Erythroid progenitor cells of the abnormal clone in polycythemia vera (PV) are capable of colony formation in vitro without the addition of erythropoietin, the regulatory hormone required for normal in vivo and-in vitro erythropoiesis. This property of "erythropoietin-independent" colony formation has been considered a marker for the abnormal clone in PV, although recent studies indicate that not all erythropoietic members of the clone may be capable of exhibiting this abnormal phenotype. The present studies were undertaken to investigate the level of maturation at which establishment of an erythropoietin-independent phenotype might be determined. A series of experiments was performed on the replated progeny of single primitive hemopoietic cells already committed to erythropoiesis (primitive BFU-E). First, conditions were established to maximize the number of erythroid colonies obtainable in secondary assays of replated primary colonies of primitive BFU-E origin. Time course studies and experiments with irradiated peripheral blood "feeder" cells treated in different ways established that results were best when primary colonies were allowed to grow for 9 days prior to replating and when 9 day old feeders stored at 4°C were included in the secondary assay medium. Second, a technique was developed for dividing such colonies between 2 secondary assay cultures. Experiments with normal primary colonies transferred to 2 secondary assays, both containing erythropoietin, showed that the variation between true replicates was random, indicating that the procedure used divided each primary colony equally. Third, it was shown that secondary assays to which no erythropoietin was added failed to support erythroid colony formation by progenitors present in normal 9 day old primary colonies. Finally, the distribution of erythropoietin-dependent and erythropoietin-independent phenotypes in individual colonies derived from primitive BFU-E from 5 patients with. PV was assessed by replating experiments. Most of the replated colonies from PV cultures that yielded erythroid colonies in secondary assays containing 3 units of erythropoietin per ml also produced some erythroid colonies in the paired replicate that contained < 0.01 units of erythropoietin per ml. However, fewer colonies were consistently obtained in the low erythropoietin cultures. These results indicate that in PV, most of the primitive erythroid bursts that generate phenotypically abnormal progeny capable of erythroid colony formation under conditions which are non-permissive for normal cells also produce significant numbers of progeny that are phenotypically normal in this respect. It is concluded that the capacity for erythropoietin-independent growth and maturation exhibited in vitro by terminally differentiating members of the abnormal clone in PV is not commonly fixed at or prior to the primitive BFU-E stage of erythropoietic cell development. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Thesis (M.A.)--Boston University

Polycythemia Vera är en livslång blodsjukdom som innebär en överproduktion av blodceller. Vid noggrannhet i behandlingen har sjukdomen god prognos. Att leva med långvarig sjukdom innebär en långvarig och regelbunden kontakt med sjukvården. Det är viktigt att möjliggöra delaktighet för dessa patienter då detta skulle kunna medföra att egenvårdsförmågan ökar och beroendet av sjukvården minskar. För att främja långvarigt sjukas delaktighet har e-hälsotjänsten PODS-Patient Online Decision System tagit fram. PODS är utformat för patienter med Polycythemia Vera. För att tjänsten ska bli patientanpassad bör patienter få komma till tals angående tjänstens utformning och innehåll. Syftet med denna studie är att beskriva patienters uppfattning av e- hälsotjänsten PODS vid en introduktion. Semistrukturerade intervjuer genomfördes med sex informanter som är diagnostiserade med Polycythemia Vera. Intervjuerna bearbetades och tolkades genom innehållsanalys enligt Lundman och Hällgren Graneheim (2012 ss. 194-195). Resultatet i studien visar att patienter sätter stort värde på en välfungerande vårdkontakt, då detta inger en känsla av trygghet. PODS meddelandefunktion ansågs kunna bidra till en smidig kontakt med vården. I dagsläget uppfattas PODS vara användarvänligt i sin utformning. Det fanns dock frågetäcken gällande praktiska lösningar. Överskådligheten av blodvärdena som erbjuds i programmet uppskattas då det gav möjlighet till en fördjupad förståelse för den egna hälsan. PODS har potential att fungera för andra patientgrupper. Det erfordras förbättringar och utveckling av programmets samt organisationen omkring det. Om detta kommer till stånd finns det behov av att vidare studera hur en längre tids användning av PODS upplevs av patienterna.

