IL-8 in bone marrow and peripheral blood of patients with B-cell acute lymphoblastic leukemia is associated with high regulatory T cell counts, degree of tumor infiltration and expression of CXCR1 in blasts.

INTRODUCTION: Regulatory T cells (Treg cells) in a tumor environment and the expression of forkhead box P3 (FOXP3) in tumor cells have been associated with a poor prognosis. There are few studies evaluating Treg cells and FOXP3 in B-cell acute lymphoblastic leukemia (B-cell ALL). This study aimed to evaluate the frequencies of Treg cells in bone marrow (BM) and peripheral blood (PB) of patients with B-cell ALL and to determine their associations with the circulating cytokine profile and the expression of CXCR1 (IL-8 receptor) in Treg cells, as well as to compare FOXP3 expression in blasts of patients with B-cell ALL and normal lymphoid precursors. METHODS: Samples of BM and PB from patients with B-cell ALL and healthy controls were studied. Treg cells, cytokines, FOXP3 and CXCR1 were evaluated using flow cytometry and analyzed. RESULTS: A total of 20 patients with B-cell ALL and 10 healthy controls were included. In B-cell ALL patients, Treg cell frequencies increased significantly, with higher percentages in the PB. Absolute Treg cell counts were associated with absolute blast counts in the BM and PB and with an IL-8 concentration. The IL-8 and IL-6 levels were associated with the CXCR1 expression in PB Treg cells. In addition, a greater expression of FOXP3 was observed in leukemic blasts than in normal lymphoid precursors. CONCLUSIONS: These results suggest that the presence of Treg cells and cytokines in the tumor environment may correspond to mechanisms to evade the immune response. For that reason, it would be important to monitor these parameters in B-cell ALL to establish their effect on the disease prognosis.

Influence of Dose Intensity in Consolidation with HIDAC and Other Clinical and Biological Parameters in the Survival of AML.

BACKGROUND: The impact of the dose intensity administered in consolidation in Latin America is unknown. This study aimed to evaluate the relative dose intensity (RDI) in consolidation and its impact in overall survival. METHODS: A retrospective study of 86 patients with AML who were diagnosed between 2010 and 2016 with a 2-year follow-up in a fourth-level Colombian hospital was carried out. Clinical characteristics were reported, Kaplan-Meier was used for estimating the overall survival, and Cox regression was used for multivariate analysis. RESULTS: The median overall survival (OS) was 20.83 months, and the median event-free survival (EFS) was 16.83 months. 64.3% of the patients achieved remission after the 7 + 3 chemotherapy induction treatment. Patients under 30 years of age, with white blood cell counts less than 100.000 cells/mm3 who responded to induction treatment had a better OS. Additionally, patients receiving an RDI greater than 0.75 of the planned consolidation dose had better survival. The prognostic variables with impact in the OS were the leukocyte count in peripheral blood at diagnosis, the RDI in consolidation treatment with HIDAC and the response obtained after induction. CONCLUSION: This retrospective study allowed us to know the epidemiology of AML in a reference Colombian Hospital. Additionally, in our knowledge, it is the first study that reports the RDI in consolidation with HIDAC in Latin America as a prognostic factor that directly impacts the OS.

The nutrition risk index is associated with bacteremia within 30 days after autologous stem cell transplantation in patients with multiple myeloma.

OBJECTIVES: To assess whether the nutrition risk index (NRI) is associated with the risk of bacteremia within the first days after autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). MATERIALS AND METHODS: Retrospective cohort study of adult patients with MM taken to ASCT at the Hospital Universitario San Ignacio (Bogotá, Colombia) between 2005 and 2019. The outcome of interest was the incidence of bacteremia at 30 days. Multivariate analysis was used to identify whether the NRI was associated with bacteremia, controlling by different confounding variables. RESULTS: One hundred and twenty-four patients with a median age of 58.5 years (IQR: 54-64) were included. 47.1% were in stage ISS III. 36.0% had moderate or severe malnourishment (NRI < 97.5). 11.2% presented bacteremia in the first 30 days after transplantation. In the univariate analysis, the NRI < 97.5 was associated with bacteremia (OR: 1.88; 95% CI: 1.30-2.72, P = .001); however, this association was not significant in the multivariate analysis, unlike the presence of mucositis (OR: 11.59; 95% CI: 1.9-68.3, <0.01), one or more previous lines of therapy (OR: 12.0; 95% CI: 2.1-67.4; P < .01), and duration of aplasia (OR: 1.70; 95% CI: 1.2-2.4, P < .01). CONCLUSIONS: Patients with moderate or severe malnourishment have a higher incidence of bacteremia in the 30 days post-ASCT in patients with MM. Additional risk factors associated with bacteremia include the presence of mucositis, one or more previous lines of therapy, and the duration of aplasia.

