Your Treatment Can Break Your MRD Panel
Targeted therapies can alter antigen expression enough to undermine the assumptions on which an MRD panel was validated.
By Juan Manuel Ojeda · CFCM
PRIMARY EVIDENCE · PEER-REVIEWED
Primary evidence
Chen M, Zhou J, Zhao W, et al. CD72 as a complementary B-lineage marker for longitudinal measurable residual disease surveillance after CD19 CAR-T therapy in R/R B-ALL. Cytometry Part B. Published 3 August 2026. DOI: 10.1002/cyto.b.70057.
What it actually demonstrates
The study assessed CD72 as a CD19-independent complementary B-lineage marker. It included correlation work in 66 B-ALL samples, specificity evaluation across 129 leukaemia patients and retrospective longitudinal analysis of 129 patients treated with CD19 CAR-T. Four clinically confirmed CD19-negative relapses retained CD72 expression.
Evidence boundary
Evidence boundary: CD72 is presented as a complementary marker, not a universal replacement for CD19 or other B-lineage markers. Local panel validation remains necessary.
Primary record →MRD assays are often treated as stable analytical systems, but the biological target is not stable. Therapy can select clones, modulate antigen density or remove the very marker used to identify a lineage.
That creates a validation problem. Sensitivity established in untreated disease does not necessarily describe performance after antigen-directed treatment. A robust MRD strategy needs marker redundancy and an explicit plan for therapy-driven phenotypic change.
The lesson extends beyond any single marker: the treatment history belongs in the analytical context. Clinical flow laboratories should know which therapies can alter the phenotype their panels depend on.
CFCM view
The important question is not whether the technology or marker is interesting. It is whether it changes a validated clinical workflow in a measurable, reproducible and explainable way.
CFCM is an independent publication. References to manufacturers, instruments, reagents, software or therapies do not constitute endorsement. Technical content should be interpreted in the context of local validation, applicable regulation and manufacturer instructions for use.