Measurable Residual Disease (MRD) by Flow Cytometry in Adult B-Acute Lymphoblastic Leukaemia (B-ALL) and Acute Myeloid Leukaemia (AML): Correlation with Molecular MRD Testing and Clinical Outcome at One Year

Riana van der Linde; Prudence N Gatt; Sandy Smith; Marian A Fernandez; Lachlin Vaughan; Emily Blyth; Jennifer Curnow; David A Brown; Elizabeth Tegg; Sarah C Sasson

doi:10.3390/cancers15205064

Measurable Residual Disease (MRD) by Flow Cytometry in Adult B-Acute Lymphoblastic Leukaemia (B-ALL) and Acute Myeloid Leukaemia (AML): Correlation with Molecular MRD Testing and Clinical Outcome at One Year

Cancers (Basel). 2023 Oct 19;15(20):5064. doi: 10.3390/cancers15205064.

Authors

Riana van der Linde^{1

2}, Prudence N Gatt^{2

3}, Sandy Smith⁴, Marian A Fernandez⁴, Lachlin Vaughan^{1

5}, Emily Blyth^{2

3

5}, Jennifer Curnow^{2

5}, David A Brown^{2

3

6}, Elizabeth Tegg^{1

2}, Sarah C Sasson^{2

6}

Affiliations

¹ Department of Laboratory Haematology, Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead Hospital, Westmead, NSW 2145, Australia.
² Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Camperdown, NSW 2050, Australia.
³ Westmead Institute for Medical Research, University of Sydney, Sydney, NSW 2145, Australia.
⁴ Flow Cytometry Unit, Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead Hospital, Westmead, NSW 2145, Australia.
⁵ Department of Haematology, Western Sydney Local Health District, Westmead Hospital, Westmead, NSW 2145, Australia.
⁶ Department of Clinical Immunology and Immunopathology, Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead Hospital, Westmead, NSW 2145, Australia.

Abstract

Measurable residual disease (MRD) detected by flow cytometry (FC) is well established in paediatric B- lymphoblastic leukaemia (B-ALL) and adult chronic lymphocytic leukaemia (CLL), but its utility in adult B-ALL and adult acute myeloid leukaemia (AML) is less clear. In this prospective MRD study, one of the largest in Australia to date, we examined consecutive bone marrow aspirates from adult participants with B-ALL (n = 47) and AML (n = 87) sent for FC-MRD testing at a quaternary referral hospital in Sydney. FC-MRD results were correlated to corresponding Mol-MRD testing where available and clinical outcomes at three-month intervals over 1 year. B-ALL showed a moderate positive correlation (r_s = 0.401, p < 0.001), while there was no correlation between FC-MRD and Mol-MRD for AML (r_s = 0.13, p = 0.237). Five FC-MRD patterns were identified which had significant associations with relapse (X²(4) = 31.17(4), p > 0.001) and survival (X²(4) = 13.67, p = 0.008) in AML, but not in B-ALL. The three-month MRD results were also strongly associated with survival in AML, while the association in B-ALL was less evident. There was a moderate correlation between FC-MRD and Mol-MRD in B-ALL but not AML. The association of FC-MRD with relapse and survival was stronger in AML than in B-ALL. Overall, these findings suggest divergent utilities of FC-MRD in AML and B-ALL.

Keywords: AML; B-ALL; MRD; measurable residual disease; minimal residual disease; molecular MRD.

Grants and funding

This research received no external funding.