Biometría del calcáneo en beneficio de la técnica quirúrgica: estudio cadavérico / Biometry of the calcaneus for the benefit of the surgical technique: Cadaver study

Introducción Es importante una elección adecuada de material de osteosíntesis en la técnica quirúrgica de fijación interna en fracturas del calcáneo, pues las dimensiones del calcáneo varían de una población a otra. En el manejo de estas fracturas muchas veces el material no se adecua al tamaño y morfología de cada paciente. Este estudio describe las características biométricas del calcáneo, para lograr un mayor entendimiento de las dimensiones de este. Materiales y Métodos Se realizó un estudio descriptivo, con 31 piezas óseas de calcáneos. Se midieron la longitud máxima, altura, longitud de la pared lateral al sustentáculo tali y, basadas en zonas de seguridad para el riesgo de lesión anatómica, se midió el ancho en cada zona. Los ángulos de Böhler y Gissane se midieron por fotografías y radiografías. Resultados La media de la longitud máxima fue de 67.14±4.51mm, la media de la longitud de la pared lateral al sustentáculo tali fue de 34.82±3.28mm, y la media de la altura fue de 40.11±3.40mm. El ancho tomado en 6 puntos diferentes, mostró que la zona IIIB presentó mayor ancho con una media de 25.35±2.67mm. La media de los ángulos de Böhler y Gissane fue de 25.45°± 4.80 y 25.86°±6; 122.9°± 5.81 y 114.15°± 9.86; respectivamente. Discusión Las medidas halladas en nuestra muestra son menores comparados a otras poblaciones, en tanto los ángulos no mostraron mayor variación. Estos hallazgos pueden usarse para la realización de investigaciones comparativas entre poblaciones, evaluando así condiciones patológicas y adaptaciones de protocolos terapéuticos.

Background The appropriate choice of osteosynthesis material in the surgical technique of internal fixation in calcaneal fractures is of great importance, since it varies from one population to another. In the management of calcaneal fractures, the material is often not adapted to the size and morphology of each patient. A study was carried out to describe the biometric characteristics of the calcaneus, for a better understanding of the dimensions of this bone in our population. Methods A descriptive study was conducted on 31 bone pieces of calcaneus. The maximum length, height, and length of the lateral wall to the posterior third of sustentaculum tali were measurement and, based on safety zones for risk of anatomical injury; the width was measured in each zones. The angles of Böhler and Gissane were measured by photographs and radiographs. Results The maximum length had a mean of 67.14±4.51mm, the mean of the length of the lateral wall to the posterior third of sustentaculum tali was 34.82±3.28mm, and the mean of the height was 40.11±3.40mm. The width was taken at 6 different points, observing that the zone IIIB has a greater width, with a mean of 25.35±2.67mm. The mean of the Böhler and Gissane angles was 25.45°±4.80 and 25.86°±6; 122.9°±5.81 and 114.15°±9.86; respectively. Discussion Measurements of our sample are smaller compared to other populations. However, the angles showed no greater variation. These findings can be used to conduct comparative studies between populations, for evaluating pathological conditions, and adaptations of therapeutic protocols.

Loss of T-Cell Multifunctionality and TCR-Vß Repertoire Against Epstein-Barr Virus Is Associated With Worse Prognosis and Clinical Parameters in HIV+ Patients.

