Background With the emergence of tyrosine kinase inhibitors and the incorporation of stringent measurable residual disease (MRD) monitoring, risk stratification for BCR-ABL1-positive acute lymphoblastic leukemia (ALL) patients has changed significantly. However, whether this monitoring can replace conventional risk factors in determining whether patients need allogeneic stem cell transplantation is still unclear. This study aimed to determine the impact of BCR-ABL1 monitoring on the outcome of patients with BCR-ABL1-positive ALL after allogeneic stem cell transplantation. Methods We retrospectively analyzed the survival outcome of patients with BCR-ABL1-positive ALL based on the quantification of BCR-ABL1 at 3 timepoints: the end of induction (timepoint 1), post-consolidation week 16 (timepoint 2), and the end of treatment for patients who were either transplant-eligible or non-transplant eligible (timepoint 3). Results From 2006 to 2018, a total of 96 patients newly diagnosed with BCR-ABL1-positive ALL were treated with chemotherapy and tyrosine kinase inhibitors. Thirty-eight (41.3%) patients achieved complete remission, and 33 patients underwent allogeneic stem cell transplantation. Our data showed that pre-transplant MRD monitoring by real-time quantitative polymerase chain reaction had the highest correlation with survival in patients with BCR-ABL1-positive ALL, especially for those who underwent allogeneic stem cell transplantation. Conclusion Patients without MRD pre-transplantation had superior survival compared with those who had MRD, and they had excellent long-term outcomes after allogeneic stem cell transplantation.

The Sysmex XN-3000 is a new automated haematology analyser designed to improve the accuracy of cell counts and the specificity of the flagging events of unusual parameters. By comparing the previous full blood count (FBC) reference intervals in Malaysia for Sysmex XE-5000, we determined a reference interval for all parameters measured by the Sysmex XN-3000 for the Malaysian population. Through the voluntary recruitment of 397 adults ages 18-45 years, both genders, and the three main ethnic groups, FBC was performed on the two analysers. Qualified healthy participants were screened using a health questionnaire. This was followed by reference intervals, probability distribution measurements, and dispersion with point estimate determination. Complete data were available in 390 subjects comprising 222 females and 168 males, which were included in the reference interval calculation. Parameters such as haemoglobin, red blood cell count, platelet count including immature platelet fraction (IPF) showed significant differences in Malaysians. XN-3000 showed excellent precision and linearity results. Within- and between-run precisions were met for all parameters tested, except for IPF. For all parameters tested, ≤ 0.5% carry-over was seen. An acceptable correlation with both XN-3000 and XE-5000 was achieved in comparison studies performed. XN-3000 showed good analytical performance and could provide a solution for laboratories with medium-to-high workloads and evolving clinical needs. Local guidelines are required for the establishment of reference intervals.