Co-expressed miRNAs in gastric adenocarcinoma.

Co-expression networks may provide insights into the patterns of molecular interactions that underlie cellular processes. To obtain a better understanding of miRNA expression patterns in gastric adenocarcinoma and to provide markers that can be associated with histopathological findings, we performed weighted gene correlation network analysis (WGCNA) and compare it with a supervised analysis. Integrative analysis of target predictions and miRNA expression profiles in gastric cancer samples was also performed. WGCNA identified a module of co-expressed miRNAs that were associated with histological traits and tumor condition. Hub genes were identified based on statistical analysis and network centrality. The miRNAs 100, let-7c, 125b and 99a stood out for their association with the diffuse histological subtype. The 181 miRNA family and miRNA 21 highlighted for their association with the tumoral phenotype. The integrated analysis of miRNA and gene expression profiles showed the let-7 miRNA family playing a central role in the regulatory relationships.

Regulatory network reconstruction reveals genes with prognostic value for chronic lymphocytic leukemia.

BACKGROUND: The clinical course of chronic lymphocytic leukemia (CLL) is highly variable; some patients follow an indolent course, but others progress to a more advanced stage. The mutational status of rearranged immunoglobulin heavy chain variable (IGVH) genes in CLL is a feature that is widely recognized for dividing patients into groups that are related to their prognoses. However, the regulatory programs associated with the IGVH statuses are poorly understood, and markers that can precisely predict survival outcomes have yet to be identified. METHODS: In this study, (i) we reconstructed gene regulatory networks in CLL by applying an information-theoretic approach to the expression profiles of 5 cohorts. (ii) We applied master regulator analysis (MRA) to these networks to identify transcription factors (TFs) that regulate an IGVH mutational status signature. The IGVH mutational status signature was developed by searching for differentially expressed genes between the IGVH mutational statuses in numerous CLL cohorts. (iii) To evaluate the biological implication of the inferred regulators, prognostic values were determined using time to treatment (TTT) and overall survival (OS) in two different cohorts. RESULTS: A robust IGVH expression signature was obtained, and various TFs emerged as regulators of the signature in most of the reconstructed networks. The TF targets expression profiles exhibited significant differences with respect to survival, which allowed the definition of a reduced profile with a high value for OS. TCF7 and its targets stood out for their roles in progression. CONCLUSION: TFs and their targets, which were obtained merely from inferred regulatory associations, have prognostic implications and reflect a regulatory context for prognosis.

Proteins interaction network and modeling of IGVH mutational status in chronic lymphocytic leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is an incurable malignancy of mature B-lymphocytes, characterized as being a heterogeneous disease with variable clinical manifestation and survival. Mutational statuses of rearranged immunoglobulin heavy chain variable (IGVH) genes has been consider one of the most important prognostic factors in CLL, but despite of its proven value to predict the course of the disease, the regulatory programs and biological mechanisms responsible for the differences in clinical behavior are poorly understood. METHODS: In this study, (i) we performed differential gene expression analysis between the IGVH statuses using multiple and independent CLL cohorts in microarrays platforms, based on this information, (ii) we constructed a simplified protein-protein interaction (PPI) network and (iii) investigated its structure and critical genes. This provided the basis to (iv) develop a Boolean model, (v) infer biological regulatory mechanism and (vi) performed perturbation simulations in order to analyze the network in dynamic state. RESULTS: The result of topological analysis and the Boolean model showed that the transcriptional relationships of IGVH mutational status were determined by specific regulatory proteins (PTEN, FOS, EGR1, TNF, TGFBR3, IFGR2 and LPL). The dynamics of the network was controlled by attractors whose genes were involved in multiple and diverse signaling pathways, which may suggest a variety of mechanisms related with progression occurring over time in the disease. The overexpression of FOS and TNF fixed the fate of the system as they can activate important genes implicated in the regulation of process of adhesion, apoptosis, immune response, cell proliferation and other signaling pathways related with cancer. CONCLUSION: The differences in prognosis prediction of the IGVH mutational status are related with several regulatory hubs that determine the dynamic of the system.