As neoplasias mieloproliferativas (NMPs) são um grupo de doenças derivadas de uma transformação clonal de célula tronco hematopoiéticas no qual a linhagem celular mielóide é predominantemente expandida no sangue periférico. As NMPs Philadelphia-negativas incluem policitemia vera (PV), trombocitemia essencial (TE) e mielofibrose primária (MFP) que compartilham muitas características hematológicas, clínicas e evolutivas. A mutação da JAK2 (JAK2V617F) está presente em cerca de 95% dos pacientes com PV, entre 50 a 70% com TE e 40 a 50% com MFP. No entanto, os testes moleculares para diagnóstico são muitas vezes um desafio devido ao alto custo e a disponibilidade de equipamentos especializados. Objetivo: Verificar o impacto do teste molecular da mutação JAK2V617F para o diagnóstico de NMPs nos pacientes atendidos no Hospital de Clínicas de Porto Alegre. Métodos: Foram avaliados 87 pacientes com suspeita de NMPs. As amostras de sangue periférico foram analisadas para a mutação JAK2V617F pelo método genético molecular de PCR alelo-específico e os resultados correlacionados com os dados clínico-laboratoriais. Para estabelecimento do diagnóstico, foram utilizados os critérios da Organização Mundial da Saúde (OMS) de 2016. Resultados: Dos 87 pacientes avaliados, 27,6% foram diagnosticados como PV, 39,1% como TE, 4,6% como MFP e 28,7% não contemplavam os critérios para o diagnóstico NMPs. A comparação da utilização do teste da mutação JAK2V617F mostrou que, apenas 41,7% dos pacientes com PV sem utilizar o teste, teriam sido diagnosticados comparados a 91,7% utilizando este teste como um dos critérios no diagnóstico final (p = 0,004). Na TE e na MFP, este critério não foi estatisticamente significativo. Conclusão: O teste molecular para a mutação de JAK2V617F no nosso hospital teve um impacto significativo no diagnóstico dos pacientes com PV, mostrando ser uma ferramenta importante para o diagnóstico final desta NMP. / Myeloproliferative neoplasms (MPNs) are a group of disorders derived from a clonal transformation of stem cell on which myeloid cell lineage is predominantly expanded in the peripheral blood. Philadelphia-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) which share many hematological, clinical, and evolutionary characteristics. The JAK2 mutation (JAK2V617F) is present in about 95% of patients with PV, between 50 to 70% with ET and 40 to 50% PMF. However, the molecular diagnostic tests are often a challenge due to the high cost and the availability of specialized equipment. Objective: To verify the impact of molecular testing of the JAK2V617F mutation for the diagnosis of MPNs in patients attended at Hospital de Clinics, Porto Alegre. Methods: A total of 97 patients were evaluated with suspected of MPNs. The peripheral blood samples were analyzed for the JAK2V617F mutation by the molecular genetic allelespecific PCR method and the results correlated with the clinical-laboratory data. To establish the diagnosis, the 2016 World Health Organization (WHO) criteria were used. Results: Of the 87 patients evaluated, 27.6% were diagnosed as PV, 39.1% as ET, 4.6% as PMF and 28.7% did not meet criteria for MPNs diagnosis. Comparison of the use of the JAK2V617F test showed that only 41.7% of patients with PV without the mutation test were diagnosed compared to 91.7% using this test as one of the criteria for the final diagnosis (p = 0.004). In the ET and the PMF, this criterion was not statistically significant. Conclusion: The molecular test for the JAK2V617F mutation in our hospital had a significant impact in the diagnosis of patients with PV, showing to be an important tool for the final diagnosis of this MPN.