Epstein-Barr virus (EBV) is an oncogenic virus associated with the development of aggressive and poor-prognosis B-cell lymphomas in patients infected with human immunodeficiency virus (HIV+ patients). The most important risk factors for these malignancies include immune dysfunction, chronic immune activation, and loss of T-cell receptor (TCR) repertoire. The combination of all these factors can favor the reactivation of EBV, malignant cell transformation, and clinical progression toward B-cell lymphomas. The overarching aim of this study was to evaluate the frequency, phenotype, functionality, and distribution of TCR clonotypes for EBV-specific T-cell subpopulations in HIV+ patients at different clinical stages and for HIV+ patients with B-cell lymphoma, as well as to establish their association with clinical variables of prognostic value. Factors were studied in 56 HIV+ patients at different clinical stages and in six HIV+ subjects with diagnosed B-cell lymphoma. We found a significant decrease in all subpopulations of EBV-specific CD4+ T cells from HIV+ patients at stage 3 and with B-cell lymphoma. EBV-specific effector CD8+ T cells, particularly effector memory cells, were also reduced in HIV+ patients with B-cell lymphoma. Interestingly, these cells were unable to produce IFN-γ and lacked multifunctionality in HIV+ patients. The TCR-Vß repertoire, which is key for protection against EBV in healthy individuals, was less diverse in HIV+ patients due to a lower frequency of TCR-Vß2+, Vß4+, Vß7.1+, Vß9+, Vß13.6+, Vß14+, Vß17+, Vß22+ CD4+, Vß14+, and Vß17+ CD8+ T cells. HIV+ patients with positive plasma EBV loads (EBV+HIV+) had a noteworthy decrease in the levels of both TNF-α+ and multifunctional TNF-α+/IL-2+ and TNF-α+/IFN-γ+ CD8+ T cells. Altogether, our findings demonstrate that HIV+ patients have significant alterations in the immune response to EBV (poor-quality immunity) that can favor viral reactivation, escalating the risk for developing EBV-associated B-cell lymphomas.

Study of body fluid samples using flow cytometry: Six years of experience at the Hospital Universitario San Ignacio - Pontificia Universidad Javeriana, Bogota - Colombia / Estudio de muestras de fluidos corporales utilizando citometría de flujo: seis años de experiencia en el Hospital Universitario San Ignacio - Pontificia Universidad Javeriana Bogotá, Colombia / Estudo de amostras de fluídos corporais utilizando citometria de fluxo: seis anos de experiencia no Hospital Universitário San Ignacio - Pontificia Universidad Javeriana, Bogotá, Colômbia

Abstract Flow cytometry (FCM) was implemented in 2008 at the Pontificia Universidad Javeriana and later at the Hospital Universitario San Ignacio to examine special samples of patients with hematological malignancies and solid tumors other than bone marrow and peripheral blood for diagnosis and monitoring. This study describes the main findings of special sample evaluation over a six-year period. In all, 1070 samples of body fluids from patients with benign and malignant diseases were examined by FCM. These samples were stabilized with TransFixTM and stained with six-color immunophenotyping panels. Samples included cerebrospinal fluid, bronchoalveolar lavage, pleural fluid, pericardial fluid and ascite fluid from patients with acute and chronic leukemia, myelodysplastic syndromes, lymphomas, myeloma, autoimmune diseases, immunodeficiencies and solid tumors, among others. Flow cytometry provided important information for the classification and detection of minimal numbers of tumor cells in leukemia and lymphoma cases. This work represents the first national report describing FCM implementation in special samples for diagnosis and clinical monitoring of patients with malignant and benign pathologies.