Frog skin cultures secrete anti-yellow fever compounds.

There is an urgent need to develop novel antimicrobial substances. Antimicrobial peptides (AMPs) are considered as promising candidates for future therapeutic use. Because of the re-emergence of the Flavivirus infection, and particularly the yellow fever virus (YFV), we have compared the antiviral activities from skin secretions of seven different frog species against YFV (strain 17D). Secretions from Sphaenorhynchus lacteus, Cryptobatrachus boulongeri and Leptodactylus fuscus displayed the more powerful activities. S. lacteus was found to inhibit viral lysis of Vero E6 cells even at the highest viral concentration evaluated of 10 LD50. We also report the identification of a novel frenatin-related peptide from S. lacteus and found that this peptide-on its own-can lead to 35% protection against YVF, while displaying no cytotoxicity against somatic cells even at fivefold higher concentrations. These results are attractive and support the need for continued exploration of new sources of AMPs from frog skin secretions such as those described here in the development of new compounds for the treatment of infectious diseases in general and specific viral infections in particular.

Clustering of Expression Data in Chronic Lymphocytic Leukemia Reveals New Molecular Subdivisions.

Although the identification of inherent structure in chronic lymphocytic leukemia (CLL) gene expression data using class discovery approaches has not been extensively explored, the natural clustering of patient samples can reveal molecular subdivisions that have biological and clinical implications. To explore this, we preprocessed raw gene expression data from two published studies, combined the data to increase the statistical power, and performed unsupervised clustering analysis. The clustering analysis was replicated in 4 independent cohorts. To assess the biological significance of the resultant clusters, we evaluated their prognostic value and identified cluster-specific markers. The clustering analysis revealed two robust and stable subgroups of CLL patients in the pooled dataset. The subgroups were confirmed by different methodological approaches (non-negative matrix factorization NMF clustering and hierarchical clustering) and validated in different cohorts. The subdivisions were related with differential clinical outcomes and markers associated with the microenvironment and the MAPK and BCR signaling pathways. It was also found that the cluster markers were independent of the immunoglobulin heavy chain variable (IGVH) genes mutational status. These findings suggest that the microenvironment can influence the clinical behavior of CLL, contributing to prognostic differences. The workflow followed here provides a new perspective on differences in prognosis and highlights new markers that should be explored in this context.

Determination of the HER2 amplification status by in situ fluorescent hybridization and concordance with immunohistochemistry for breast cancer samples in Colombia.

OBJECTIVES: To determine the status of the HER2 amplification in Breast cancer performed in peripheral laboratories in Colombia by immunohistochemistry and its comparison with central laboratories and the FISH status. METHODS: Four thousand one hundred and five cases referred for the determination of the HER2 status by FISH and/or IHQ to the Department of Pathology of the Fundacion Santa Fe were studied. The analysis included correlation between the IHQ HER2 score submitted by the peripheral laboratory (PL), the HER2 score emitted in the CL and the FISH studies performed in the central laboratory (CL). RESULTS: Two thousand five hundred and eight HER2 IHQ studies were performed in the (CL), using the Dako Herceptest. With the following results: 68.2 % negative (0-1+); 16,4% indeterminate (2+); 15.3% 3+ and 2.3 % not adequate. 1360/ 1719 cases studied by FISH came from the (PL), and 329 (19.1%) from the (CL). Comparing the IHQ score emitted by the PL and the positive FISH status showed: 6/28 0+ were positive (21. 4%); 7/31 1+ (22. 5%); 397/1240 2+ (32.8%) and 74/91 3+ (81. 3%). In the CL the results were 1/9 0+ (11.1%); 3/18 1+ (16.7%); 154/292 2+ (53%); and 9/9 3+ (100%). Only 1/4 negative cases (0/1+) was in house. CONCLUSION: The false negative rate (22%), and false positive results (18.7%), of the HER2 status performed by IHQ in peripheral laboratories in Colombia is unacceptable high as well as the inadequacy of tissue indicating that pre-analytical factors have to be improved in Colombia in order to get optimal results.

