Detection of BCR-ABL Fusion Gene in Chronic Myeloid Leukemia by Novel Digital PCR / 中国实验血液学杂志

OBJECTIVE@#To establish a new digital polymerase chain reaction (dPCR) system for the detection of BCR-ABL fusion gene in patients with chronic myeloid leukemia (CML), and explore its analytical performance and clinical applicability in the detection of BCR-ABLp190/210/230.@*METHODS@#A new dPCR system for detecting BCR-ABLp190/210/230 was successfully developed, and its sensitivity difference with qPCR and improvement of drug side effects in patients with CML during drug reduction or withdrawal were compared.@*RESULTS@#Among 176 samples, qPCR and dPCR showed high consistency in the sensitivity of detecting BCR-ABL (82.39%), and the positive rate of dPCR was about 5 times higher that of qPCR (20.45% vs 3.98%). During follow-up, blood routine (25% vs 10%), kidney/liver/stomach (25% vs 20%) and cardiac function (10% vs 0) were significantly improved after drug reduction or withdrawal in patients with initial dPCR negative compared with before drug reduction or withdrawal.@*CONCLUSIONS@#This new dPCR detection system can be applied to the detection of BCR-ABLp190/210/230. It has better consistency and higher positive detection rate than qPCR. Drug withdrawal or dose reduction guided by dPCR has a certain effect on improving drug side effects.

Progress of circulating tumor DNA in Bˉcell nonˉHodgkin lymphoma / 白血病·淋巴瘤

Monitoring the disease status of the patients with nonˉHodgkin lymphoma (NHL) at the molecular level is of great significance in the accurate individualized management. The novel next generation sequencingˉbased methods enable the quantitative detection of circulating tumor DNA (ctDNA) in peripheral blood with great sensitivity, which can overcome the shortages of biopsies and imaging scans. As a new biomarker of NHL, ctDNA provides the opportunity for disease genotyping, prognosis evaluation, therapeutic response and recurrence monitoring, which may ultimately improve the prognosis of NHL patients.

Recomendaciones metodológicas para el monitoreo molecular BCR-ABL1 en pacientes con leucemia mieloide crónica por pcr cuantitativa en tiempo real / Guidelines for molecular monitoring of BCR-ABL1 in chronic myeloid leukemia patients by RT-qPCR

Actualmente las guías clínicas para el manejo de pacientes con leucemia mieloide crónica incluyen el monitoreo molecular de BCR-ABL1 por PCR cuantitativa en tiempo real; esta metodología permite definir la respuesta molecular. A pesar de la probada importancia pronóstica de la respuesta molecular, en muchos casos no se tiene en cuenta que la PCR cuantitativa puede producir datos muy variables, que pueden afectar la validez de los resultados, y hacer difícil la comparación entre diferentes laboratorios. Por lo tanto, para un manejo clínico óptimo, es absolutamente necesaria la estandarización de las metodologías de medición de BCR-ABL1. La estrategia para obtener valores de BCR-ABL1 comparables consiste en la adopción de la escala internacional. La conversión a la escala internacional se logra mediante la aplicación de un factor de conversión específico para cada laboratorio; este factor de conversión se puede obtener mediante el uso de calibradores secundarios validados, que hoy se producen en Argentina, en el marco del programa nacional de armonización. Por otra parte, con el objetivo de mitigar las diferencias entre laboratorios y facilitar criterios uniformes en la interpretación de los resultados y presentación de los informes, decidimos preparar estas guías de laboratorio. Esto permitirá además a los laboratorios poder evaluar su calidad de trabajo, tarea muy importante, en particular para aquellos centros más aislados, que no tienen fácil acceso a costosos kits comerciales o programas internacionales de intercambio de muestras.

Current clinical guidelines for managing chronic myeloid leukemia include molecular monitoring of BCR-ABL1 transcript quantitative reverse-transcription PCR. Despite the proven prognostic significance of molecular response, it is not widely appreciated that quantitative reverse-transcription PCR potentially produces highly variable data, which may affect the validity of results, making comparability between different laboratories difficult. Therefore, standardized reporting of BCR-ABL1 measurements is needed for optimal clinical management. An approach to achieve comparable BCR-ABL1 values is the use of an international reporting scale. Conversion to the international scale is achieved by the application of laboratory specific conversion factor that is obtained by using validated secondary reference calibrators. Moreover, with the aim to mitigate the interlaboratory imprecision of quantitative BCR-ABL1 measurements and to facilitate local laboratory results interpretation and reporting, we decide to prepare laboratory guidelines that will further facilitate interlaboratory comparative studies and independent quality-assessment programs, which are of paramount importance for worldwide standardization of BCR-ABL1 monitoring results, in particular for those most isolated laboratories, with not easy access to commercial kits or sample interchange programs.