Resumen La citometría de flujo fue implementada en 2008 en la Pontificia Universidad Javeriana y posteriormente en el Hospital San Ignacio con el fin de examinar, para diagnóstico y monitoreo, muestras especiales de pacientes con malignidades hematológicas y tumores sólidos, distintos de los de médula ósea y sangre periférica. Este estudio describe los principales hallazgos de la evaluación de estas muestras especiales en un periodo de seis años. En total, se examinaron por citometría de flujo 1070 muestras de fluidos corporales de pacientes con enfermedades malignas y benignas. Estas muestras se estabilizaron con TransFix™ y teñidas con paneles inmunofenotípicos de seis colores. Las muestras incluyeron líquido cefalorraquídeo, lavado broncoalveolar, fluido pleural, fluido pericárdico y fluido ascítico, provenientes de pacientes con leucemia aguda y crónica, síndromes mielodisplásicos, linfomas, mieloma, enfermedades autoinmunes, inmunodeficiencias y tumores sólidos, entre otras enfermedades. La citometría de flujo proporcionó información importante sobre la clasificación y detección de números mínimos de células tumorales en casos de leucemia y linfoma. Este trabajo representa el primer reporte nacional que describe la implementación de citometría de flujo en muestras especiales para diagnóstico y monitoreo clínico de pacientes con patologías malignas y benignas.

Resumo A citometria de fluxo foi implementada em 2008 na Pontificia Universidad Javeriana e posteriormente no Hospital San Ignacio com a finalidade de examinar amostras especiais de pacientes com malignidades hematológicas e tumores sólidos diferentes aos de medula óssea e sangue periférico para diagnóstico e monitoramento. Este estudo descreve as principais descobertas a partir da avaliação de amostras especiais em um período de 6 anos. Se examinaram por citometria de fluxo um total de 1.070 amostras de fluídos corporais de pacientes doenças malignas e benignas. Estas amostras se estabilizaram com TransFix™ e coradas com painéis imunofenotípicos de seis cores. As amostras incluíram fluído cérebro-espinhal, lavado broncoalveolar, fluído pleural, fluído pericárdico e fluído ascético, provenientes de pacientes com leucemias aguda e crónica, síndromes mielodisplásicos, linfomas, mielomas, doenças autoimunes, imunodeficiência, e tumores sólidos, entre outras doenças. A citometria de fluxo proporcionou informações importantes sobre a classificação e detecção de um número mínimo de células tumorais nos casos de leucemia e linfomas. Este trabalho representa o primeiro relato nacional que descreve a implementação de citometria de fluxo em amostras especiais para diagnóstico e monitoramento clínico de pacientes com patologias malignas e benignas.

Prognostic stratification improvement by integrating ID1/ID3/IGJ gene expression signature and immunophenotypic profile in adult patients with B-ALL.

BACKGROUND: Survival of adults with B-Acute Lymphoblastic Leukemia requires accurate risk stratification of patients in order to provide the appropriate therapy. Contemporary techniques, using clinical and cytogenetic variables are incomplete for prognosis prediction. METHODS: To improve the classification of adult patients diagnosed with B-ALL into prognosis groups, two strategies were examined and combined: the expression of the ID1/ID3/IGJ gene signature by RT-PCR and the immunophenotypic profile of 19 markers proposed in the EuroFlow protocol by Flow Cytometry in bone marrow samples. RESULTS: Both techniques were correlated to stratify patients into prognostic groups. An inverse relationship between survival and expression of the three-genes signature was observed and an immunophenotypic profile associated with clinical outcome was identified. Markers CD10 and CD20 were correlated with simultaneous overexpression of ID1, ID3 and IGJ. Patients with simultaneous expression of the poor prognosis gene signature and overexpression of CD10 or CD20, had worse Event Free Survival and Overall Survival than patients who had either the poor prognosis gene expression signature or only CD20 or CD10 overexpressed. CONCLUSION: By utilizing the combined evaluation of these two immunophenotypic markers along with the poor prognosis gene expression signature, the risk stratification can be significantly strengthened. Further studies including a large number of patients are needed to confirm these findings.

High expression of ID family and IGJ genes signature as predictor of low induction treatment response and worst survival in adult Hispanic patients with B-acute lymphoblastic leukemia.