OBJETIVOS: Determinar la correlación entre el estado de amplificación del oncogén HER2 en cáncer de seno por inmunohistoquímica y FISH, en laboratorios periféricos y en un laboratorio central de referencia en Colombia. MÉTODOS: Se estudiaron 4105 casos referidos al Departamento de Patología de la Fundación Santa fe de Bogotá para la determinación del estado de amplificación del HER2 por FISH y/o IHQ. El análisis incluyó la correlación entre los scores del HER2 por IHQ en ambos laboratorios y los estudios de FISH realizados en el laboratorio central. RESULTADOS: Dos mil quinientos ocho casos fueron estudiados para HER2 por IHQ en el LC (Herceptest de DAKO); 68.2% fueron negativos (score de 0-1+); 16.4% indeterminados (2+) y 15,3% positivos (3+); 2,3% fueron inadecuados. 1360 de 1689 casos estudiados por FISH (80.5%) provenían de LP, y 329 (19.5%) del LC. En los LP se encontró amplificación por FISH en: 6/28 casos catalogados por IHQ como 0+ (21.4%); 7/31 1+ (22.5%) ; 397/1210 2+ (2.8%) y 74/91 3+ (81.3%). En el LC se encontró amplificación por FISH en 1/9 casos catalogados por IHQ como 0+ (11.1%); 3/18 1+ (16.7%), 154/292 2+ (53%); y 10/10 3+ (100%) . Un de los 4 casos falsos negativos fue procesado en su totalidad en el LC. CONCLUSIÓN: Los resultados falsos negativos (22.0%) y falsos positivos (18.7%) en el estado del HER2 determinado por IHQ en los LP son inaceptablemente altos en Colombia, indicando se requiere establecer mecanismos estrictos de control de calidad.

[Correlation of the t(9;22), t(12;21), and DNA hyperdiploid content with immunophenotype and proliferative rate of leukemic B-cells of pediatric patients with B-cell acute lymphoblastic leukemia]. / Correlación de la t(9;22), t(12;21) e hiperdiploidía de ADN con el inmunofenotipo y la tasa de proliferación de células B neoplásicas en niños con leucemia linfoblástica aguda de precursores.

INTRODUCTION: Between 60 and 80% of patients with B-cell acute lymphoblastic leukemia show genetic abnormalities which influence the prognosis of the disease and the biology of the tumor. OBJECTIVE: To analyze different genetic abnormalities in acute B lymphoblastic leukemia in children, its relationship with the immunophenotype and the proliferative rate compared with normal B cell precursors. MATERIALS AND METHODS: We assessed immunophenotype, DNA content and proliferative rate in 44 samples by flow cytometry, and translocations t(9;22), t(12;21), t(4;11), and t(1;19) by RT-PCR. Using a hierarchical cluster analysis, we identified some immunophenotypic patterns associated to genetic abnormalities when compared with normal B cell precursors. RESULTS: DNA quantification showed that 21% of the cases had high hyperdiploidy and 47.7% has low hyperdiploidy. The presence of hyperdiploidy was associated with increased tumor proliferation and aberrant immunophenotypes, including abnormal expression of CD10, TdT, CD38, and CD45 and an increased size of the lymphoblasts. The presence of t(9;22) and t(12;21) discriminates normal cells from tumor cells with aberrant immunophenotype in the expression of CD19, CD22, CD13, CD33, CD38, CD34, and CD45. CONCLUSIONS: The aberrant immunophenotype profile detected in neoplastic cells along with abnormalities in the proliferative rate were significantly associated with DNA hyperdiploidy and clearly distinguished lymphoblasts with t(9;22) and t(12;21) from normal B cell precursors. The identification of these parameters is useful as a tool for classification and monitoring of these patients.