As neoplasias mieloproliferativas (NMPs) são um grupo de doenças derivadas de uma transformação clonal de célula tronco hematopoiéticas no qual a linhagem celular mielóide é predominantemente expandida no sangue periférico. As NMPs Philadelphia-negativas incluem policitemia vera (PV), trombocitemia essencial (TE) e mielofibrose primária (MFP) que compartilham muitas características hematológicas, clínicas e evolutivas. A mutação da JAK2 (JAK2V617F) está presente em cerca de 95% dos pacientes com PV, entre 50 a 70% com TE e 40 a 50% com MFP. No entanto, os testes moleculares para diagnóstico são muitas vezes um desafio devido ao alto custo e a disponibilidade de equipamentos especializados. Objetivo: Verificar o impacto do teste molecular da mutação JAK2V617F para o diagnóstico de NMPs nos pacientes atendidos no Hospital de Clínicas de Porto Alegre. Métodos: Foram avaliados 87 pacientes com suspeita de NMPs. As amostras de sangue periférico foram analisadas para a mutação JAK2V617F pelo método genético molecular de PCR alelo-específico e os resultados correlacionados com os dados clínico-laboratoriais. Para estabelecimento do diagnóstico, foram utilizados os critérios da Organização Mundial da Saúde (OMS) de 2016. Resultados: Dos 87 pacientes avaliados, 27,6% foram diagnosticados como PV, 39,1% como TE, 4,6% como MFP e 28,7% não contemplavam os critérios para o diagnóstico NMPs. A comparação da utilização do teste da mutação JAK2V617F mostrou que, apenas 41,7% dos pacientes com PV sem utilizar o teste, teriam sido diagnosticados comparados a 91,7% utilizando este teste como um dos critérios no diagnóstico final (p = 0,004). Na TE e na MFP, este critério não foi estatisticamente significativo. Conclusão: O teste molecular para a mutação de JAK2V617F no nosso hospital teve um impacto significativo no diagnóstico dos pacientes com PV, mostrando ser uma ferramenta importante para o diagnóstico final desta NMP. / Myeloproliferative neoplasms (MPNs) are a group of disorders derived from a clonal transformation of stem cell on which myeloid cell lineage is predominantly expanded in the peripheral blood. Philadelphia-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) which share many hematological, clinical, and evolutionary characteristics. The JAK2 mutation (JAK2V617F) is present in about 95% of patients with PV, between 50 to 70% with ET and 40 to 50% PMF. However, the molecular diagnostic tests are often a challenge due to the high cost and the availability of specialized equipment. Objective: To verify the impact of molecular testing of the JAK2V617F mutation for the diagnosis of MPNs in patients attended at Hospital de Clinics, Porto Alegre. Methods: A total of 97 patients were evaluated with suspected of MPNs. The peripheral blood samples were analyzed for the JAK2V617F mutation by the molecular genetic allelespecific PCR method and the results correlated with the clinical-laboratory data. To establish the diagnosis, the 2016 World Health Organization (WHO) criteria were used. Results: Of the 87 patients evaluated, 27.6% were diagnosed as PV, 39.1% as ET, 4.6% as PMF and 28.7% did not meet criteria for MPNs diagnosis. Comparison of the use of the JAK2V617F test showed that only 41.7% of patients with PV without the mutation test were diagnosed compared to 91.7% using this test as one of the criteria for the final diagnosis (p = 0.004). In the ET and the PMF, this criterion was not statistically significant. Conclusion: The molecular test for the JAK2V617F mutation in our hospital had a significant impact in the diagnosis of patients with PV, showing to be an important tool for the final diagnosis of this MPN.

