved slightly, but RAPD persisted, and disc pallor developed in both eyes. The patient died two months later. DISCUSSION: Central retinal artery and vein occlusions have been described as complications of Essential thrombocythemia, but not of PV. We observed a rare case of bilateral neuropathy suggestive of AION. This condition has so far not been associated with PV.

Polycythemia: physiology, diagnosis, and treatment based on 303 cases.

Includes bibliography.

Policitemia Vera: scoperta di saggi di biopsia liquida finalizzata a identificare i biomarcatori correlati al rischio trombotico

La Policitemia Vera (PV) è una neoplasia mieloproliferativa con un aumentato rischio di trombosi e di progressione verso la Mielofibrosi. L'infiammazione cronica è comunemente osservata nelle neoplasie mieloproliferative, compresa la PV. La rete infiammatoria, tra le varie componenti, comprende le vescicole extracellulari (EVs), che svolgono un ruolo nella comunicazione cellula-cellula. Inoltre, le componenti microbiche circolanti sono state recentemente indicate come potenziali modificatori dell'infiammazione, della coagulazione e dell’emopoiesi in generale. Qui abbiamo studiato il DNA microbico delle EVs circolanti attraverso. Sangue periferico e feci sono stati raccolti da pazienti con PV (n=38) e da donatori sani (n=30). Le EVs circolanti derivate da megacariociti (MK) e piastrine (PLT) sono state analizzate mediante citometria a flusso. Dopo l'estrazione del DNA microbico dalle feci e dalle EV isolate, è stata sequenziata la regione V3-V4 del 16S rDNA. La percentuale di EVs di MK era ridotta nei pazienti con PV rispetto ai donatori sani. Al contrario, la proporzione di EVs di PLT era aumentata. La PV è stata associata anche a una firma del DNA microbico delle EVs isolate con una maggiore diversità e una composizione microbica distinta rispetto alla controparte sana. Nei pazienti con PV c’è una maggiore proporzione di EVs associate al lipopolisaccaride. Il profilo del microbioma intestinale non differiva tra PV e doantori. Inoltre, l'aumento della proporzione di EVs di MK e la riduzione di EVs di piastre identificavano i pazienti con pregressa trombosi. Le EVs dei pazienti con trombosi erano impoverite di DNA di Staphylococcus ma arricchite di DNA di Actinobacteria e Anaerococcus. Inoltre, questi pazienti avevano livelli più bassi di EVs associate al lipopolisaccaride. I pazienti con fibrosi midollare avevano una maggiore proporzione di PE-EV ed erano arricchite in DNA di Collinsella e Flavobacterium. Questi dati possono contribuire a perfezionare la prognosi della PV e a identificare nuovi bersagli farmacologici.

Dysregulated hematopoiesis and a progressive neurological disorder induced by expression of an activated form of the human common beta chain in transgenic mice

Previously we described activating mutations of h beta(c), the common signaling subunit of the receptors for the hematopoietic and inflammatory cytokines, GM-CSF, IL-3, and IL-5. The activated mutant, h beta(c)FI Delta, is able to confer growth factor-independent proliferation on the murine myeloid cell line FDC-P1, and on primary committed myeloid progenitors. We have used this activating mutation to study the effects of chronic cytokine receptor stimulation. Transgenic mice were produced carrying the h beta(c)FI Delta cDNA linked to the constitutive promoter derived from the phosphoglycerate kinase gene, PGK-1. Transgene expression was demonstrated in several tissues and functional activity of the mutant receptor was confirmed in hematopoietic tissues by the presence of granulocyte macrophage and macrophage colony-forming cells (CFU-GM and CFU-M) in the absence of added cytokines. All transgenic mice display a myeloproliferative disorder characterized by splenomegaly, erythrocytosis, and granulocytic and megakaryocytic hyperplasia. This disorder resembles the human disease polycythemia vera, suggesting that activating mutations in h beta(c) may play a role in the pathogenesis of this myeloproliferative disorder. In addition, these transgenic mice develop a sporadic, progressive neurological disease and display bilateral, symmetrical foci of necrosis in the white matter of brain stem associated with an accumulation of macrophages. Thus, chronic h beta(c) activation has the potential to contribute to pathological events in the central nervous system.