Gastric mucosa-associated lymphoid tissue lymphomas and Helicobacter pylori infection: a Colombian perspective.

AIM: To assess the significance of chromosome translocation t(11;18)(q21;q21), B-cell lymphoma 10 (BCL-10) protein and Helicobacter pylori (H. pylori) infection in gastric mucosa-associated lymphoid tissue (MALT) lymphoma in Colombia. METHODS: Fifty cases of gastric MALT lymphoma and their respective post-treatment follow-up biopsies were examined to assess the presence of the translocation t(11;18)(q21;q21) as identified by fluorescence in situ hybridization; to detect protein expression patterns of BCL10 using immunohistochemistry; and for evaluation of tumor histology to determine the correlation of these factors and resistance to H. pylori eradication. RESULTS: Infection with H. pylori was confirmed in all cases of gastric MALT lymphoma in association with chronic gastritis. Bacterial eradication led to tumor regression in 66% of cases. The translocation t(11;18)(q21;q21) was not present in any of these cases, nor was there evidence of tumor transformation to diffuse large B-cell lymphoma. Thirty-four percent of the patients showed resistance to tumor regression, and within this group, 7 cases, representing 14% of all those analyzed, were considered to be t(11;18)(q21;q21)-positive gastric MALT lymphomas. Protein expression of BCL10 in the nucleus was associated with the presence of translocation and treatment resistance. Cases that were considered unresponsive to therapy were histologically characterized by the presence of homogeneous tumor cells and a lack of plasmacytic differentiation. Responder cases exhibited higher cellular heterogeneity and a greater frequency of plasma cells. CONCLUSION: Both t(11;18)(q21;q21)-positive MALT lymphoma cases and those with nuclear BCL10 expression are considered resistant to H. pylori eradication. It is suggested that chronic antigenic stimulation is not a dominant event in resistant cases.

Condición laboral asociada a complicaciones en el embarazo en noreste de México / Employment status related to pregnancy complications in northeast Mexico

INTRODUCCIÓN: Las complicaciones clínicas en el embarazo son predictores importantes para la mortalidad materna y desenlace del embarazo dependiendo de la atención que reciban las mujeres en este periodo trascendental de la vida. Algunos de los determinantes asociados con el problema están ligados a la situación laboral y la ocupación de la madre durante el embarazo. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en el año 2012, en la Unidad de Medicina Familiar # 43 del Instituto Mexicano del Seguro Social. Se realizó un muestreo aleatorio de un total de 2314 se seleccionaron 318 mujeres que accedieron a participar. El objetivo principal del estudio de analizar la asociación del estatus laboral con las complicaciones durante la gestación (definidas como cualquier paciente que durante la gestación haya padecido preeclampsia, eclampsia, amenaza de aborto, amenaza de parto prematuro, infección de vías urinarias) se incluyeron además variables sociodemográficas conocidas por su relación con las complicaciones prenatales. RESULTADOS: La media de la edad fue de 26 años. La media del índice de masa corporal fue de 27. Las mujeres trabajadoras presentaron una probabilidad 64 % más alta que las no trabajadoras de presentar complicaciones en el embarazo (OR=1.64; IC95 %: 1.04-2.58). La infección de vías urinarias en las mujeres trabajadoras fue un 75 % más probable (OR=1.75; IC 95 %: 1.12-2.73), las mujeres trabajadoras tuvieron 2.72 veces más probabilidad de padecer una amenaza de aborto que las no trabajadoras (OR=2.72; IC 95 %:1.36-5.45), las trabajadoras tuvieron 2.20 veces mayor probabilidad de padecer amenaza de parto prematuro que las no trabajadoras (OR=2.20; IC 95 %: 0.91-5.29). Además las trabajadoras tuvieron una probabilidad 96 % más alta de que su embarazo terminara en cesárea (OR=1.96; IC 95 %:1.25-3.07). CONCLUSIONES: Los resultados sugieren que la actividad laboral es un factor importante para la presentación de complicaciones en el embarazo