As neoplasias mieloproliferativas (NMPs) são um grupo de doenças derivadas de uma transformação clonal de célula tronco hematopoiéticas no qual a linhagem celular mielóide é predominantemente expandida no sangue periférico. As NMPs Philadelphia-negativas incluem policitemia vera (PV), trombocitemia essencial (TE) e mielofibrose primária (MFP) que compartilham muitas características hematológicas, clínicas e evolutivas. A mutação da JAK2 (JAK2V617F) está presente em cerca de 95% dos pacientes com PV, entre 50 a 70% com TE e 40 a 50% com MFP. No entanto, os testes moleculares para diagnóstico são muitas vezes um desafio devido ao alto custo e a disponibilidade de equipamentos especializados. Objetivo: Verificar o impacto do teste molecular da mutação JAK2V617F para o diagnóstico de NMPs nos pacientes atendidos no Hospital de Clínicas de Porto Alegre. Métodos: Foram avaliados 87 pacientes com suspeita de NMPs. As amostras de sangue periférico foram analisadas para a mutação JAK2V617F pelo método genético molecular de PCR alelo-específico e os resultados correlacionados com os dados clínico-laboratoriais. Para estabelecimento do diagnóstico, foram utilizados os critérios da Organização Mundial da Saúde (OMS) de 2016. Resultados: Dos 87 pacientes avaliados, 27,6% foram diagnosticados como PV, 39,1% como TE, 4,6% como MFP e 28,7% não contemplavam os critérios para o diagnóstico NMPs. A comparação da utilização do teste da mutação JAK2V617F mostrou que, apenas 41,7% dos pacientes com PV sem utilizar o teste, teriam sido diagnosticados comparados a 91,7% utilizando este teste como um dos critérios no diagnóstico final (p = 0,004). Na TE e na MFP, este critério não foi estatisticamente significativo. Conclusão: O teste molecular para a mutação de JAK2V617F no nosso hospital teve um impacto significativo no diagnóstico dos pacientes com PV, mostrando ser uma ferramenta importante para o diagnóstico final desta NMP. / Myeloproliferative neoplasms (MPNs) are a group of disorders derived from a clonal transformation of stem cell on which myeloid cell lineage is predominantly expanded in the peripheral blood. Philadelphia-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) which share many hematological, clinical, and evolutionary characteristics. The JAK2 mutation (JAK2V617F) is present in about 95% of patients with PV, between 50 to 70% with ET and 40 to 50% PMF. However, the molecular diagnostic tests are often a challenge due to the high cost and the availability of specialized equipment. Objective: To verify the impact of molecular testing of the JAK2V617F mutation for the diagnosis of MPNs in patients attended at Hospital de Clinics, Porto Alegre. Methods: A total of 97 patients were evaluated with suspected of MPNs. The peripheral blood samples were analyzed for the JAK2V617F mutation by the molecular genetic allelespecific PCR method and the results correlated with the clinical-laboratory data. To establish the diagnosis, the 2016 World Health Organization (WHO) criteria were used. Results: Of the 87 patients evaluated, 27.6% were diagnosed as PV, 39.1% as ET, 4.6% as PMF and 28.7% did not meet criteria for MPNs diagnosis. Comparison of the use of the JAK2V617F test showed that only 41.7% of patients with PV without the mutation test were diagnosed compared to 91.7% using this test as one of the criteria for the final diagnosis (p = 0.004). In the ET and the PMF, this criterion was not statistically significant. Conclusion: The molecular test for the JAK2V617F mutation in our hospital had a significant impact in the diagnosis of patients with PV, showing to be an important tool for the final diagnosis of this MPN.