Estudio de marcadores moleculares en neoplasias mieloproliferativas

Las neoplasias mieloproliferativas (NM) son un grupo de enfermedades clonales de la célula hematopoyética madre. Entre las NM clásicas se encuentran la policitemia vera (PV), la trombocitemia esencial (TE) y la mielofibrosis primaria (MFP). Durante muchos años el diagnóstico de estas patologías se hacía por exclusión utilizando biomarcadores de clonalidad poco específicos. En el año 2005, la descripción de la mutación JAK2V617F supuso un avance importante en el diagnóstico de estas patologías. Posteriormente, se han descrito mutaciones en otros genes como mutaciones en MPL, TET2, ASXL1, IDH1, IDH2, c-CBL, EZH2, IKZF1 y LNK, en distintas neoplasias mieloides y en porcentaje variable. Aun así, ninguno de estos genes son marcadores específicos de ninguna NM y todavía existe un porcentaje elevado de pacientes con TE y MFP sin un marcador de clonalidad conocido. Además, todos estos genes se han descrito como eventos genéticos implicados en la transformación de una NM a leucemia mieloide aguda. El objetivo de este proyecto fue estudiar varios marcadores moleculares en neoplasias mieloproliferativas Philadelphia negativas. En primer lugar, se estudió la modulación de la carga alélica JAK2V617F en pacientes con PV o TE que recibieron tratamiento citoreductor y a su vez se analizó la dinámica natural de la carga alélica en pacientes que no recibieron tratamiento. Posteriormente, se analizaron la presencia de alteraciones en los genes previamente mencionados, en distintos grupos de pacientes. En primer lugar, se analizó la presencia de mutaciones en TET2, ASXL1, IDH1, IDH2 y CBL en un grupo de pacientes JAK2 y MPL negativos, para determinar la frecuencia de alteraciones de estos genes en este grupo de pacientes y determinar su valor en el diagnóstico de estas patologías. En segundo lugar, se estudió la presencia de mutaciones en estos genes incluyendo EZH2, IKZF1 y LNK para estudiar la incidencia y el valor pronóstico de estas alteraciones en las NM que progresan a mielofibrosis.

Infarctus cérébraux artériels d'origine hématologique : expérience lausannoise et revue de la littérature

RÉSUMÉ Introduction. Les hémopathies représentent une cause rare d'accident vasculaire cérébral (AVC), faisant l'objet de peu de publications, mais sont très fréquemment recherchées après un AVC par de coûteux bilans dont la rentabilité reste à définir. Matériel et Méthodes. Dans le registre lausannois des AVC, nous nous sommes intéressés de façon rétrospective aux dossiers des patients hospitalisés entre 1979 et 2001 pour un premier AVC ischémique artériel, dont la cause a été attribuée à une pathologie hématologique. Sur 4 697 patients, 22 (0,47 p. 100) ont vu leur AVC imputé à l'une des causes hématologiques suivantes : maladie de Vaquez , polyglobulie secondaire , thrombocytémie essentielle , thrombocytose secondaire , myélome multiple , MD , déficit en protéine S , syndrome anticorps antiphospholipides , hyperhomocystéinémie . Chaque hémopathie retrouvée a donné lieu à une revue de la littérature. Conclusion. À la lumière de ces données, nous concluons qu'une formule sanguine représente un bilan hématologique de dépistage suffisant pour l'immense majorité des patients hospitalisés pour un premier AVC artériel ischémique. Les recherches d'anticorps antiphospholipides, de thrombophilies héréditaires et d'hyperhomocystéinémie peuvent être limitées à des cas sélectionnés. SUMMARY Cerebral infarction of arterial origin and haematological causation: the Lausanne experience and a review of the literature. Introduction. Hematological diseases are seldom found as the etiology of ischemic strokes, but are frequently investigated by expensive laboratory tests after a first cerebral vascular event. Methods. In the Lausanne Stroke Registry, we retrospectively reviewed the cases of patients hospitalized between 1979 and 2001 for a first ischemic arterial stroke which was attributed to a hematological etiology. Of 4697 patients, 22 (0.47 per cent) had a stroke due to one of the following hematological pathology: polycythemia vera, secondary polycythemia, essential thrombocytemia, secondary thrombocytosis, multiple myeloma, CIVD, protein S deficiency, antiphospholipid antibody syndrome, moderate homocysteinemia. A literature review was undertaken for each hemopathy. Conclusion. In light of the results of these data, we concluded that a complete blood count provides sufficient hematological screening for the majority of patients hospitalized for an arterial stroke. The antiphospholipid antibody syndrome is a rare cause of cerebral infarction, which needs to be investigated in young patients, in cases of multiple or recurring stroke or in the presence of a typical history. Inherited thrombophilias are not a significant risk factor for arterial cerebral infarction and their investigation is only warranted for a sub-group of young patients with a cryptogenic stroke, in which group the prevalence is slightly increased. Moderate homocysteinemia must be considered as a cerebrovascular risk factor of minor importance, but potentially treatable by a substitution of vitamin B12, B 6 and folates. The efficacy of this substitution in the prevention of cardiovascular events needs yet to be demonstrated.