BACKGROUND: B-Acute lymphoblastic leukemia (B-ALL) represents a hematologic malignancy with poor clinical outcome and low survival rates in adult patients. Remission rates in Hispanic population are almost 30% lower and Overall Survival (OS) nearly two years inferior than those reported in other ethnic groups. Only 61% of Colombian adult patients with ALL achieve complete remission (CR), median overall survival is 11.3 months and event-free survival (EFS) is 7.34 months. Identification of prognostic factors is crucial for the application of proper treatment strategies and subsequently for successful outcome. Our goal was to identify a gene expression signature that might correlate with response to therapy and evaluate the utility of these as prognostic tool in hispanic patients. METHODS: We included 43 adult patients newly diagnosed with B-ALL. We used microarray analysis in order to identify genes that distinguish poor from good response to treatment using differential gene expression analysis. The expression profile was validated by real-time PCR (RT-PCT). RESULTS: We identified 442 differentially expressed genes between responders and non-responders to induction treatment. Hierarchical analysis according to the expression of a 7-gene signature revealed 2 subsets of patients that differed in their clinical characteristics and outcome. CONCLUSIONS: Our study suggests that response to induction treatment and clinical outcome of Hispanic patients can be predicted from the onset of the disease and that gene expression profiles can be used to stratify patient risk adequately and accurately. The present study represents the first that shows the gene expression profiling of B-ALL Colombian adults and its relevance for stratification in the early course of disease.

Reconstrucción de defectos óseos segmentarios postraumáticos mediante técnica de inducción de membrana / Surgical treatment of post-traumatic segmental bone defects through the induction membrane technique

Objetivos: Describir y evaluar los resultados del tratamiento quirúrgico de defectos óseos postraumáticos (DOPT) segmentarios mediante técnica de inducción de membrana. Material y métodos: Estudio descriptivo longitudinal de 20 casos de DOPT segmentarios tratados en el Hospital Nacional Cayetano Heredia de Lima, desde enero de 2009 a junio de 2014, mediante reconstrucción en dos etapas con técnica de inducción de membrana. En la primera etapa se indujo la formación de membrana con un espaciador de cemento óseo impregnado con antibiótico. En la segunda etapa se reemplazó el espaciador por injerto óseo. Se evaluó el tiempo de consolidación, grado de acortamiento de la extremidad y resultado funcional. Se registraron las complicaciones. Resultados: Se incluyeron 20 pacientes (15 varones y 5 mujeres), con edad promedio de 29 años (rango: 13-54). Once casos fueron DOPT en tibia, 7 casos en fémur, uno en radio y uno en cúbito. El 90% de los DOPT fueron en longitud mayor o igual a 50 mm, con un promedio de 73 mm; 60% de los casos tenían cultivos positivos al inicio del tratamiento. Presentaron consolidación el 90% de los casos con un único aporte de injerto óseo, el tiempo promedio para la consolidación fue 8 meses. Uno requirió un segundo aporte de injerto y un caso presentó persistencia de infección sin consolidación. Conclusiones: La técnica de inducción de membrana es un método eficaz para el tratamiento de DOPT segmentarios. (AU)

Objectives: To describe the results of surgical treatment of post-traumatic segmental bone defects (PSBD) through the induction membrane technique. Material and Methods: Observational study in patients attended at Hospital Nacional Cayetano Heredia in Lima from January 2009 to June 2014, in whom a two-step reconstruction procedure for PSBD was performed using the induction membrane technique. In the first step, the formation of a membrane was induced with an antibiotic spacer block followed by replacement of the spacer with bone grafting. Time to bone consolidation, degree of shortening of the extremity, functional status and complications were recorded. Results: Twenty patients were included in the study (15 males and 5 females); mean age was 29 year (range: 13-54). Eleven cases had PSBD in the tibia, 7 in the femur, 1 in the radius and 1 in the ulna; in 90% of cases the PSBD had a length of at least 50mm (mean of 73 mm); 60% of cases had a positive culture at the beginning of treatment. Ninety percent consolidated the fracture with a single procedure in a meantime of 8 months. One patient required a second procedure and one presented a persistent infection without consolidation. Conclusions: The induction membrane technique is an efficacious procedure for managing PSBD. (AU)

Mesenchymal stem cells promote leukaemic cells aberrant phenotype from B-cell acute lymphoblastic leukaemia.

