Monitoring minimal residual disease in the bone marrow using next generation sequencing

Abstract

Achieving minimal residual disease (MRD) negativity in the bone marrow is one of the strongest prognostic factors in multiple myeloma. Consequently, MRD testing is routinely performed in clinical trials and moving towards standard of care. This review focuses on the role of next generation sequencing (NGS) of tumor-specific immunoglobulin V(D)J sequences for MRD tracking. The immunoglobulin variable regions are ideal targets for tracking, because every tumor cell shares an identical gene sequence, which is stable over time and generally distinct from the immunoglobulin sequences of normal B-cells. Several excellent assays for NGS-based MRD testing are available, both commercial and community-based, including one that is FDA-approved. These assays can achieve the gold standard analytical sensitivity of one tumor cell per million (10 −6), requiring a minimum input of 3 million bone marrow cells. Ongoing clinical trials will outline how MRD testing should be used to inform dynamic risk-adopted therapy.

Perspective: sensitive detection of residual lymphoproliferative disease by NGS and clonal rearrangements—how low can you go?

“…This amount is three times as much as may be expected if the same initial reasoning is used for DNA requirements. As Rustad and Boyle phrased it, calling the phenomenon the "rule of three," reaching 1 in 10 million is more than a technical challenge [45] and requires a minimum of 30 million cells. One can easily envision an exhaust of biological material, while reaching a low 10 −7 detection level.…”

“…On the basis of these calculations, even the impressive assessment of MRD in autografts using 103 mg (59−288 mg) of DNA [31] may fall short of the material needed to reach the desired threshold with sufficient confidence. It is realized that the "rule of three," derived from the Poisson distribution, may be insufficient in practice [45] because one would expect a loss of material, carrying DNA from several laboratory steps or if the conclusion requires more than a single observation to confirm MRD clinically. This theoretical basis also justifies the use of replicates when requirements are not met for each individual analysis.…”

Impact of pre-transplantation minimal residual disease (MRD) on the outcome of Allogeneic hematopoietic stem cell transplantation for acute leukemia

“…However, even if the patient is in CR status, the MRD may be detected in some patients. MRD can be detected by flow cytometry (FCM), polymerase chain reaction (PCR), real-time quantitative polymerase chain reaction (RQ-PCR), reverse transcriptase polymerase chain reaction (RT-PCR) or next generation sequencing (NGS) [11,12]. The detection of MRD is critical for predicting the outcome of transplantation and for selecting the intensity of further treatment strategy [13][14][15].…”

TLR7/8 agonist treatment induces an increase in bone marrow resident dendritic cells and hematopoietic progenitor expansion and mobilization

“…This amount is three times as much as one may expect if the same initial reasoning is used for DNA requirements. As Rustad and Boyle phrased it, calling the phenomenon the "rule of three", reaching one in a 10 million is more than a technical challenge [45], which will require a minimum of 30 million cells. One can easily envision an exhaust of biological material, whilst reaching a low 10 -7 detection level.…”

“…Based on these calculations, even the impressive assessment of MRD in autografts using 103 μg (59-288 μg) of DNA [31] may fall short of material to reach the desired threshold at sufficient confidence. It is realized that the rule of three, derived from the Poisson distribution, may be insufficient in practice [45] as one would expect a loss of material, carrying DNA from several laboratory steps or if the conclusion requires more than a single observation to confirm MRD clinically, etc. This theoretical basis also justifies the usage of replicates, when requirements are not met for each individual analysis.…”