A Neoplasia Mieloproliferativa Crônica (NMPC)- Politemia Vera é uma desordem clonal caracterizada pelo acúmulo de eritrócitos, leucócitos, plaquetas e progenitores normais na ausência de um estímulo definido. Apesar dos avanços no diagnóstico de PV e da descrição de mecanismos envolvidos no estabelecimento da doença sua patogênese permanece desconhecida entretanto, alterações no mecanismo regulador da apoptose parecem estar envolvidos em sua fisiopatologia. A compreensão acerca do funcionamento da maquinaria apoptótica e sua possível regulação por microRNAs em pacientes com Policitemia Vera parece revelar novos alvos para estudo e consequentemente transformar-se em novas terapias para a doença. Neste contexto os objetivos deste trabalho foram avaliar em leucócitos de sangue periférico e células CD34+ de medula óssea dos pacientes de PV: (1) a quantificação da expressão de microRNAs cujos alvos são RNAs associados a regulação da apoptose; (2) Correlação dos níveis de expressão dos miRNAs com os de RNAm das moléculas pró e antiapoptóticas da família Bcl-2 e dos receptores de morte; (3) Correlação dos níveis de expressão dos miRNAs com os seguintes dados clínico-laboratoriais dos pacientes: concentração de hemoglobina, hematócrito e percentagem da mutação JAK2. Os pacientes com Policitemia Vera apresentam aumento de expressão dos microRNAs 29c, 16, 21, 26a, 130b e let-7d e diminuição de miR15a e 34c em leucócitos de sangue periférico; Aumento de expressão dos miRs 29c, 16 e 21; diminuição na expressão de miR 130b e let-7d em células CD34+ ; alteração na expressão de genes pró e anti-apoptóticos em leucócitos de sangue periférico com aumento de a1, mcl-1 e diminuição de bcl-2, ciap-2, bax e fas-L,alteração na expressão de genes pró e anti-apoptóticos em células CD34+ com aumento de expressão de fas, bid, mcl-1, bcl-xl e c-flip; diminuição na expressão de bik. Observamos diminuição na expressão protéica de BCL-2 em pacientes quando comparado aos indivíduos controle.Notamos também a correlação entre a alteração na expressão de microRNAs e seus respectivos genes alvo e destes com parâmetros hematológicos analisados. Os linfócitos dos pacientes de PV apresentam maior resistência a apoptose do que os indivíduos controles quando induzidos por: Actinomicina, etoposídeo, citarabina e cicloheximida. Concluindo, os dados obtidos sugerem a participação dos microRNAs na regulação da maquinaria apoptótica e a participação desta desregulação na fisiopatologia da PV. Estes resultados contribuem para o melhor entendimento da fisiopatologia da PV e serão úteis futuramente para o desenho de novos alvos terapêuticos e descrição de marcadores de prognóstico. / Polycythaemia vera (PV) is a clonal disorder characterized by an accumulation of normal red and white cells, platelets, and their progenitors in absence of a definable stimulus. Despite the advances in PV diagnosis and the description of the mechanisms involved in disease establishment its pathogenesis remains unclear. The apoptosis deregulation might have a role in PV physiopathology. Fully understanding the basic apoptotic pathway and its potential regulation by microRNA in PV patients cells might unveil targets for manipulation, which may be translated into novel therapies for disease.The aims of this study were to avaluate in leukocytes and CD34+ cells: (1) The microRNA expression whose RNA target are associated with apoptosis regulation (2) Correlation between microRNA expression and the mRNA levels of anti and pro-apoptotic family Bcl-2 expression and death receptors; (3) Correlation between microRNA expression and the clinical data of patients: hemoglobin concentration, hematocrit and JAK2 percentage. Patientes with Polycythemia Vera shows increased expression of microRNAs 29c, 16, 21, 26a, 130b and let-7d and 34c and 15a decrease in peripheral leukocytes; incresead expression of miRs 29c, 16 and 21, decrease in miR130b and let-7d expression in CD34+ cells; deregulation in pro and anti-apoptotic gene expression in peripheral leukocytes with increase in a1, mcl-1 and decrease in bcl-2, ciap-2, bax and fas-L, deregulation in pro and anti-apoptotic gene expression in CD34+ cells with increased expression of fas, bid, mcl-1, bcl-xl and c-flip and decreased expression of bik. Decreased in proteic expression of BCL-2 in peripheral leukocytes of patients when compared to controls. Correlation between de deregulated expression of microRNA and their genes target and those with hematological parameters. Lymphocytes from PV patients shows higher resistance to apoptosis than controls when induced by: Actinomicin, etoposide, cytarabine and cycloheximide. In conclusion the data suggest the involvement of microRNA in apoptosis regulation and the involvement of apoptosis machinery in the PV pathophysiology. These results will contribute for a better understanding of PV pathophysiology and will be useful for the discover of future therapies.