INTRODUCTION: Pregnancy complications are important indicators for maternal mortality and pregnancy outcome, depending on the medical care that women receive in this crucial period of life. Some of the factors associated with this problem are linked to the employment status and occupation of the mother during the pregnancy period. MATERIAL AND METHODS: A cross-sectional study was conducted in 2012 at the Family Medicine Unit # 43 of the Mexican Social Security Institute. In a random sample of a total of 2314 women, 318 agreed to participate. The main objective of the study is to analyze the association of employment status with complications during pregnancy (women who have suffered preeclampsia, eclampsia, threatened abortion, preterm labor, urinary tract infection during pregnancy). Socio-demographic variables involved with prenatal complications were also included. RESULTS: The mean age was 26 years old and the mean BMI was 27. Working women had a 64% higher probability of having pregnancy complications (OR = 1.64; 95% CI: 1.04-2.58) than those who did have a work. Urinary tract infection was 75% higher in working women (OR = 1.75; 95% CI 1.12-2.73). Working women were 2.72 times more likely to have a threatened abortion than those who did not work (OR = 2.72; 95% CI 1.36-5.45) and workers were 2.20 times more likely to have preterm labor than non-worker women (OR = 2.20; 95% CI 0.91-5.29). urthermore worker women had a 96% higher risk of having a cesarean section (OR = 1.96; 95% CI 1.25-3.07). CONCLUSIONS: The results suggest that work activity is an important factor in the development of pregnancy complications

Mortalidad por Influenza pA(H1N1) 2009 en el noreste de México / Mortality from pandemic influenza A (H1N1) in northeast of Mexico

Objetivo. Determinar los factores asociados a la mortalidad por influenzapA(H1N1) en los pacientes hospitalizados por infección respiratoria agudagrave (IRAG) confirmada por reacción en cadena de la polimerasa (PCR)en el Instituto Mexicano del Seguro Social (IMSS).Material y métodos. En el IMSS en la delegación de Nuevo León entre el1 de junio de 2009 y 9 de marzo de 2010 se realizó un estudio observacionalretrospectivo de casos y controles, utilizando la base de datos del Sistemade Información en Línea para la Vigilancia Epidemiológica de Influenza(SINOLAVE). Se incluyeron 278 pacientes hospitalizados con IRAG (controles)y 50 pacientes con IRAG que fallecieron (casos) debido a la infecciónpor virus influenza pA(H1N1).Resultados. Los factores asociados a la mortalidad en los pacientes hospitalizadospor IRAG debida a influenza pA(H1N1) fueron la edad (OR: 1,03IC95% 1,01-1,05) y la obesidad (OR: 4,44 IC95% 1,85-1,6), utilizando unmodelo de regresión logística.Conclusión. Podemos concluir que en la delegación de Nuevo León delIMSS, la influenza pA(H1N1) afectó principalmente a adultos jóvenes, sinembargo las muertes se presentaron en mayor número en los pacientes alincrementar la edad y en pacientes con alguna comorbilidad.Palabras clave: Influenza pandémica A(H1N1), mortalidad, infección respiratoriaaguda grave, factores de riesgo, razón de probabilidad.

Objective. To determine factors associated with mortality from pAinfluenzA(H1N1) – confirmed by polymerase chain reaction (PCR) – Inhospitalized patients with severe acute respiratory infection (SARI) in theMexican Social Security Institute (IMSS). Methods. In the IMSS in the Delegation of Nuevo Leon between June 1, 2009 and March9, 2010 a retrospective observational case-control study was conducted using the database ofOnline Information System for Epidemiological Surveillance of Influenza (SINOLAVE). 278inpatients with SARI (controls) and 50 SARI patients who died (cases) due to infection withinfluenza virus pA(H1N1) were included.Results. In the logistic regression model factors associated with mortality in patientshospitalized due to SARI pA influenzA(H1N1) were age (OR: 1.03 95% CI 1.01-1.05) andobesity (OR: 4.44 95 1.85 to 1%, 0.6).Conclusion. We can conclude that the delegation of Nuevo León of the IMSS, pAinfluenzA(H1N1) affects mainly young adults, though the deaths occurred in greater numbersin patients with increasing age and in patients with comorbidities.

