Molecular monitoring of chronic myeloid leukaemia patients treated with tyrosine kinase inhibitors (TKI) is essential for therapeutic stratification. In this context inter-laboratory reproducibility is mandatory. This requires standardization and strict alignment to international scale (IS), as established by the IRIS laboratories. We compared economic and analytical performances, including the possibility of reporting results on the international scale, of an automated cartridge-based assay (Xpert BCR-ABL MonitorTM, Cepheid) to classical non-automated analysis on 181 blood samples from TKI treated CML patients in up to three experienced laboratories. The automated Xpert BCR-ABL MonitorTM assay greatly improved reproducibility between non standardized laboratories. Reproducible sensitivity covered 5 logs, on condition that pre-analytical delays were less than 6 hours. Results were convertible to the international reporting scale. Assessment of average costs showed that this automated assay could be economically relevant for annual activity levels below 300, although cost stability was achieved at 600, compared to 1200 annual tests for non-automated testing. The Xpert BCR-ABL MonitorTM assay could therefore be used in local laboratories for routine quantification of e13/e14-a2 transcripts and might contribute to simplified standardization. However, its prognostic impact relative to non-automated quantification remains to be tested prospectively within appropriate clinical trials.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.