Class of 2011 Abstract / OBJECTIVES: To assess the role of patient, payer, clinical and disease-related factors in charges and mortality among adult inpatient cases of polycythemia vera in the United States from 2004 to 2008. METHODS: This retrospective cohort study utilized hospital discharge records from the Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) five consecutive years from 2004 to 2008. RESULTS: There were a total of 156,490 episodes of care involving polycythemia vera between 2004 and 2008. Average age upon admission was 65.94 years (±16.03), with 56% of cases being male (n=87,662). The mean length of stay was 5.14 days (±5.31) and inpatient mortality occurred in 3.1% of cases (n=4,927). The mean number of procedures performed was 1.43 (±2.08) and the mean number of diagnoses on record was 9.56 (±3.86). Charges for each episode of care averaged $32,620 (±42,801), summing to a national bill of $5.02 billion (2010 dollars) over the five-year time horizon. Higher charges were associated with longer length of stay, larger hospital bed size, urban hospital location, teaching status, increased number of diagnoses and procedures, private payer, Western U.S. region, and higher income bracket. Increased mortality was associated with increased age, increased number of diagnoses and procedures, self pay, payer other than Medicare, Medicaid, private or self, and the comorbidities of congestive heart failure, coagulopathy, and fluid/electrolyte disorders. CONCLUSION: Polycythemia vera is associated with considerable burden of illness.

A Neoplasia Mieloproliferativa Crônica (NMPC)- Politemia Vera é uma desordem clonal caracterizada pelo acúmulo de eritrócitos, leucócitos, plaquetas e progenitores normais na ausência de um estímulo definido. Apesar dos avanços no diagnóstico de PV e da descrição de mecanismos envolvidos no estabelecimento da doença sua patogênese permanece desconhecida entretanto, alterações no mecanismo regulador da apoptose parecem estar envolvidos em sua fisiopatologia. A compreensão acerca do funcionamento da maquinaria apoptótica e sua possível regulação por microRNAs em pacientes com Policitemia Vera parece revelar novos alvos para estudo e consequentemente transformar-se em novas terapias para a doença. Neste contexto os objetivos deste trabalho foram avaliar em leucócitos de sangue periférico e células CD34+ de medula óssea dos pacientes de PV: (1) a quantificação da expressão de microRNAs cujos alvos são RNAs associados a regulação da apoptose; (2) Correlação dos níveis de expressão dos miRNAs com os de RNAm das moléculas pró e antiapoptóticas da família Bcl-2 e dos receptores de morte; (3) Correlação dos níveis de expressão dos miRNAs com os seguintes dados clínico-laboratoriais dos pacientes: concentração de hemoglobina, hematócrito e percentagem da mutação JAK2. Os pacientes com Policitemia Vera apresentam aumento de expressão dos microRNAs 29c, 16, 21, 26a, 130b e let-7d e diminuição de miR15a e 34c em leucócitos de sangue periférico; Aumento de expressão dos miRs 29c, 16 e 21; diminuição na expressão de miR 130b e let-7d em células CD34+ ; alteração na expressão de genes pró e anti-apoptóticos em leucócitos de sangue periférico com aumento de a1, mcl-1 e diminuição de bcl-2, ciap-2, bax e fas-L,alteração na expressão de genes pró e anti-apoptóticos em células CD34+ com aumento de expressão de fas, bid, mcl-1, bcl-xl e c-flip; diminuição na expressão de bik. Observamos diminuição na expressão protéica de BCL-2 em pacientes quando comparado aos indivíduos controle.Notamos também a correlação entre a alteração na expressão de microRNAs e seus respectivos genes alvo e destes com parâmetros hematológicos analisados. Os linfócitos dos pacientes de PV apresentam maior resistência a apoptose do que os indivíduos controles quando induzidos por: Actinomicina, etoposídeo, citarabina e cicloheximida. Concluindo, os dados obtidos sugerem a participação dos microRNAs na regulação da maquinaria apoptótica e a participação desta desregulação na fisiopatologia da PV. Estes resultados contribuem para o melhor entendimento da fisiopatologia da PV e serão úteis futuramente para o desenho de novos alvos terapêuticos e descrição de marcadores de prognóstico. / Polycythaemia vera (PV) is a clonal disorder characterized by an accumulation of normal red and white cells, platelets, and their progenitors in absence of a definable stimulus. Despite the advances in PV diagnosis and the description of the mechanisms involved in disease establishment its pathogenesis remains unclear. The apoptosis