Determination of the HER2 amplification status by in situ fluorescent hybridization and concordance with immunohistochemistry for breast cancer samples in Colombia / Determinación del estado de amplificación del Oncogén HER2 por hibridación in situ fluorecente y concordancia con el método de inmunohistoquímica en muestras de mujeres Colombianas con Cáncer de seno

Objectives: To determine the status of the HER2 amplification in Breast cancer performed in peripheral laboratories in Colombia by immunohistochemistry and its comparison with central laboratories and the FISH status. Methods: Four thousand one hundred and five cases referred for the determination of the HER2 status by FISH and/or IHQ to the Department of Pathology of the Fundacion Santa Fe were studied. The analysis included correlation between the IHQ HER2 score submitted by the peripheral laboratory (PL), the HER2 score emitted in the CL and the FISH studies performed in the central laboratory (CL). Results: Two thousand five hundred and eight HER2 IHQ studies were performed in the (CL), using the Dako Herceptest. With the following results: 68,2 % negative (0-1+); 16,4% indeterminate (2+); 15,3% 3+ and 2,3 % not adequate. 1360/ 1719 cases studied by FISH came from the (PL), and 329 (19,1%) from the (CL). Comparing the IHQ score emitted by the PL and the positive FISH status showed: 6/28 0+ were positive (21, 4%); 7/31 1+ (22, 5%); 397/1240 2+ (32, 8%) and 74/91 3+ (81, 3%). In the CL the results were 1/9 0+ (11,1%); 3/18 1+ (16,7%); 154/292 2+ (53%); and 9/9 3+ (100%). Only 1/4 negative cases (0/1+) was in house. Conclusion: The false negative rate (22%), and false positive results (18,7%), of the HER2 status performed by IHQ in peripheral laboratories in Colombia is unacceptable high as well as the inadequacy of tissue indicating that pre-analytical factors have to be improved in Colombia in order to get optimal results.

Objetivos: Determinar la correlación entre el estado de amplificación del oncogén HER2 en cáncer de seno por inmunohistoquímica y FISH, en laboratorios periféricos y en un laboratorio central de referencia en Colombia. Métodos: Se estudiaron 4105 casos referidos al Departamento de Patología de la Fundación Santa fe de Bogotá para la determinación del estado de amplificación del HER2 por FISH y/o IHQ. El análisis incluyó la correlación entre los scores del HER2 por IHQ en ambos laboratorios y los estudios de FISH realizados en el laboratorio central. Resultados: Dos mil quinientos ocho casos fueron estudiados para HER2 por IHQ en el LC (Herceptest de DAKO); 68.2% fueron negativos (score de 0-1+); 16.4% indeterminados (2+) y 15,3% positivos (3+); 2,3% fueron inadecuados. 1360 de 1689 casos estudiados por FISH (80.5%) provenían de LP, y 329 (19.5%) del LC. En los LP se encontró amplificación por FISH en: 6/28 casos catalogados por IHQ como 0+ (21.4%); 7/31 1+ (22.5%) ; 397/1210 2+ (2.8%) y 74/91 3+ (81.3%). En el LC se encontró amplificación por FISH en 1/9 casos catalogados por IHQ como 0+ (11.1%); 3/18 1+ (16.7%), 154/292 2+ (53%); y 10/10 3+ (100%) . Un de los 4 casos falsos negativos fue procesado en su totalidad en el LC. Conclusión: Los resultados falsos negativos (22.0%) y falsos positivos (18.7%) en el estado del HER2 determinado por IHQ en los LP son inaceptablemente altos en Colombia, indicando se requiere establecer mecanismos estrictos de control de calidad.