BACKGROUND AND OBJECTIVES: The role of bone marrow-mesenchymal stem cells (BM-MSC) in leukaemic cell control is controversial. The purpose of this work was to evaluate BM-MSC role regarding the viability, proliferation and immunophenotype of normal B-cell precursors from control (Ct) patients and leukaemic cells from B-acute lymphoblastic leukaemia (B-ALL) patients. PATIENTS AND METHODS: BM-MSC were isolated and characterised from voluntary donors. Mononuclear cells isolated from Ct and B-ALL bone marrow samples were cultured in the presence or absence of BM-MSC for 7days. Cell viability was determined with LIVE/DEAD and proliferation index evaluated by CFSE labelling. Cell population immunophenotypes were characterised by estimating CD19, CD10, CD20 and CD45 antigens by flow cytometry. RESULTS: After co-culture, B-ALL cells exhibited higher viability (20-40%) as compared to just cells (3-10%). Ct and B-ALL absolute cell counts were higher in the presence of BM-MSC (Ct: 25/mm(3)cf8/mm(3), B-ALL: 15/mm(3)cf3/mm(3)). Normal B-cell subpopulations in co-culture had increased expression of CD19 and CD10 (Pre-pre B) and CD45 and CD20 antigens (Pre-B). B-ALL cells co-cultured with BM-MSC showed an increase in CD19 and CD20, although the greatest increase was observed in the CD10 antigen. CONCLUSIONS: Lymphoid cell maintenance, at early stages of differentiation, was significantly promoted by BM-MSC in normal and leukaemic cells. Co-cultures also modulated the expression of antigens associated with the B-ALL asynchronous phenotype as CD10 co-expressed with CD19 and CD20. To our knowledge, this is the first time that CD10, CD19 and CD20 leukaemic antigens have been reported as being regulated by BM-MSC.

Uso de plasma rico en plaquetas autólogo en el tratamiento quirúrgico de pseudoartrosis atrófica de fémur y tibia / Use of autologous platelet-rich plasma in the surgical treatment of atrophic pseudoarthrosis of the femur and fibula

Objetivo: Describir y evaluar los resultados del tratamiento quirúrgico de pseudoartrosis atrófica de fémur o tibia mediante el uso de plasma rico en plaquetas (PRP) autólogo. Material y métodos: Estudio descriptivo longitudinal de 20 casos (19 pacientes) de pseudoartrosis atrófica de fémur o tibia tratados quirúrgicamente con PRP autólogo en el Hospital Nacional Cayetano Heredia de Lima, desde enero del 2008 hasta enero del 2012. El PRP fue preparado en el banco de sangre del hospital a partir de una unidad de sangre autóloga. Se evaluó el tiempo de consolidación ósea mediante radiografías seriadas y se registraron las complicaciones. Resultados: Se incluyeron 12 varones y 7 mujeres, con edad promedio de 33,8 años (15 a 67 años). Se evidenció consolidación en el 95% de los pacientes, el tiempo promedio para la consolidación fue 25 semanas. Se observó un caso de persistencia de infección con cultivo positivo a E. coli y un caso de refractura. Conclusiones: El PRP autólogo tiene un efecto beneficioso en la reparación del tejido óseo en casos de pseudoartrosis atrófica.

Objective: To describe the results of the use of autologous platelet-rich plasma (PRP) in the surgical treatment of atrophic pseudoarthrosis of the femur and fibula. Methods: Case series of 20 patients treated with PRP at Hospital Nacional Cayetano Heredia from January 2008 to January 2012. PRP was prepared at the Hospital´s Blood Bank from an autologous blood sample. Time to bone consolidation was registered by serial radiographic imaging and a registry of complications was performed. Results: A total of 12 male and 7 female patients were included; mean age was 33,8 years (15-67). Bone consolidation was observed in 95% of patients with a mean consolidation time of 25 weeks. One patient had a refracture and one had a persistent E. coli infection. Conclusions: Autologous PRP has a beneficial bone remodeling effect in patients with atrophic pseudoarthrosis.