deregulation might have a role in PV physiopathology. Fully understanding the basic apoptotic pathway and its potential regulation by microRNA in PV patients cells might unveil targets for manipulation, which may be translated into novel therapies for disease.The aims of this study were to avaluate in leukocytes and CD34+ cells: (1) The microRNA expression whose RNA target are associated with apoptosis regulation (2) Correlation between microRNA expression and the mRNA levels of anti and pro-apoptotic family Bcl-2 expression and death receptors; (3) Correlation between microRNA expression and the clinical data of patients: hemoglobin concentration, hematocrit and JAK2 percentage. Patientes with Polycythemia Vera shows increased expression of microRNAs 29c, 16, 21, 26a, 130b and let-7d and 34c and 15a decrease in peripheral leukocytes; incresead expression of miRs 29c, 16 and 21, decrease in miR130b and let-7d expression in CD34+ cells; deregulation in pro and anti-apoptotic gene expression in peripheral leukocytes with increase in a1, mcl-1 and decrease in bcl-2, ciap-2, bax and fas-L, deregulation in pro and anti-apoptotic gene expression in CD34+ cells with increased expression of fas, bid, mcl-1, bcl-xl and c-flip and decreased expression of bik. Decreased in proteic expression of BCL-2 in peripheral leukocytes of patients when compared to controls. Correlation between de deregulated expression of microRNA and their genes target and those with hematological parameters. Lymphocytes from PV patients shows higher resistance to apoptosis than controls when induced by: Actinomicin, etoposide, cytarabine and cycloheximide. In conclusion the data suggest the involvement of microRNA in apoptosis regulation and the involvement of apoptosis machinery in the PV pathophysiology. These results will contribute for a better understanding of PV pathophysiology and will be useful for the discover of future therapies.

Caractérisée par la présence de la mutation JAK2 V617F, la polyglobulie primitive voit son développement contenu par des saignées mais est associée à une incidence plus élevée de cancers. Une exploration globale de l'immunité des patients a été réalisée par la quantification des sous populations lymphocytaires de l'immunité innée et adaptative. Ceci a permis la mise en évidence d'une diminution des lymphocytes B et d'une augmentation des cellules NK. Les cellules NK sont réputées pour leurs propriétés antitumorales mais elles ne sont pourtant pas capables d'éradiquer la PV, posant la question de leurs capacités fonctionnelles. Si les cellules NK des patients présentent une activité cytotoxique basale inférieure aux témoins, elles ne présentent pas d'anomalies de l'expression de leurs récepteurs, de la production de molécules cytolytiques ou de prolifération. Par contre, les cellules NK d'un patient ayant développé une érythroleucémie ou des cellules NK de sujets âgés par rapport à des témoins plus jeunes présentent des anomalies d'expression des récepteurs. L'augmentation des cellules NK pourrait être liée à la mutation JAK2 V617F. Si cette mutation est présente dans les lymphocytes de tous les patients, il existe des arguments pour sa présence dans les cellules NK de certains patients. Enfin, une analyse transcriptomique a permis de définir un profil d'expression propre aux cellules NK des patients. / Characterized by the presence of the JAK2 V617F mutation, polycythemia vera's development is content by phlebotomy but is associated with a higher incidence of cancer. A global exploration of the immunity of patients was performed by quantification of lymphocyte subpopulations of innate and adaptive immunity. This allowed the detection of a decrease in B cells and an increase in NK cells. NK cells are known for their antitumor properties but they are not yet able to eradicate PV, raising the question of their functional abilities. If NK cells of patients have a lower basal cytotoxic activity than healthy donors, they do not show abnormal expression of their receptors, the production of cytolytic molecules or proliferation. On the contrary, NK cells from a patient who developed erythroleukemia or NK cells from elderly healthy donors compared with younger healthy donors exhibit abnormalities of receptors expression. The increase in NK cells could be related to the JAK2 V617F mutation. If the mutation is present in cells of all patients, there are arguments for its presence in the NK cells of some patients. Finally, transcriptome analysis has identified an expression profile specific to NK cells of patients.