Correlación de la t(9;22), t(12;21) e hiperdiploidía de ADN con el inmunofenotipo y la tasa de proliferación de células B neoplásicas en niños con leucemia linfoblástica aguda de precursores / Correlation of the t(9;22), t(12;21), and DNA hyperdiploid content with immunophenotype and proliferative rate of leukemic B-cells of pediatric patients with B-cell acute lymphoblastic leukemia

Introducción. Del 60 al 80 % de los pacientes con leucemia linfoblástica aguda de precursores B presentan alteraciones genéticas que influyen en el pronóstico de la enfermedad y en la biología del tumor. Objetivo. Analizar distintas alteraciones genéticas en leucemia linfoblástica aguda de precursores B en niños, y su relación con el inmunofenotipo y con la tasa de proliferación, en comparación con precursores B normales. Materiales y métodos. En 44 pacientes se evaluó, por citometría de flujo, el inmunofenotipo, el contenido de ADN y la proliferación, y por RT-PCR, las traslocaciones t(9;22), t(12;21), t(4;11) y t(1;19). Mediante un análisis jerarquizado de conglomerados se identificaron los patrones inmunofenotípicos de expresión asociados a las traslocaciones, tomando como referencia precursores B normales. Resultados. La cuantificación del ADN mostró que el 21 % de los casos de leucemia linfoblástica aguda de precursores B eran hiperdiploides de índice alto y, el 47,7 %, hiperdiploides de índice bajo. La presencia de hiperdiploidía se asoció con mayor proliferación tumoral y con inmunofenotipos aberrantes, que incluyeron expresión anormal de CD10, TdT, CD38 y CD45 y un mayor tamaño de los linfoblastos. La presencia de t(9;22) y t(12;21) discrimina células normales de células tumorales con aberraciones en la expresión de CD19, CD20, CD13, CD33, CD38, CD34 y CD45. Conclusiones. El perfil de aberraciones fenotípicas detectado en conjunto con anormalidades en la proliferación tumoral, se asocia de forma significativa con hiperdiploidiía de ADN y discrimina de forma clara linfoblastos con t(9;22) y t(12;21) de los precursores B normales. La identificación de estos parámetros será de gran utilidad como herramienta para la clasificación y seguimiento de los pacientes.

Introduction: Between 60 and 80% of patients with B-cell acute lymphoblastic leukemia show genetic abnormalities which influence the prognosis of the disease and the biology of the tumor. Objective: To analyze different genetic abnormalities in acute B lymphoblastic leukemia in children, its relationship with the immunophenotype and the proliferative rate compared with normal B cell precursors. Materials and methods: We assessed immunophenotype, DNA content and proliferative rate in 44 samples by flow cytometry, and translocations t(9;22), t(12;21), t(4;11), and t(1;19) by RT-PCR. Using a hierarchical cluster analysis, we identified some immunophenotypic patterns associated to genetic abnormalities when compared with normal B cell precursors. Results: DNA quantification showed that 21% of the cases had high hyperdiploidy and 47.7% has low hyperdiploidy. The presence of hyperdiploidy was associated with increased tumor proliferation and aberrant immunophenotypes, including abnormal expression of CD10, TdT, CD38, and CD45 and an increased size of the lymphoblasts. The presence of t(9;22) and t(12;21) discriminates normal cells from tumor cells with aberrant immunophenotype in the expression of CD19, CD22, CD13, CD33, CD38, CD34, and CD45. Conclusions: The aberrant immunophenotype profile detected in neoplastic cells along with abnormalities in the proliferative rate were significantly associated with DNA hyperdiploidy and clearly distinguished lymphoblasts with t(9;22) and t(12;21) from normal B cell precursors. The identification of these parameters is useful as a tool for classification and monitoring of these patients.