Population-based incidence of myeloid malignancies: fifteen years of epidemiological data in the province of Girona, Spain

Myeloid malignancies (MMs) are a heterogeneous group of hematologic malignancies presenting different incidence, prognosis and survival.1–3 Changing classifications (FAB 1994, WHO 2001 and WHO 2008) and few available epidemiological data complicate incidence comparisons.4,5 Taking this into account, the aims of the present study were: a) to calculate the incidence rates and trends of MMs in the Province of Girona, northeastern Spain, between 1994 and 2008 according to the WHO 2001 classification; and b) to predict the number of MMs cases in Spain during 2013. Data were extracted from the population-based Girona Cancer Registry (GCR) located in the north-east of Catalonia, Spain, and covering a population of 731,864 inhabitants (2008 census). Cases were registered according to the rules of the European Network for Cancer Registries and the Manual for Coding and Reporting Haematological Malignancies (HAEMACARE project). To ensure the complete coverage of MMs in the GCR, and especially myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS), a retrospective search was performed. The ICD-O-2 (1990) codes were converted into their corresponding ICD-O-3 (2000) codes, including MDS, polycythemia vera (PV) and essential thrombocythemia (ET) as malignant diseases. Results of crude rate (CR) and European standardized incidence rate (ASRE) were expressed per 100,000 inhabitants/year

Differential expression of apoptosis-related genes from death receptor pathway in chronic myeloproliferative diseases

Background Chronic myeloproliferative disorders (MPDs) are clonal haematopoietic stem cell malignancies characterised by an accumulation of mature myeloid cells in bone marrow and peripheral blood. Deregulation of the apoptotic machinery may be associated with MPD physiopathology. Aims To evaluate expression of death receptors` family members, mononuclear cell apoptosis resistance, and JAK2 allele burden. Subjects and Methods Bone marrow haematopoietic progenitor CD34 cells were separated using the Ficoll-hypaque protocol followed by the Miltenyi CD34 isolation kit, and peripheral blood leukocytes were separated by the Haes-Steril method. Total RNA was extracted by the Trizol method, the High Capacity Kit was used to synthesise cDNA, and real-time PCR was performed using SybrGreen in ABIPrism 7500 equipment. The results of gene expression quantification are given as 2(-Delta Delta Ct). The JAK2 V617F mutation was detected by real-time allelic discrimination PCR assay. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll-hypaque protocol and cultured in the presence of apoptosis inducers. Results In CD34 cells, there was mRNA overexpression for fas, faim and c-flip in polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF), as well as fasl in PMF, and dr4 levels were increased in ET. In leukocytes, fas, c-flip and trail levels were increased in PV, and dr5 expression was decreased in ET. There was an association between dr5 and fasl expression and JAK2V617F mutation. PBMCs from patients with PV, ET or PMF showed resistance to apoptosis inducers. Conclusions The results indicate deregulation of apoptosis gene expression, which may be associated with MPD pathogenesis leading to accumulation of myeloid cells in MPDs.

Interação entre Citocinas, Plaquetas e Fibrogênese na Investigação da Metaplasia Mielóide Hepática

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Deregulation of apoptosis-related genes is associated with PRV1 overexpression and JAK2 V617F allele burden in Essential Thrombocythemia and Myelofibrosis

Background: Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF) are Chronic Myeloproliferative Neoplasms (MPN) characterized by clonal myeloproliferation/myeloaccumulation without cell maturation impairment. The JAK2 V617F mutation and PRV1 gene overexpression may contribute to MPN physiopathology. We hypothesized that deregulation of the apoptotic machinery may also play a role in the pathogenesis of ET and PMF. In this study we evaluated the apoptosis-related gene and protein expression of BCL2 family members in bone marrow CD34(+) hematopoietic stem cells (HSC) and peripheral blood leukocytes from ET and PMF patients. We also tested whether the gene expression results were correlated with JAK2 V617F allele burden percentage, PRV1 overexpression, and clinical and laboratory parameters. Results: By real time PCR assay, we observed that A1, MCL1, BIK and BID, as well as A1, BCLW and BAK gene expression were increased in ET and PMF CD34(+) cells respectively, while pro-apoptotic BAX and anti-apoptotic BCL2 mRNA levels were found to be lower in ET and PMF CD34(+) cells respectively, in relation to controls. In patients' leukocytes, we detected an upregulation of anti-apoptotic genes A1, BCL2, BCL-XL and BCLW. In contrast, pro-apoptotic BID and BIMEL expression were downregulated in ET leukocytes. Increased BCL-XL protein expression in PMF leukocytes and decreased BID protein expression in ET leukocytes were observed by Western Blot. In ET leukocytes, we found a correlation between JAK2 V617F allele burden and BAX, BIK and BAD gene expression and between A1, BAX and BIK and PRV1 gene expression. A negative correlation between PRV1 gene expression and platelet count was observed, as well as a positive correlation between PRV1 gene expression and splenomegaly. Conclusions: Our results suggest the participation of intrinsic apoptosis pathway in the MPN physiopathology. In addition, PRV1 and JAK2 V617F allele burden were linked to deregulation of the apoptotic machinery.

