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Introducción: La leucemia promielocítica se considera una enfermedad bien definida por sus peculiares características clínicas, morfológicas, citogenéticas y moleculares. El descubrimiento de los mecanismos oncogenéticos implicados en la génesis de la enfermedad hacen de esta variante de leucemia uno de los modelos más relevantes de investigación traslacional. Objetivo: Caracterizar los transcritos de fusión del gen PML/RARα en pacientes con leucemia promielocítica. Métodos: Se realizó una investigación observacional, ambispectiva, descriptiva, longitudinal, en pacientes con diagnóstico de leucemia promielocítica, en el Instituto de Hematología e Inmunología, entre enero de 2001 y diciembre de 2020. El universo estuvo constituido por 105 pacientes que cumplieron los criterios de inclusión y exclusión. Resultados: No existe relación entre los transcritos y la edad, sexo, color de piel y las características clínicas. La presencia del transcrito de fusión bcr3 se asoció a mayores cifras de hemoglobina y menor valor de plaquetas. La incidencia de recaída no se relacionó con los transcritos de fusión y no se comprobó que existiera influencia de éstos, sobre la supervivencia global en pacientes con leucemia promielocítica. Conclusiones: Las características de los transcritos de fusión del gen PML/RARα son similares a los reportes internacionales, sobre todo en poblaciones de origen latino(AU)
Introduction: Promyelocytic leukemia is considered a well-defined entity due to its peculiar clinical, morphological, cytogenetic and molecular characteristics. The discovery of the oncogenetic mechanisms involved in the genesis of the disease makes this variant of leukemia one of the most relevant models for translational research. Objective: To characterize the fusion transcripts of the PML/RARα gene in patients with promyelocytic leukemia. Methods: An observational, ambispective, descriptive, longitudinal investigation was carried out in patients diagnosed with promyelocytic leukemia at the Institute of Hematology and Immunology, between January 2001 and December 2020. The sample consisted of 105 patients who met the criteria for inclusion and exclusion. Results: There is no relationship between the transcripts and age, sex, skin color and clinical characteristics. The presence of the bcr3 fusion transcript was associated with higher hemoglobin levels and lower platelet counts. The incidence of relapse was not related to fusion transcripts and their influence on overall survival in patients with promyelocytic leukemia was not proven. Conclusions: The fusion transcripts´scharacteristicsof the PML/RARα gene are similar to international reports, especially from populations of Latin origin(AU)
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HumanosRESUMEN
Background & objectives: Chronic myelogenous leukaemia (CML) is the commonest leukaemia in Asia. There is a paucity data on cytogenetic and molecular analyses of Indian CML patients. This apparently reflects the low availability of cytogenetic and molecular techniques in our country. This study aimed to document various types of BCR-ABL fusion transcripts in different phases of CML and to compare the Ph chromosome positivity/negativity vis-a-vis BCR-ABL fusion transcripts in adult CML patients. Methods: Between June 2004 and February 2009, 208 patients were diagnosed as CML in chronic phase (CP), accelerated phase (AP) and blast crisis (BC), according to standard criteria. Cytogenetic and molecular genetic analyses were performed in all patients. Various types of BCR-ABL hybrid transcripts were compared with phases of CML and cytogenetic abnormalities. Results: Among 208 CML patients, b3a2 BCR-ABL transcripts were most commonly detected (66.82%) followed by b2a2 (28.84%), b3a2 + b2a2 (3.36%), b3a2 + e19a2 (0.48%) and b2a2 + e19a2 (0.48%). b3a2 transcripts were more frequently detected than b2a2 transcripts, in the whole group of 208 as well as in 183 CML-CP patients (P<0.0001). Ph chromosome was positive in 135 of 139 patients with b3a2 transcripts and 56 of 60 patients with b2a2 transcripts, difference not being significant. Additional cytogenetic abnormalities detected in 3.8 per cent patients in CML-CP and 44 per cent patients in CMLAP/ BC, did not show predilection for any BCR-ABL transcript type. Interpretation & conclusions: This study documents higher Ph positivity (96.15%) by cytogenetic analysis among CML patients, as confirmed by qualitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in a large patient group from north India. Both the techniques contribute towards understanding the disease biology, and have important implications for diagnosis and management of CML patients.