Características clínicas y paraclínicas de las neoplasias mieloproliferativas crónicas cromosoma Filadelfia negativas / Clinical and paraclinical characteristics of chronic myeloproliferative neoplasms Philadelphia chromosome negative

Objetivo: describir las características clínicas y paraclínicas de los pacientes con neoplasias mieloproliferativas crónicas cromosoma Filadelfia negativa valorados en la consulta externa de hematología del Hospital de San José desde enero de 2005 hasta mayo de 2010. Material y métodos: estudio de serie de casos en el que se incluyeron los pacientes diagnosticados con neoplasias mieloproliferativas crónicas cromosoma Filadelfia negativas. Resultados: un total de 34 pacientes con neoplasias mieloproliferativas (NM) cromosomas Filadelfia negativas fueron identificados. El principal diagnóstico encontrado fue de trombocitemia esencial en 17 pacientes (50%), policitemia Vera Rubra en seis pacientes (17.6%), neoplasia mieloproliferativa asociadas a eosinofilia en seis pacientes (17.6%), mielofibrosis primaria en tres pacientes (8.8%) Y neoplasias mieloproliferativas no clasificables en dos pacientes (5.8%). La mediana de edad fue de 63.5 años (RIQ: 51 a 74) y 21 pacientes (61.7%) correspondían al sexo femenino. Dos pacientes del número total progresaron a mielofibrosis (5.8%), ningún paciente desarrolló leucemia aguda. Veintisiete pacientes (79.4%) recibieron hidroxiurea como manejo farmacológico principal. Catorce pacientes presentaron complicaciones (41.1%), de los cuales cinco fueron episodios trombóticos (14.7%), tres episodios hemorrágicos (8.8%), tres pacientes presentaron hipertensión pulmonar (8.8%) y un paciente desarrolló vértigo (2.9%). Finalmente el tiempo desde el diagnóstico hasta la aparición de complicaciones fue de 19.55 meses (RIQ: 8-50.23) Conclusiones: las neoplasias mieloproliferativas crónicas cromosoma Filadelfia negativas son patologías muy raras, el mayor número se agrupan en trombocitemia esencial, policitemia Vera y neoplasias asociadas a eosinofilia. La principal opción terapéutica es la hidroxiurea con una baja toxicidad. No es posible analizar la presencia de las mutaciones tirosina-kinasas (JAK2 V617F, PGDFRA, ...

Objective: describe features clinics and patients with chronic myeloproliferative neoplasm chromosome Philadelphia negative valued at the Hospital San Jose hematology outpatient from January 2005 until May 2010. Materials and methods: Studio series case included patients diagnosed with chronic myeloproliferative neoplasm chromosome Philadelphia negative. Results: A total of 34 chronic myeloproliferative neoplasm chromosome Philadelphia negative patients were identified. The main found diagnosis was Essential Thrombocythemia in 17 patients (50%), Polycythemia Rubra Vera in six patients (17.6%), chronic myeloproliferative neoplasm associated with eosinophilia in six patients (17.6%), myelofibrosis primary in three patients (8.8%) and chronic myeloproliferative neoplasm not classifiable in two patients (5.8%). The median age was 63.5 years (R: 51-74) and 21 patients (61.7%) were female. Two patients in the total number progressed Myelofibrosis (5.8%), no patient acute leukemia development. Twenty-seven patients (79.4%) received Hydroxyurea as main pharmacological management. Fourteen patients presented complications (41.1%), of which fve were thrombotic episodes (14.7%), three bleeding episodes (8.8%), three patients had pulmonary hypertension (8.8%) and one patient developed Vertigo (2.9%). Finally the time since diagnosis until the occurrence of complications was 19.55 months (R: 8-50.23). Conclusión: neoplasm Mieloproliferativas Chronicles are very rare pathologies, as many are grouped into essential Thrombocythemia, Polycythemia Vera and neoplasms associated with Eosinophilia. The main therapeutic option is with a low toxicity Hydroxyurea. It is not possible to analyze the presence of mutations tyrosine kinases (JAK2 V617F PGDFRA PDGFRB, FGFR1) because they are tools of recent entry to the diagnostic arsenal and whose impact as a prognostic factor or therapeutic is in studio. Thrombotic venous events are frequently found in these patients. ...