Excessive erythrocytosis in adult mice overexpressing erythropoietin leads to hepatic, renal, neuronal, and muscular degeneration

To investigate the consequences of inborn excessive erythrocytosis, we made use of our transgenic mouse line (tg6) that constitutively overexpresses erythropoietin (Epo) in a hypoxia-independent manner, thereby reaching hematocrit levels of up to 0.89. We detected expression of human Epo in the brain and, to a lesser extent, in the lung but not in the heart, kidney, or liver of tg6 mice. Although no acute cardiovascular complications are observed, tg6 animals have a reduced lifespan. Decreased swim performance was observed in 5-mo-old tg6 mice. At about 7 mo, several tg6 animals developed spastic contractions of the hindlimbs followed by paralysis. Morphological analysis by light and electron microscopy showed degenerative processes in liver and kidney characterized by increased vascular permeability, chronic progressive inflammation, hemosiderin deposition, and general vasodilatation. Moreover, most of the animals showed severe nerve fiber degeneration of the sciatic nerve, decreased number of neuromuscular junctions, and degeneration of skeletal muscle fibers. Most probably, the developing demyelinating neuropathy resulted in muscular degeneration demonstrated in the extensor digitorum longus muscle. Taken together, chronically increased Epo levels inducing excessive erythrocytosis leads to multiple organ degeneration and reduced life expectancy. This model allows investigation of the impact of excessive erythrocytosis in individuals suffering from polycythemia vera, chronic mountain sickness, or in subjects tempted to abuse Epo by means of gene doping.

Hematopoietic and endothelial progenitor cell trafficking in patients with myeloproliferative diseases

BACKGROUND AND OBJECTIVES. The presence of circulating hematopoietic progenitor cells in patients with myeloproliferative diseases (MPD) has been described. However, the exact nature of such progenitor cells has not been specified until now. The aim of this work was to investigate the presence of endothelial precursor cells in the blood of patients with MPD and to assess the role of the endothelial cell lineage in the pathophysiology of this disease. DESIGN AND METHODS. Endothelial progenitor cell marker expression (CD34, prominin (CD133), kinase insert domain receptor (KDR) or vascular endothelial growth factor receptor 2 (VEGFR2), and von Willebrand factor) was assessed in the blood of 53 patients with MPD by quantitative polymerase chain reaction. Clonogenic stem cell assays were performed with progenitor cells and monocytes to assess differentiation towards the endothelial cell lineage. The patients' were divided according to whether they had essential thrombocythemia (ET, n=17), polycythemia vera (PV, n=21) or chronic idiopathic myelofibrosis (CIMF, n=15) and their data compared with data from normal controls (n=16) and patients with secondary thrombo- or erythrocytosis (n=17). RESULTS. Trafficking of CD34-positive cells was increased above the physiological level in 4/17 patients with ET, 5/21 patients with PV and 13/15 patients with CIMF. A subset of patients with CIMF co-expressed the markers CD34, prominin (CD133) and KDR, suggesting the presence of endothelial precursors among the circulating progenitor cells. Clonogenic stem cell assays confirmed differentiation towards both the hematopoietic and the endothelial cell lineage in 5/10 patients with CIMF. Furthermore, the molecular markers trisomy 8 and JAK2 V617F were found in the grown endothelial cells of patients positive for trisomy 8 or JAK2 V617F in the peripheral blood, confirming the common clonal origin of both hematopoietic and endothelial cell lineages. INTERPRETATION AND CONCLUSIONS. Endothelial precursor cells are increased in the blood of a subset of patients with CIMF, and peripheral endothelial cells bear the same molecular markers as hematopoietic cells, suggesting a primary role of pathological endothelial cells in this disease.