The JRC has developed a new reference material to support the monitoring of chronic myelogenous leukaemia (CML), a cancer of the white blood cells. In the EU, about 9600 new patients per year are diagnosed, and CML accounts for 70% of all childhood leukaemia cases.
Currently this form of leukaemia cannot be cured, but it can be kept under control with specific enzyme inhibitors. Regular monitoring of the patient is needed to ensure optimal treatment. This is done by measuring the number of specific genetic fragments (BCR-ABL1 transcripts). Until now, it has been difficult to compare results from different laboratories, as no common material for the calibration of the monitoring equipment was available.
To enhance consistency of measurements, the JRC has therefore developed a certified reference material (CRM), coded as ERM®-AD623a–f, making use of specifically tailored plasmids suitable for the calibration of BCR-ABL1 measurements.
The reference material helps laboratories harmonise their measurements, and will therefore improve the treatment of the patient. In essence, this new reference material is an essential tool to correctly assess the human response to leukaemia treatment and to allow for early detection of relapse.
The CRM is a plasmid containing selected deoxyribonucleic acid (DNA) fragments specific for the transcript of breakpoint cluster region gene (BCR), the transcript of the glucuronidase beta gene (GUSB) and the fusion transcript from the BCR gene and the c-abl oncogene 1 (BCR-ABL b3a2).
The CRM has been certified for the copy number ratio of these specific fragments per plasmid and for the copy number concentration of the plasmid per volume of solution. ERM-AD623 was prepared according to ISO Guide 34 and characterised by expert laboratories of demonstrated competence using the most advanced counting method for small DNA amounts, the so-called digital polymerase chain reaction. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM).
The preparation and certification of ERM®-AD623 is described in detail in the corresponding certification report.