Figure 2.

Example of MRD analysis in MM using next generation flow approach and Infinicyt software (Cytognos). (a) Bone marrow PC compartment represents 0.04% of total nucleated cells including 98.5% of normal PCs (blue) and 1.5% of aberrant PCs (red). These aberrant plasma cells represent 0.0004% of total nucleated cells translating in MRD positive result reaching the sensitivity of 10⁻⁶. The typical aberrant phenotype: CD45⁻/CD38^dim/CD19⁻/CD56⁺/CD27⁻/CD81⁻/CD117⁺/cyKappa⁺. (b) NGF is optimal tool also for follow-up of patients with non-secretory multiple myeloma. Bone marrow PC compartment represents 0.16% of total nucleated cells including 50% of normal PCs (blue) and 50% of aberrant PCs (red). Aberrant PCs in this case have rare immunophenotype with CD38- and lack of cytoplasmic staining of kappa or lambda light chains: CD45⁺/CD38⁻/CD19⁻/CD56⁺/CD27⁻/CD81⁺/CD117⁻/cyKappa⁻/cyLambda⁻.